U.S. patent application number 11/616723 was filed with the patent office on 2007-05-24 for machinery facility condition monitoring method and system and abnormality diagnosis system.
This patent application is currently assigned to NSK LTD.. Invention is credited to Hirotoshi Aramaki, Takanori Miyasaka, Yasushi Mutou, Juntaro Sahara.
Application Number | 20070118333 11/616723 |
Document ID | / |
Family ID | 32034524 |
Filed Date | 2007-05-24 |
United States Patent
Application |
20070118333 |
Kind Code |
A1 |
Miyasaka; Takanori ; et
al. |
May 24, 2007 |
MACHINERY FACILITY CONDITION MONITORING METHOD AND SYSTEM AND
ABNORMALITY DIAGNOSIS SYSTEM
Abstract
An abnormality diagnosis system for diagnosing a presence or
absence of an abnormality of a bearing unit for a railway vehicle
axle, comprises a sensing/processing portion for outputting a
signal generated from the bearing unit as an electric signal, a
calculating/processing portion for making an abnormality diagnosis
of the bearing unit based on an output of the sensing/processing
portion, a result outputting portion for outputting a decision
result of the calculating/processing portion, and a
controlling/processing portion for feeding back a control signal to
a control system of the railway vehicle based on the decision
result.
Inventors: |
Miyasaka; Takanori;
(Kanagawa, JP) ; Aramaki; Hirotoshi; (Kanagawa,
JP) ; Mutou; Yasushi; (Kanagawa, JP) ; Sahara;
Juntaro; (Kanagawa, JP) |
Correspondence
Address: |
SUGHRUE-265550
2100 PENNSYLVANIA AVE. NW
WASHINGTON
DC
20037-3213
US
|
Assignee: |
NSK LTD.
Tokyo
JP
141-8560
|
Family ID: |
32034524 |
Appl. No.: |
11/616723 |
Filed: |
December 27, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10526031 |
Feb 28, 2005 |
7184930 |
|
|
PCT/JP03/11114 |
Aug 29, 2003 |
|
|
|
11616723 |
Dec 27, 2006 |
|
|
|
Current U.S.
Class: |
702/183 ;
340/679 |
Current CPC
Class: |
F16C 19/52 20130101;
F16C 2326/10 20130101; F16C 2360/31 20130101; F05B 2260/80
20130101; B61F 15/20 20130101; G01M 13/045 20130101; B61K 9/04
20130101; G01N 2291/2696 20130101; G01M 17/10 20130101; F16C 19/386
20130101; F03D 80/70 20160501; G01N 2291/02881 20130101; Y02E 10/72
20130101 |
Class at
Publication: |
702/183 ;
340/679 |
International
Class: |
G21C 17/00 20060101
G21C017/00; G08B 21/00 20060101 G08B021/00 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 30, 2002 |
JP |
2002-252877 |
Nov 21, 2002 |
JP |
2002-338423 |
Dec 20, 2002 |
JP |
2002-370800 |
Jan 17, 2003 |
JP |
2003-010131 |
Feb 25, 2003 |
JP |
2003-048309 |
Jun 26, 2003 |
JP |
2003-182996 |
Aug 28, 2003 |
JP |
2003-304700 |
Claims
1. A machinery facility abnormality diagnosis system for sensing a
presence or absence of an abnormality of a sliding member or a
rotating body in a machinery facility, comprising: a sensor unit
having one of plural sensing elements for sensing a signal emitted
from the machinery facility; and a calculating/processing portion
for executing a calculating process to decide the presence or
absence of the abnormality in the machinery facility based on an
output of the sensing element; wherein the calculating/processing
portion is composed of a microcomputer.
2. A machinery facility abnormality diagnosis system according to
claim 1, wherein the sensor unit is incorporated into the sliding
member or the rotating body.
3. A machinery facility abnormality diagnosis system according to
claim 2, wherein the microcomputer is fitted to the sliding member
or the rotating body or a mechanism parts that supports the sliding
member or the rotating body.
4. A machinery facility abnormality diagnosis system according to
claim 1, wherein the microcomputer and the sensor unit are mounted
on a single device board, and are fitted to the sliding member or
the rotating body or a mechanism parts that supports the sliding
member or the rotating body as a single processing unit.
5. A machinery facility abnormality diagnosis system according to
claim 1, wherein the calculating/processing portion is installed in
a single casing.
6. A machinery facility abnormality diagnosis system according to
claim 5, wherein the sensor unit is arranged integrally in the
casing.
7. A machinery facility abnormality diagnosis system according to
claim 1, wherein the sensing element senses at least one of
temperature, vibration displacement, vibration speed, vibration
acceleration, force, distortion, acoustic, acoustic emission,
ultrasonic waves, and rotation speed.
8. A machinery facility abnormality diagnosis system according to
claim 1, wherein the calculating/processing portion includes
central processing unit, amplifier, analog/digital converter,
filter, comparator, pulse counter, timer, interruption controller,
ROM, RRAM, digital/analog converter, communication module, and
external interface.
9. A machinery facility abnormality diagnosis system according to
claim 1, wherein the calculating/processing portion executes at
least one process or more of calculation of feature parameters of a
standard deviation and a peak factor, envelope detection, FFT,
filtering, wavelet transform, short-time FFT, calculation of a
feature frequency due to a defect of the rotating body and
comparison/decision.
10. A bearing unit including an inner ring having an inner ring
raceway surface, an outer ring having an outer ring raceway
surface, a plurality of rolling elements arranged relatively
rotatably between the inner ring raceway surface and the outer ring
raceway surface, and a retainer for holding rollably the rolling
elements, whereby a bearing to which a radial load is applied is
arranged in a bearing housing, the bearing unit comprising: an
abnormality sensing means provided in a loading range of the
bearing housing, for sensing an abnormality from at least one
selected from a vibration sensor and a temperature sensor
installed/fixed in a single case.
11. A bearing unit according to claim 10, wherein a flat portion is
provided to a part of an outer peripheral surface of the bearing
housing on a loading range side, and the abnormality sensing means
is fixed to the flat portion.
12. A bearing unit according to claim 11, wherein the abnormality
sensing means is arranged on an outer diameter portion of the
bearing housing on the loading range side in a center portion of a
bearing width.
13. A bearing unit according to claim 10, wherein the abnormality
sensing means is arranged on an outer diameter portion of the
bearing housing on the loading range side in a width area of the
inner ring raceway surface or the outer ring raceway surface.
14. A bearing unit according to claim 10, wherein a case of the
abnormality sensing means has a signal carrying means that sends
out a sensed signal, and a decision result outputting portion that
decides a presence or absence of the abnormality based on the
signal sent out via the signal carrying means and output a decision
result.
15. A bearing unit according to claim 10, wherein the abnormality
sensing means is embedded/fixed on a recess portion formed on the
bearing housing, and then secured by molding a clearance between
the abnormality sensing means and the recess portion.
16. A bearing unit according to claim 15, wherein the abnormality
sensing means is fixed to the recess portion via a spacer.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This is a continuation of U.S. application Ser. No.
10/526,031 filed Feb. 28, 2005, which is a national stage
application filed under 35 U.S.C. .sctn. 371 of PCT International
Appln. No. PCT/JP03/11114 filed on Aug. 29, 2003, the above-noted
applications incorporated herein by reference in their
entirety.
TECHNICAL FIELD
[0002] The present invention relates to a machinery facility
condition monitoring method and system and an abnormality diagnosis
system and, more particularly, a machinery facility condition
monitoring method and system and an abnormality diagnosis system
capable of monitoring conditions such as an abnormality, and so
forth in a machinery facility such as a railway vehicle facility, a
machine tool, a windmill, a reduction gear, an electric motor, or
the like including at least one of a rotating body and a sliding
member such as a rolling bearing, a sliding bearing, a ball screw,
a linear guide, a linear ball bearing, and the like without
decomposition of the machinery facility.
BACKGROUND ART
[0003] In the prior art, in order to prevent generation of the
failure due to the wear or the failure of the rotating body or the
sliding member, a thorough overhaul and a visual inspection are
applied periodically to the machinery facility such as the railway
vehicle facility, the machine tool, the windmill, or the like. In
the thorough overhaul and the visual inspection, the rotating body
or the sliding member is removed from the machinery facility and
decomposed after the facility is operated for a predetermined
period, and then the skilled expert who handling the inspection
checks a degree of the wear, the presence or absence of defects
that are found by the inspection, in the case of the bearing unit,
there are the indentation due to the capture of the foreign matter,
etc., the flaking due to the rolling contact fatigue, other wear,
and others. Also, in the case of the gear, there are the fracture
or wear of the teeth, or the like. When the person who handles an
inspection detects an abnormality such as unevenness, wear, and the
like, which are not found in a new rotating body or sliding member,
such person exchanges the defective parts for the new one and then
assembles the rotating body or the sliding member once again (see
the catalog "ROLLING BEARING" (CAT. No. 1101e, page B340 to page
B351) issued by Nippon Seiko K.K.).
[0004] However, in the method of decomposing the overall machinery
facility and inspecting the failure with the eye of the person in
charge, a decomposing operation of removing the rotating body or
the sliding member from the machinery facility and a fitting
operation of fitting again the inspected rotating body or sliding
member into the machinery facility require much time and labor.
Thus, such a problem existed that a substantial increase in an
upkeep cost required for maintaining, managing, or the like the
machinery facility is brought upon.
[0005] In particular, in the case of the windmill, most of the
windmills are used in an offshore area and also the number of the
installed windmills is large. It is the existing circumstances of
maintaining/managing operations of the windmill that the person in
charge of the maintenance goes to the installation location of the
windmill and then conducts the inspection of rotating parts of the
windmill there. For this reason, such a problem existed that it
take an enormous time and cost to maintain/manage the windmill and
thus a maintenance efficiency is poor. Also, it is possible that
the inspection itself causes the defect of the rotating body or the
sliding member. For instance, the indentation that has not been put
before the inspection is made on the rotating body or the sliding
member when the machinery facility is reassembled after the
decomposition and the inspection, and so forth. Also, since the
person in charge of the inspection must check a number of bearings
with the eye within a limited time, there existed the problem that
such a possibility still remains that such person fails to find the
defect. In addition, since a decision level of the defect varies
between individuals and thus exchange of the parts is carried out
even though the defect is not found substantially, the above
inspection entails a useless cost.
[0006] Also, in order to overcome the disadvantages caused by such
visual inspection, it is studied that the sensor for sensing the
sound or the vibration generated during the rotation of the bearing
is provided on the body of the vehicle in which the bearing is
used, and then the abnormality such as the wear, the failure, or
the like of the bearing is sensed based on the sensed signal of the
sensor.
[0007] However, in the case where the sensor is fitted onto the
body of the vehicle, an SN ratio of the sensed signal from the
sensor is worsened because the sensor is provided away from the
bearing. Thus, there existed such a problem that it is difficult to
sense/decide the abnormality with high precision.
[0008] Also, as an bearing unit in the prior art, in a bearing unit
1100 having a sensor module shown in FIG. 50, a module hole 1103 is
formed on an outer peripheral surface of an outer ring 1102 of a
rolling bearing 1101, and then a module 1104 into which a speed
sensor, a temperature sensor, and an acceleration sensor are
installed is inserted/fixed into the module hole 1103. Then, sensed
signals generated from respective sensors in the module 1104 are
transmitted to a remote processing unit provided in the locomotive,
which pulls the freight cars and the passenger cars in which the
rolling bearings 1101 are provided, via the communication
channel.
[0009] As to the speed, the instantaneous speed of the journal is
sensed based on the pulse generated by the rotating wheel, and then
such speed and the speed of other bearings that are operating under
the same conditions are compared with each other. Thus, the overall
period history to which the bearing assembly is subjected is
saved/recorded. As to the temperature, such temperature and the
temperature of other bearings that are operating under the same
conditions are compared with each other by a simple level
detection. As to the vibration, a simple RMS measurement of an
energy level is carried out over a predetermined period of time,
and then such energy level and the past energy level stored in a
processing unit are compared with each other. Thus, such energy
level and the energy level of other bearings that are operating
under the same conditions are compared with each other (see
JP-T-2001-500597 (pp. 10 to 16, FIG. 1)).
[0010] Also, as another configurative example of the bearing unit,
in an abnormality sensing unit 1110 of the rolling bearing unit
shown in FIG. 51, a sensor fitting hole 1113 is formed in the lower
end portion of an outer ring 1112 of a double row tapered roller
bearing 1111, and then a sensor unit 1117 having a rotation speed
sensor 1114, a temperature sensor 1115, and an acceleration sensor
1116 therein is inserted/supported into the sensor fitting hole
1113 (for example, see JP-A-2002-295464 (pp. 4 to 5, FIG. 1)).
[0011] In addition, as other configurative example of the bearing
unit, in a sensor built-in rotation supporting member 1120 shown in
FIG. 52, a sensor fitting hole 1123 is formed in the lower end
portion of an outer ring 1122 of a double row tapered roller
bearing 1121, and then a sensor unit 1126 having a rotation speed
sensor 1124 and a temperature sensor 1125 therein is
inserted/supported into the sensor fitting hole 1123 (for example,
see JP-A-2002-292928 (pp. 4 to 5, FIG. 1)).
[0012] Further, as other configurative example, an abnormality
sensing unit 1130 of the bearing unit shown in FIG. 53 has a pickup
1132 for converting a mechanical vibration of a bearing 1131 into
an electric vibration to output, an automatic gain control
amplifier 1133 for amplifying an output of the pickup 1132, and a 1
to 15 kHz bandpass filter 1134 for removing noises generated from
the driving system and other mechanical systems from the output of
the amplifier 1133. Also, the unit 1130 has a root-mean-square
calculator 1135 for calculating a root mean square value of the
output of the bandpass filter 1134 and supplying the value to a
gain control terminal of the automatic gain control amplifier 1133,
an envelope circuit 1136 for receiving an output of the bandpass
filter 1134, a root-mean-square calculator 1137 for receiving an
output of the envelope circuit 1136, and an alarm circuit 1138 for
receiving an output of the root-mean-square calculator 1137 and
issuing an alarm by using a lamp or a contact output when such
output value exceeds a predetermined value (for example, see
JP-A-2-205727 (pp. 2 to 3, FIG. 1)).
[0013] Furthermore, as other configurative example, an abnormality
diagnosis system 1140 of the rolling bearing shown in FIG. 54 has a
configuration that includes a microphone 1142 arranged in vicinity
of a rolling bearing 1141, an amplifier 1143, an electronic device
1144, a speaker 1145, and a monitor 1146. The electronic device
1144 is a calculating/processing unit, and has a transducer 1147 as
a converting portion, a HDD 1148 as a recording portion, an
abnormality diagnosing portion 1149 as a calculating/processing
portion, and an analog converting/outputting portion 1150 (for
example, see JP-A-2000-146762 (pp. 4 to 6, FIG. 1)).
[0014] Besides, as other configurative example, in an abnormality
diagnosing method and an abnormality diagnosing system 1160 of the
bearing shown in FIG. 55, an electric signal waveform that a sensor
1161 outputs is converted into the digital file by an
analog/digital converter 1162, then is sent out to a waveform
processing portion 1163, and then is subjected to the enveloping
process by the waveform processing portion 1163 to get an envelope
spectrum. Then, an inner ring flaw component, an outer ring flaw
component, and a rolling element flaw component, which are
particular frequency components of the bearing constituent parts,
are extracted from the envelope spectrum by the waveform processing
portion 1163 in the extracting step by using predetermined
equations. Then, a calculating portion 1164 executes the
calculating step, a deciding portion 1165 executes the comparing
step, an outputting portion 1166 outputs the decided result, and a
speaker 1167 and a monitor 1168 inform the inspector of the result
(for example, see JP-A-2001-021453 (pp. 5 to 6, FIG. 1)).
[0015] However, in the configurations of the bearing unit set forth
in JP-T-2001-500597 and JP-A-2002-295464, since the sensor fitting
hole is provided in the outer ring, the type of the outer rings
constituting the bearing is increased such as the outer ring in
which the hole is not provided and the outer ring in which the hole
is provided. As a result, there is a possibility of generating the
installing error, and the like, and also a lot of man-hours are
needed to manage the parts. Also, it is possible that the outer
ring with the hole hinders the sealing performance in the
bearing.
[0016] Also, in the abnormality diagnosis system set forth in
JP-A-2-205727, JP-A-2000-146762, and JP-A-2001-021453, merely the
measure against the vibration noise is disclosed. In the case where
the bearing is used to support the axle of the railway vehicle, it
is possible that this diagnosis system decides a great shock
generated when the railway vehicle passes over the rail joint as an
abnormal signal. Thus, the abnormality decision may be largely
affected.
[0017] Also, in order to overcome the disadvantages caused by the
overhaul inspection or the visual inspection, there is proposed a
monitoring system that includes a sensor for sensing the sound or
the vibration generated during the rotation of the bearing and an
information processing system for analyzing a sensed signal of the
sensor to decide whether or not the abnormality is generated and
uses a personal computer as the information processing system (for
example, see JP-A-2002-71519).
[0018] However, the personal computer used as the information
processing system in the monitoring system in the prior art has
normally such a configuration that a motherboard and an interface
for receiving an output of the sensor are installed into a
general-purpose casing. Thus, the information processing system
needs a relatively large installing space and also has a tendency
that does not endure the vibration, and the like well.
[0019] For this reason, in order to prevent an influence of the
vibration on the bearing unit, etc., a space in which the personal
computer is provided must be secured in the position that is
distant from the bearing unit, etc. to some extent. In addition,
this monitoring system becomes large in size. Therefore, in the
case of the machinery facility in which the assurance of the large
installing space is difficult, such a problem has arisen that such
monitoring system is of little utility.
[0020] Also, in order to prevent a deterioration of the SN ratio of
the signal sensed by the sensor, it is preferable that the sensor
should be incorporated into the constituent parts itself of the
bearing unit if possible. However, the personal computer that
cannot stand up to the external vibration, and the like and is
large in size must be separated as far as possible away from the
bearing unit, or the like as the vibration generating source. As a
result, the personal computer is apart from the sensor at a
predetermined distance or more, and thus it is possible that the
problem such as a reduction in a sensing precision due to the
influence of the external noise on the information transmission
path between the sensor and the personal computer, or the like is
caused.
[0021] The present invention has been made in view of the above
problems, and it is an object of the present invention to provide a
high-precision machinery facility abnormality diagnosis system
capable of deciding the presence or absence of an abnormality in a
state of normal use without decomposition of a facility like a
machinery facility such as a railway vehicle facility, a machine
tool, a windmill, or the like, which requires much time and labor
to decompose, and thus capable of reducing
maintenance/administrative costs and being hardly affected by the
noise, and the like.
DISCLOSURE OF THE INVENTION
[0022] The present invention can be attained by configurations
described in the following.
[0023] (1) An abnormality diagnosis system for diagnosing a
presence or absence of an abnormality of a bearing unit for a
railway vehicle axle, comprising:
[0024] a sensing/processing portion for outputting a signal
generated from the bearing unit as an electric signal;
[0025] a calculating/processing portion for making an abnormality
diagnosis of the bearing unit based on an output of the
sensing/processing portion;
[0026] a result outputting portion for outputting a decision result
of the calculating/processing portion; and
[0027] a controlling/processing portion for feeding back a control
signal to a control system of the railway vehicle based on the
decision result.
[0028] (2) An abnormality diagnosis system according to (1),
wherein the calculating/processing portion includes
[0029] a data accumulating/distributing portion for accumulating
the electric signal fed from the sensing/processing portion and
distributing the signal to an appropriate distributing route
according to a type of the electric signal,
[0030] an analyzing portion for calculating a predetermined
physical quantity in regarding to the bearing unit based on the
electric signal distributed from the data accumulating/distributing
portion,
[0031] a first data saving portion for saving bearing unit data in
regarding to the bearing unit,
[0032] a comparing/deciding portion for making the abnormality
diagnosis of the bearing unit by comparing/referring an analyzed
result of the analyzing portion with the bearing unit data saved in
the first data saving portion,
[0033] a second data saving portion for saving the analyzed result
of the analyzing portion and a decision result of the
comparing/deciding portion.
[0034] (3) An abnormality diagnosis system according to (2),
wherein the analyzing portion includes
[0035] a filtering processing portion for removing a noise
component of the electric signal fed from the
calculating/processing portion or extracting a particular frequency
component to output, and
[0036] a frequency analyzing portion for executing a frequency
analysis of a signal output from the filtering processing portion,
and
[0037] the comparing/deciding portion makes the abnormality
diagnosis of the bearing unit based on a result of the frequency
analysis of the frequency analyzing portion.
[0038] (4) An abnormality diagnosis system according to (2) or (3),
wherein the analyzing portion has a temperature analyzing portion
that calculates a temperature of the bearing unit based on the
signal output from the data accumulating/distributing portion,
and
[0039] the comparing/deciding portion makes the abnormality
diagnosis of the bearing unit based on the temperature calculated
by the temperature analyzing portion.
