U.S. patent application number 12/225163 was filed with the patent office on 2009-04-23 for elevator drive.
Invention is credited to Olaf Breidenstein, Torsten Gessner, Gunther Herrmann, Markus Jetter, Nis-Anton Mollgaard, Uwe Resag, Jochen Schulze, Eberhard Vogler, Andreas Wilhelm.
Application Number | 20090101449 12/225163 |
Document ID | / |
Family ID | 38229380 |
Filed Date | 2009-04-23 |
United States Patent
Application |
20090101449 |
Kind Code |
A1 |
Breidenstein; Olaf ; et
al. |
April 23, 2009 |
Elevator Drive
Abstract
Disclosed are an elevator drive, a clamping arrangement for an
elevator machine, a braking mechanism for an elevator system, and a
rotor fixture for an elevator machine. The inventive elevator drive
is subdivided into a number of segments, to each of which a
converter is assigned.
Inventors: |
Breidenstein; Olaf;
(Neuhausen, DE) ; Schulze; Jochen; (Reutlingen,
DE) ; Vogler; Eberhard; (Neuhausen, DE) ;
Wilhelm; Andreas; (Waschenbeuren, DE) ; Gessner;
Torsten; (Ratingen, DE) ; Herrmann; Gunther;
(Lichtenwald, DE) ; Jetter; Markus; (Filderstadt,
DE) ; Mollgaard; Nis-Anton; (Schorndorf, DE) ;
Resag; Uwe; (Aichtal, DE) |
Correspondence
Address: |
SHLESINGER, ARKWRIGHT & GARVEY LLP
1420 KING STREET, SUITE 600
ALEXANDRIA
VA
22314
US
|
Family ID: |
38229380 |
Appl. No.: |
12/225163 |
Filed: |
March 14, 2007 |
PCT Filed: |
March 14, 2007 |
PCT NO: |
PCT/EP2007/002251 |
371 Date: |
September 16, 2008 |
Current U.S.
Class: |
187/277 ;
187/350; 310/156.12; 310/198; 310/71; 310/77; 310/89 |
Current CPC
Class: |
H02K 11/33 20160101;
H02K 5/225 20130101; B66B 11/0438 20130101; H02P 27/06 20130101;
B66B 1/308 20130101; H02K 3/28 20130101; H02K 2201/15 20130101;
H02P 25/22 20130101; B66B 5/16 20130101; H02K 16/04 20130101 |
Class at
Publication: |
187/277 ;
187/350; 310/198; 310/71; 310/89; 310/77; 310/156.12 |
International
Class: |
B66B 1/30 20060101
B66B001/30; B66B 1/44 20060101 B66B001/44; H02K 3/28 20060101
H02K003/28; H02K 3/52 20060101 H02K003/52; H02K 5/22 20060101
H02K005/22; H02K 7/102 20060101 H02K007/102; H02K 21/16 20060101
H02K021/16 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 16, 2006 |
EP |
06005374.1 |
Claims
1-46. (canceled)
47. An elevator drive having an electric motor which is subdivided
into a number of segments, with each segment having an associated
converter and each segment comprising an independent m-phase
system, with each coil of the stator winding being in a
concentrated form.
48. The elevator drive as claimed in claim 47, in which the
electric motor has a rotor and a stator, with the stator being
subdivided into a number of segments, and with each segment having
an associated converter.
49. The elevator drive as claimed in claim 47, which is in the form
of a direct drive.
50. The elevator drive as claimed in claim 48, in which the stator
is subdivided into segments in the circumferential direction.
51. The elevator drive as claimed in claim 47, in which the
electric motor is in the form of a synchronous motor with
permanent-magnet excitation.
52. The elevator drive as claimed in claim 47, in which each
winding in the stator is in the form of a single-tooth winding.
53. The elevator drive as claimed in claim 48, in which the
individual coils of the stator winding can be connected in parallel
or in series with a winding phase.
54. The elevator drive as claimed in claim 47, in which the
individual segments are galvanically and/or magnetically isolated
from one another.
55. The elevator drive as claimed in claim 48, in which the flux
produced by permanent magnets of the rotor is guided via pole
shoes.
