U.S. patent application number 14/155635 was filed with the patent office on 2014-07-17 for fan motor with anti-dirt sticking function and apparatus having fan motor.
This patent application is currently assigned to FANUC CORPORATION. The applicant listed for this patent is FANUC CORPORATION. Invention is credited to Makoto Takeshita, Kazuhiro Yamamoto.
Application Number | 20140199191 14/155635 |
Document ID | / |
Family ID | 51015158 |
Filed Date | 2014-07-17 |
United States Patent
Application |
20140199191 |
Kind Code |
A1 |
Yamamoto; Kazuhiro ; et
al. |
July 17, 2014 |
FAN MOTOR WITH ANTI-DIRT STICKING FUNCTION AND APPARATUS HAVING FAN
MOTOR
Abstract
A fan motor including a stator; a rotor having a cylindrical
part arranged around the stator and a plurality of blades sticking
out from an outer periphery of the cylindrical part to a radial
direction, the rotor rotating about an axial line to blow a gas;
and a housing having a disk part arranged at a side of the stator,
a shroud part arranged around the blades, and a plurality of stays
extending from an outer circumferential edge portion of the disk
part to the radial direction to connect the disk part and the
shroud part beside the blades. The stays are arranged at an
upstream side from the blades in a blowing direction of the
gas.
Inventors: |
Yamamoto; Kazuhiro;
(Yamanashi, JP) ; Takeshita; Makoto; (Yamanashi,
JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
FANUC CORPORATION |
Yamanashi |
|
JP |
|
|
Assignee: |
FANUC CORPORATION
Yamanashi
JP
|
Family ID: |
51015158 |
Appl. No.: |
14/155635 |
Filed: |
January 15, 2014 |
Current U.S.
Class: |
417/423.7 |
Current CPC
Class: |
F04D 25/0646 20130101;
F04D 29/5813 20130101 |
Class at
Publication: |
417/423.7 |
International
Class: |
F04D 25/06 20060101
F04D025/06; F04D 29/58 20060101 F04D029/58 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 16, 2013 |
JP |
2013-005602 |
Claims
1. A fan motor comprising: a stator having a coil; a rotor having a
cylindrical part arranged around the stator and a plurality of
blades sticking out from an outer periphery of the cylindrical part
to a radial direction, the plurality of blades being arranged in a
circumferential direction, the rotor rotating about an axial line
to blow a gas in parallel to the axial line through the blades; and
a housing having a disk part arranged at a side of the stator, a
shroud part arranged around the blades, and a plurality of stays
extending from an outer circumferential edge portion of the disk
part to the radial direction to connect the disk part and the
shroud part beside the blades, the plurality of stays being
arranged in the circumferential direction, wherein the stays are
arranged at an upstream side from the blades in a blowing direction
of the gas.
2. The fan motor according to claim 1, further comprising a printed
circuit board on which an electronic device controlling a current
supplied to the coil is mounted, wherein the disk part has a
holding part holding the printed circuit board.
3. The fan motor according to claim 2, wherein at least one of the
stator and the printed circuit board is surrounded by a resin
material.
4. The fan motor according to claim 1, wherein at least one of the
disk part and the stays have a slanted part slanted to an opposite
side of the blowing direction of the gas toward an outside in the
radial direction.
5. The fan motor according to claim 1, wherein surfaces at upstream
sides of the stays are slanted with respect to the axial line.
6. An apparatus having a fan motor, comprising: a fan motor
according to claim 1; a passage-forming member forming a passage
through which cooling air generated by driving of the fan motor
passes; and a cooled member cooled by the cooling air passing
through the passage.
7. The apparatus having a fan motor according to claim 6, wherein
the cooled member is an electronic device for controlling a drive
motor of a robot or machine tool.
8. The apparatus having a fan motor according to claim 6, wherein
the fan motor is arranged with the axial line facing a vertical
direction and with the stays facing downward.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a fan motor with an
anti-dirt sticking function and to an apparatus having a fan motor,
which is used for a machine tool or robot, etc.
[0003] 2. Description of the Related Art
[0004] In general, a machine tool or robot is used in an
environment pervaded by dust, refuse, cutting fluid mist, etc. For
this reason, when providing a fan motor (also referred to as a
"cooling fan") for cooling the electronic devices, etc. used for a
machine tool or robot, operation of the fan motor causes the dust
and other air-borne matter to collect at the fan motor and stick to
the fan motor. If air-borne matter sticks to the fan motor in this
way, operation of the fan motor will be obstructed and the cooling
performance will deteriorate. As an apparatus for preventing such
deterioration of the cooling performance, in the past, the
apparatus described in Japanese Patent Publication No. 4775778
(J4775778B) has been known. The apparatus described in JP4775778B
provides a nozzle near the fan motor and ejects compressed air from
the nozzle to thereby remove air-borne matter stuck to the fan
motor.