[0040] (5) An abnormality diagnosis system according to any one of
(2) to (4), wherein the analyzing portion has a rotation analyzing
portion that calculates a rotation speed of the bearing unit based
on the signal output from the data accumulating/distributing
portion, and
[0041] the comparing/deciding portion makes the abnormality
diagnosis of the bearing unit based on the rotation speed
calculated by the rotation analyzing portion.
[0042] (6) An abnormality diagnosis system according to any one of
(1) to (5), wherein the calculating/processing portion outputs data
saved in the second data saving portion to the
controlling/processing portion in response to the abnormality
diagnosis result.
[0043] (7) An abnormality diagnosis system according to any one of
(1) to (6), wherein the filtering processing portion extracts only
a frequency component of 1 kHz or less.
[0044] (8) An abnormality diagnosis system according to any one of
(1) to (7), wherein a sensing element of the sensing/processing
portion is arranged on a stationary portion of the bearing unit in
a loading range.
[0045] (9) An abnormality diagnosis system according to any one of
(1) to (8), wherein the data accumulating/distributing portion does
not output the electric signal containing a noise component, which
exceeds a predetermined level, to the analyzing portion.
[0046] (10) An abnormality diagnosis system according to any one of
(1) to (9), wherein the comparing/deciding portion makes the
abnormality diagnosis of the bearing unit by comparing levels of a
frequency due to the abnormality and its higher harmonics with a
reference value.
[0047] (11) An abnormality diagnosis system according to any one of
(1) to (10), wherein the comparing/deciding portion decides that
the abnormality is generated when at least one of peak values of
the frequency due to the abnormal and its higher harmonics is
larger than a predetermined reference value.
[0048] (12) An abnormality diagnosis system according to any one of
(1) to (11), wherein the comparing/deciding portion estimates a
degree of damage of the bearing unit based on the peak values of
the frequency due to the abnormal and its higher harmonics.
[0049] (13) An abnormality diagnosis system according to any one of
(1) to (12), wherein the comparing/deciding portion makes the
abnormality diagnosis by comparing the levels of the frequency due
to the abnormal and its higher harmonics.
[0050] (14) An abnormality diagnosis system according to any one of
(1) to (13), wherein the comparing/deciding portion makes the
abnormality diagnosis based on a square mean or a partial overall
of a frequency band containing the frequency due to the
abnormal.
[0051] (15) An abnormality diagnosis system according to any one of
(1) to (14), wherein the comparing/deciding portion makes the
abnormality diagnosis by applying a cepstrum analysis to a
frequency spectrum.
[0052] (16) An abnormality diagnosis system according to any one of
(1) to (15), wherein the signal is transmitted between the
sensing/processing portion and the calculating/processing portion
and the calculating/processing portion and the
controlling/processing portion via a cable that has waterproof,
oil-resistant, dustproof, rust-preventive, and moisture-proof
functions, and heat-resistant, voltage-proof, and electromagnetic
noise-resistant properties respectively.
[0053] (17) An abnormality diagnosis system according to any one of
(1) to (15), wherein a radio communicating device is provided to
the sensing/processing portion and the calculating/processing
portion and the calculating/processing portion and the
controlling/processing portion respectively, and the signal is
transmitted therebetween by using the radio communicating device
via radio.
[0054] (18) An abnormality diagnosis system according to any one of
(1) to (15), wherein the signal is transmitted between the
sensing/processing portion and the calculating/processing portion
and the calculating/processing portion and the
controlling/processing portion via the cable that has waterproof,
oil-resistant, dustproof, rust-preventive, and moisture-proof
functions, and heat-resistant, and electromagnetic noise-resistant
properties respectively, or the signal is transmitted therebetween
by using the radio communicating device.
[0055] (19) An abnormality diagnosis system according to any one of
(1) to (18), wherein the abnormality diagnosis is made in real
time.
[0056] (20) An abnormality diagnosis system according to any one of
(1) to (18), wherein the abnormality diagnosis is made at a time
different from a vehicle traveling time, based on data accumulated
in the data accumulating/distributing portion.
[0057] (21) An abnormality diagnosis system according to any one of
(1) to (20), wherein the presence or absence of the abnormality of
a bearing in the bearing unit and an abnormality occurring location
are diagnosed.
[0058] (22) An abnormality diagnosis system according to any one of
(1) to (20), wherein a flat portion of a wheel is diagnosed.
[0059] (23) An abnormality diagnosis system according to any one of
(1) to (20), wherein the presence or absence of the abnormality of
a gear in the bearing unit and an abnormality occurring location
are diagnosed.
[0060] (24) An abnormality diagnosis system for a machinery
facility having a rotating body, comprising:
[0061] a sensor unit having a sensor fitted to a constituent parts
of the rotating body to sense a physical quantity of the rotating
body in a rotating operation;
[0062] a calculating/processing portion for deciding a presence or
absence of an abnormality of the rotating body by analyzing an
output signal of the sensor unit and then comparing an analyzed
result with predetermined reference data; and
[0063] a controlling/processing portion for displaying the analyzed
result of the calculating/processing portion and a decision result
of the calculating/processing portion, and controlling an operation
of the machinery facility in response to the decision result.
[0064] (25) An abnormality diagnosis system according to (24),
wherein the sensor unit has an output amplifying means for
amplifying the output signal of the sensor.
[0065] (26) An abnormality diagnosis system according to (24) or
(25), wherein the sensor unit has a radio communicating means for
transmitting the output signal to the calculating/processing
portion via radio.
[0066] (27) An abnormality diagnosis system according to (26),
wherein the calculating/processing portion and the
controlling/processing portion are provided to a monitoring base
station that is remote from the rotating body.
[0067] (28) An abnormality diagnosis system according to (27),
wherein the sensor unit is fitted to a bearing of a railway
vehicle, and the sensor unit diagnoses the abnormality of the
bearing.
[0068] (29) A machinery facility abnormality diagnosis system for
sensing a presence or absence of an abnormality of a sliding member
or a rotating body in a machinery facility, comprising:
[0069] a sensor unit having one of plural sensing elements for
sensing a signal emitted from the machinery facility; and
[0070] a calculating/processing portion for executing a calculating
process to decide the presence or absence of the abnormality in the
machinery facility based on an output of the sensing element;
[0071] wherein the calculating/processing portion is composed of a
microcomputer.
[0072] (30) A machinery facility abnormality diagnosis system
according to (29), wherein the sensor unit is incorporated into the
sliding member or the rotating body.
[0073] (31) A machinery facility abnormality diagnosis system
according to (30), wherein the microcomputer is fitted to the
sliding member or the rotating body or a mechanism parts that
supports the sliding member or the rotating body.
[0074] (32) A machinery facility abnormality diagnosis system
according to (29), wherein the microcomputer and the sensor unit
are mounted on a single device board, and are fitted to the sliding
member or the rotating body or a mechanism parts that supports the
sliding member or the rotating body as a single processing
unit.
[0075] (33) A machinery facility abnormality diagnosis system
according to any one of (29) to (32), wherein the
calculating/processing portion is installed in a single casing.
[0076] (34) A machinery facility abnormality diagnosis system
according to (33), wherein the sensor unit is arranged integrally
in the casing.
[0077] (35) A machinery facility abnormality diagnosis system
according to any one of (29) to (34), wherein the sensing element
senses at least one of temperature, vibration displacement,
vibration speed, vibration acceleration, force, distortion,
acoustic, acoustic emission, ultrasonic waves, and rotation
speed.
[0078] (36) A machinery facility abnormality diagnosis system
according to any one of (29) to (35), wherein the
calculating/processing portion includes central processing unit,
amplifier, analog/digital converter, filter, comparator, pulse
counter, timer, interruption controller, ROM, RRAM, digital/analog
converter, communication module, and external interface.
[0079] (37) A machinery facility abnormality diagnosis system
according to any one of (29) to (36), wherein the
calculating/processing portion executes at least one process or
more of calculation of feature parameters of a standard deviation
and a peak factor, envelope detection, FFT, filtering, wavelet
transform, short-time FFT, calculation of a feature frequency due
to a defect of the rotating body and comparison/decision.
[0080] (38) A condition monitoring method for a machinery facility
having at least one of a rotating body and a sliding member,
comprising the steps of:
[0081] analyzing a predetermined physical quantity of the machinery
facility based on a signal generated from the machinery
facility;
[0082] provisionally diagnosing a presence or absence of an
abnormality of the machinery facility by comparing/allocating an
analyzed result with information serving as references to decide
whether or not the abnormality is present in the machinery
facility, every first time period; and
[0083] diagnosing the presence or absence of the abnormality of the
machinery facility and an abnormal location, by executing a total
evaluation, which decides the abnormality when a number of times
the abnormality is provisionally diagnosed exceeds a threshold
value, after a comparison/allocation is executed predetermined
number of times or based on a compared/allocated result obtained
every second time period.
[0084] (39) A condition monitoring method for a machinery facility
having at least one of a rotating body and a sliding member,
comprising the steps of:
[0085] analyzing a predetermined physical quantity of the machinery
facility based on a signal generated from the machinery
facility;
[0086] provisionally diagnosing a presence or absence of an
abnormality of the machinery facility by comparing/allocating an
analyzed result with information serving as references to decide
whether or not the abnormality is present in the machinery
facility, every first time period; and
[0087] diagnosing the presence or absence of the abnormality of the
machinery facility and an abnormal location, by executing a total
evaluation, which decides a degree of the abnormality according to
a number of times the abnormality is provisionally diagnosed, after
a comparison/allocation is executed predetermined number of times
or based on a compared/allocated result obtained every second time
period.
[0088] (40) A machinery facility condition monitoring method
according to (38) to (39), wherein the signal is A/D-converted into
a digital signal, then a process of analyzing a frequency of the
digital signal is executed, and then a frequency component
generated due to a damage of the machinery facility and calculated
based on an operating signal of the machinery facility is
compared/allocated with a frequency component derived based on
actually measured data every first time period.
[0089] (41) A machinery facility condition monitoring method
according to (40), wherein the signal is subjected to an amplifying
process and a filtering process.
[0090] (42) A machinery facility condition monitoring method
according to (40) or (41), wherein at least one of the rotating
body and the sliding member of the machinery facility is any one of
rolling bearing, ball screw, linear guide, and linear ball bearing,
and the operating signal of the machinery facility is either a
rotation speed signal in the rolling bearing and the ball screw or
a moving speed signal in the linear guide and linear ball
bearing.
[0091] (43) A machinery facility condition monitoring system for a
machinery facility having at least one of a rotating body and a
sliding member and using the condition monitoring method set forth
in (38) or (39), comprising:
[0092] at least one sensing/processing portion for sensing a signal
generated from the machinery facility;
[0093] a calculating/processing portion having a microcomputer that
executes a calculating process to decide a condition of the
machinery facility based on the signal output from the
sensing/processing portion; and
[0094] a controlling/processing portion having at least one of a
result outputting portion that outputs a decision result of the
calculating/processing portion and a controller that feeds back a
control signal to a control system of the machinery facility based
on the decision result.
[0095] (44) A machinery facility condition monitoring system
according to (43), wherein at least one of the sensing/processing
portion and the microcomputer is installed into the rotating body
and the sliding member.
[0096] (45) A machinery facility condition monitoring system
according to (43) or (44), wherein at least one of the rotating
body and the sliding member is a bearing to which a radial load is
applied, and the sensing/processing portion is fixed in a radial
load loading range of a bearing housing that is fitted onto a
raceway ring of the bearing.
[0097] (46) An abnormality diagnosis system for a railway vehicle
bearing unit using the machinery facility condition monitoring
system set forth in any one of (43) to (45).
[0098] (47) An abnormality diagnosis system for a windmill bearing
unit using the machinery facility condition monitoring system set
forth in any one of (43) to (45).
[0099] (48) An abnormality diagnosis system for a machine tool
spindle bearing unit using the machinery facility condition
monitoring system set forth in any one of (43) to (45).
[0100] (49) A machine equipment abnormality diagnosis system
comprising:
[0101] a sensing/processing portion having a sensor unit that is
fixed to a bolt screwed into a housing of the machine equipment and
outputs a signal generated from the machine equipment as an
electric signal;
[0102] a calculating/processing portion for making an abnormality
diagnosis of the machine equipment based on an output of the
sensing/processing portion; and
[0103] a controlling/processing portion for feeding back a control
signal to a control system of the machine equipment based on a
result of the abnormality diagnosis.
[0104] (50) A machine equipment abnormality diagnosis system
according to (49), wherein the calculating/processing portion
includes
[0105] the calculating/processing portion includes
[0106] a data accumulating/distributing portion for accumulating
the electric signal fed from the sensing/processing portion and
distributing the signal to an appropriate distributing route
according to a type of the electric signal,
[0107] an analyzing portion for calculating a predetermined
physical quantity in regarding to the machine equipment based on
the electric signal distributed from the data
accumulating/distributing portion,
[0108] a first data saving portion for saving machine equipment
data in regarding to the machine equipment,
[0109] a comparing/deciding portion for making the abnormality
diagnosis of the machine equipment by comparing the physical
quantity calculated by the analyzing portion with the machine
equipment data saved in the first data saving portion,
[0110] a second data saving portion for saving the analyzed result
of the analyzing portion and a result of the abnormality diagnosis
of the comparing/deciding portion.
[0111] (51) A machine equipment abnormality diagnosis system
according to (49) or (50), wherein the calculating/processing
portion and the controlling/processing portion are composed of a
microcomputer or an IC chip.
[0112] (52) A machine equipment abnormality diagnosis system
according to any one of (49) to (51), wherein the signal is
transmitted between the sensing/processing portion and the
calculating/processing portion or the calculating/processing
portion and the controlling/processing portion without a wire
connection.
[0113] (53) A bearing unit including an inner ring having an inner
ring raceway surface, an outer ring having an outer ring raceway
surface, a plurality of rolling elements arranged relatively
rotatably between the inner ring raceway surface and the outer ring
raceway surface, and a retainer for holding rollably the rolling
elements, whereby a bearing to which a radial load is applied is
arranged in a bearing housing,
[0114] the bearing unit comprising:
[0115] an abnormality sensing means provided in a loading range of
the bearing housing, for sensing an abnormality from at least one
selected from a vibration sensor and a temperature sensor
installed/fixed in a single case.
[0116] (54) A bearing unit according to (53), wherein a flat
portion is provided to a part of an outer peripheral surface of the
bearing housing on a loading range side, and the abnormality
sensing means is fixed to the flat portion.
[0117] (55) A bearing unit according to (54), wherein the
abnormality sensing means is arranged on an outer diameter portion
of the bearing housing on the loading range side in a center
portion of a bearing width.
[0118] (56) A bearing unit according to (53), wherein the
abnormality sensing means is arranged on an outer diameter portion
of the bearing housing on the loading range side in a width area of
the inner ring raceway surface or the outer ring raceway
surface.
[0119] (57) A bearing unit according to any one of (53) to (56),
wherein a case of the abnormality sensing means has a signal
carrying means that sends out a sensed signal, and a decision
result outputting portion that decides a presence or absence of the
abnormality based on the signal sent out via the signal carrying
means and output a decision result.
[0120] (58) A bearing unit according to any one of (53) to (57),
wherein the abnormality sensing means is embedded/fixed on a recess
portion formed on the bearing housing, and then secured by molding
a clearance between the abnormality sensing means and the recess
portion.
[0121] (59) A bearing unit according to (58), wherein the
abnormality sensing means is fixed to the recess portion via a
spacer.
[0122] (60) A bearing unit according to any one of (53) to (59),
wherein a filtering processing portion for removing an unnecessary
frequency band from a vibration waveform from the vibration sensor,
an envelope processing portion for detecting an absolute value of a
filtered waveform transferred from the filtering processing
portion, a frequency analyzing portion for analyzing a frequency of
a waveform transferred from the envelope processing portion, a
comparing/collating portion for comparing a frequency generated due
to a damage calculated based on a rotation speed with a frequency
derived based on actually measured data, and a result outputting
portion for identifying a presence or absence of the abnormality
and an abnormal location based on a compared result in the
comparing/collating portion are provided.
BRIEF DESCRIPTION OF THE DRAWINGS
[0123] FIG. 1 is a view showing a railway vehicle abnormality
diagnosis system according to a first embodiment of the present
invention;
[0124] FIG. 2 is a block diagram showing an internal structure of a
sensor unit;
[0125] FIG. 3 is a view showing a data accumulating/distributing
portion;
[0126] FIG. 4 is a table showing relational expressions indicating
relationships between defects of respective members of a bearing
and abnormal vibration frequencies generated in respective
members;
[0127] FIG. 5 is a view showing a relationship between a loading
range and a non-loading range in the bearing;
[0128] FIG. 6 is a view showing a time-variant waveform of an
oscillating signal sensed from the bearing in the first
embodiment;
[0129] FIG. 7 is a view showing a frequency spectrum of the
vibration signal sensed from the bearing in the first
embodiment;
[0130] FIG. 8 is a view showing a frequency spectrum of the
vibration signal sensed from the bearing in the first embodiment
after an enveloping process;
[0131] FIG. 9 is a flowchart showing a process flow in a first
method;
[0132] FIG. 10 is a graph showing a frequency spectrum when no
abnormality is generated;
[0133] FIG. 11 is a graph showing a frequency spectrum when the
abnormality is generated in an outer ring;
[0134] FIG. 12 is a graph showing a relationship between the
frequency spectrum and a reference value when a retainer has a
flaw;
[0135] FIG. 13 is a flowchart showing a process flow in a second
method;
[0136] FIG. 14 is a view explaining the second method;
[0137] FIG. 15 is a flowchart showing a process flow in a third
method;
[0138] FIG. 16 is a view showing a frequency spectrum when an outer
ring has the flaw;
[0139] FIG. 17 is a view explaining a fourth method;
[0140] FIG. 18 is a graph showing a relationship between a size of
flaking and a level difference between peaks appearing on the
actually measured frequency spectrum data and a reference
level;
[0141] FIG. 19 is a flowchart showing a process flow in a fifth
method;
[0142] FIG. 20 is a view showing frequency spectrum levels and a
reference line;
[0143] FIG. 21 is a flowchart showing a process flow in a sixth
method;
[0144] FIG. 22 is a graph showing a frequency spectrum when the
abnormality is generated in the outer ring;
[0145] FIG. 23 is a graph showing a frequency spectrum when no
abnormality is generated in the outer ring;
[0146] FIG. 24 is another graph showing a frequency spectrum when
the abnormality is generated in the outer ring;
[0147] FIG. 25 is another graph showing a frequency spectrum when
no abnormality is generated in the outer ring;
[0148] FIG. 26 is a block diagram showing an internal configuration
of a sensor unit in a railway vehicle abnormality diagnosis system
according to a second embodiment of the present invention;
[0149] FIG. 27 is a view showing the railway vehicle abnormality
diagnosis system according to the second embodiment of the present
invention;
[0150] FIG. 28 is a block diagram showing a schematic configuration
of a rotating body abnormality diagnosis system according to a
third embodiment of the present invention;
[0151] FIG. 29 is a block diagram showing a schematic configuration
of a rotating body abnormality diagnosis system according to a
fourth embodiment of the present invention;
[0152] FIG. 30 is a block diagram showing a schematic configuration
of a machinery facility abnormality diagnosis system according to a
fifth embodiment of the present invention;
[0153] FIG. 31 is a block diagram showing a schematic configuration
of a microcomputer shown in FIG. 30;
[0154] FIG. 32 is a block diagram showing a schematic configuration
of a machinery facility abnormality diagnosis system according to a
sixth embodiment of the present invention;
[0155] FIG. 33 is a block diagram showing a schematic configuration
of a machinery facility abnormality diagnosis system according to a
seventh embodiment of the present invention;
[0156] FIG. 34(a) is a block diagram showing a schematic
configuration of a machinery facility abnormality diagnosis system
according to an eighth embodiment of the present invention;
[0157] FIG. 34(b) is a side view showing a bearing fitting state in
FIG. 34(a);
[0158] FIG. 35(a) is a block diagram showing a schematic
configuration of a machinery facility abnormality diagnosis system
according to a ninth embodiment of the present invention;
[0159] FIG. 35(b) is a side view showing a bearing fitting state in
FIG. 35(a);
[0160] FIG. 36 is a block diagram showing a schematic configuration
of a machinery facility abnormality diagnosis system according to a
tenth embodiment of the present invention;
[0161] FIG. 37 is a sectional view showing a machinery facility to
which a condition monitoring system according to an eleventh
embodiment of the present invention is applied;
[0162] FIG. 38 is a schematic view showing the condition monitoring
system according to the eleventh embodiment;
[0163] FIG. 39 is a block diagram of a calculating/processing
portion in FIG. 38;
[0164] FIG. 40 is a flowchart showing procedures of a diagnosis
process in a condition monitoring method;
[0165] FIG. 41 is a view showing a bearing housing of a railway
vehicle bearing unit serving as a machinery facility to which an
abnormality diagnosis system according to a twelfth embodiment of
the present invention is applied;
[0166] FIG. 42 is a view showing a railway vehicle abnormality
diagnosis system in the twelfth embodiment;
[0167] FIG. 43 is a view showing a variation of the abnormality
diagnosis system according to the twelfth embodiment of the present
invention;
[0168] FIG. 44 is a view showing another variation of the
abnormality diagnosis system according to the twelfth embodiment of
the present invention;
[0169] FIG. 45 is a schematic view showing a bearing unit according
to a thirteenth embodiment of the present invention;
[0170] FIG. 46 is a signal processing system diagram in an
abnormality sensing means in the bearing unit shown in FIG. 45;
[0171] FIG. 47 is a signal processing system diagram using a method
different from FIG. 46;
[0172] FIG. 48 is a sectional view showing a bearing unit according
to a fourteenth embodiment of the present invention;
[0173] FIG. 49 is a sectional view showing a bearing unit according
to a fifteenth embodiment of the present invention;
[0174] FIG. 50 is a sectional view showing a bearing unit in the
prior art;
[0175] FIG. 51 is a sectional view showing another bearing unit in
the prior art;
[0176] FIG. 52 is a sectional view showing still another bearing
unit in the prior art;
[0177] FIG. 53 is a block diagram showing another configurative
example in the prior art;
[0178] FIG. 54 is a block diagram showing still another
configurative example in the prior art; and
[0179] FIG. 55 is a block diagram showing yet still another
configurative example in the prior art.