56. The elevator drive as claimed in claim 48, in which the
arrangement of the permanent magnets in the rotor together with
pole shoes arranged between them form flux concentration for the
magnetic flux.
57. The elevator drive as claimed in claim 47, in which the
magnetic field of the individual segments spreads out only in the
area of the segment, and produces a torque in the individual
segment.
58. The elevator drive as claimed in claim 47, in which the
individual segments can be connected in parallel or in series with
one another as required, depending on the requirement, and can then
be operated using a converter.
59. An electric motor for an elevator drive as claimed in claim
47.
60. A segment for an electric motor, which segment represents at
least one winding of a stator winding, in which case a converter
may be associated with this segment.
61. An electric motor for an elevator drive, comprising a motor
housing and a number of motor windings which are connected to at
least one terminal, with ribs or webs between which the at least
one terminal is arranged being arranged on the motor housing.
62. The electric motor as claimed in claim 61, which is in the form
of a synchronous motor with a rotor and a stator, with the stator
windings being connected to the at least one terminal.
63. The electric motor as claimed in claim 61, in which the ribs
are arranged in the circumferential direction.
64. The electric motor as claimed in claim 61, in which the profile
of the ribs does not exceed a predetermined height above the
housing surface.
65. The electric motor as claimed in claim 62, in which a plurality
of terminals are arranged between at least two ribs.
66. The electric motor as claimed in claim 61, in which the
terminals are arranged adjacent one another between the ribs,
and/or one behind the other in the circumferential direction.
67. The electric motor as claimed in claim 61, in which connections
of the motor windings are likewise arranged between the ribs.
68. The electric motor as claimed in claim 61, in which motor
connecting cables lead downward away from the terminals out of the
motor area.
69. The electric motor as claimed in claim 68, in which the motor
connecting cables are passed out of the motor area alongside one
another.
70. The electric motor as claimed in claim 61, in which edges,
which point away from the motor housing, of at least two ribs which
are located adjacent one another are connected to one another by a
cover.
71. The electric motor as claimed in claim 61, in which the ribs
are used as supporting ribs in order to make the housing
robust.
72. A motor housing for an electric motor comprising ribs between
which at least one terminal is arranged.
73. A method for monitoring a brake which is operated by spring
force, wherein a force which is required to load or bias at least
one spring is taken into account.
74. The method as claimed in claim 73, in which the force which is
required for the at least one spring to reach a limit position is
taken into account.
75. The method as claimed in claim 74, in which the limit position
is checked by means of a device which is provided.
76. The method as claimed in claim 73, in which the at least one
spring is biased electromechanically, electrically, mechanically,
pneumatically or hydraulically.
77. The method as claimed in claim 73, which is used for a
hydraulically ventilated brake, with an oil-pressure/time profile
being detected and/or a check carried out in a limit position to
determine whether the applied force required to reach the limit
position corresponds to a predetermined value.
78. The method as claimed in claim 77, in which the hydraulic
pressure in the hydraulic oil system is checked indirectly or
directly via suitable devices.
79. The method as claimed in claim 73, which is carried out in an
elevator drive having an electric motor which is subdivided into a
number of segments, with each segment having an associated
converter and each segment comprising an independent m-phase
system, with each coil of the stator winding being in a
concentrated form.
80. A braking device for an elevator installation, which is
operated by spring force, in order to carry out a method for
monitoring a brake which is operated by said spring force, wherein
a force which is required to load or bias at least one spring is
taken into account, said braking device comprising and a device for
monitoring a force which is required to load or bias at least one
spring.
81. An elevator drive, comprising a braking device operated by
spring force, wherein a force which is required to load or bias at
least one spring is taken into account.
82. An electric motor for an elevator installation, having a stator
and a rotor which is mounted floating on a motor shaft with a rotor
hub and is attached by means of a clamping element.
83. The electric motor as claimed in claim 82, in which the
clamping element is formed by at least one shrinking disk.
84. The electric motor as claimed in claim 83, in which a shrinking
disk is arranged at each of the two axial ends on the rotor
hub.