[0005] However, in a configuration like the apparatus which is
described in JP4775778B which ejects compressed air from a nozzle
to the fan motor, air-borne matter is forcibly blown into the fan
motor, for example, into the clearance between the stator and rotor
of the motor, and sticks inside the motor. Due to this, operation
of the fan motor is conversely liable to be obstructed.
SUMMARY OF THE INVENTION
[0006] A fan motor of one aspect of the present invention includes:
a stator having a coil; a rotor having a cylindrical part arranged
around the stator and a plurality of blades sticking out from an
outer periphery of the cylindrical part to a radial direction, the
plurality of blades being arranged in a circumferential direction,
the rotor rotating about an axial line to blow a gas in parallel to
the axial line through the blades; and a housing having a disk part
arranged at a side of the stator, a shroud part arranged around the
blades, and a plurality of stays extending from the outer
circumferential edge portion of the disk part to the radial
direction to connect the disk part and the shroud part beside the
blades, the plurality of stays being arranged in the
circumferential direction, wherein the stays are arranged at an
upstream side from the blades in a blowing direction of the
gas.
[0007] Further, an apparatus having a fan motor of another aspect
of the present invention includes: the above fan motor; a
passage-forming member forming a passage through which cooling air
generated by driving of the fan motor passes; and a cooled member
cooled by the cooling air passing through the passage.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The objects, features, and advantages of the present
invention will become clearer from the following description of
embodiments in relation to the attached drawings. In the attached
drawings,
[0009] FIG. 1A is a front view which shows the general
configuration of an apparatus which has fan motors according to an
embodiment of the present invention,
[0010] FIG. 1B is a perspective view which shows the general
configuration of an apparatus which has fan motors according to an
embodiment of the present invention,
[0011] FIG. 2 is a perspective view which shows the overall
configuration of the fan motors of FIG. 1A and FIG. 1B,
[0012] FIG. 3 is a cross-sectional view cut along the line III-III
of FIG. 2,
[0013] FIG. 4 is a view along the arrow IV of FIG. 3,
[0014] FIG. 5 is a perspective view which shows the configuration
of a fan motor of a comparative example of an embodiment of the
present invention,
[0015] FIG. 6 is a cross-sectional view cut along the line VI-VI of
FIG. 5,
[0016] FIG. 7 is a view which shows a modification of FIG. 3,
[0017] FIG. 8 is a view which shows another modification of FIG.
3,
[0018] FIG. 9 is a view which shows a modification of a fan motor
according to an embodiment of the present invention,
[0019] FIG. 10A is a view which shows a modification of FIG.
1A,
[0020] FIG. 10B is a view which shows a modification of FIG.
1B,
[0021] FIG. 11A is a view which shows another modification of FIG.
1A, and
[0022] FIG. 11B is a view which shows another modification of FIG.
1B.
DETAILED DESCRIPTION
[0023] Below, referring to FIG. 1A to FIG. 6, a fan motor according
to an embodiment of the present invention will be explained. FIG.
1A and FIG. 1B are a front view and a perspective view which show
the general configuration of an apparatus 100 having a fan motors
according to an embodiment of the present invention. This apparatus
100 is an apparatus for cooling various devices which are provided
at a robot or machine tool, etc. which is used in an environment
pervaded by dust, refuse, cutting fluid mist, etc. (these being
sometimes referred to all together as "air-borne matter").
[0024] As shown in FIGS. 1A and 1B, the apparatus 100 has a
radiator 101 and a case 102 which are placed next to each other, a
first fan motor 110 and second fan motor 120 which are respectively
provided at the radiator 101 and the case 102, and electronic
devices 103 which are cooled by the fan motors 110 and 120. The
electronic devices 103 include a control circuit for controlling a
drive motor of the robot or machine tool (for example, a servo
motor). The radiator 101 and the case 102 are formed overall as
substantially box shapes. The case 102 are fastened to the radiator
101.
[0025] The radiator 101 is configured by a plurality of
substantially rectangular shaped thin sheet fins 104a which extend
from a side surface 101a to a side surface 101b at the opposite
side, extend in the up-down direction, and are separated from each
other (see FIG. 10B). Air passages AP are formed in the up-down
direction between adjoining fins 104a. A top surface and bottom
surface of the radiator 101 are open. At the bottom surface, an
inlet 105 is formed, while at the top surface, an outlet 106 is
formed. At the top surface of the radiator 101, the first fan motor
110 is arranged facing the outlet 106. Due to rotation of the fan
motor 110, as shown by the arrow mark in FIG. 1A, cooling air flows
through the radiator 101 and fan motor 110 from the bottom to the
top.