BEST MODE FOR CARRYING OUT THE INVENTION
[0180] A machinery facility condition monitoring method and system
and an abnormality diagnosis system according to the present
invention will be explained in detail with reference to the
accompanying drawings hereinafter.
First Embodiment
[0181] FIG. 1 shows a railway vehicle abnormality diagnosis system
according to a first embodiment of the present invention. An
abnormality diagnosis system 1 includes a sensing/processing
portion 20 having sensor units 22 each provided to each row of a
rolling bearing 21 to output a condition of each row as an electric
signal, a calculating/processing portion 30 for
calculating/processing the electric signals output from the sensor
units 22 to decide the condition such as defect, abnormality, or
the like of a railway vehicle facility 10, and a
controlling/processing portion 40 for controlling and outputting
the decided result of the calculating/processing portion 30.
[0182] The abnormality diagnosis system 1 senses the generation of
the abnormality due to the wear or the failure of a plurality of
rolling bearings 21 in the bearing unit that bears the axle of the
railway vehicle. Each rolling bearing 21 has an outer ring 23 as a
stationary portion that is fitted into the vehicle body side, an
inner ring 24 fitted onto the axle and rotated together with the
axle, and rolling elements 25 such as balls, rollers, or the like
held between an outer ring raceway formed on the inner peripheral
surface side of the outer ring 23 and an inner ring raceway formed
on the peripheral surface side of the inner ring 24 by a retainer
(not shown) and arranged rollably between both raceways. Also, the
sensor unit is secured to the outer ring 23 of each rolling bearing
21. In FIG. 1, the sensing/processing portion 20 is constructed by
sensing portions 20a, 20b, 20c each consisting of the sensor unit
22 secured to each rolling bearing 21.
[0183] The sensor unit 22 has sensors as a plurality of sensing
elements that sense various information generated from the
machinery facility during the running, e.g., sound J1, temperature
J2, vibration (vibration displacement, vibration speed, vibration
acceleration) J3, rotation speed J4, distortion J5 generated on the
outer ring of the bearing, AE (acoustic emission), moving speed,
force, ultrasonic wave, etc., as physical quantities that are
changed in response to a rotating condition of the bearing 21. Each
sensor outputs the sensed physical quantity to the
calculating/processing portion 30 as the electric signal.
[0184] Here, since the calculating/processing portion 30 can
distribute/process appropriately the electric signals every sensed
information, respective sensing elements are arranged independently
in different locations respectively. Thus, a plurality of sensing
elements for sensing independently the particular signals such as
sound, temperature, vibration, rotation speed, distortion, AE,
moving speed, force, ultrasonic wave, and others may be employed in
combination. Alternately, a composite sensor unit constructed by
installing a plurality of sensing elements into an inside of a
housing to sense simultaneously plural types of signals may be
employed as the sensor unit 22, in place of independent arrangement
of a plurality of sensing elements. Also, a multidirectional
simultaneous vibration sensor for sensing the vibration in the
multiple directions by one sensor may be employed as the vibration
sensor.
[0185] In addition, in order to execute the sensing at a high SN
ratio, the signal can be sensed with good sensitivity by fitting
the sensor unit 22, especially a vibration sensing element 22d (see
FIG. 2(a)), to a portion to which a load is applied (loading range)
and thus the higher-precision measurement can be attained. Where
the "loading range" denotes an area in which the load is applied to
the rolling elements, as shown in FIG. 5. In the case where the
sensor unit is fitted inevitably to a non-loading range when the
space used to fit the sensor is absent in the loading range, a
high-tension cable that generates noises is provided to the loading
range, or the like, the measurement can be carried out by enhancing
a signal sensing sensitivity by virtue of a filtering process
executed by a filtering processing portion 34 described later, or
the like.
[0186] In the present embodiment, as shown in FIG. 2(a), the sensor
unit 22 has such a structure that various sensing elements 22b,
22c, and 22d are installed into a unit case 22a. Then, explanation
will be made hereunder under the assumption that the temperature
sensing element 22b for sensing the temperature of the bearing 21,
the rotation sensing element 22c for sensing the rotation speed of
the inner ring (axle) of the bearing 21, and the vibration sensing
element 22d for sensing the vibration generated in the bearing 21
are provided in the unit case 22a.
[0187] Respective sensing elements 22b to 22c amplify the electric
signals corresponding to the sensed vibration, temperature, and
rotation speed via an amplifier 50 as an output amplifying means,
and then output the signals to the calculating/processing portion
30. The amplifier 50 may be provided in the unit case 22a of the
sensor respectively as shown in FIG. 2(b), or the amplifier 50 may
be provided between the sensor unit 22 and the
calculating/processing portion 30 respectively as shown in FIG. 1,
or the amplifier 50 may be provided to an interior of the
calculating/processing portion 30. It is preferable that amplifiers
22e, 22f, and 22g should be provided to the sensing elements 22b,
22c, and 22d in the unit case 22a respectively. There is such a
possibility that the noise is superposed on the signal during when
the signal output from the sensor unit 22 is being transmitted to
the calculating/processing portion 30 via the cable, and thus the
reliability of measurement is lowered. In this event, if a signal
level is amplified in advance via the amplifier 50, the signal is
hard to accept the influence of the noise and thus the reliability
can be improved.
[0188] The signal is transmitted between the sensor unit 22 and the
calculating/processing portion 30 via the cable. In order to
improve a measuring precision such as reduction of noise, etc., it
is preferable that the cable should have waterproof, oil-resistant,
dustproof, rust-preventive, moisture-proof, heat-resistant, and
electromagnetic noise-resistant properties. Similarly, in order to
improve a measuring precision such as reduction of noise, etc., it
is preferable that respective sensing elements 22b to 22d in the
sensor unit 22 should have waterproof, oil-resistant, dustproof,
rust-preventive, moisture-proof, heat-resistant, and
electromagnetic noise-resistant properties. For example, if all
sensing elements are incorporated into the sensor unit and then the
waterproof, oil-resistant, dustproof, rust-preventive,
moisture-proof, heat-resistant, and electromagnetic noise-resistant
properties are provided to the unit case 22a of the sensor unit 22,
these properties can be embodied.
[0189] The calculating/processing portion 30 is a unit that
executes the calculating process of the electric signals as the
outputs that are received from respective sensing elements (the
temperature sensing element 22b, the rotation sensing element 22c,
and the vibration sensing element 22d in the present embodiment) in
the sensor unit 22, and then identifies the presence or absence of
the abnormality of the bearing and an abnormality occurring
location by comparing the analyzed result analyzed by the
calculating process and the reference data. Here, the reference
data denote reference values of various physical quantities that
are sensed by respective sensing elements in the normal condition
of the bearing 21 serving as the diagnosed object. More
particularly, the reference data contain the information about a
frequency component generated by the wear or the failure of the
particular portion of the bearing 21, and the like, in addition to
the information of the normal bearing 21 about sound, temperature,
vibration, rotation speed, distortion, AE, moving speed, force,
ultrasonic wave, and the like.
[0190] For instance, the calculating/processing portion 30 may be
constructed by using the personal computer or the general-purpose
computer into which the existing operating system and the software
applications used to execute the abnormality diagnosis. Otherwise,
the calculating/processing portion 30 may be constructed as an
arithmetic unit that are composed of processing and saving circuits
provided independently to respective portions.
[0191] The calculating/processing portion 30 includes a data
accumulating/distributing portion 31, a temperature analyzing
portion 32, a rotation analyzing portion 33, the filtering
processing portion 34, a vibration analyzing portion 35, a
comparing/deciding portion 36, an internal data saving portion 37
serving as a first data saving portion, a data
accumulating/outputting portion 38 serving as a second data saving
portion. Then, configurations and functions of respective portions
of the calculating/processing portion 30 will be explained in
detail hereunder.
[0192] FIG. 3 is a view showing the data accumulating/distributing
portion 31 serving as a first data accumulating portion. The data
accumulating/distributing portion 31 has a data accumulating
portion 31a, a sampling portion 31c, and a sampling reference
setting portion 31b. The data accumulating portion 31a is a data
saving medium that save the output signals from the sensing
elements 22b to 22d every signal, and can be constructed by various
memories, the hard disk, and the like.
[0193] The data accumulating portion 31a receives the signals sent
out from the sensing elements 22b to 22d, and then stores
temporarily such signals and also allocates such signals to any of
the analyzing portions 32, 33, 34 in response to the type of
signal. Various signals are A/D-converted into digital signals by
an A/D converter (not shown) at the preceding stage to the data
accumulating/distributing portion 31. In this event, the A/D
conversion and the amplification may be applied in reverse
order.
[0194] The sampling reference setting portion 31b sets the
reference values that are used to exclude areas, in which the
influence of the noise appears largely, from the analog signal
being output from the vibration sensing element 22d, based on the
information derived from an external inputting portion 100. Here,
the inputting portion 100 is an inputting means such as a mouse, a
keyboard, or the like, and the user can set arbitrarily the
reference values via the inputting portion 100.
[0195] The sampling portion 31c cuts out vibration, temperature,
and rotation speed data serving as the time-variant data into a
predetermined length data, and then executes the sampling to output
the signal to the analyzing portions in the subsequent stage. When
the output signal from the vibration sensing element 22d contains
the larger noise than the reference value being set by the sampling
reference setting portion 31b, the sampling portion 31c does not
execute the sampling of the signal in a period of time containing
such noise not to output the signal to the filtering processing
portion 34. More particularly, the sampling portion 31c detects two
points A and B at which the signal level exceeds a certain
predetermined value, and then controls not to output the data to
the filtering processing portion 34 and the vibration analyzing
portion 35 in a time interval A to B. Accordingly, it is possible
not to execute the frequency analysis within the time interval that
contains the data on which the large noise is superposed, so that a
possibility of executing the false abnormality diagnosis can be
reduced. In this case, the sampling reference setting portion 31b
and the sampling portion 31c are not always provided. Also, if the
similar effect can be achieved, these portions may be arranged in
another location, e.g., the preceding stage of the data
accumulating portion 31a, or the like.
[0196] The temperature analyzing portion 32 calculates the
temperature of the bearing based on the output signal fed from the
temperature sensing element 22b, and then sends out the calculated
temperature to the comparing/deciding portion 36. The temperature
analyzing portion 32 has a temperature transformation table
responding to characteristics of the sensing elements, for example,
and calculates the temperature data based on a level of the sensed
signal.
[0197] The rotation analyzing portion 33 calculates the rotation
speed of the inner ring 24, i.e., the axle based on the output
signal fed from the rotation sensing element 22c, and then sends
out the calculated rotation speed to the comparing/deciding portion
36. For example, when the rotation sensing element 22c is composed
of an encoder fitted to the inner ring 24, a magnet fitted to the
outer ring 23, and a magnetism sensing element, a signal output
from the rotation sensing element 22c is given as a pulse signal
that responds to a shape of the encoder and the rotation speed. The
rotation analyzing portion 33 contains a predetermined
transformation function or transformation table in response to the
shape of the encoder, and calculates the rotation speed of the
inner ring 24 and the axle from the pulse signal based on the
function or the table.
[0198] The vibration analyzing portion 35 executes the frequency
analysis of the vibration generated in the bearing 21 based on the
output signal from the vibration sensing element 22d. More
specifically, the vibration analyzing portion 35 is composed of an
FFT computing portion that calculates the frequency spectrum of the
vibration signal and calculates the frequency spectrum of the
vibration in compliance with the FFT algorithm. The calculated
frequency spectrum is fed to the comparing/deciding portion 36.
Also, the vibration analyzing portion 35 may be constructed to
execute the enveloping process as the preprocessing prior to the
FFT to calculate the envelope of the vibration signal and thus
attain a reduction of the noise. The vibration analyzing portion 35
also outputs the envelope data obtained after the enveloping
process to the comparing/deciding portion 36, as the case may
be.
[0199] Normally the abnormal frequency bands of the vibration
caused due to the rotation of the bearing are decided depending
upon a size of the bearing, the number of rolling elements, etc.
Respective relationships between the defect of respective members
of the bearing and the abnormal vibration frequencies generated in
respective members are given as shown in FIG. 4. In the frequency
analysis, the maximum frequency that permits the Fourier transform
(Nyquist frequency) is decided in response to a sampling time, and
thus preferably the frequency that is in excess of the Nyquist
frequency should not be contained in the vibration signal.
Therefore, the present embodiment is constructed such that the
filtering processing portion 34 is provided between the data
accumulating/distributing portion 31 and the vibration analyzing
portion 35, a predetermined frequency band is cut out from the
vibration signal by the filtering processing portion 34, and the
vibration signal containing only the cut-out frequency band is sent
out to the vibration analyzing portion 35. When the axle is being
rotated at a low speed in the railway vehicle, only the frequency
component of 1 kHz or less, for example, may be extracted.
[0200] Also, the filtering processing portion 34 may be arranged in
such a manner that the portion first causes the vibration analyzing
portion 35 to calculate the frequency spectrum without the
filtering process, then estimates previously the frequency band in
which the peak will be observed, and then executes the filtering
process in answer to the frequency band to execute newly the
frequency analysis. With this arrangement, the unnecessary noise
can be eliminated effectively and thus the high-precision frequency
analysis can be executed.
[0201] FIG. 6 is a view showing a time-variant waveform of an
oscillating signal as the vibration information J3 in regarding to
the vibration of the rolling bearing 21 sensed by the sensor unit
22 in the present embodiment, FIG. 7 shows the frequency spectrum
of the vibration signal sensed by the vibration analyzing portion
35 in the present embodiment, and FIG. 8 shows the frequency
spectrum of the vibration signal sensed by the vibration analyzing
portion 35 in the present embodiment after the enveloping
process.
[0202] In this manner, the vibration analyzing portion 35 applies
the frequency analysis to the vibration signal and calculates the
frequency spectrum shown in FIG. 7 or FIG. 8. The strong spectrum
is observed at a predetermined frequency period from FIG. 8. It is
understood from the relational expression given in FIG. 4 that this
corresponds to a frequency component generated due to the damage of
the outer ring 23 of the rolling bearing 21.
[0203] In FIG. 3, the temperature analyzing portion 32, the
rotation analyzing portion 33, and the vibration analyzing portion
35 are illustrated. But respective analyzing portions may be
provided in response to the information that are sensed by
respective sensing elements in the sensor unit 22.
[0204] The comparing/deciding portion 36 compares the frequency
spectrum of the vibration sensed by the vibration analyzing portion
35 with the reference value saved in the internal data saving
portion 37 or the reference value calculated from the frequency
spectrum to decide whether or not the abnormal vibration is being
generated. Where the reference values are the data of the frequency
components generated due to the wear or the failure of the
particular location of the bearing or predetermined values
contained in the spectrum calculated every frequency spectrum. In
order to expect an accuracy of the decision, the comparing/deciding
portion 36 refers to the analyzed result of the temperature and the
rotation speed obtained by the temperature analyzing portion 32 and
the rotation analyzing portion 33 and specification data of various
data of the bearing accumulated in the internal data saving portion
37, etc., simultaneously with the decision based on the comparison
between the frequency components.
[0205] More particularly, if it is decided based on the frequency
spectrum of the vibration that the abnormality occurs, the
comparing/deciding portion 36 checks the temperature of the bearing
and then decides that the serious abnormality is being generated if
the temperature exceeds a predetermined value. Also, if only any
one indicates the abnormality, the comparing/deciding portion 36
decides that any abnormality occurs. Then, if both results are
normal, the comparing/deciding portion 36 decides that no
abnormality occurs. If only any one indicates the abnormality, it
may be decided that the abnormality occurs when the results are not
varied after the decision is made in plural number of times. The
comparing/deciding portion 36 outputs the result of the abnormality
diagnosis to the data accumulating/outputting portion 38.
[0206] As the particular abnormality diagnosis process executed by
the comparing/deciding portion 36 based on the vibration
information, following methods will be listed.
[0207] (1) Method of Using Root-Means-Square Values of the Envelope
Data as the Reference Value
[0208] The present method calculates the frequency components
generated at the time of abnormality based on the expressions in
FIG. 4. Then, the root-means-square values of the envelope data are
calculated and then the reference values used in the comparison are
calculated from the root-means-square values. Then, the frequencies
that are in excess of the reference values are calculated and then
compared with the frequency components generated at the time of
abnormality. Then, explanation will be made with reference to FIG.
9 hereunder.
[0209] First, the vibration of the bearing is sensed by the
vibration sensing element 22d installed in the sensor unit case 22a
(step S101). The sensed signal is amplified by a predetermined
amplification factor and then converted into the digital signal by
an A/D converter (step S102). The vibration signal converted into
the digital signal is saved in the data accumulating/distributing
portion 31 in a predetermined format (step S103).
[0210] Then, the frequency spectrum of the digital signal is
calculated (step S104). Then, the filtering processing portion 34
selects a filter bandwidth that is applied to the digital signal,
based on the calculated frequency spectrum (step S105). Then, the
filtering processing portion 34 executes the filtering process to
remove the frequency components other than the selected filter band
(step S106), and then outputs the digital signal after the
filtering process to the vibration analyzing portion 35. Then, the
vibration analyzing portion 35 applies the enveloping process to
the digital signal after the filtering process (step S107). Then,
the frequency spectrum of the digital signal after the enveloping
process is calculated (step S108).
[0211] At the same time, the root-means-square value of the digital
signal after the enveloping process is calculated (step S109).
Then, the reference value used in the abnormality diagnosis is
calculated based on the root-means-square value (step S112). Where
the root-means-square value is calculated as a square root of a
square mean of the frequency spectrum after the enveloping process.
The reference value is calculated as follows based on the
root-means-square value in accordance with an Equation (1) or (2).
(Reference value)=(Root-means-square value)+.alpha. (1) (Reference
value)=(Root-means-square value).times..beta. (2)
[0212] .alpha., .beta.: predetermined value variable according to
the type of data Then, frequencies generated due to the abnormality
of the bearing are calculated based on a table shown in FIG. 4
(step S110). Then, levels of abnormal frequency components of
respective members corresponding to the calculated frequencies,
i.e., an inner ring flaw component Si (Zfi), an outer ring flaw
component So (Zfc), a rolling element flaw component Sb (2fb), and
a retainer flaw component Sc (fc) are extracted (step S111). Then,
respective components Si, So, Sb, Sc are compared with the
reference value calculated in step S112 (step S113). Then, if all
component values are smaller than the reference value, it is
decided that no abnormality is generated in the bearing (step
S114). In contrast, if any component exceeds the reference value,
it is decided that the abnormality is generated in the concerned
location (step S115).
[0213] FIG. 10 is a graph showing the frequency spectrum when no
abnormality is generated, and FIG. 11 is a graph showing the
frequency spectrum when the abnormality is generated in the outer
ring. In an example in FIG. 10, the reference value was derived as
-29.3 dB from the envelope data. If the inner ring flaw component
Si(Zfi), the outer ring flaw component So (Zfc), the rolling
element flaw component Sb (2fb), and the retainer flaw component Sc
(fc) are compared with a line of the reference value depicted in
FIG. 10, the levels of all components are smaller than the
reference value. As a result, it is decided that this bearing is
normal. In contrast, in the case in FIG. 11, since the outer ring
flaw component So (Zfc) is protruded largely from the reference
value, it can be decided that the abnormality is generated in the
outer ring of the bearing.