85. The electric motor as claimed in claim 82, in which the rotor
is mounted on the shaft with the rotor hub, with the shaft being
cylindrical in the area of the rotor hub.
86. The electric motor as claimed in claim 82, in which the rotor
hub has an outer area which is conical.
87. An electric motor, comprising: a stator and a rotor which is
mounted floating on a motor shaft with a rotor hub and is attached
by means of a clamping element, a motor housing and a number of
motor windings which are connected to at least one terminal, with
ribs or webs between which the at least one terminal is arranged
being arranged on the motor housing, and stator windings being
connected to the at least one terminal in the form of a synchronous
motor.
88. An electric motor an for an elevator installation, comprising:
a stator and a rotor which is mounted floating on a motor shaft
with a rotor hub and is attached by means of a clamping element,
and said electric motor is subdivided into a number of segments,
with each segment having an associated converter and each segment
comprising an independent m-phase system, with each coil of the
stator winding being in a concentrated form.
89. An elevator drive, comprising: an electric motor having a
stator and a rotor which is mounted floating on a motor shaft with
a rotor hub and is attached by means of a clamping element, and a
braking device which is operated by spring force, wherein a force
which is required to load or bias at least one spring is taken into
account and wherein a device is provided for monitoring a force
which is required to load or bias at least one spring.
90. An electric motor, in particular as claimed in claim 82, in
which a traction sheave is attached by means of a clamping
element.
91. A rotor for an electric motor, wherein said rotor is mounted
floating on a motor shaft with a rotor hub and is attached by means
of a clamping element.
92. The method as claimed in claim 73, which is carried out using
an electric motor having a motor housing and a number of motor
windings which are connected to at least one terminal, with ribs or
webs between which the at least one terminal is arranged being
arranged on the motor housing.
Description
[0001] The invention relates to an elevator drive, to a terminal
arrangement for an elevator machine, to a braking device for an
elevator installation and to a rotor mounting for an elevator
machine.
[0002] In known elevator drives, these drives are operated with a
converter which is appropriate for their power or rating. This
means that one converter is used for one elevator drive,
respectively. For relatively high elevator ratings, provision is at
the moment made for a plurality of drives which are each operated
by one or more converters, to act on one motor shaft, or for a
plurality of drives to move the elevator independently of one
another, at the same time, and adjacent one another.
[0003] Indeed, it should be noted that converters with an
appropriate rating are required for both low and high ratings. In
this case, the cost ratio for converter ratings above a specific
rating (>100 kVA peak output rating) rises more than
proportionally, thus additionally increasing the costs for
elevators of more than a specific elevator rating.
[0004] However, the conventional procedure is also problematic in
terms of the availability of the elevator. Particularly in the
high-rating range, availability of the elevator should always be
ensured. In the event of faults or failures which are caused by a
defective converter, the elevator will come to rest. This is also
the case, for example, if the motor winding fails.
[0005] If a plurality of drives are acting on one shaft, this leads
to a major increase in the physical length of the drive unit and
therefore in the space required for the drive. It is therefore
necessary to provide additional space in the machine room in order
to satisfy this increased space requirement. For this purpose, the
drives must be specially synchronized and there is a risk of the
shaft being driven non-uniformly along its length.
[0006] This therefore results in the object of providing a drive
for an elevator, and an electric motor for a drive such as this,
which ensures fail-safe operation. A further aim is to reduce the
production costs, particularly for drives with a high drive rating,
in particular for a gearless elevator drive. Power losses during
operation should be low, thus resulting in high efficiency.
[0007] The elevator drive according to the invention has an
electric motor which is subdivided into a number of segments with
each segment having an associated converter. This elevator drive is
used, for example, for drives of more than 50 kW.
[0008] In one refinement, the elevator drive has an electric motor
with a rotor and a stator, with the stator being subdivided into a
number of segments, and with each segment having an associated
converter. In this case, the rotor normally acts on one shaft. The
motor principle is designed such that it is possible to operate an
elevator direct drive using a plurality of converters. The winding
structure of the stator winding is in this case designed such that
a failure of one coil does not necessarily lead to a failure of the
elevator installation.