[0026] The case 102 has an outlet 107 at its top surface. The
second fan motor 120 is arranged below the outlet 107 while facing
the outlet 107. Below the fan motor 120, a plurality of electronic
devices 103 are arranged. If the fan motor 120 rotates, air is
sucked in from a not shown inlet to the inside of the case 102 and
is discharged from the outlet 107. Due to this, air flows along the
surface of the electronic device 103 whereby the electronic devices
103 are cooled.
[0027] The electronic devices 103 are supported while contacting
the radiator 101. For this reason, when rotation of the first fan
motor 110 causes cooling air to flow through the passages AP in the
radiator 101, the heat which is generated by the electronic devices
103 is dissipated through the radiator 101. In this way, in the
present embodiment, since a pair of fan motors 110, 120 are
provided at the apparatus 100, the air which flows through the
radiator 101 and the air which flows through the inside of the case
102 enable the electronic devices 103 inside of the case 102 to be
efficiently cooled.
[0028] Next, the configuration of the fan motors 110, 120 according
to an embodiment of the present invention will be explained. FIG. 2
is a perspective view which shows the overall configuration of the
fan motors 110, 120 (view seen from above at a slant), while FIG. 3
is a cross-sectional view cut along the line III-III of FIG. 2. In
FIG. 3, only one side from the center axis of the fan motors 110,
120 (axial line L0 which extends in top-bottom direction) is shown.
As shown in FIG. 2 and FIG. 3, each of the fan motors 110, 120 has
a stator 10 which is configured and arranged about the axial line
L0, a rotor 20 which rotates about the axial line L0, and a housing
30 which is arranged around the rotor 20.
[0029] The stator 10 has a substantially cylindrically shaped iron
core 11 which has a plurality of projecting parts which project out
in the radial direction, and a coil 12 which is wound around these
projecting parts and form a plurality of stator poles. The rotor 20
has a shaft 21 which is arranged at the inside of the iron core 11
and extends along the axial line L0, a cylindrical part 22 which is
arranged about the axial line L0 and around the stator 10, a
plurality of blades 23 which stick out in the radial direction from
the outer periphery of the cylindrical part 22 and are arranged at
regular intervals in the circumferential direction, and a disk part
24 which connects the top end part of the shaft 21 and the top end
part of the cylindrical part 22 above the stator 10. At the inner
circumference of the cylindrical part 22, a plurality of permanent
magnets 25 which form a plurality of rotor magnetic poles and are
arranged in the circumferential direction, are attached.
[0030] FIG. 4 is a view along an arrow IV of FIG. 3 (view seen from
below). In FIG. 4, illustration of the stator 10 and the rotor 20
is omitted. As shown in FIG. 3 and FIG. 4, the housing 30 has a
disk part 31 which is arranged below the stator 10, a cylindrically
shaped shroud part 32 which is arranged about the axial line L0 and
around the blades 23, and a plurality of stays 33 (in the figure,
four) which extend from the outer circumferential edge portion of
the disk part 31 in the radial direction and connect the disk part
31 and shroud part 32 below the blades 23 and are arranged in the
circumferential direction. The outer periphery 31b of the disk part
31 is substantially positioned on the downward extension of the
outer periphery of the cylindrical part 22.
[0031] As shown in FIG. 3, the stays 33 have top surfaces 331 which
face the blades 23 and bottom surfaces 332 at the opposite sides.
At the top surface 311 of the disk part 31, a recessed part 31a is
formed. In the recessed part 31a, a printed circuit board 34 which
is supported by the disk part 31 is held. That is, the recessed
part 31a functions as a holding part of the printed circuit board
34. The printed circuit board 34 is an electronic device (board)
which controls the current which is supplied to the coil 12. At the
inner circumferential edge of the disk part 31, a cylindrical part
35 is provided facing upward in a protruding manner. At the inside
circumference of the cylindrical part 35, a pair of top and bottom
bearings 36 are supported. At the insides of the bearings 36, a
shaft 21 is rotatably supported.
[0032] Next, the operation of an apparatus 100 having the fan motor
according to the present embodiment will be explained. Below, the
case of using an apparatus 100 in an environment pervaded by
cutting fluid mist will be explained. If drive current is supplied
to the coil 12 of the stator 10 through the printed circuit board
34, the fan motors 110, 120 rotate. Due to this, air is sucked in
from below the fan motors 110, 120 and is blown out upward, as
shown by the arrow of FIG. 2. At this time, along with the flow of
air, cutting fluid mist also flows toward the fan motors 110,
120.