[0214] Also, FIG. 12 is a graph showing a relationship between the
frequency spectrum and the reference value when the retainer has
the flaw. In FIG. 12, a peak that is larger than the reference
value is observed at a frequency fc corresponding to the flaw of
the retainer. In this manner, since the presence or the absence of
the peak of the generated frequency can be decided by the
comparison between levels in the frequencies due to the bearing and
the reference value, even a small peak shown in FIG. 12 can be
diagnosed appropriately.
[0215] Here, the root-mean-square value is employed, but either a
mean value such as the running means, or the like or a peak factor
(=peak level/mean value) may be employed.
[0216] (2) Method of Calculating a Peak of the Spectrum and then
Comparing a Peak Frequency and an Abnormal Frequency
[0217] The present method calculates the frequency components
generated at the time of abnormality based on the expressions in
FIG. 4. Then, it is collated whether or not the peaks, which exceed
a predetermined occurring number of times or exceeds the reference
value, among the frequency spectrum calculated by the
comparing/deciding portion 36 correspond to the frequency
components at which the abnormality occurs. Then, explanation will
be made in detail with reference to a flowchart shown in FIG. 13
hereunder.
[0218] Since the process flows up to step S108 are similar to those
set forth in the method (1), their explanation will be omitted
herein. In the present method, first the peak value of the
resultant frequency spectrum is calculated (step S201). Here, in
order to derive the peak of the frequency, at first difference data
indicating a difference between a level of a data point in each
frequency component and a level of a preceding data point in each
frequency component is calculated. Then, an inflection point at
which a sign of the difference data is changed from plus to minus
is found out, and then it is decided that the peak value appears at
the frequency values in regarding to the difference data that give
positive/negative criterions. In this case, only the frequency
spectrum a ridge (inclination) of which shows a steep and sharp
peak is selected as the object of the peak values that are
necessary for the diagnosis. For this reason, only when a gradient
is larger or smaller than a predetermined reference value (e.g., 1
or -1), it is decided that the frequency spectrum gives the
peak.
[0219] FIG. 14 is a view showing the frequency spectrum. In FIG.
14, a point B out of three successive points A (X.sub.0,Y.sub.0), B
(X.sub.1,Y.sub.1), C (X.sub.2,Y.sub.2) gives the peak. In this
case, since difference data .delta..sub.1 between A and B is given
as .delta..sub.1=Y.sub.1-Y.sub.0>0 and the difference data
.delta..sub.2 between B and C is given as
.delta..sub.2=Y.sub.2-Y.sub.1<0, the difference data is changed
from positive to negative. Then, if a gradient
(Y.sub.1-Y.sub.0)/(X.sub.1-X.sub.0)>1 or a gradient
(Y.sub.2-Y.sub.1)/(X.sub.2-X.sub.1)<-1 is satisfied here, it is
decided that the point B gives the peak.
[0220] Then, the abnormal frequency is calculated from the
specification of the bearing based on FIG. 4 (step S202). Then, the
levels of the abnormal frequency components of respective members
corresponding to the calculated frequency, i.e., the inner ring
flaw component Si (Zfi), the outer ring flaw component So (Zfc),
the rolling element flaw component Sb (2fb), and the retainer flaw
component Sc (fc) are extracted (step S203). Then, it is decided by
comparing the peak frequency with the frequencies generated at the
time of abnormality whether or not the peak frequency agrees with
the calculated abnormal frequency (step S204). Then, if a certain
peak corresponds to the abnormal frequency, it is decided that the
abnormality is generated in the member that corresponds to the
concerned abnormal frequency (step S206). In contrast, if the peak
corresponds to no frequency, it is decided that no abnormality is
generated (step S205).
[0221] (3) Method of Using a Fundamental Frequency and a Particular
Harmonic
[0222] The present method compares peak frequencies of a primary
value as a fundamental frequency of the abnormal frequency
component, a secondary value having a twice frequency of the
fundamental frequency, and a quaternary value having a quadruple
frequency of the fundamental frequency with the frequencies
generated at the time of abnormality respectively, and then decides
finally that the abnormality is generated if it is decided that the
abnormality is generated at least two frequencies, or decides that
no abnormality is generated if the frequency at which it is decided
that the abnormality is generated is one or less. Then, explanation
will be made in detail with reference to FIG. 15 hereunder.
[0223] The process flow required until the frequency spectrum is
calculated and the frequencies generated due to the abnormality are
calculated is similar to the process flow in the method (1). In the
present method, as shown in FIG. 15, first it is decided in the
comparison whether or not the spectrum value exceeds the reference
value at the frequency of the fundamental component (primary
component) generated at the time of abnormality (step S301). If the
spectrum value exceeds the reference value, it is decided that the
primary components coincide with each other. Then, the process goes
to step S302. In contrast, if the primary components do not
coincide with each other, the process goes to step S311.
[0224] In step S302, it is decided whether or not the spectrum
value exceeds the reference value at the frequency of the secondary
component that has the twice frequency of the fundamental component
generated at the time of abnormality. If the spectrum value exceeds
the reference value, it is decided that the secondary components
coincide with each other. Then, in step S322, it is decided finally
that the abnormality is generated in the concerned location. In
contrast, in S302, if the secondary components do not coincide with
each other, the process goes to step S312.
[0225] Also, in step S311, it is decided whether or not the
spectrum value exceeds the reference value at the frequency of the
secondary component that has the twice frequency of the fundamental
component generated at the time of abnormality. If the spectrum
value exceeds the reference value, it is decided that the secondary
components coincide with each other. Then, the process goes to step
S312. In contrast, if the secondary components do not coincide with
each other, the process goes to step S321, wherein it is decided
finally that the abnormality is not generated in the concerned
location.
[0226] In step S312, it is decided whether or not the spectrum
value exceeds the reference value at the frequency of the
quaternary component that has the quadruple frequency of the
fundamental component generated at the time of abnormality. If the
spectrum value exceeds the reference value, it is decided that the
quaternary components coincide with each other. Then, in step S322,
it is decided finally that the abnormality is generated in the
concerned location. In contrast, if the quaternary components do
not coincide with each other, it is decided finally that the
abnormality is not generated in the concerned location.
[0227] FIG. 16 is a view showing the frequency spectrum when the
outer ring has the flaw. It is understood that harmonics that are
the natural-number multiple of Zfc as the fundamental frequency are
observed. It is appreciated that, if the reference value is -10 dB
in this case, the spectrum value exceeds the reference value at all
the primary, secondary, and quaternary components. Therefore,
according to the process in the present method, it is decided that
the abnormality is generated in the outer ring.
[0228] Normally, such a situation may be considered that a large
peak generated accidentally due to the influence of the noise, or
the like is observed at the frequencies corresponding to the
abnormality. According to the process in the present method, if the
peak value does not exceed the reference value at least two
frequencies out of the primary, secondary, and quaternary
components, it is not decided that the abnormality is generated.
Thus, it is possible to reduce a possibility of misjudgment.
[0229] In the flowchart shown in FIG. 15, the comparison is made in
order of the primary, secondary, and quaternary components. But the
comparison is made in order of the larger peak level. In this case,
if the largest peak is smaller than the reference value, it can be
decided at that time that no abnormality is generated, and thus a
calculation time can be shortened. Also, a combination of the
primary value, the secondary value, and the tertiary value or a
combination of the secondary value, the quaternary value, and the
sexenary value may be used as the combination of frequency
components.
[0230] (4) Method Conducting an Abnormality Diagnosis and
Estimating a Degree of the Damage
[0231] In the methods (1) to (3), the presence or absence of the
abnormality is diagnosed. But a size of the damage can be estimated
as follows. FIG. 17 is a view showing the frequency spectrum after
the enveloping process. In FIG. 17, the large peak is observed at
the frequency Zfc, and thus it is understood that the damage is
generated in the outer ring. A size of the damage generated in the
outer ring in which the abnormality occurs can be estimated by
comparing a peak value Ln at this Zfc and a reference level L.sub.0
as a mean value of the overall frequency spectrum.
[0232] FIG. 18 shows a relationship between a size of flaking and a
level difference between peaks appearing on the actually measured
frequency spectrum data d1 and the reference level when the flaking
as the damage of the raceway ring is generated in the rolling
bearing. In this manner, normally the level difference is increased
in proportion to a size of the damage. Therefore, conversely the
size of the damage can be estimated if the level difference between
the peak on the actually measured frequency spectrum data d1 and
the reference level is sensed. In this event, an increase of the
peak level on the actually measured frequency spectrum data d1
becomes most conspicuous at the peak that corresponds to the
primary value of the frequency components. Therefore, when the
abnormality is sensed, an extent of the damage can be estimated by
calculating a level difference I between a primary value Ln of the
harmonic components and a reference level L.sub.0. Thus, an
exchange timing of the damaged parts can be decided in response to
the extent of the damage. As a result, exchange of the parts can be
carried out at an appropriate timing without the excessive exchange
of parts or maintenance, and thus an upkeep cost can be
reduced.
[0233] (5) Method of Using a Level Difference of a Natural-Number
Multiple Harmonic Component of the Fundamental Frequency as a
Reference Value
[0234] The present method counts the number of times 2, 3, 4, . . .
, n-degree levels having 2, 3, 4, . . . , n-tuple frequencies of
the fundamental frequency respectively exceed the reference value
of the primary level as the fundamental frequency of the abnormal
frequency components, and then decides that the abnormality is
generated when these 2, 3, 4, . . . , n-degree levels exceed the
reference value in a predetermined number or more. More
particularly, the counting is carried out when the n-degree value
is {(primary level)-(n-1-)a} (dB) or more with respect to the
primary level. Where a is an arbitrary value. Then, explanation
will be made with reference to a flowchart shown in FIG. 19
hereunder.
[0235] FIG. 19 is a flowchart showing a process flow in the present
method. In the present method, the processes required until the
frequency spectrum is calculated are identical to the processes in
step S101 to step S108 in the flowchart in FIG. 9. The processes in
step S108 et seq. are shown in FIG. 19.
[0236] First, the abnormal frequency due to the abnormality in the
bearing is calculated every part (outer ring, inner ring, rolling
element, or retainer) of the bearing by referring to the
expressions (step S401). Then, the level of the frequency spectrum
corresponding to the abnormal frequency is extracted (step S402).
Then, levels of the frequency spectra that correspond to the
natural-number multiple (2, 3, . . . , n-tuple) frequencies of the
abnormal frequency are extracted respectively (step S403). Here,
assume that secondary, tertiary, quaternary, and quinary components
having twice, thrice, quadruple, and quintuple frequencies of the
abnormal frequency as the base are extracted.
[0237] Then, the levels of the secondary, tertiary, quaternary, and
quinary components are checked on the basis of the primary
component as the base (step S404). Here, if the levels of
respective components exceed {(primary level)-3(n-1)} (dB), the
count indicating that the abnormality is generated is executed.
More particularly, the count indicating that the abnormality is
generated is executed in respective components in following cases.
[0238] (level of the secondary component)>(level of the primary
component)-3 [0239] (level of the tertiary component)>(level of
the primary component)-6 [0240] (level of the quaternary
component)>(level of the primary component)-9 [0241] (level of
the quinary component)>(level of the primary component)-12
[0242] Then, the final abnormality decision is made by checking
whether or not the count number of times indicating that the
abnormality is present exceeds the predetermined number of times
(step S405). Here, it is decided finally that the abnormality is
generated step S406 if the count number of times indicating that
the abnormality is present exceeds two times, while it is decided
finally that no abnormality is generated step S407 if the count
number of times is once or less.
[0243] FIG. 20 is a view showing a relationship between a level of
the frequency spectrum and a reference line when the inner ring of
the cylindrical roller bearing (outer diameter 215 mm, inner
diameter 100 mm, width 47 mm, and number of roller 14) is rotated
at about 300 min.sup.-1. In FIG. 20, a straight line is a criterion
line obtained by connecting the above reference values by a line.
In the case where the bearing has the flaw, the values of the
secondary components or more are in excess of the criterion line,
but the peak level of the secondary and quaternary compositions,
which correspond to the roller missing sound also generated in the
normal condition, fall below this criterion line. Since normally
the higher order components of the roller missing sound (rolling
element missing sound) are low rather than the case where the outer
ring has the flaw, most of the sound values fall below this
criterion line, as shown in FIG. 20. As a result, even when the
peaks of the roller missing sound, or the like appear at the same
frequencies as the case where the outer ring has the defect, it is
possible to decide whether or not the bearing is abnormal or
normal, with good precision by comparing the levels of the higher
order components mutually.
[0244] (6) Method of Using a Square Mean or a Partial Overall of a
Level Every Frequency Band
[0245] The present method executes the abnormality diagnosis by
using not the peak level value itself of the frequency caused due
to the abnormality but a square mean or a partial overall of the
level of the frequency band containing the frequency caused due to
the abnormality. Here, the square mean Vi and the partial overall
Si are given by following equations. Where V.sub.RMS and S.sub.OA
are the square mean and the partial overall in the full frequency
band respectively. The overall denotes a total sum in the
particular specified interval. < Formula .times. .times. 1 >
.times. Vi = 1 m .times. k = 1 m .times. ( P k - P _ m ) 2 ( 1 ) Si
= k = 1 m .times. P k ( 2 ) V RMS = 1 N .times. i = 1 N .times. ( P
i - P _ ) 2 ( 3 ) S OA = i = 1 N .times. P i .times. .times. where
( 4 ) N .DELTA. .times. .times. f < f s 2 ( 5 ) ##EQU1##
[0246] m: cut-out frequency bandwidth (number of data)
[0247] /Pm: spectrum mean value in the interval m
[0248] Pi: spectrum value at the frequency i
[0249] /P: spectrum mean value in the interval N
[0250] fs: sampling frequency
[0251] .DELTA.f: width of neighboring frequencies (frequency
resolution)
[0252] FIG. 21 is a flowchart showing a process flow in the present
method. In the present method, the processes required until the
frequency spectrum is calculated are identical to the processes in
step S101 to step S108 in the flowchart in FIG. 9. The processes in
step S108 et seq. are shown in FIG. 21.
[0253] First, the abnormal frequency caused due to the abnormality
in the bearing is calculated by referring to the expressions shown
in FIG. 4 every part (outer ring, inner ring, rolling element, or
retainer) of the bearing (step S501). Then, the square mean (Vi) or
the partial overall (Si) in the frequency band containing the
calculated frequency, and a normalized value as the square mean
(V.sub.RMS) or the partial overall (S.sub.OA) of the overall
frequency spectrum band are calculated (step S502). Then, a
quotient value obtained by dividing the square mean (Vi) or the
partial overall (Si) in the primary component bandwidth by the
normalized value (V.sub.RMS or S.sub.OA) or a difference value
between them is calculated (step S503).
[0254] Then, it is decided whether or not the quotient value or the
difference value is within the normal range, more particularly
whether or not the quotient value or the difference value exceeds a
predetermined value, by comparing/collating the quotient value or
the difference value with the saved reference data (step S504).
Then, if the quotient value or the difference value is more than or
less than a predetermined reference value, it is decided that the
abnormality is generated, and then the abnormality occurring
location is identified based on the frequency band (step S505).
Here, it may be determined by the actual measurement that the
abnormality decision should be made depending on whether the above
value is more than the predetermined reference value or is less
than the predetermined reference value. Except the above case, it
is decided that no abnormality is generated (step S506).
[0255] The above method will be explained by referring to the
actual measured result. FIG. 22 is a graph showing the frequency
spectrum when the abnormality is generated in the outer ring, and
FIG. 23 is a graph showing the frequency spectrum when no
abnormality is generated in the outer ring. The abnormal peak
frequency band is present near the left end (around 10 to 20 Hz) of
FIG. 22. The square mean value Va of the overall spectrum is 0.016.
Also, the square mean value Vn of the overall spectrum
corresponding to FIG. 20 is 0.008. Suppose that the frequency
bandwidth extracted with respect to the abnormal frequency band
(fundamental frequency) generated due to the flaw of the outer ring
is 2 Hz, the value derived by normalizing the square mean value by
V in this bandwidth is 90.78 in the case in FIG. 22 and is 38.47 in
the case in FIG. 23. It is understood that, when the abnormality is
generated, the normalized value is about 2.4 times larger than that
in the normal condition. Therefore, if a predetermined threshold
value is provided either between 90.78 and 38.47 or to a ratio
between the normal condition and the abnormal condition, it can be
decided that the abnormality is generated in the outer ring when
the normalized value is larger than the threshold value.
[0256] Meanwhile, FIG. 24 and FIG. 25 show examples in which plural
bands are employed. FIG. 24 is a graph showing an envelope
frequency spectrum of the machinery facility having the roller
bearing, which has the damage in its outer ring, and the normal
gear (the number of teeth; 31). In FIG. 24, five frequency peaks
are observed and also the secondary component to the quinary
component are observed in every integral multiple of the
fundamental frequency. FIG. 25 shows an observed data in the normal
condition corresponding to FIG. 24, and no singular frequency is
found.
[0257] Then, the above approach is also applied to the data in FIG.
24 and FIG. 25. The value derived by normalizing a sum of the
square mean values in respective bands of the fundamental frequency
to the quinary component, which are generated due to the flaw of
the outer ring, by the square mean value of the overall spectrum is
given as 11.64 in the case in FIG. 24 and 5.19 in the case in FIG.
25. Here, the quinary harmonic means the fifth peak that is counted
from the fundamental frequency. It is understood that, when the
abnormality is generated, the normalized value is about 2.2 times
larger than that in the normal condition. Therefore, if a
predetermined threshold value is provided either between 11.64 and
5.19 or to a ratio between the normal condition and the abnormal
condition, it can be decided that the abnormality is generated in
the outer ring when the normalized value is larger than the
threshold value.
[0258] The above processes are the particular processing pattern
when the decision to check whether or not the abnormality is caused
is made by the comparing/deciding portion 36. The
comparing/deciding portion 36 may be constructed to execute the
abnormality diagnosis by using plural deciding methods out of these
methods. In order to improve an accuracy of the abnormality
diagnosis, it is preferable that the abnormality should be decided
by using plural deciding methods.
[0259] The data accumulating/outputting portion 38 is a saving
portion for saving the decision result of the comparing/deciding
portion 36, and is composed of a hard disc, a memory medium, or the
like. The data accumulating/outputting portion 38 outputs the
decision result to a controlling portion 41 and a result outputting
portion 42. The data accumulating/outputting portion 38 is
constructed to output the result to the controlling/processing
portion 40 in real time, but is not limited to this. The data
accumulating/outputting portion 38 may be constructed to output
periodically to the controlling/processing portion 40, or may be
constructed to output the result only when the result is necessary
for an operation of the controlling/processing portion 40 (when it
is decided that the abnormality occurs), as explained in the
following.
[0260] The controlling/processing portion 40 has the result
outputting portion 42 as a displaying means for displaying the
analyzed result or the decision result of the
calculating/processing portion 30 in a predetermined display mode,
and the controlling portion 41 for feeding back a control signal S1
to a control system, which controls an operation of a driving
system of the vehicle into which the bearing 21 is incorporated, in
response to the decision result of the comparing/deciding portion
36.
[0261] More specifically, the result outputting portion 42 informs
of the analyzed result or the decision result of the
calculating/processing portion 30 by a monitor, an image display,
or a printing output to a printer, and also informs of the result
by flashing an alarm lamp or operating an alarm when the decision
result of the calculating/processing portion 30 indicates that the
abnormality is generated.
[0262] For example, when the decision result of the
calculating/processing portion 30 indicates that the abnormality is
generated, the controlling portion 41 feeds a control signal S1
instructing a travel stop of the vehicle, a reduction of the speed,
or the like to a travel controller of the vehicle in answer to a
degree of the abnormality. In the present embodiment, a plurality
of sensor units 22 sense continuously a condition of the bearing in
the bearing unit, and the calculating/processing portion 30
executes the abnormality diagnosis sequentially based on the sensed
data. Therefore, the controlling/processing portion 40 informs
immediately of the abnormality when the abnormality occurs, and
then performs the control of the vehicle. That is, a flow of
sensing, analyzing, deciding and result outputting processes are
carried out in real time.
[0263] Now, the sensor unit 22 may be constructed to execute the
measurement constantly or may be constructed to execute the
measurement every predetermined time. Also, instead of the
real-time abnormality diagnosis, only the measurement and the
accumulation of measured data may be executed during the traveling
of the vehicle and then the analysis may be executed later in
another location. For example, only the measurement may be carried
out in the daytime and then the analysis, the decision, and the
result output may be carried out together with in the
nighttime.
[0264] As explained above, the axle bearing unit abnormality
diagnosis system 1 in the present embodiment is the abnormality
diagnosis system that diagnoses the presence or absence of the
abnormality of the bearing unit of the railway vehicle axle bearing
unit, and includes the sensing/processing portion 20 having a
plurality of sensing elements for outputting the signal generated
from the bearing unit as the electric signal, the
calculating/processing portion 30 performs the calculating process
to execute the abnormality diagnosis of the bearing unit based on
the output of the sensing/processing portion 20, the result
outputting portion 42 for outputting the decision result from the
calculating/processing portion 30, and the controlling portion 41
for feeding back the control signal to the control system of the
railway vehicle based on the decision result.