[0009] In particular, the elevator drive according to the invention
is in the form of a direct drive, and therefore is gearless. In
contrast to funicular railway drives in which an epicyclical
transmission/gear is normally used, this gearless drive is possible
since the weight difference between the full elevator and the empty
elevator is less than in the case of funicular railways.
[0010] The stator is typically subdivided into segments or sectors
in the circumferential direction.
[0011] A synchronous motor with permanent-magnet excitation, for
example a brushless synchronous motor is suitable as an electric
motor for the drive. The rotor is therefore fitted with a number of
permanent magnets.
[0012] Each coil of the stator winding is preferably in a
concentrated form. Each winding in the stator may be in the form of
a single-tooth winding. The individual coils of the stator winding
can be connected in parallel or in series to form a winding
phase.
[0013] In one refinement of the invention, the individual segments
are galvanically isolated from one another. The flux produced by
the permanent magnets is typically guided via pole shoes.
[0014] The arrangement of the magnets in the rotor together with
pole shoes arranged between them preferably form flux concentration
for the magnetic flux.
[0015] The magnetic field of the individual segments preferably
spreads out only in the area of the segment, and produces a torque
in the individual segment.
[0016] The individual segments can be connected in parallel or in
series with one another as required, depending on the requirement,
and can then be operated using a converter.
[0017] The number of segments of the electric motor, in particular
of a synchronous motor with permanent-magnet excitation, can be
calculated using the following variables:
p=number of pole pairs u=coil sides per groove and layer m=number
of phases Q=number of slots
[0018] The elevator drive according to the invention is designed
such that it can be subdivided into individual segments, with each
segment having an associated converter. Segmentation is possible in
the case of a suitable choice of the ratio of magnet poles to
stator slots in conjunction with a preferably concentrated winding
which is also referred to as a single-tooth winding.
[0019] One segment typically comprises an independent m-phase
system which is operated by one converter. This means that the
total rating required by the elevator can be divided by the number
of segments. Each individual converter need provide only this
rating, reduced by the ratio of the total rating to the number of
segments. This allows the drive, as well as all the components
which are required in conjunction with the stator and the rotor, to
be produced at a lower cost.
[0020] Furthermore, smaller converters can be operated more easily
at higher switching frequencies, for example as far as possible
above 8 kHz, so that the drive is quieter. The larger the
converters, the greater the extent to which higher switching
frequencies cause problems. Lower frequencies lead to louder
motors. A further advantage of the segmented design of the motor of
the elevator drive which is arranged adjacent to or in the elevator
shaft in buildings and in the vicinity of rooms in which people
live, is therefore the reduced noise developed.
[0021] The invention likewise relates to an electric motor and a
drive machine for an elevator drive as described above.
[0022] The invention also relates to a segment for an electric
motor, which segment represents at least one winding of a stator
winding, in which case a converter may be associated with this
segment. This segment can therefore be used in an electric motor
according to the invention of an elevator drive according to the
invention.
[0023] Furthermore, a stator is described having a stator winding
which comprises a number of windings, with the stator winding being
subdivided into segments and with each segment comprising at least
one winding, and in which case a converter can be associated with
each segment. This stator can therefore be used as a stator of an
electric motor as described above, for the elevator drive, as
explained above.
[0024] The invention also relates to a terminal arrangement for an
electric motor of an elevator drive, in particular of an elevator
drive of the type described above, and to an electric motor having
a terminal arrangement such as this. The terminal arrangement
explained in the following text can therefore be used for an
electric motor as described above, but is not restricted to an
application such as this.
[0025] According to the present-day prior art, gearless elevator
drives are in the form of synchronous motors with permanent-magnet
excitation. In this case, each individual motor winding must be
formed from the stator and must be connected to terminals in order
then to be passed from there as a motor connecting cable to
individual frequency converters. A plurality of terminals and
terminal boxes are therefore required on the motor. This is
problematic particularly in the case of large motors, in which the
cables, terminals and frequency converters to be used are difficult
to handle because of the increasing size.