[0033] In the present embodiment, the stays 33 are arranged below
the blades 23, i.e., at the upstream side in the flow of cooling
air. For this reason, the cutting fluid mist which flows toward the
fan motors 110, 120 strikes the stays 33, and thus can be prevented
from entering between the rotor 20 (cylindrical part 22) and stator
10. This point will be explained while using FIG. 5 which shows the
configuration of a fan motor 130 of a comparative example of the
present embodiment and FIG. 6 which is a cross-sectional view cut
along the line VI-VI of FIG. 5. FIGS. 5 and 6 and FIGS. 2 and 3
differ in the arrangement of the stays 33. In FIGS. 5 and 6, the
same constituents as FIGS. 2 and 3 are assigned the same
referential marks.
[0034] In FIGS. 5 and 6, the stays 33 are arranged above the blades
23, i.e., at the downstream side of the cooling air. In this
configuration, the cutting fluid mist which flows into the fan
motor 130 strikes the bottom surfaces of the stays 33 whereby, as
shown by the arrow A of FIG. 6, the cutting fluid mist is liable to
enter between the rotor 20 and stator 10. If the cutting fluid mist
enters the inside of the motor and the cutting fluid mist sticks to
the inside of the motor, the rotation of the fan motor 130 will be
obstructed. As a result, the fan motor 130 will fall in durability
and it will become difficult to stably cool the electronic devices
103 over a long period of time. Further, in the configuration of
FIGS. 5 and 6, the cutting fluid mist which collects at the top
surfaces of the stays 33, as shown by the arrow B of FIG. 6, enters
the clearance between the cylindrical part 35 and the shaft 21,
whereby the bearings 36 are liable to decline in lifetime.
[0035] On this point, in the present embodiment, as shown in FIG.
3, the stays 33 are arranged at the upstream side in the cooling
air, so the cutting fluid mist which strikes the stays 33 can be
prevented from entering inside the motor and the fan motors 110,
120 can be rotated well in an environment pervaded by the cutting
fluid mist. As a result, the fan motor 130 rises in durability and
stable cooling performance of the apparatus 100 can be obtained.
Further, the stays 33 are arranged at the bottom of the fan motors
110, 120, so cutting fluid mist can be prevented from entering the
clearance between the cylindrical part 35 and the shaft 21 and a
drop in lifetime of the bearing 36 can be prevented.
[0036] FIG. 7 is a view which shows a modification of FIG. 3. In
FIG. 7, the stator 10 and the printed circuit board 34 are
surrounded by a nonconductive resin material 15. Due to this,
cutting fluid mist, etc. can be prevented from sticking at the
stator 10 or the printed circuit board 34. If covering the
surroundings of the stator 10 and the printed circuit board 34 by
the resin material 15, the clearance 16a between the permanent
magnets 25 and the stator 10 becomes smaller. For this reason, if
cutting fluid mist enters the clearance 16a, the cutting fluid mist
will easily stick there. Therefore, it is necessary to reliably
prevent entry of cutting fluid mist to the clearance 16a. On this
point, as illustrated, it is effective to arrange the stays 33 at
the upstream side of the cooling air.
[0037] FIG. 8 is a view which shows another modification of FIG. 3.
In FIG. 8, the top surface 311 of the disk part 31 and the top
surfaces 331 of the stays 33 are slanted downward toward the
outside in the radial direction, i.e., to the opposite side in the
blowing direction of the cooling air, whereby slanted parts 311a,
331a are formed. In FIG. 8, although a resin material 15 is
provided around the stator 10, the resin material 15 may also be
omitted. By providing the slanted parts 311a, 331a at the top
surfaces 311, 331 of the disk part 31 and stays 33 in this way,
when cutting fluid mist enters the clearance 16b between the rotor
20 (cylindrical part 22 and permanent magnets 25) and the disk part
31, the cutting fluid mist is ejected along the slanted parts 311a,
331a to the outside in the radial direction and the cutting fluid
mist can be prevented from sticking at the clearance 16b.