[0265] Also, in the abnormality diagnosis system 1 in the present
embodiment, the outputs of the sensor units 22 incorporated in
advance into the bearings 21 are analyzed by respective analyzing
portions 32, 33, 35 of the calculating/processing portion 30 to
check whether or not the abnormality is caused due to the wear or
the failure of the constituent parts of the bearing 21. Then, the
abnormality diagnosis system 1 decides the presence or absence of
the abnormality by comparing the analyzed result with the reference
data prepared previously in the internal data saving portion
37.
[0266] Accordingly, this abnormality diagnosis system 1 can decide
whether or not the abnormality due to the wear or the failure of
the constituent parts of the sensor built-in bearing 21 is present.
Therefore, the presence or absence of the abnormality can be
decided in the normal condition of use not to decompose the sensor
built-in bearing 21 itself or the railway vehicle itself containing
the bearing 21. As a result, a frequency of overhauling/assembling
operations that take a lot of time and labor can be reduced, and
thus maintenance/administrative costs can be reduced.
[0267] Also, the decision is made mechanically based on the
analysis and the comparison executed by specified calculating
processes. Therefore, the decision is seldom varied owing to a
degree of expertise or individual differences of the person in
charge of inspection rather than the visual inspection in the prior
art, and thus the reliability of the diagnosis to check the
presence or absence of the abnormality can be improved.
[0268] Also, the sensor units 22 are installed directly into the
outer ring, or the like as the constituent parts of the rotating
body constituting the rolling bearing 21, and then the sensors can
sense physical quantities generated from the rolling bearing 21
with high sensitivity. Therefore, such a possibility can be reduced
that peaks of the frequency components of the sound or the
vibration generated by other articles around the rolling bearing 21
exert a harmful influence upon an SN ratio of the signal sensed by
the sensor, and thus improvement of analysis/decision precisions
can be attained by improving the SN ratio of the output signal of
the sensor.
[0269] As a consequence, such a possibility can be eliminated that,
for example, the sensed signal of the sensor unit 22 is largely
distorted by the peak of the frequency component of the noise
generated when the railway vehicle passes over the rail joint, the
vibration generated from the devices, and the like regardless of
the bearing 21, and the like. Also, reduction of a computing load
and reduction of a loss of time required for the analysis can be
achieved by improving the SN ratio of the output signal of the
sensor unit, and thus improvement of the analysis/decision
precisions and the acceleration of the process can be achieved.
[0270] Also, in the present embodiment, since the amplifiers that
which amplify the sensor output respectively are built in the
sensor unit 22, the output signal of the sensor unit 22 has already
been amplified to have the large amplitude. Therefore, the
influence of the noise superposed on the signal transmission path
between the sensor unit 22 and the calculating/processing portion
30, or the like can be suppressed. As a result, reduction of a
process precision due to the noise can be prevented, and thus the
reliability of the abnormality diagnosis can be improved.
[0271] In this event, the abnormality diagnosis system 1 in the
present embodiment diagnoses the presence or absence of the
abnormality of the bearing in the bearing unit and the abnormality
occurring location, but the system is not limited to this
configuration. The system may be constructed to diagnose the flat
portion of the axle, or may be constructed to diagnose the presence
or absence of the abnormality of the gear in the bearing unit and
the abnormality occurring location. Therefore, various large-size
rotating bodies that take a lot of time and labor to remove and fit
the parts can be chosen as the object of the abnormality diagnosis
in the present invention.
[0272] As above, the approaches (1) to (6) are described as the
particular processes of the abnormality diagnosis executed by the
comparing/deciding portion 36 based on the vibration information.
But the present invention is not limited to the above approaches.
The abnormality diagnosis may be executed by analyzing the
frequency spectrum by virtue of the cepstrum analysis.
Second Embodiment
[0273] Next, a machinery facility abnormality diagnosis system
according to a second embodiment of the present invention will be
explained in detail hereunder. In this case, the same reference
symbols are affixed to the portions similar to those in the first
embodiment, and thus their redundant explanations will be omitted
or simplified hereunder.
[0274] In the present embodiment, as shown in FIG. 27, a
sensing/processing portion 51 consisting of sensing portions 51a,
51b, 51c each having a sensor unit 52 that communicates with the
calculating/processing portion 30 via radio is provided in place of
the sensing/processing portion 20. The sensing portions 51a, 51b,
51c are constructed by fitting the sensor unit 52 onto the outer
ring 23 of the bearing 21 respectively. In the sensor unit 52, a
temperature sensing element 52b, a rotation sensing element 52c, a
vibration sensing element 52d, and a transmitting portion 52h for
radio communication are fitted into an interior of a sensor case
52a. An amplifier for amplifying the signals sensed by the sensing
elements 52b to 52d by a predetermined amplification factor may be
provided to the sensing element respectively. The transmitting
portion 52h transmits the signals to a receiving portion 60
provided in the calculating/processing portion 30 via radio.
[0275] With the above arrangement, the sensor unit can be fitted to
the bearing unit without regard to the wiring between the
sensing/processing portion 51 and the calculating/processing
portion 30, and the like. Therefore, a margin for arrangement of
the sensors is increased and thus it can be facilitated to fit the
sensor unit to the position that enhances a sensing precision. The
calculating/processing portion 30 and the controlling/processing
portion 40 may be connected via radio communication by providing
the similar transmitter portion and receiver portion.
[0276] Other configurations and operations are similar to those in
the first embodiment.
Third Embodiment
[0277] FIG. 28 is a block diagram showing a schematic configuration
of a machinery facility abnormality diagnosis system according to a
third embodiment of the present invention. In a rotating body
abnormality diagnosis system 60, the sensor unit installed into the
sensor built-in bearing 21 that bears the axle is improved in the
abnormality diagnosis system 1 in the first embodiment, and also a
installing mode of the calculating/processing portion 30 and the
controlling/processing portion 40, which execute predetermined
processes based on the output signal of the sensor unit, are
devised.
[0278] The particular configurations of the processing methods of
the calculating/processing portion 30 and the
controlling/processing portion 40 are similar to those in the first
embodiment. Therefore, the same reference numbers are affixed to
the common configurations, and thus explanation of the
calculating/processing portion 30 and the controlling/processing
portion 40 will be omitted herein.
[0279] A sensor unit 61 in the present embodiment is similar to the
first embodiment in that, as shown in FIG. 28, the sound J1, the
temperature J2, the vibration J3, the rotation speed J4, the
distortion J5, AE, the moving speed, the force, the ultrasonic
wave, and others and that these sensed signals are amplified by the
amplifier 50 (not shown) to output.
[0280] The sensor unit 61 in the present embodiment has a radio
communication device that transmits the output signal fed from the
amplifier 50 via radio. An output of the sensor unit 61 is sent out
to a signal transmitting/receiving device 63 via radio
communication.
[0281] For example, the signal transmitting/receiving device 63 is
provided to sides of railway tracks, away stations, etc. at an
appropriate interval within an effective range of a radio signal
along the traveling route of a railway vehicle 65 on which the
sensor built-in bearing 21 is mounted. The signal
transmitting/receiving device 63 sends out the signal received from
the sensor unit 61 to an information processing center 67 via cable
or radio communication.
[0282] The information processing center 67 has the
calculating/processing portion 30 and the controlling/processing
portion 40. The information processing center 67 receives the
output signals of the sensor units 61 via the signal
transmitting/receiving device 63 and accumulates the signals in the
data accumulating/distributing portion 31 in the
calculating/processing portion 30. Then, the data
accumulating/distributing portion 31 distributes the received
signals to respective analyzing portions 32, 33, 35 in the
calculating/processing portion 30. Predetermined processes are
applied to the distributed signals in respective analyzing portions
32, 33, 35.
[0283] The identification information (ID information) used to
identify the sensor unit that outputs the signal are contained in
the output of the sensor unit 61. The calculating/processing
portion 30 and the controlling/processing portion 40 decide from
which bearing 21 the received output is sent out, based on the
identification information to discriminate the data and execute the
process and the accumulation every bearing. As a result, the
information processing center 67 causes the calculating/processing
portion 30 and the controlling/processing portion 40 to share with
a plurality of railway vehicles 65, and thus performs the central
management of the abnormality diagnosis of a plurality of bearings
21.
[0284] Also, a radio communication device (not shown) for feeding
back a control signal S1 to a control system of the railway vehicle
65 via radio communication is added to the controlling/processing
portion 40 provided in the information processing center 67.
[0285] In the above abnormality diagnosis system 60, a margin for
arrangement of the calculating/processing portion 30 and the
controlling/processing portion 40 can be enhanced rather than the
case where the output of the sensor unit 61 is transmitted to the
calculating/processing portion via the signal line provided on the
railway vehicle having the bearings, and thus the install of the
rotating body abnormality diagnosis system 60 can be
facilitated.
[0286] Also, since the identification information (ID information)
are contained in the signal output from the sensor unit 61, the
calculating/processing portion 30 and the controlling/processing
portion 40 in the information processing center 67 can be shared
with a plurality of railway vehicles 65. Thus, the central
management of the abnormality diagnosis of a large number of
bearings 21 can be carried out and thus improvement in an
efficiency of the abnormality diagnosing process of the bearing 21
and reduction in a cost of the abnormality diagnosing equipment can
be attained.
[0287] Other configurations and operations are similar to those in
the first embodiment.
Fourth Embodiment
[0288] FIG. 29 shows a schematic configuration of a machinery
facility abnormality diagnosis system according to a fourth
embodiment of the present invention. In this case, the same
reference symbols are affixed to the portions similar to those in
the first embodiment, and thus their redundant explanations will be
omitted or simplified hereunder.
[0289] In a machinery facility abnormality diagnosis system 70 in
the fourth embodiment, the sensor built-in bearing 21 shown in the
first embodiment is used as the bearing that bears the axle of the
railway vehicle 65, and then the data sensed by the sensor unit 22
incorporated into the bearing 21 are analyzed/decided by a
calculating/processing portion 73 and a controlling/processing
portion 75 provided in an information processing center 71 that is
provided away from the railway vehicle 65.
[0290] In the calculating/processing portion 73, constituent means
for analyzing/deciding the signals output from the sensor unit 22
are common to the first embodiment, but the data
accumulating/distributing portion 31 for accumulating temporarily
the output data from the sensor unit 22 and also distributing the
data to the analyzing portions 32, 33, 35 in response to the data
type can be detachably attached easily.
[0291] Also, the railway vehicle 65 is equipped with an
accumulating portion connector (not shown). The data
accumulating/distributing portion 31 attached to this accumulating
portion connector can accumulate the signals output by the sensor
units 22 in the bearings 21 therein.
[0292] In this abnormality diagnosis system 70, the data
accumulating/distributing portion 31 that accumulates the outputs
of the sensor units 22 therein is removed from the railway vehicle
65 and then is carried into the information processing center 71
and connected to the calculating/processing portion 73 in the
information processing center 71. Then, various data stored in the
data accumulating/distributing portion 31 are analyzed/decided by
the calculating/processing portion 73, and then the result
outputting portion 42 in the controlling/processing portion 75
informs the caretaker, or the like of the decision result and the
analyzed result in the calculating/processing portion 73.
[0293] After the analysis/decision of the accumulated data are
completed, the data accumulating/distributing portion 31 is
subjected to the maintenance such as erase of the used data, or the
like, as the case may be, and then is returned to the railway
vehicle 65 to use again.
[0294] The abnormality diagnosis system 70 having the above
configuration is unsuited to the real-time analysis/decision. But
this system is suited to the case where the data accumulated in the
data accumulating/distributing portion 31 are kept safe for a long
term or are analyzed in detail.
[0295] Also, like the case of the third embodiment, the
calculating/processing portion 73 and the controlling/processing
portion 75 provided in the information processing center 71 can be
shared with a number of vehicles. Therefore, the abnormality
diagnosis system 70 is suited to reduction in the cost of equipment
required to execute the abnormality diagnosis.
[0296] Other configurations and operations are similar to those in
the first embodiment.
Fifth Embodiment
[0297] FIG. 30 shows a machinery facility abnormality diagnosis
system according to a fifth embodiment of the present invention. In
this event, the same reference symbols are affixed to the portions
similar to those in the first embodiment, and thus their redundant
explanations will be omitted or simplified hereunder.
[0298] A machinery facility abnormality diagnosis system 80 in the
fifth embodiment detects generation of the abnormality generated
due to the wear or the failure of constituent parts of the rolling
bearing 21 from the rolling bearing 21 that bears the axle of the
railway vehicle. In other words, the rolling bearing 21 that bears
the axle corresponds to at least one of the rotating body and the
sliding member as the diagnosed object from which the presence or
absence of the abnormality is sensed, and the carriage or the
railway vehicle whose axle is supported by the rolling bearings 21
corresponds to a machinery facility 90 that contains one or plural
rotating bodies or sliding members.
[0299] In the case of the present embodiment, the bearing 21 is the
sensor built-in bearing in which the sensor unit 22 for sensing
various physical quantities such as sound, vibration, or the like
generated in the rotating operation of the bearing and outputting
them as the electric signal is fitted into the outer ring as the
constituent parts of the bearing. A plurality of the sensor
built-in bearings 21 are used in one vehicle.
[0300] The machinery facility abnormality diagnosis system 80 in
the present embodiment includes a plurality of sensor units 22
provided every bearing 21, a microcomputer 81 as the
calculating/processing portion that decides the presence or absence
of the abnormality in the bearing 21 by analyzing the outputs of
the sensor units 22 based on predetermined calculating processes
and then comparing the analyzed result with reference data prepared
in advance, and the controlling/processing portion 40 for
displaying the analyzed result and the decision result of the
microcomputer 81 in a predetermined display mode and feeding back
the control signal to the control system of the railway vehicle in
response to the decision result.
[0301] The physical quantity in the sliding operation (rotating
operation) of the bearing 21 as the sliding member is the physical
quantity that is changed in response to the rotating condition of
the bearing 21. For example, various information such as sound and
vibration generated by the bearing 21, rotation speed and
temperature, distortion generated on the constituent parts of the
sliding member, and the like may be considered.
[0302] Like the first embodiment, the sensor unit 22 includes one
or plural sensing elements that sense a lot of information such as
sound J1, temperature J2, vibration (vibration displacement,
vibration speed, vibration acceleration) J3, rotation speed J4 of
the bearing, distortion J5 generated on the outer ring of the
bearing, AE, moving speed, force, ultrasonic wave, etc. as the
physical quantity that is changed in response to the rotating
condition of the bearing 21. Then, the sensor unit 22 sends out
these sensed information to the microcomputer
(calculating/processing portion) 81 as the sensed signals.
[0303] The sensor unit 22 has such a configuration that various
sensors are installed/held every sensed information in the sensor
case 22a secured to the outer ring of the bearing. Also, an output
amplifying means for amplifying the output signals of respective
sensors to output is built in the sensor case 22a.
[0304] The reference data that are compared with the analyzed
result are various physical quantities that are sensed in the
normal condition of the bearing 21 as the diagnosed object by the
sensor unit. More particularly, there are information such as
frequency components generated by the wear and the failure of the
particular location of the bearing 21, and the like, in addition to
sound information of the normal bearing 21, temperature information
of the bearing, vibration information, rotation speed information
of the bearing, distortion information generated on the outer ring
of the bearing, and others.
[0305] The microcomputer 81 is a one-chip microcomputer or a
one-board microcomputer that is developed for the system in the
present embodiment. The similar processes to those executed in the
inside of the calculating/processing portion 30 are executed in the
inside of the microcomputer 81. More specifically, as shown in FIG.
31, the microcomputer 81 has the data accumulating/distributing
portion 31, the temperature analyzing portion 32, the rotation
analyzing portion 33, the filtering processing portion 34, the
vibration analyzing portion 35, the comparing/deciding portion 36,
and the internal data saving portion 37, and executes the
calculating process of the electric signals as the output received
from the sensor to identify the presence or absence of the
abnormality of the bearing and the abnormality occurring location,
as explained in the first embodiment. Then, the microcomputer 81
outputs the abnormality diagnosis result to the
controlling/processing portion 40. In the present embodiment, the
analyzed result in the analyzing portions 32, 33, 35 and the
decision result in the comparing/deciding portion 36 are output
directly to the controlling/processing portion 40. But the data
accumulating/outputting portion may be provided, like the first
embodiment.
[0306] The controlling/processing portion 40 has the result
outputting portion 42 as the displaying means for the analyzed
result and the decision result in the microcomputer 81 in a
predetermined display mode, and the controlling portion 41 for
feeding back the control signal S1 to the control system, which
controls an operation of a driving mechanism of the vehicle into
which the bearings 21 are incorporated, in response to the decision
result of the comparing/deciding portion 36. The operations/effects
of the controlling/processing portion are similar to those
explained in the first embodiment.
[0307] In the machinery facility abnormality diagnosis system 80 in
the present embodiment explained as above, the presence or absence
of the abnormality due to the wear and the failure of the
constituent parts of the rolling bearing 21 can be decided by
analyzing the output of the sensor unit 22, which is incorporated
previously into the rolling bearing 21 as the sliding member, by
virtue of the microcomputer 81 as the information processing device
and then comparing the analyzed result with the reference data
prepared previously. Therefore, the abnormality can be decided
still in the normal condition of use without overhaul of the
rolling bearing 21 itself and the railway vehicle itself.
[0308] As a result, a frequency of the troublesome
overhauling/assembling operations can be reduced and thus the
maintenance/administrative costs can be reduced. Also, since the
decision is made mechanically based on the analysis and the
comparison executed by specified calculating processes, the
decision is hardly varied owing to a degree of expertise or
individual differences of the person in charge of inspection rather
than the visual inspection in the prior art, and thus the
reliability of the diagnosis to check the presence or absence of
the abnormality can be improved.
[0309] Also, the information processing portion is constructed by
using the microcomputer 81, and the microcomputer 81 itself can be
prepared as a one-chip or one-board small dedicated unit.
Therefore, the overall system can be downsized considerably in
comparison with the monitoring system that uses the general-purpose
personal computer as the information processing device, and thus an
occupied space required for the equipment can be reduced. As a
result, the installation of the information processing portion into
the machinery facility containing the sliding member (i.e., railway
vehicle, or the like) can be facilitated.
[0310] Also, the sensor unit 22 is incorporated directly into the
outer ring as the constituent parts constituting the rolling
bearing 21, or the like, and thus the sensor unit 22 can sense the
physical quantity generated by the rolling bearing 21 with high
sensitivity. Therefore, such a possibility can be reduced that the
peaks of the frequency components of the sound or the vibration
generated by other articles surrounding the rolling bearing 21
exert the harmful influence upon the SN ratio of the signal sensed
by the sensor, and thus improvement of the analysis/decision
precisions can be attained by improving the SN ratio of the output
signal of the sensor.
[0311] In addition, since the information processing portion can be
formed in a compact size and also there is no need to use the large
general-purpose casing, or the like, an earthquake-proof property
as the information processing device can be improved easily. As a
result, the information processing portion as well as the sensor
unit 22 can be arranged in close vicinity to the rolling bearing
21, and thus the reliability of the abnormality diagnosis can be
improved because the rolling bearing 21 and the microcomputer 81
are arranged closely to avoid the influence of the external
noise.
[0312] Also, in the present embodiment, an output amplifying means
(amplifier) for amplifying the output signal to output is built in
the sensor unit itself. In this event, the output amplifying means
for amplifying the sensor output may be connected between the
sensor unit 22 and the microcomputer 81, or may be built in the
microcomputer 81 side.
Sixth Embodiment
[0313] FIG. 32 is a block diagram showing a schematic configuration
of a machinery facility abnormality diagnosis system according to a
sixth embodiment of the present invention.
[0314] A machinery facility abnormality diagnosis system 100 in the
present embodiment is constructed such that a single microcomputer
81 processes the information of a plurality of sensor units 22.
Since remaining configurations are similar to those in the fifth
embodiment, the same reference numbers as those in the fifth
embodiment are affixed to the common configurations, and thus
explanation of the microcomputer 81 and the controlling/processing
portion 40 will be omitted herein.
[0315] In case the microcomputer 81 has an enough processing
performance in reserve, the single microcomputer 81 is caused to
process the information of a plurality of sensor units 22 in this
manner. Therefore, the number of equipments of the expensive
microcomputer 81 can be reduced and a cost reduction can be
attained.