[0026] It should be noted that each individual terminal box can be
closed so as to be touch-proof, in which case the motor windings
which are passed out individually must be passed through the motor
into the terminal boxes. The confusion between the connections
increases with the number of windings passed out and with the
number of motor connecting cables. Furthermore, in some cases,
there is only limited accessibility to the terminal boxes, because
of the large number of terminal boxes. Furthermore, the laying of
motor connecting cables to the motor is complex and the physical
space required for the motor is increased by the large number of
terminal boxes.
[0027] This results in the problem of designing an electric motor
and a motor housing such that a plurality of motor windings can be
passed out at terminals and only a small number of terminal boxes
are required in this case, such that only a smaller amount of
additional physical space is required because of the multiplicity
of terminals, and clarity is provided for the motor connecting
cables. Furthermore, the access to the motor should not be
restricted by motor connecting cables. In consequence, the aim is
to propose an electric motor, in particular a gearless motor, which
can be produced and installed at low cost and in which the cabling
and wiring can be implemented in a simple manner.
[0028] The proposed electric motor is intended for an elevator
drive, in particular for an elevator drive of the type described
above, as claimed in one of claims 1 to 13. This has a motor
housing and a number of motor windings which are connected to at
least one terminal, with ribs or webs between which the at least
one terminal, normally a plurality of terminals, is or are arranged
being arranged on the motor housing.
[0029] The described electric motor is used in particular for
driving elevators whose cab or car is connected via supporting
means to a counterweight, for example as in the case of cable
elevators (traction drive elevators).
[0030] The motor housing of the electric motor which in particular
has a plurality of motor windings, is designed such that a type of
cable duct is formed between two ribs of the motor housing. This
area is preferably formed on both sides of the motor such that the
terminals and the motor windings that are passed out can be laid
and secured therein, that is to say between the two ribs or webs.
The required protection against touching the connecting terminals
can therefore also be achieved by a small number of simple
sheet-metal covers. By way of example, the motor connecting cable
is passed out downward and can be passed from there directly into a
cable duct without having to restrict the accessibility to the
motor. The accessibility to the possibly large number of terminals
can be achieved just by removing a small number of covers.
[0031] The proposed electric motor is preferably in the form of a
synchronous motor with a rotor and a stator, with the stator
windings being connected to the at least one terminal.
[0032] It is possible to arrange the ribs in the circumferential
direction. Furthermore the profile of the ribs should not exceed a
predetermined height above the housing surface.
[0033] It is possible to arrange the ribs in circumferential
direction. Further, the ribs should not exceed a predetermined
height above the housing surface over their course or profile.
[0034] It is possible to provide for a plurality of terminals to be
arranged between at least two ribs. Furthermore, the terminals can
be arranged adjacent one another between the ribs, and/or one
behind the other in the circumferential direction.
[0035] In one refinement, the connections of the motor windings are
likewise arranged between the ribs.
[0036] In the case of the described electric motor, it is possible
to provide for motor connecting cables to lead downward away from
the terminals out of the motor area. In this case, the motor
connecting cables are preferably passed out of the motor area
alongside one another.
[0037] Furthermore, the edges of at least two adjacent ribs and
which are pointing away from the motor housing are connected to one
another by a cover.
[0038] It is possible that the ribs are used as supporting ribs in
order to make the housing robust, and to have suitable dimensions
and to be arranged in a suitable manner for this purpose.
[0039] The motor housing according to the invention has ribs
between which at least one terminal is arranged. In particular,
this motor housing is suitable for electric motors of the type
described above.
[0040] The invention provides that a motor for an elevator drive is
subdivided into a plurality of segments, with at least one motor
winding in each case being provided for each phase. The segments
are connected by cables to terminals, and the motor housing
typically has ribs in the circumferential direction on its outside,
with at least two ribs forming a space between them in which the
terminals, the cables of the motor windings and the motor
connecting cables can be accommodated.
[0041] The ribs should be designed such that they are not lower
than a defined rib height along a predetermined rib length, and a
type of cable duct is formed in the intermediate space between two
ribs of the motor housing. This area is optimized, in particular on
both sides of the machine, such that the terminals and the motor
windings that are passed out, and their connections can be laid and
mounted between the ribs.
[0042] A closed installation area for the cables and terminals can
be formed, and the required touching protection for the connecting
terminals can be achieved by a small number of simple sheet-metal
covers which can be attached to the ribs.