[0038] The stays 33 which are arranged at the upstream side from
the blades 23 in the blowing direction of the cooling air may be
configured in various ways other than that explained above. FIG. 9
is a perspective view of fan motors 110 and 120 which show one
example (view seen from slant below). In FIG. 9, illustration of
the housing 30 is partially omitted. As shown in FIG. 9, the bottom
surface 332 of the stay 33 is slanted in the up-down direction
(short direction) across the entire length in the diametrical
direction. The cross-sectional shapes of the stays 33 in the short
direction are triangular shapes. Due to this, the flow of air at
the bottom surfaces 332 of the stays 33 becomes smooth and the flow
rate characteristics of the fan motors 110 and 120 can be
improved.
[0039] In the above embodiment (FIG. 1A and FIG. 1B), although the
first fan motor 110 is arranged at the top part of the radiator
101, the configuration of the apparatus 100 is not limited to this.
FIGS. 10A and 10B are views which show a modification of FIGS. 1A
and 1B. In FIGS. 10A and 10B, the first fan motor 110 is arranged
facing the inlet 105 at the bottom of the radiator 101. According
to this configuration, the air which is sucked in by the first fan
motor 110 passes through the radiator 101 and is discharged from
the outlet 106. In each of the configurations of FIGS. 1A and 1B
and FIGS. 10A and 10B as well, the axial line L0 is directed toward
the vertical direction and the stays 33 are arranged below relative
to the blades 23, so the cutting fluid mist can be prevented from
entering the bearings 36 due to gravity.
[0040] FIGS. 11A and 11B are views which show another modification
of FIGS. 1A and 1B. In FIGS. 11A and 11B, at the side surface of
the radiator 101, an inlet 105 is provided, while at the top and
bottom surfaces, outlets 106 are provided. The first fan motor 110
is arranged facing the inlet 105 at the side portion of the
radiator 101. That is, the axial line L0 of the fan motor 110
extends in the horizontal direction. According to this
configuration, the air which is sucked in by the first fan motor
110 flows through the inside of the radiator 101 upward and
downward, and is discharged from the top and bottom outlets 106. As
shown in FIGS. 11A and 11B, when providing the fan motor 110 at the
side surface of the radiator 101, it is possible to keep dirt from
being sucked in from the floor surface or dirt from dropping down
from above to the fan motor 110. The fan motor 110 may also be
arranged with an axial line L0 other than in the vertical direction
and horizontal direction, i.e., in the slanted direction.
[0041] The above embodiment and modifications can be further
modified in various ways. For example, in FIG. 7, although the
circumferences of the stator 10 and the printed circuit board 34
are covered by a resin material 15, just one of either of these may
also be covered by the resin material 15. In FIG. 8, although both
the disk part 31 and the stays 33 of the housing 30 are provided
with slanted parts 311a, 331a which slant to the opposite side in
the blowing direction of the cooling air, just one of either of
these may also be provided with slanted parts. In FIG. 9, although
the surfaces 332 of the stays 33 at the upstream side in the
blowing direction of the cooling air are provided at a slant with
respect to the axial line L0 and the stays 33 are made triangular
shapes in cross-section, they may also be made trapezoidal shapes
in cross-section. Although the disk part 31 of the housing 30 is
provided with a holding part 31a for holding the printed circuit
board 34 (FIG. 3), this may also be omitted.
[0042] In the above embodiment, the first fan motor 110 and the
second fan motor 120 are configured the same. However, they may
also be configured different from each other. Either of the first
fan motor 110 and the second fan motor 120 (for example, the second
fan motor 120) may be omitted to configure the apparatus 100. In
the above embodiment, although passages AP through which cooling
air generated due to driving of the first fan motor 110 passes are
formed by the radiator 101, the configuration of the
passage-forming member is not limited to this. In the above
embodiment, although the electronic device which controls the drive
motor of the robot or machine tool is included in the electronic
devices 103 cooled by the cooling air which flows through the
radiator 101, the cooled member may be any member.
[0043] In the above embodiment, although the fan motors 110, 120
are used for the apparatus 100 which cools electronic devices 103
which are provided at a robot or machine tool, a fan motor and an
apparatus having a fan motor of the present invention may also be
similarly applied to other machinery. It is also possible to blow
something other than cooling air to the fan motor. The gas which is
below in parallel to the axial line L0 through the blades 23 is not
limited to cooling air.
[0044] The above embodiment can be freely combined with one or more
of the modifications.
[0045] According to the present invention, the stays of the fan
motor are arranged at the upstream side from the blades of the fan
motor in the blowing direction, so air-borne matter which strikes
the stays can be prevented from entering the inside of the motor
and sticking of air-borne matter at the inside of the motor can be
prevented.
[0046] While the present invention has been described with
reference to the preferred embodiments thereof, those skilled in
the art would understand that various modifications and changes may
be made thereto without departing from the scope of the appended
claims.
* * * * *