[0316] In the above embodiments, install positions of the
microcomputer 81 are not particularly mentioned. It is preferable
that the microcomputer 81 as well as the sensor unit 22 should be
fitted to the rotating body or the sliding member or the mechanism
parts for supporting the sliding member. By doing this, such a
system instating mode can be realized that both the sensor unit 22
and the microcomputer 81 are arranged in close vicinity to each
other on the same constituent member. Therefore, a length of the
signal line between the sensor unit 22 and the microcomputer 81 is
not extended, and thus generation of the disadvantages caused by
interwining of the signal line, and the like can be prevented.
[0317] Also, the influence of the external noise upon the signal
transmission line between the sensor unit 22 and the microcomputer
81 can be reduced, and thus the reliability of the sensed signal
can be improved.
Seventh Embodiment
[0318] FIG. 33 shows a machinery facility abnormality diagnosis
system according to a seventh embodiment of the present
invention.
[0319] In a machinery facility abnormality diagnosis system 110 in
the seventh embodiment, the microcomputer 81 and the sensor unit 22
are mounted on a single device substrate and then fitted to the
constituent parts of the rolling bearing 21 as a single processing
unit 112. Since the rolling bearing 21 and the
controlling/processing portion 40 to which the microcomputer 81
outputs the decision result may have the same configuration as
those in the above embodiments, their explanation will be omitted
herein. According to the abnormality diagnosis system 110
constructed in this manner, the fitting of the monitoring system to
the machinery facility 90 can be completed by fitting the single
processing unit 112 thereto, and thus a fitting workability can be
improved.
[0320] In the machinery facility abnormality diagnosis system
according to the present invention, the sensor unit 22 and the
microcomputer 81 are not connected via the signal cable, or the
like, and the signal may be transmitted/received via radio
communication. When doing this, a margin for arrangement of the
microcomputer 81 and the controlling/processing portion can be
enhanced rather than the case where the output of the sensor unit
22 is transmitted to the microcomputer 81 via the signal cable that
is provided on the equipment containing the sliding member, and
thus the installation of the machinery facility abnormality
diagnosis system can be further facilitated.
Eighth Embodiment
[0321] FIG. 34(a) and FIG. 34(b) show a machinery facility
abnormality diagnosis system according to an eighth embodiment of
the present invention.
[0322] In a machinery facility abnormality diagnosis system 151 of
the eighth embodiment, a diagnosis unit 161 constructed by mounting
a microcomputer containing a CPU 152 to execute the calculating
process, an amplifier circuit (Amp) 153, A/D converters (ADCs) 154,
155, external memories (RAM, ROM, ROM) 156, 157, 158, and the
communication circuits (LANIF, SCI) 159, 160 on a board (not shown)
is installed into a case (casing) 161A. Then, a piezoelectric
sensor 162, a temperature sensor 163, and a rotating pulse
generator 164 are fitted to the bearing 21 as the sensors.
[0323] The piezoelectric sensor 162 detects a vibration acoustic
signal generated when the rolling elements (not shown) of the
bearing 21 pass over the flaw on the raceway ring (not shown), an
AE (acoustic emission) signal generated when the minute crack is
developing, or the like, and converts such signal into a voltage or
charge signal. The voltage or charge signal is amplified at about
20 to 40 dB by a pre-amplifier (preamplifier circuit) 165 arranged
in close vicinity to the piezoelectric sensor 162. Then, the signal
after entered into the case 161A is converted into a voltage
signal, a level of which corresponds to an input range of the A/D
converter 154, by the amplifier circuit 153. The voltage signal
converted by the amplifier circuit 153 is input into the A/D
converter 154 via a bandpass filter (BPF) 166 and then is fed to a
predetermined port of the microcomputer including the CPU 152. The
A/D converter 154 is an external high-precision A/D converter with
a 16-bit resolution.
[0324] Because the analog bandpass filter 166 is put at the
preceding stage of the A/D converter 154 to pass the frequency of 1
kHz to 10 kHz, the low-frequency mechanical vibration and the
aliasing caused due to an upper limit frequency in the A/D
conversion can be prevented. This filtering function can be
replaced with a digital filter such as PLD, or the like that is put
at the subsequent stage of the A/D converter. Such preprocess
filtering may be executed in the CPU calculation, but the
preprocess filtering is separated from the CPU calculation because
a processing speed and a program size are influenced.
[0325] Since the A/D converted value is obtained as the signed
integer, a full-wave rectified waveform can be derived by
calculating an absolute value of a finite-time wave. Because the
full-wave rectified waveform is finite, the FFT operation is
executed after an influence of both ends is lessened by applying
the Window process. Since a floating-point operational unit is not
provided to the microcomputer containing the CPU 152, a fixed point
operation that can be calculated by using the integer only is
used.
[0326] The resultant frequency distribution is compared with the
frequency of an envelope having a damping waveform decided by the
rotating speed and the number of the rolling elements in order of
higher intensity. At this time, bearing specifications stored in
the external memories 157, 158 and the speed value derived from the
rotating pulse generator 164 are employed.
[0327] The piezoelectric sensor 162 can get acoustic/elastic
wave/AE signals. But its sampling frequency is set to 100 kHz for
the purpose of sensing the flaking/damage mainly.
[0328] The voltage signal generated by the temperature sensor 163
is input into the A/D converter 155 via the amplifier circuit (not
shown) and is given to a predetermined port of the microcomputer
including the CPU 152. The A/D converter 155 is an external
high-precision A/D converter with 10-bit resolution. The
temperature sensor 163 and the rotating pulse generator 164 are set
to a sampling frequency that is lower than that of the
piezoelectric sensor 162.
[0329] The external memory 156 is formed of RAM, and the external
memories 157, 158 are formed of ROM. Also, the communication
circuit 159 is composed of a LAN interface, and is connected to a
LAN line (Local Area Network) 167 via a twisted pair, a coaxial
cable, an optical fiber cable, or the like. When a radio LAN is
employed, the communication circuit 159 is connected to the LAN
line 167 via radio. The communication circuit 160 gives a serial
communication interface, and is connected to a program
loading/diagnostic data transmitting and receiving terminal
168.
[0330] The communication circuit 160 is used to transmit/receive in
serial an extent of coincidence between the sensed frequency and
respective flaw frequencies of the outer ring, the inner ring, the
rolling elements, and the retainer of the bearing 21. A
parallel-type communication circuit may be employed if it is used
within a short distance. Preferably a dedicated IC for ensuring a
security should be interposed in the communication line.
[0331] The machinery facility abnormality diagnosis system 151
further includes a timer counter (TMUCNT) 169, a direct memory
access controller (DMA) 170, an interruption controller (INTC) 171,
a D/A converter (DAC) 172, and an active gain control (AGC) 173.
The D/A converter 172 is connected to a diagnostic output connector
and/or display 174.
[0332] The timer counter 169 counts up a pulse signal generated by
the rotating pulse generator 164 and then gives the number of
counted pulses to a predetermined port of the microcomputer
including the CPU 152.
[0333] The interruption controller 171 and the timer counter 169
are used to feed the signal to the microcomputer including the CPU
152 at a predetermined sampling period. Normally the data are
transferred to the external memory 156 via the microcomputer
including the CPU 152. But the direct transfer may be applied by
the direct memory access controller 170 to shorten extremely the
sampling period.
[0334] When the operator can come close to the diagnosis unit 161
or when the diagnosis unit 161 can be put near the machine
operator, the diagnostic output connector and/or display 174 is
used to give the LED display or the liquid crystal screen display
via the LCD driver, give the sound output using the D/A output, or
the like.
[0335] In the machinery facility abnormality diagnosis system 151,
all the data digitized by the signal processing are calculated by
the microcomputer including the CPU 152, and various processing
programs are loaded on the external memories 157, 158 attached
separately. Also, since at least one machinery facility abnormality
diagnosis system 151 is used in one unit of the bearing 21, the
specifications (dimensions of respective portions, material, number
of the rolling elements, lubricant, date of manufacture) of the
bearing 21 and the specifications (frequency characteristic,
sensitivity) of the sensors 162, 163, 164 are stored in the
external memories 157, 158.
[0336] Also, since RMS, peak, crutosis, peak factor, etc. are
assigned to predetermined addresses of the external memory 156 as
amplitude parameters, the external device can inquire about the
data by using the communication function.
[0337] In the machinery facility abnormality diagnosis system 151,
the piezoelectric sensor 162, the temperature sensor 163, and the
rotating pulse generator 164 for sensing acoustic/elastic wave,
ultrasonic wave, and mechanical vibration, for example, are fitted
to the bearing 21, and then the diagnosis unit 161 capable of
amplifying/digitizing the signals generated by these sensors, then
applying the calculating process to the signals by virtue of the
microcomputer containing the CPU 152, and then outputting the
calculated result is installed into the single case 161A. For this
reason, the condition of the bearing 21 can be monitored with a
simple configuration without overhaul and also the defect or the
abnormality of the bearing 21 can be inspected. As a result, time
and labor required to overhaul and assemble the bearing 21 can be
reduced and the damage of the bearing 21 caused by the overhauling
and the assembling can be prevented. In addition, since the
monitoring can be executed effectively with good precision, the
higher-precision diagnosis can be carried out and thus the defect
that the visual inspection could overlook can be found. Also, the
diagnosis unit 161 can be installed into various machinery
equipments other than the bearing 21 because such diagnosis unit
161 can be formed in a compact size by using small-size sensors,
the microcomputer, IC, and the circuit board, and the diagnosis
unit 161 can be installed flexibly into various machinery
equipments because such diagnosis unit 161 can have a communication
capability, so that the diagnosis unit 161 can contribute to the
reduction in a cost aspect and the energy saving measure. Since the
ultrasonic pulse echo approach can be utilized by providing not
only a function of amplifying the signals from respective sensors
but also a function of sending the pulse signal to the
piezoelectric sensor 162, for example, to the diagnosis unit 161,
the damage of the mechanical sliding surface in the stationary time
and the metal contact condition between the sliding surfaces in the
running time can be sensed/diagnosed.
[0338] Also, in the machinery facility abnormality diagnosis system
151, one or more out of temperature, vibration displacement,
vibration speed, vibration acceleration, force, distortion,
acoustic, acoustic emission, ultrasonic wave, and rotating speed
can be sensed by the piezoelectric sensor 162, the temperature
sensor 163, and the rotating pulse generator 164. Therefore, the
condition of the bearing 21 can be monitored without fail and also
the defect or abnormality of the bearing 21 can be inspected
without fail.
[0339] Also, in the machinery facility abnormality diagnosis system
151, the microcomputer containing the CPU 152, the amplifier
circuit 153, the A/D converter circuits 154, 155, the external
memories 156, 157, 158, the communication circuits 159, 160, the
timer counter 169, the direct memory access controller 170, the
interruption controller 171, the D/A converter 172, and the active
gain control 173 are employed in the calculating process.
Therefore, the diagnosis system that is excellent in a cost aspect
can be realized by using a combination of the general-purpose parts
without custom parts.
[0340] Also, in the machinery facility abnormality diagnosis system
151, one process or more out of calculation of feature parameters
of a standard deviation and a peak factor, envelope detection, FFT,
filter, wavelet transform, short-time FFT, and calculation of a
feature frequency due to the defect of the rotating body and the
comparing/deciding processes can be executed in a digital fashion.
Therefore, since the monitoring can be executed effectively with
good precision, the higher-precision diagnosis can be carried out
and thus the defect that the visual inspection could overlook can
be found surely.
Ninth Embodiment
[0341] FIG. 35(a) and FIG. 35(b) show a machinery facility
abnormality diagnosis system according to a ninth embodiment of the
present invention.
[0342] In a machinery facility abnormality diagnosis system 181 of
the ninth embodiment, an impact sensor 183 that is formed as a
bimorph of a piezoelectric ceramic element is installed a case 182A
of a diagnosing unit 182, and also the impact sensor 183 and the
temperature sensor 163 are arranged integrally in the case 182A.
Since other configurations are similar to those in the eighth
embodiment, the same reference numbers as those in the eighth
embodiment are affixed to the common configurations, and thus
explanation about them will be omitted herein.
[0343] In the machinery facility abnormality diagnosis system 181,
an impact generated when the bearing 21 goes down is detected.
Normally, the feature parameter computing expressions for the
natural impulse elastic waves generated at the time of failure of
the bearing 21 are stored in the external memory 158. If the
feature parameter decided based on a waveform signal, which is
digitized via the impact sensor 183, an amplifier filter portion
184, and the A/D converter 155 as the high-precision external A/D
converter with 10-bit resolution, and the rotation speed has the
dimension, mean value of the vibration value, standard deviation
(rms), maximum value, peak (average of ten values counted from the
maximum absolute value), etc. are calculated previously. Meanwhile,
if the feature parameter is dimensionless, wave waveform, peak
factor, impact index, skewness, crutosis, etc. are calculated
previously. The approach of sensing the defect of the bearing 21
from the frequency domain data, which is obtained by the FFT
operation by the microcomputer including the CPU 152, is similar to
the seventh embodiment. In this event, the impact sensor 183 and
the amplifier filter portion 184 may be integrated as far as the
frequency band permits.
[0344] The data of cross frequency of the feature parameter in
other frequency domain, extreme frequency, degree of irregularity,
degree of contain of the rotating frequency, degree of contain of
the rotating frequency harmonics, degree of contain of the defect
feature frequency component powers of respective parts of the
bearing 21, etc. are registered in the external memory 156, and
then are updated in a predetermined period.
[0345] The degradation diagnosis of the bearing 21 by the feature
parameters may be executed by the microcomputer including the CPU
152 in the case 182A. Alternately, if the diagnosis is recognized
by using the regression analysis in which a large number of
parameters are related complicatedly or the learning algorithm
using the neural network, the data may be processed by transmitting
the data to the computer, into which the recognition program is
installed, separately via the LAN line 167, or the like. Otherwise,
it is preferable that the custom IC exclusively used for the
recognition program or another microcomputer should be added.
[0346] In the machinery facility abnormality diagnosis system 181,
the diagnosis unit 182 can be constructed by using small-size
electronic parts, small-size sensors, and short wirings in addition
to the microcomputer including the CPU 152. Thus, such diagnosis
unit 182 can be installed into the space-saving case 182A and thus
the inspection/diagnosis can be executed by such diagnosis unit 182
incorporated into the bearing 21. Also, the diagnosis unit 182 can
be constructed in a compact size, and a cost can be further reduced
by omitting the signal line extended from the sensors to the
calculating/processing device.
Tenth Embodiment
[0347] FIG. 36 shows a machinery facility abnormality diagnosis
system according to a tenth embodiment of the present
invention.
[0348] In a machinery facility monitoring system 191 of the tenth
embodiment, a DSP (digital signal processor, capable of executing a
product-sum operation in a filtering operation and a data transfer
at a high speed) 192 is incorporated into the
calculating/processing portion.
[0349] In this embodiment, the eighth and ninth embodiments are
revised such that the DSP 192 takes charge of the digital signal
processing such as digital filtering, FFT, and the like and also
the microcomputer containing the CPU 152 executes other processes.
Also, for the same purpose, the calculating/processing portion can
be constructed by using a PLD (programmable logic device) without
the DSP.
[0350] In the above embodiment, the sliding member that is
diagnosed to check whether or not the abnormality is present is not
limited to the rolling bearing. More particularly, the sliding
bearing, and the like correspond to the sliding member in addition
to various rolling bearings. Also, constituent parts of the
longitudinal motion mechanism such as the ball screw, the linear
guide, etc. correspond to the sliding member as the diagnosis
object of the present invention. Also, various large-size rotary
sliding members such as the gear or the wheel of the railway
vehicle, etc., which take enormous time and labor to remove and
fit, can be selected as the abnormality diagnosis object of the
present invention.
[0351] In the above embodiment, the machinery facility abnormality
diagnosis system itself is equipped with the controlling/processing
portion that feeds back the signal responding to the decision
result to a controller that controls an operation of the mechanism,
into which the sliding members are incorporated, of the machinery
facility such that the sensing of the abnormality by this
abnormality diagnosis system leads quickly to the maintenance and
the operation management of the machinery facility. However, the
controlling/processing portion may be constructed as the
independent equipment (system) that can be connected to the
abnormality diagnosis system.
Eleventh Embodiment
[0352] Next, a machinery facility condition monitoring system
according to an eleventh embodiment of the present invention will
be explained hereunder. In this event, the same reference symbols
are affixed to the portions similar to those in the fifth
embodiment, and thus their redundant explanations will be omitted
or simplified hereunder.
[0353] As shown in FIG. 37, a railway vehicle facility 210 as a
machinery facility, to which a condition monitoring system 230 (see
FIG. 38) is applied, includes a double row tapered roller bearing
211 as at least one of the rotating body and the sliding member as
the sensed object and a bearing housing 212 constituting a part of
the railway vehicle carriage.
[0354] The double row tapered roller bearing 211 has a pair of
inner rings 214, 214 having inner ring raceway surfaces 215, 215
inclined like a tapered outer surface on their outer peripheral
surfaces, a single outer ring 216 having a pair of outer ring
raceway surfaces 217, 217 inclined like a tapered inner surface on
an inner peripheral surface, tapered rollers 218 as a plurality of
rolling elements arranged in double rows between the inner ring
raceway surfaces 215, 215 of the inner rings 214, 214 and the outer
ring raceway surfaces 217, 217 of the outer ring 216, annular
pressed retainers 219, 219 for holding rollably the tapered rollers
218, and a pair of sealing members 220, 220.
[0355] The bearing housing 212 has a housing 221, a front lid 222
fitted to a front end portion of the housing 221, and a rear lid
223 fitted to a rear end portion of the housing 221.
[0356] An axle 224 is press-fitted into the inner ring of the
double row tapered roller bearing 211. A radial load imposed by
weights of various members, etc. and any axial load are applied to
the double row tapered roller bearing 211. An upper area of the
outer ring 216 serves as a loading range. Where the loading range
denotes an area in which the load is applied to the rolling
element.
[0357] The housing 221 constitutes a side frame of the railway
vehicle carriage, and is formed like a circular ring to cover the
outer peripheral surface of the outer ring 216. A pair of recess
portions 225, 225 are formed on the outer peripheral surface of the
housing 221 in the center portion of each row of the double row
tapered roller bearing 211 in the axial direction. The recess
portions 225, 225 receive therein the sensor units 22, 22
constituting a part of the condition monitoring system 230 and
having the same configuration as the first embodiment.
[0358] Next, the condition monitoring system 230 of the eleventh
embodiment will be explained hereunder. The condition monitoring
system 230 is different from the fifth embodiment only in the
process that is executed by a comparing/deciding portion 252 in a
calculating/processing portion 250 constructed by the
microcomputer, but the processes in the sensing/processing portion
20 and the controlling/processing portion 40 are equivalent to the
abnormality diagnosis system in the fifth embodiment. In other
words, the condition monitoring system 230 includes the
sensing/processing portions 20, 20 having the sensor units 22, 22
provided to the rows of the double row tapered roller bearing 211
respectively to output the condition of respective rows as the
electric signal, the calculating/processing portions 250, 250 for
calculating/processing the electric signals output from the sensor
units 22, 22 to decide the conditions such as the defect, the
abnormality, or the like of the railway vehicle facility 210, and
the controlling/processing portion 40 for controlling/outputting
the decision result of the calculating/processing portions 250,
250.
[0359] The sensor units 22, 22 has sensors as a plurality of
sensing elements that can sense the information such as sound J1,
temperature J2, vibration J3, rotation speed J4, distortion J5, AE
(acoustic emission), moving speed, force, ultrasonic wave, etc.,
which are generated from the machinery facility during the running,
as the physical quantity that changes in response to the rotating
state of the bearing 211 and then output the information to the
calculating/processing portions 250, 250 as the electric signal.
Here, since the calculating/processing portions 250, 250 can
appropriately distribute/process the electric signals every sensed
information, a plurality of sensing elements for sensing
independently the particular signal such as sound, temperature,
vibration, rotation speed, distortion, AE, moving speed, force,
ultrasonic wave, or the like respectively may be employed in
combination as the sensor units 22, 22, otherwise a composite
sensor unit capable of sensing a plurality of information at the
same time may be employed as the sensor unit 22.
[0360] Also, the fitting position of the sensor unit 22 is selected
on the outer peripheral portion of the housing 221 in the loading
range of the radial load. Therefore, when the damage is caused on
the bearing raceway surface, for example, a collision force
generated when the rolling element passes over the damaged portion
is larger in the loading range than the non-loading range. Thus,
the abnormal vibration can be sensed in the loading range of the
bearing with good sensitivity.
[0361] In addition, the sensor unit 22 is fitted into the recess
portion 225 formed in the housing 221. Therefore, since the sensor
unit 22 is never affected by the fitting state of the sensor unit
22 and the surrounding environment (noise, moisture, wind pressure,
etc.), the signal can be sensed at a high SN ratio (noise-to-signal
ratio) with high precision. Here, the sensor unit 22 may be
incorporated into the rotating body, the sliding member, or the
like.