[0043] The motor connecting cables which are required to supply
power to the motor are passed out, for example in the lower motor
area, and can be passed directly from there into a cable duct,
without a confusion of cables restricting the accessibility to the
machine. Cables can be fed in from one side, and can be fed out on
the other side.
[0044] This makes it possible to close each individual terminal box
such that it is touch-proof. It should be noted that the individual
motor windings which are passed out of the motor and the stator
must be passed through the motor into the terminal boxes. The
clarity is not restricted by the proposed arrangement of the
connections and the windings that are passed out, as well as the
number of motor connecting cables. The accessibility to the
terminal boxes is excellent, even when there are a multiplicity of
terminal boxes.
[0045] The laying of motor connecting cables to the motor has been
found to be a simple activity. Furthermore, the physical space
required for the motor is not increased by the terminal boxes.
[0046] In the case of elevators, particular importance is attached
to monitoring of the brakes. Spring fracture monitoring for safety
brakes operated by spring force is described in the following text.
This principle can be used for an elevator drive and an electric
motor for elevator drives of the type described above.
[0047] The principle of brakes operated by spring force as a safety
component is known from the prior art. In this case, a spring which
is biased electromechanically, hydraulically or in some similar
manner is used in the event of braking in order to cause the spring
force to act as a braking force via brake linings or other devices
on brake disks, brake drums or similar devices. Since the energy to
bias the spring often has to be kept available all the time, this
inevitably leads to operation of the brake in the event of a power
failure, and this is known by the expression "fail safe".
[0048] These brakes operated by spring force have a wide field of
use. They are used wherever drives must be braked or held. Brakes
operated by spring force such as these are used, for example, for
elevator drives, funicular railway drives, funfair ride concerns,
and wind power installations, etc. In these fields of application,
brakes operated by spring force carry out safety tasks. By way of
example, the installation must be brought to rest quickly during
operation or, in the event of an emergency, the complete
installation must be braked and brought to rest in order to avoid
danger to people or the installation.
[0049] The described brake principle has disadvantages, however,
when subject to certain preconditions. The springs which are used
as spiral springs or cup-type springs and are used individually or
in a pack can fracture or become soft, and the force they produce
can thus decrease. The condition of the brake and of the braking
springs must therefore be regularly checked. If the springs, which
are kept biased, or else the spring packs are covered by housings
or other machine parts, or cannot be seen from the outside, the
condition of the springs cannot be identified visually. Frequent
operation of the brake, for example as a brake blocking function
during operation, occurs when the installation is in operation
briefly and must then be fixed again in a different state.
[0050] Particularly in elevator operation a blocking brake such as
this is in action during each individual movement. In every
stopping position at which the elevator stops, the elevator cab is
held by a brake such as this via its drive. In this case, when
stopping during operation of the stopping points, the elevator car
is in many elevator installations not held directly by the brake
but indirectly by the brakes acting on the cables, on the traction
sheave or on the drive. The brake is released again at the start of
movement, as a result of which a very high number of switching
operations in terms of brake closing and opening can be reached
over the life of the brake, as a result of which the springs or the
spring packs can fail as a result of repeated stress failure,
material fatigue or the like over the course of time. If the
springs are now also installed in a housing or the like, it is
extremely difficult to identify a failure such as this of an
individual spring in this spring pack. However, this is
unacceptable from the safety point of view since failure of one
spring or of a plurality of springs in a pack leads to loss of
braking power or even to complete failure of the braking power.
[0051] In the case of brakes which are operated by spring force and
are hydraulically ventilated, the spring installation is very
frequently concealed or hidden, since the spring pack composed of
cup-type springs is installed in brake calipers or in a
corresponding apparatus, and the hydraulic areas must be designed
to be liquid-tight. In order to allow the failure of an individual
spring in a pack to be identified, the complete brake caliper must
be dismantled, and this leads to relatively long interruptions in
operation.
[0052] This results in the object of ensuring safe and rapid
detection of spring fracture or other spring failure in braking
springs, particularly in the case of safety-brake springs which are
installed in housings or are concealed, that is to say which cannot
be monitored visually.