[0362] Also, it is preferable that the function or the process of
waterproof, oil-resistant, dustproof, rust-preventive,
moisture-proof, heat-resistant, and electromagnetic noise-resistant
properties should be added or applied to the sensor unit 22 to
lessen the influence of the noise. In addition, it is more
preferable that an amplifier function should be built in the
sensing/processing portions 20, 20 and thus there is no need to
provide the special amplifier and the anxiety in regard to the
entering of the noise from the intermediate cable, or the like can
be removed.
[0363] The calculating/processing portions 250, 250 execute the
calculating/processing operations to decide the condition such as
the defect, the abnormality, or the like of the machinery facility
based on the electric signals output from the sensing/processing
portions 20, 20. Such operations are executed by the microcomputer.
The microcomputer consists of an IC chip on which CPU, MPU, DSP,
etc. are mounted, a memory, and the like.
[0364] As shown in FIG. 39, each of the calculating/processing
portions 250, 250 includes the data accumulating/distributing
portion 31, the temperature analyzing portion 32, the rotation
analyzing portion 33, the filtering processing portion 34, the
vibration analyzing portion 35, the comparing/deciding portion 252,
and the internal data saving portion 37. These portions except the
comparing/deciding portion 252 have the equivalent functions to
those in the first embodiment.
[0365] The data accumulating/distributing portion 31 receives the
electric signals fed from respective sensing elements and
accumulates them temporarily, and also has collecting and
distributing functions of allocating the signal to any of the
analyzing portions 32, 33, 35 in response to the type of the
signal. Various signals are A/D-converted into the digital signal
by an A/D converter (not shown) before they are fed to the data
accumulating/distributing portion 31, then are amplified by an
amplifier (not shown), and then are sent to the data
accumulating/distributing portion 31. In this event, the A/D
conversion and the amplification may be applied in reverse
order.
[0366] The temperature analyzing portion 32 calculates the
temperature of the bearing 211 based on the output signal from the
sensing element that senses the temperature information J2, and
then transmits the calculated temperature to the comparing/deciding
portion 252. The analyzing portion 32 has a temperature conversion
table that responds to characteristics of the sensing elements, and
calculates the temperature data based on a level of the sensed
signal.
[0367] The rotation analyzing portion 33 calculates the rotation
speed of the inner ring 214, i.e., the axle 224, based on the
output signal from the sensing element that senses the rotation
speed information J4, and then transmits the calculated rotation
speed to the comparing/deciding portion 252. In this case, when the
sensing element is composed of an encoder fitted to the inner ring
214, a magnet fitted to the outer ring 216, and a magnetism sensing
element, the signal output from the sensing element is given as a
pulse signal that responds to a shape of the encoder and the
rotation speed. The rotation analyzing portion 33 has a
predetermined transformation function or transformation table in
response to a shape of the encoder, and then calculates the
rotation speed of the inner ring 214 and the axle 224 in compliance
with the function or the table.
[0368] The vibration analyzing portion 35 executes the frequency
analysis of the vibration generated in the bearing 211, based on
the output signal from the sensing element that senses the
vibration information J3. More particularly, the vibration
analyzing portion 35 is an FFT calculating portion for calculating
the frequency spectrum of the vibration signal, and calculates the
frequency spectrum of the vibration based on the FFT algorithm.
Then, the calculated frequency spectrum is transmitted to the
comparing/deciding portion 252. Also, the vibration analyzing
portion 35 may execute the absolute-value process and the envelope
process as the preprocessing of FFT, and may convert the frequency
spectrum into the frequency component necessary for the diagnosis
only. The vibration analyzing portion 35 may also output the
envelope data obtained after the envelope process to the
comparing/deciding portion 252, as the case may be.
[0369] Normally, the abnormal frequency band of the vibration
generated due to the rotation of the bearing are decided depending
upon a size of the bearing, the number of the rolling elements,
etc. The relationships between the defects of respective members of
the bearing and the abnormal vibration frequencies generated in
respective members are given as shown in FIG. 4. In the frequency
analysis, the maximum frequency at which the Fourier transform can
be applied (Nyquist frequency) is decided according to the sampling
time. Thus, preferably the frequency that is in excess of the
Nyquist frequency should not be contained in the vibration signal.
Therefore, the present embodiment is constructed such that the
filtering processing portion 34 is provided between the data
accumulating/distributing portion 31 and the vibration analyzing
portion 35, then a predetermined frequency band is cut out by the
filtering processing portion 34, and then the vibration signal
containing only the cut-out frequency band is transmitted to the
vibration analyzing portion 35. When the axle is rotating at a low
speed in the railway vehicle, only the frequency component of 1 kHz
or less, for example, may be extracted.
[0370] In FIG. 39, the temperature analyzing portion 32, the
rotation analyzing portion 33, and the vibration analyzing portion
35 are illustrated. The analyzing portions may be provided in
answer to the information that are sensed by respective sensing
elements in the sensor unit.
[0371] The comparing/deciding portion 252 compares/collates the
results analyzed by the temperature analyzing portion 32, the
rotation analyzing portion 33, and the vibration analyzing portion
35 with the information as the diagnosis reference, which is used
to check the presence or absence of the abnormality of the bearing,
every first time period t.sub.1 to provisionally diagnose whether
or not the abnormality is generated in the bearing. Also, the
comparing/deciding portion 252 transmits the provisional diagnosis
results, which have been compared/collated every first time period
t.sub.1, to the internal data saving portion 37 to save them.
[0372] In addition, when the comparing/deciding portion 252 has
executed the comparison/decision predetermined number of times or a
second time period t.sub.2 that is longer than the first time
period t.sub.1 has elapsed, such comparing/deciding portion 252
makes the total evaluation, in which the bearing is considered as
the abnormal state when the number of times the bearing is
diagnosed provisionally as the abnormality exceeds a threshold
value, based on the provisional diagnosis results saved in the
internal data saving portion 37, and thus diagnoses the presence or
absence of the abnormality in the bearing and its abnormal
location. In this event, the total evaluation may be constructed to
decide an extent of abnormality based on the number of times the
bearing is diagnosed provisionally as the abnormal state and then
diagnose the presence or absence of the abnormality and its
abnormal location.
[0373] More specifically, the comparing/deciding portion 252
compares/collates the frequency spectrum of the vibration
calculated by the vibration analyzing portion 35 with the reference
values saved in the internal data saving portion 37 every first
time period t.sub.1 to provisionally diagnose whether or not the
abnormal vibration is being generated. Where the reference values
are data values of frequency components due to the wear and the
damage of the particular location of the bearing calculated based
on the rotation speed signal of the period signal as the operating
signal of the machinery facility.
[0374] As the provisional diagnosis processing method executed by
the comparing/deciding portion 252 based on the vibration
information, any one of above methods (1) to (3) and (5) to (6) may
be employed.
[0375] The comparing/deciding portion 252 executes the
comparison/collation every first time period t.sub.1 by using the
above methods (1) to (3) and (5) to (6), and then transmits the
provisional diagnosis result about the presence or absence of the
abnormality to the internal data saving portion 37 to save the
result therein. Also, when the comparing/deciding portion 252 has
executed the comparison/decision predetermined number of times or a
second time period t.sub.2 that is longer than the first time
period t.sub.1 has elapsed, such comparing/deciding portion 252
makes the total evaluation, in which the bearing is considered as
the abnormal state when the number of times the bearing is
diagnosed provisionally as the abnormality exceeds a threshold
value, based on the provisional diagnosis results saved in the
internal data saving portion 37, and thus diagnoses the presence or
absence of the abnormality in the bearing and its abnormal
location.
[0376] In this case, the result of each sensed object in the
comparing/deciding portion 252 may be saved in a storing medium
such as memory, HDD, or the like, or the result may be transmitted
to the controlling/processing portion 40.
[0377] The controlling/processing portion 40 has the result
outputting portion 42 as a displaying means for displaying the
analyzed result and the decision result of the
calculating/processing portions 250, 250 in a predetermined display
mode, and the controlling portion 41 for feeding back the control
signal responding to the decision result of the comparing/deciding
portion 252 to the control system that controls the operation of
the driving mechanism of the vehicle into which the bearing 211 is
fitted.
[0378] More particularly, the result outputting portion 42 informs
of the analyzed result and the decision result of the
calculating/processing portion 250 by the monitor, the image
display, the printing output to the printer, and also informs of
the abnormality by the alarm device such as the light, the buzzer,
or the like when the decision result of the comparing/deciding
portion 252 indicates that the abnormality exists.
[0379] For example, when the decision result of the
comparing/deciding portion 252 indicates that the abnormality is
present, the controlling portion 41 feeds the control signal
indicating the travel stop of the vehicle, the reduction of speed,
or the like to a travel controller of the vehicle in response to an
extent of the abnormality. In the present embodiment, a plurality
of sensor units 22 measures continuously the condition of the
bearing of the bearing unit, and the calculating/processing portion
250 conducts sequentially the abnormality diagnosis based on the
measured data. Therefore, the controlling/processing portion 40
informs of the abnormality immediately to execute the control of
the vehicle when the abnormality occurs. In other words, a flow of
sensing, analyzing, deciding, and result outputting are carried out
in real time.
[0380] In this case, any means may be employed to transmit the
signal between the sensing/processing portion 20, the
calculating/processing portion 250, and the calculating/processing
portion 250 if the signal can be transmitted/received precisely.
The cable may be employed or the radio may be employed in light of
the network.
[0381] Next, the diagnosis process in the condition monitoring
method in the present embodiment will be explained with reference
to FIG. 40 hereunder.
[0382] First, a counter in the microcomputer is initialized into
n=0 (step S601), and the diagnosis is started. Then, the signal
such as the sound, the vibration, or the like generated from the
railway vehicle facility 210 and sensed by the sensor in the
sensing/processing portion 20 is input into the microcomputer (step
S602). Then, the signal generated from the railway vehicle facility
210 is converted into the digital signal by the A/D converter (step
S603). Then, the digital signal is subjected to the amplifying
process by the amplifier (step S604). After the amplifying process
is executed, the counted value of the counter is set to n=n+1 (step
S605). Then, the filtering process is applied to the amplified
digital signal by the filtering processing portion 34 (step S606),
and thus the noise component is removed or the particular frequency
component is extracted.
[0383] Then, the digital signal, after the filtering processing, is
sent to the vibration analyzing portion 35, and the analyzing
process such as the enveloping process, the frequency analysis,
etc. are executed there (steps S607, S608). Thus, the frequency
components based on the actually measured data representing the
signals sensed from the railway vehicle facility 210 are derived.
Meanwhile, the rotation speed signal of the railway vehicle
facility 210 is sensed by the sensor in the sensing/processing
portion 20 (step S609). Then, a theoretical frequency component
generated due to the damage of the railway vehicle facility 210 and
serving as a reference value is calculated based on the rotation
speed signal (step S610). Then, the frequency components based on
the actually measured data are compared/collated with the
theoretical frequency component calculated in step S610 by the
comparing/deciding portion 252 every first time period t.sub.1
according to any of the above approaches (1) to (3) and (5) to (6)
(step S611), and the provisional diagnosis to check whether or not
the abnormality is present in the particular location of the
railway vehicle facility is executed. The result is saved together
with the counter value n in the internal data saving portion 37
(step S612).
[0384] Then, the counter value n is compared with a predetermined
number of times N (step S613). Then, if the counter value n is
smaller than the predetermined number of times N, the process goes
back to step S602 and then the processes in steps S602 to S612 are
repeated. In contrast, if the counter value n is in excess of the
predetermined number of times N, the evaluation in which the
bearing is considered as the abnormal state when the number of
times the bearing is diagnosed as the abnormal state in the
provisional diagnosis exceeds the threshold value (referred to as
the "total evaluation" hereinafter) is executed by using N saved
results, and thus the presence or absence of the abnormality in the
railway vehicle facility 210 and its location are diagnosed (step
S614). Then, the diagnosis result is saved or is fed to the
controlling/processing portion 40, and then the diagnosis result is
displayed (step S615) or the feedback control is applied by the
controlling portion 41. Thus, the diagnosis is ended.
[0385] As a consequence, in the condition monitoring method in the
present embodiment, the total evaluation in which the presence or
absence of the abnormality and its location are diagnosed by using
plural compared/collated results is employed. Therefore, the
influence of the impulsive noise, etc. upon the diagnosis can be
lessened and thus the monitoring can be executed effectively with
good precision.
[0386] In the present embodiment, since the frequency component is
compared/collated every first time period t.sub.1, the timing in
the total evaluation may be evaluated by employing any second time
period t.sub.2 longer than the first time period t.sub.1 instead of
the predetermined number of times N.
[0387] Also, the amplifying process and the filtering process in
the condition monitoring method in the present embodiment may be
executed arbitrarily, and thus carried out as the case may be.
[0388] In addition, in step S614 in FIG. 40, the total evaluation
in which the presence or absence of the abnormality and its
location are decided by comparing the number of times the bearing
is provisionally diagnosed as the abnormal state with the threshold
value is employed. Alternately, as a variation of the present
embodiment, the condition monitoring can be executed by using the
total evaluation in which an extent of the damage is decided based
on the number of times the bearing is provisionally diagnosed as
the abnormal state. As a result, the maintenance can be applied on
schedule to the machinery facility an operation of which is not
immediately stopped, or the like.
[0389] In the present embodiment, the condition monitoring is
applied to the double row tapered roller bearing in the railway
vehicle facility. But the condition monitoring may also be applied
to other machinery facilities such as a machine tool, the windmill,
and others.
[0390] Also, the double row tapered roller bearing as the rolling
bearing is employed as the rotating body or the sliding member. But
the condition monitoring method and system can also be applied to
the ball screw, the linear guide, the linear ball bearing, or the
like in addition to the rolling bearing. In this case, as the
operation signal of the machinery facility used to calculate the
reference value in the comparison/collation, the rotation speed
signal is used in the case of the rolling bearing, the ball screw,
or the like as the rotating body whereas the moving speed is used
in the case of the linear guide, the linear ball bearing, or the
like as the sliding member.
[0391] Further, if the sensor including at least one sensing
element selected from at least sound, temperature, vibration,
rotation speed, distortion, AE, and moving speed is provided, the
presence or absence of the abnormality can be analyzed by the
condition monitoring method and system. But it is preferable that
the presence or absence of the abnormality should be analyzed by
using at least one of the sensing elements of sound, vibration, and
AE. Also, from an aspect of capable of utilizing the past
abnormality database, it is desired to analyze the presence or
absence of the abnormality by using the vibration information.
However, in case the abnormality should be sensed in an initial
stage of occurrence of the minute crack or in case the internal
defect should be sensed, it is appropriate to employ the AE
information in place of the vibration information. If the
temperature information is employed in combination with the
vibration information or the AE information, such information can
have the larger effect than the case where such information is
employed solely.
Twelfth Embodiment
[0392] Next, a machinery facility abnormality diagnosis system
according to a twelfth embodiment of the present invention will be
explained hereunder. In this event, the same reference symbols are
affixed to the portions similar to those in the first embodiment,
and thus their redundant explanations will be omitted or simplified
hereunder.
[0393] FIG. 41 is a view showing a bearing housing 301 of the
railway vehicle bearing unit serving as the machinery facility to
which an abnormality diagnosis system 310 according to the twelfth
embodiment of the present invention is applied. The bearing housing
301 is fitted to cover an end portion of the axle of the railway
vehicle, and holds rotatably the axle of the railway vehicle via a
bearing (not shown in FIG. 41) incorporated into the inside. Also,
a cover 302 for covering the end portion of the axle of the railway
vehicle is fitted to a housing 303 in the bearing housing 301.
[0394] The bearing housing 301 is fixed by four bolts 304 provided
to four corners via the housing 303. Also, a hole used to measure
the temperature of the bearing is provided to a side surface of the
housing 303 and is stopped with a bolt 305. In the present
embodiment, the sensor unit 22 of the above sensing/processing
portion 20 is fitted to an end surface of the bolt 304 or the bolt
305, and the signals generated from the bearing in the bearing
housing are sensed by respective sensors in the sensor unit 22.
[0395] FIG. 42 is a view showing an overall configuration of the
abnormality diagnosis system 310 using the sensor unit 22 in the
present embodiment. As shown in FIG. 42, a rolling bearing 306 is
put into the bearing housing 301. The rolling bearing 306 is
constructed by arranging rolling elements 309 made of a plurality
of balls or rollers between an outer ring 307 fitted into the
housing 303 and an inner ring 308 fitted onto the axle of the
railway vehicle. Thus, the bearing housing 301 bears rotatably the
axle of the railway vehicle via the rolling bearing 306.
[0396] As shown in FIG. 42, the sensor unit 22 is fitted to the end
surface of the bolt 304 or 305 secured to the surface of the
housing 303. The sensor unit 22 can be fitted to the end surface of
the bolt 304 used to fix the bearing housing, but the sensor unit
may be fitted to the end surface of the bolt 305 used to stop the
temperature sensing hole, as described above. Normally this bolt
305 is given to every rolling bearing 306 fitted to the inside. For
example, in the case of the double row bearing, the fitting
location can be selected on the row located on the wheel side, the
row located on the motor side, the middle location, or the like
according to the purpose. But it is preferable that, for
convenience of the fitting operation, the bolt 305 should be fitted
to the wheel side and the sensor unit 22 should be provided to the
end surface of the bolt 305. Also, the sensor unit 22 can be fitted
to not the end surface of the bolt 305 but the side surface or the
inside of the hole that is stopped with this bolt 305.
[0397] It is preferable that the sensor unit 22 and the bolts 304,
305 should be tightly fitted/fixed without unsteadiness, looseness,
or the like. More particularly, in view of the running conditions,
the fitting conditions, characteristics of the sensor, and so on,
the suitable fitting approach can be selected appropriately among
various approaches such as screwing, bonding, magnet, inserting,
molding integrally with the bolt, etc.
[0398] Also, in case the fitting location of the sensor unit 22 is
chosen in the noisy area, preferably the sensor unit 22 should be
fitted to be isolated from the circumference. If the sensor can be
isolated from the circumference, the noise can be reduced and also
the SN ratio can be improved.
[0399] In addition, in order to execute the sensing at the high SN
ratio, it is preferable that the sensor unit 22 should be fitted in
the loading range of the rolling bearing 306, as indicated by A1 in
FIG. 5, like the first embodiment. If the sensor unit 22 is fitted
to the portion to which the load is applied (loading range), the
signal can be sensed with good sensitivity and thus the
higher-precision measurement can be done.
[0400] Also, in case the sensor is fitted inevitably in the
non-loading range, e.g., when no space is found in the loading
range to fit the sensor, when the high-tension cable that emits the
noise is provided in the loading range, or the like, it is
preferable that the sensing sensitivity of the signal can be
enhanced by executing the filtering process.
[0401] Here, the sensor unit 22 has the similar structure/functions
to those of the sensor unit used in the first embodiment. Also, the
calculating/processing portion 30 and the controlling/processing
portion 40 shown in FIG. 42 have the similar structure/functions to
those of the sensor unit used in the first embodiment.
[0402] According to the abnormality diagnosis system 310 of the
present embodiment, the sensing/processing portion 20 consisting of
the sensor unit 22 that is fixed to the end surface of the bolt 304
or 305, which is screwed into the housing 303 of the bearing
housing 301 that supports the rolling bearing 306 as the rotating
body in the railway vehicle, and has the sensing element to output
the signal generated from the rolling bearing 306 as the electric
signal, the calculating/processing portion 30 for conducting the
abnormality diagnosis of the bearing unit based on the output of
the sensor unit 22, and the controlling/processing portion 40 for
feeding back the control signal to the control system of the
railway vehicle based on the decision result of the
calculating/processing portion 30 are provided.
[0403] More specifically, like the first embodiment, the
calculating/processing portion 30 includes the data
accumulating/distributing portion 31 for accumulating the electric
signal fed from the sensing/processing portion 20 and distributing
the signal to the suitable distributing route according to the type
of the signal, the analyzing portions 32, 33, 35 for calculating
the predetermined physical quantity in regarding to the railway
vehicle as the machinery facility based on the electric signal
distributed from the data accumulating/distributing portion 31, the
internal data saving portion 37 as the first data saving portion in
which machine equipment data concerning to the machine equipment
are saved, the comparing/deciding portion 36 for conducting the
abnormality diagnosis of the machine equipment by comparing the
physical quantity calculated by the analyzing portion with the
machine equipment data saved in the internal data saving portion,
and the data accumulating/outputting portion 38 as the second data
saving portion for saving the analyzed result by the analyzing
portion and the abnormality diagnosis result by the
comparing/deciding portion.
[0404] According to the abnormality diagnosis system 310, since the
physical information about the rolling bearing 306 are collected by
using the sensor unit 22 and the abnormality of the rolling bearing
306 is diagnosed based on the physical information to execute the
control, the defect of the rolling bearing 306 can be sensed
without decomposition of the bearing housing 301. Therefore, the
time and labor required for the decomposition and the assembling of
the bearing housing 301 can be reduced and also the damage of the
rolling bearing 306 and the bearing housing 301 attendant upon the
assembling after the decomposition can be prevented. Also, in the
present embodiment, since the diagnosis is made by the abnormality
diagnosis system 310 based on the predetermined references, it is
possible to find the defect that the visual inspection may
overlook.
[0405] Also, according to the present embodiment, since the sensor
unit 22 is fixed onto the bolt 304 or 305, there is no need to
provide particularly the flat surface, onto which the sensor unit
22 is fitted, on the bearing housing 301. Therefore, the sensor
unit 22 can be fitted without reform of the bearing housing 301. As
a result, the abnormality diagnosis can be conducted by installing
the sensor unit 22 of the abnormality diagnosis system 310 into the
bearing housing 301 without extra time/labor and cost.
[0406] In the present embodiment, explanation is made of the
rolling bearing in the bearing housing of the railway vehicle as an
example, but the present invention is not limited to this. The
present invention can also be applied to other rotating parts
(gear, wheel itself) of the railway vehicle, the windmill, the
reduction gear, the electric motor, the ball screw, the linear
guide, and others.
[0407] Also, the calculating/processing portion 30 may have the
functions of the calculating/processing portion achieved by the
microcomputer 250 in the eleventh embodiment.
[0408] Also, as shown in FIG. 43, the calculating/processing
portion 30 of the abnormality diagnosis system 310 in the present
embodiment may be constructed by the one-chip or one-board
microcomputer 81 shown in the fifth to tenth embodiments, or may be
constructed by the IC chip. In addition, the controlling/processing
portion 40 may also be constructed by the one-chip or one-board
microcomputer or the IC chip. Also the microcomputer in which the
calculating/processing portion 30 and the controlling/processing
portion 40 are integrally provided may be loaded on the machine
equipment such as the vehicle, or the like.
[0409] Also, as shown in FIG. 44, the controlling/processing
portion 40 may be removed from the vehicle and installed on the
ground, and then the radio communication may be established between
a transmitter/receiver 370 provided on the vehicle and a
transmitter/receiver 380 provided adjacent to the railway. In this
case, the functions corresponding to the controlling/processing
portion 40 can be provided to the information processing center
provided on the ground, for example. This information center may be
constructed to receive the information from the microcomputers 81
provided to a plurality of vehicles respectively and to
collectively control a plurality of vehicles intensively, for
example. In this case, the ID number, or the like may be added to
the data sent out from the vehicles respectively to identify the
information of respective vehicles. Similarly the sensor unit 22
and the microcomputer 81 may be connected via radio
communication.
[0410] As a result, the signal transmission between the
sensing/processing portion 20 and the calculating/processing
portion 30 or the calculating/processing portion 30 and the
controlling/processing portion 40 can be made without a wire
connection.
Thirteenth Embodiment
[0411] Next, a bearing unit according to a thirteenth embodiment of
the present invention will be explained hereunder. As shown in FIG.
45, a bearing unit 410 according to a thirteenth embodiment of the
present invention is constructed by a double row tapered roller
bearing 411, a bearing housing 412 constituting a part of the
carriage for the railway vehicle, and an abnormality sensing means
413.
[0412] The double row tapered roller bearing 411 has a pair of
inner rings 414, 414 having inner ring raceway surfaces 415, 415
inclined like a tapered outer surface on their outer peripheral
surfaces, a single outer ring 416 having a pair of outer ring
raceway surfaces 417, 417 inclined like a tapered outer surface on
their inner peripheral surfaces, tapered rollers 418 as the rolling
elements that are arranged in plural between the inner ring raceway
surfaces 415, 415 of the inner rings 414, 414 and the outer ring
raceway surfaces 417, 417 of the outer ring 416 in double row,
annular pressed retainers 419, 419 for holding rollably the tapered
rollers 418, and a pair of sealing members 420, 420.
[0413] A radial load applied by weights of various members, etc.
and any axial load are imposed onto the double row tapered roller
bearing 411. An upper portion of the outer ring 416 is the loading
range of the bearing.
[0414] The bearing housing 412 consists of an axle end member 421,
a housing 422, a cover 423, and a shroud 424.
[0415] An inner ring spacer 425 is arranged between the inner rings
414, 414. Also, inner ring spacers 426, 426 are arranged on both
outer sides of the inner rings 414, 414 in the axial direction. An
axle 401 is fitted into the inner rings 414, 414 and the inner ring
spacers 425, 426, 426. The inner ring raceway surfaces 415, 415 of
the inner rings 414, 414 restrict the movement of the tapered
rollers 418 in the axial direction.
[0416] The outer ring raceway surfaces 417, 417 of the outer ring
416, the inner ring raceway surfaces 415, 415 of the inner rings
414, 414, and the tapered rollers 418 are positioned such that
vertexes located on prolonged lines of respective tapered surfaces
are converged on one point on the axis line.
[0417] Out of the sealing members 420, 420, one sealing member 420
arranged on the top end portion side of the axle 401 is fitted
between the outer end portion of the outer ring 416 and the axle
end member 421.
[0418] The other sealing member 420 arranged on the counter top end
portion side of the axle 401 is fitted between the outer end
portion of the outer ring 416 and the shroud 424.
[0419] The axle end member 421 is fixed by screwing bolts 401a into
the top end portion of the axle 401 to cover the inner ring spacer
426 arranged at the top end portion of the axle 401.
[0420] The housing 422 constitutes a side frame of the railway
vehicle carriage, and is formed like the annular ring to cover the
outer peripheral surface of the outer ring 416. A pair of projected
walls 422a, 422a being projected into the inner peripheral surface
are mounted on both side end portions of the outer ring 416. Then,
a recess portion 422b in which the abnormality sensing means are
housed is formed on the outer peripheral surface of the housing 422
corresponding to the center portion of the double row tapered
roller bearing 411 in the axial direction. A flat surface 422c is
formed on a bottom portion of the recess portion 422b.
[0421] The cover 423 is put on the top end portion of the housing
422. The shroud 424 is positioned between the end portion of the
housing 422 and the axle 401 to cover the other sealing member 420
on the counter top end portion side of the axle 401.
[0422] The abnormality sensing means 413 is a composite sensor in
which a temperature sensor 427 and a vibration sensor 428 are
integrally provided. The temperature sensor 427 is a non-contact
type temperature measuring element such as a thermistor temperature
measuring element, a platinum resistance temperature sensor, a
thermocouple, or the like. The vibration sensor 428 is a vibration
measuring element such as a piezoelectric element, or the like.
[0423] Also, since the temperature sensor 427 and the vibration
sensor 428 are aligned in the axial direction of the bearing and
resin-molded in the recess portion 422b of the housing 422, such
temperature sensor 427 and such vibration sensor 428 are integrally
molded in a case 429. Thus, the abnormality sensing means 413 is
fitted in the loading range of the housing 422 and the double row
tapered roller bearing 411 in the center portion in a bearing
width. The molding material used in the resin molding is the
material that is rich in the waterproof property, the heat
resisting property, and the insulating property.
[0424] The temperature sensor 427 senses the temperature of the
double row tapered roller bearing 411 via the housing 422 to
generate the temperature data signal (voltage signal). The
temperature data signal generated by the temperature sensor 427 is
transferred to the external controlling portion via a signal
carrying means 430 provided in the case 429, and is used to sense
the seizure abnormality of the double row tapered roller bearing
411. Here, as the temperature sensor 427, a temperature fuse that
does not conduct by causing either a contact of a bimetal to
disconnect or a contact to fuse when the atmospheric temperature
exceeds a specified value may be employed. In such case, when the
temperature of the device exceeds a specified value, conduction of
the temperature fuse is cut off and thus the temperature
abnormality is sensed.
[0425] The vibration sensor 428 senses the vibration of the double
row tapered roller bearing 411 via the housing 422 to generate the
vibration data signal (voltage signal). The vibration data signal
generated by the vibration sensor 428 is transferred to the
external controlling portion via the signal carrying means 430
provided in the case 429, and is used to sense the flaking of the
inner ring raceway surfaces 415, 415 and the outer ring raceway
surfaces 417, 417 of the double row tapered roller bearing 411, the
fracture of the gear, and the flat wear of the wheel. Here, as the
vibration sensor 428, any sensor capable of transforming the
vibration such as acceleration, speed, displacement, or the like
into the electric signal may be employed. When the vibration sensor
is fitted to the device that is often exposed to the disturbance
such as the noise, and the like, it is desired that the sensor does
not suffer the noise by using the insulation type.
[0426] Since the temperature sensor 427 and the vibration sensor
428 are arranged in the case 429 formed by the molding, the
entering of the rainwater can be prevented without fail. Also,
since the temperature and the vibration can be sensed during the
rotation, the defect of a plurality of parts can be inspected
concurrently without overhaul of the system into which the rotating
parts are incorporated. Since the vibration-proof property against
the vibration applied from the outside can be improved rather than
the case where the sensor is fixed to the outside of the housing
422, the reliability of the sensing performance can be improved
tremendously. Also, since the sensor is never subjected to the
surrounding circumstances such as fitting condition, rainwater,
wind pressure, and the like in contrast to the case where
respective sensors are fixed with the screws separately, the
high-precision signal can be generated at the high SN ratio
(signal-to-noise ratio).
[0427] As shown in FIG. 46, in the first signal processing method
in the abnormality sensing means 413, the temperature data signal
generated by the temperature sensor 427 and the vibration data
signal generated by the vibration sensor 428 are input into a
comparator 431 via the signal carrying means 430. Then, the
temperature data signal value given from the temperature sensor 427
is compared with a predetermined temperature threshold value saved
in a threshold setting portion 432 in the comparator 431.
Similarly, the vibration data signal value given from the vibration
sensor 428 is compared with a predetermined vibration threshold
value saved in the threshold setting portion 432. That is, at least
one abnormality selected from the temperature sensor 427 and the
vibration sensor 428 is sensed by the abnormality sensing means
413. At this time, when the temperature data signal value exceeds
the temperature threshold value, a temperature abnormality decision
signal is output from an abnormality deciding portion 433 and also
a temperature abnormality alarm is output from a decision result
outputting portion 434.
[0428] Also, when the vibration data signal value exceeds the
vibration threshold value, a vibration abnormality decision signal
is output from the abnormality deciding portion 433 and also a
vibration abnormality alarm is output from the decision result
outputting portion 434. The alarm is transferred via cable or radio
and then operated. At this time, as the temperature threshold value
and the vibration threshold value saved in the threshold setting
portion 432 and the temperature/vibration abnormality decision
signals output from the abnormality deciding portion 433, the
root-mean-square value and the peak value in any time period may be
employed.
[0429] As shown in FIG. 47, in the second signal processing method
in the abnormality sensing means 413, the vibration data signal
generated by the vibration sensor 428 is amplified, then only a
predetermined frequency band is extracted from the vibration data
signal by a filtering portion 435 to remove the unnecessary
frequency band, and then the resultant signal is input into an
envelope processing portion 436. The absolute-value detecting
process of detecting the absolute value of the waveform is executed
in the envelope processing portion 436, then the frequency
analyzing process is executed in a frequency analyzing portion 437,
and then the actually measured data are transferred to a
comparing/collating portion 438.
[0430] Meanwhile, the calculated value data of the frequency
components, which are set as those generated due to the abnormality
such as one-sided wear, or the like of the bearing, the gear, and
the wheel in a theoretical frequency calculating portion 440 based
on rotation speed information 439, are transferred to the
comparing/collating portion 438. Then, the actually measured data
are compared/collated with the calculated value data in the
comparing/collating portion 438 to specify the presence or absence
of the vibration abnormality and the abnormal location. Then, the
presence or absence of the vibration abnormality and the identified
location are output from a result outputting portion 441. The
information are transferred to the result outputting portion 441
via cable or radio.
[0431] In the second signal processing method, for example, the
calculation of the frequency components and the
comparison/collation can be easily made based on the rotation speed
information sensed from the electric motor, or the like and design
specifications of the rotating elements parts. Also, various data
processes and calculation are applied as the processing of the
vibration data signal after the amplification. For example, such
processing may be executed by the computer, the dedicated
microchip, or the like. In addition, the calculation process may be
applied to the sensed data signal after such signal is stored in
the saving means such as the memory, or the like.
[0432] Also, because it takes much time and labor to exchange the
bearing in some machine, such machine cannot be immediately
stopped. In this case, in some cases the exchange of the bearing is
applied according to a degree of the damage. As the criterion in
such case, the root-mean-square value, the maximum value, and the
peak factor of the vibration, for example, may be employed with
respect to the previously decided reference values.
[0433] Also, as the abnormality diagnosis processing method on the
basis of the vibration information in the comparing/collating
portion 438 shown in FIG. 46, the above approaches (1) to (6) may
be employed.
[0434] According to the bearing unit 410 in the thirteenth
embodiment, since the sensors are molded with the resin in the
loading range of the bearing housing 412, particularly in the
recess portion 422b formed on the housing 422 of the bearing
housing 412 that covers the outer peripheral surface of the outer
ring 416, the temperature sensor 427 and the vibration sensor 428
can be integrally formed in a single case 429. Thus, the vibration
or temperature information accompanying the rotating condition of
the rotating parts can be sensed at the same time by sensing at
least one abnormality selected from the temperature sensor 427 and
the vibration sensor 428 by means of the abnormality sensing means
413. As a result, the defect of a plurality of parts can be
inspected simultaneously still in the actual operating state
without overhaul of the system into which the rotating parts are
incorporated.
[0435] In other words, the abnormality sensing means may be
provided in the loading range of the bearing housing. Also, it is
preferable that the abnormality sensing means should be secured
onto the flat portion provided to a part of the outer peripheral
surface of the bearing housing on the loading range side. Like the
present embodiment, when the abnormality sensing means is
embedded/fixed in the recess portion formed on the bearing housing,
preferably such means should be fitted to mold a clearance between
the abnormality sensing means and the recess portion. Also, the
abnormality sensing means may be arranged on the outer diameter
portion of the bearing housing in the loading range and in the
center portion of the bearing width.
[0436] In addition, in the present embodiment, the case of the
abnormality sensing means has a signal carrying means for sending
out the sensed signal, and a decision result outputting portion for
deciding/outputting the presence or absence of the abnormality
based on the signal sent out via the signal carrying means.
[0437] Further, the inspection executed based on the vibration
information is attained by providing the filtering processing
portion for removing the unnecessary frequency band from the
vibration waveform from the vibration sensor, the envelope
processing portion for detecting the absolute value of the filtered
waveform transferred from the filtering processing portion, the
frequency analyzing portion for analyzing the frequency of the
waveform transferred from the envelope processing portion, the
comparing/collating portion for comparing the frequency generated
due to the damage calculated based on the rotation speed with the
frequency derived based on the actually measured data, and the
result outputting portion for identifying the presence or absence
of the abnormality and the abnormal location based on the compared
result in the comparing/collating portion.
[0438] Therefore, the abnormal decision can be made still in the
normal state of use without overhaul of the bearing unit 410. As a
result, a frequency of the overhauling/assembling operations that
require a lot of time and labor can be reduced and thus the
maintenance/administrative costs can be reduced largely. Also, the
variation of the decision due to a degree of expertise or the
individual differences of the person in charge of inspection is in
no way generated rather than the visual inspection in the prior
art, and thus the reliability of the abnormality diagnosis can be
improved dramatically.
Fourteenth Embodiment
[0439] Next, a bearing unit according to a fourteenth embodiment of
the present invention will be explained with reference to FIG. 48
hereunder. In this event, the same reference symbols are affixed to
the portions similar to those in the thirteenth embodiment, and
thus their redundant explanations will be omitted or simplified
hereunder.
[0440] As shown in FIG. 48, in a bearing unit 450 in the present
embodiment, the abnormality sensing means 413 constructed by
molding integrally the temperature sensor 427 and the vibration
sensor 428 in the case 429 is fixed to the recess portion 422b
formed on the outer peripheral surface of the housing 422 via a
spacer 451.
[0441] The spacer 451 is made of a metal that has the temperature
characteristic and the natural vibration characteristic equivalent
to the housing 422. The spacer 451 is fixed by tightening screws
453, 453, which are inserted into a flange 452 arranged on the
outer peripheral portion of the housing 422, into the housing
422.
[0442] In this case, the abnormality sensing means 413 as well as
the spacer 451 can be detachably attached to the housing 422.
Therefore, when the temperature sensor 427 and the vibration sensor
428 are to be exchanged, the exchanging operation can be executed
only by taking out the screws 453, 453 not to consume much time. In
the bearing unit 450 in the fourteenth embodiment, the same signal
processing as that in the first embodiment is applied.
Fifteenth Embodiment
[0443] Next, a bearing unit according to a fifteenth embodiment of
the present invention will be explained with reference to FIG. 49
hereunder. In this case, the same reference symbols are affixed to
the portions similar to those in the thirteenth embodiment, and
thus their redundant explanations will be omitted or simplified
hereunder.
[0444] As shown in FIG. 49, in a bearing unit 460 of the present
embodiment, a pair of recess portions 422d, 422d into which the
abnormality sensing means is installed are formed on the outer
peripheral surface of the housing 422 in the position that
corresponds to the center portion in the width area of the inner
ring raceway surfaces 415, 415 of the double row tapered roller
bearing 411. First and second abnormality sensing means 461, 462 in
which the temperature sensor 427 and the vibration sensor 428 are
molded integrally in the case 429 are molded in the recess portions
422d, 422d with the resin.
[0445] The recess portions 422d, 422d are also arranged
corresponding to the center portion in the width area of the outer
ring raceway surfaces 417, 417.
[0446] In this case, the first and second abnormality sensing means
461, 462 are arranged in close vicinity to the position in which
the tapered rollers 418 come into contact with the inner and outer
ring raceway surfaces 415, 415, 417, 417 while rolling down.
Therefore, the sensing sensitivity can be improved further, and a
time required until the abnormal signal is generated when the
abnormality occurs can be shortened. In the bearing unit 460 of the
fifteenth embodiment, the same signal processing as that in the
first embodiment is applied.
[0447] Also, the abnormality sensing means in which the temperature
sensor and the vibration sensor are molded integrally may be fitted
directly to the outer peripheral surface of the housing in the
loading range. In such case, the abnormality sensing means should
be fitted to the flat portion that is formed on a part of the outer
peripheral surface of the housing. Then, the signal processing
should be applied in the similar manner to respective embodiments.
Also, like the present embodiment, the abnormality sensing means
may be arranged on the outer diameter portion of the bearing
housing in the loading range and in the width area of the inner
ring raceway surfaces or the outer ring raceway surfaces.
[0448] Also, as the bearing used in the bearing unit, a combination
of the cylindrical roller bearing and the single row radial ball
bearing, or the cylindrical roller bearing or the tapered roller
bearing or the self-aligning roller bearing may be applied.
[0449] Here, the machinery facility condition monitoring method and
system and the abnormality diagnosis system according to the
present invention are not limited to the foregoing embodiments, and
appropriate variations, improvements, etc. can be applied. Also, in
the present invention, respective embodiments can be employed in
combination in the practicable range. Also, the machinery facility
of the present invention includes the railway vehicle, the machine
tool, the windmill, the reduction gear, the electric motor, and
others, and any facility may be employed if the machinery facility
includes at least one of the rotating body and the sliding member.
Also, the rotating body or the sliding member of the present
invention includes the rolling bearing, the sliding bearing, the
ball screw, the linear guide, the linear ball bearing, other
rotating parts (gear, wheel itself), and others.
[0450] The present invention is explained in detail with reference
to particular embodiments, but it is apparent for the person
skilled in the art that various variations and modifications can be
applied without departing from a spirit and a scope of the present
invention.
[0451] This application is filed based on [0452] Japanese Patent
Application (Patent Application No. 2002-252877) filed on Aug. 30,
2002, [0453] Japanese Patent Application (Patent Application No.
2002-338423) filed on Nov. 21, 2002, [0454] Japanese Patent
Application (Patent Application No. 2002-370800) filed on Dec. 20,
2002, [0455] Japanese Patent Application (Patent Application No.
2003-010131) filed on Jan. 17, 2003, [0456] Japanese Patent
Application (Patent Application No. 2003-048309) filed on Feb. 25,
2003, [0457] Japanese Patent Application (Patent Application No.
2003-182996) filed on Jul. 26, 2003, [0458] Japanese Patent
Application (Patent Application No. 2003-304700) filed on Aug. 28,
2003, and the contents thereof are incorporated by the reference
hereinto.
INDUSTRIAL APPLICABILITY
[0459] There is provided the high-precision machinery facility
abnormality diagnosis system that is capable of deciding the
presence or absence of the abnormality in the state of normal use
without decomposition of the facility like the machinery facility
such as a railway vehicle facility, a machine tool, a windmill, or
the like, which requires much time and labor to decompose, and thus
capable of reducing the maintenance/administrative costs and being
hardly affected by the noise, and the like.
* * * * *