[0053] The method according to the invention is used for monitoring
a brake which is operated by spring force, taking into account a
force which is required to load or bias at least one spring and the
amount of force required for this purpose.
[0054] It is possible to take account of the force which is
required for the at least one spring to reach a limit position.
This limit position can be checked by means of a device limit which
is provided.
[0055] The at least one spring can be loaded or biased
electromechanically, electrically, mechanically, pneumatically or
hydraulically. By way of example, spiral springs or cup-type
springs may be used as the springs. The springs may be individual
springs, or springs combined in packs.
[0056] In the case of a hydraulically ventilated brake, for
example, an oil-pressure/time profile is detected. The hydraulic
pressure in the hydraulic oil system is in this case preferably
checked indirectly or directly via suitable devices.
[0057] The described method is used, for example, in an elevator
drive as claimed in any one of claims 1 to 13, or using an electric
motor as claimed in any one of claims 16 to 26.
[0058] The described method is therefore based on identification of
failure of one or more springs without visual inspection during
operation. To this end, the brake is typically monitored via
appropriate switches and sensors, and the monitoring is
appropriately evaluated via a control system. Any defect which
occurs can thus be identified in good time, and a warning or a
message can be produced. Those springs which are no longer
serviceable can be replaced before a malfunction occurs.
[0059] It is assumed that springs which have failed partially or
individually as a result of failure require a different amount of
force, normally less force, to bias them. In the case of a
hydraulically ventilated brake, this reduced opening force can be
detected, for example, via the oil-pressure/time profile. In this
case, the current oil pressure is preferably measured, using an oil
pressure gauge, in the immediate vicinity of the supply line to the
brake caliper. In addition, when the biased spring is in the limit
position, this limit position is identified via contacts or
suitable devices. This then results in a logical link between these
two events for identification of a failure or partial failure of a
spring.
[0060] When the limit position of the spring is detected in a
normal situation, the signal of the maximum hydraulic pressure that
is reached is always indicated first, and then the limit position
signal of the spring. However, when a spring fracture occurs, a
reduced oil pressure is in its own right sufficient to move the
spring to the limit position and to open the brake, thus resulting
in the limit position signal being produced at a time before the
maximum oil pressure signal. This monitoring can be adjusted, for
example, by appropriate choice of the setting value of a pressure
sensor. The set pressure value to be monitored must be less than
the oil pressure which is at least normally required to open the
hydraulic brake during operation. These signals can now be
evaluated by an analogue or digital control system, which then
produces the result "OK" or "spring fracture".
[0061] The brake can be monitored continuously by regular tests at
short or relatively long intervals. Alternatively, the evaluation
can be carried out on each operation of the brake.
[0062] In addition to the hydraulic loading of the spring and the
monitoring of the oil pressure, and possibly of the time required
to reach the pressure, it is also possible to use and monitor some
other biased force. For example, the spring can be biased
pneumatically, or else electrically by means of solenoid coils. In
this case, the electrical values which occur are compared with
corresponding predetermined values. "OK" or "alarm" can then be
indicated during further calculation and comparison with the limit
position monitoring.
[0063] The braking device according to the invention is used in an
elevator installation and is operated by spring force. The braking
device is used in particular to carry out a method as claimed in
any one of claims 28 to 34. This braking device is provided with a
device for monitoring a force which is required to load or bias at
least one spring.
[0064] The braking device is operated by spring force, with a
friction lining being pressed against a braking surface, for
example by means of at least one spring, and with a braking force
being produced in the process. This braking force decelerates the
braking surface which is moved translationarily or rotationally
with respect to the brake lining.
[0065] If the spring limit position is monitored, it is possible to
compare the determined values with predetermined values. If
predetermined limit values are overshot or undershot, "alarm" is
produced.
[0066] The monitoring of the limit position of the biased spring
and the monitoring of the biasing of the spring typically results
in values which can be processed and compared with one another and
with a time sequence of their occurrence.
[0067] In one refinement of the method and of the braking device,
the checking of the limit position of the biased spring and the
biasing pressure, for example of the hydraulic biasing pressure, is
linked to logic or a corresponding device, and is compared with
predetermined values. A spring fracture is identified in the event
of any discrepancy from predetermined values.
[0068] In principle a force to be applied and/or a time to be used
can be used for monitoring the biasing of the spring. The limit
position of the biased spring can be checked either directly at the
spring elements or indirectly via elements which are connected
indirectly or directly thereto. In this case the limit position can
be determined by means of any type of device or devices. By way of
example, the hydraulic pressure in a hydraulic oil system can be
checked indirectly or directly by means of any suitable
devices.
[0069] If the described braking device, for example a drum brake,
is used in a floating housing, it is necessary to produce an
opposing force during braking.
[0070] The proposed elevator drive has a braking device, as
explained above, as claimed in claim 35, in particular in order to
carry out a method as claimed in any one of claims 28 to 34.
[0071] An electric motor is also proposed for an elevator
installation, a rotor for the electric motor and a rotor mounting.
The features explained in the following text can also be combined
in any desired manner with the embodiments described above.
[0072] Nowadays, it is normal for elevator direct drives (gearless
drives) to be in the form of synchronous machines with
permanent-magnet excitation. In machines such as these, the rotor
is fitted with permanent magnets on its surface facing the stator.
This means that the surface of the rotor is permanently
magnetic.
[0073] The rotor is normally fitted to the motor shaft by an
interference fit, that is to say it is pushed onto the shaft with a
large amount of force being applied in the axial direction, with
the hub being widened, and with the necessary connecting force
being produced in this way. The rotor is then introduced, together
with the motor shaft, into the motor housing with the stator.
During assembly, that is say during insertion of the rotor into the
stator, this results in considerable complexity for the apparatus,
since the rotor must not touch the stator, and only a very small
air gap is provided between the rotor and the stator. This is
particularly evident when the motor has large dimensions.
[0074] In the case of large elevator drives, the motor shaft is
normally aligned horizontally during operation since the traction
sheave, which is mounted on the motor shaft in addition to the
rotor, is then arranged such that the cables run over the traction
sheave, coming from underneath, and are passed downward again. The
loads which are transmitted to the traction sheave by the cables
can then be transmitted essentially vertically to the motor shaft,
and then further on, for example, to two shaft bearings.
[0075] The conventional procedure has a number of inherent
disadvantages. For example, in order to fit the rotor, the motor
housing must be tilted such that the motor shaft points vertically
upward in order that the natural weight of the rotor has a
stabilizing effect on the apparatus. In this case, a mandrel must
be attached to the motor shaft, as part of the apparatus.
[0076] Furthermore, the dependency on the manufacturing tolerance
of the components used can be seen in the exact position of the
rotor with respect to the stator core. The exact position of the
rotor with respect to the stator core is important for the
electrical rating of the drive. Furthermore, because of the
interference fit, the rotor can be replaced only with the motor
shaft.
[0077] Particularly in the case of large rotors, the magnet area
results in a magnetic force, that is to say of considerably more
than 1000 kg, acting transversely with respect to the axis, which,
in the case of fitting or removal when there are small distance
differences to surfaces, for example stator surfaces, located in
the vicinity, attempts to place the magnetic area against the
opposing area located closer, with the magnets and the laminated
core of the stator easily being damaged, and making further rotor
positioning more difficult.
[0078] This therefore results in the object of proposing a motor in
which a rotor, in particular a rotor with permanent magnets, can
easily be installed in a motor housing with a stator. For this
purpose, it is helpful if the rotor can be installed in the
horizontal position. During the installation process, it is
expedient for it to be possible to move the rotor on the shaft and
thus to position it exactly on the shaft. Furthermore, it should be
simple to remove the rotor, and for it not to come into contact
with the stator during fitting and during removal.
[0079] The described electric motor is used for an elevator
installation and has a stator and a rotor which is mounted floating
on a rotor shaft with a rotor hub and is attached by means of a
clamping element.
[0080] In consequence the electric motor or the elevator drive is
designed such that the rotor is mounted in a floating manner on the
shaft. The connection between the rotor hub and the motor shaft is
made via the clamping element, which is preferably an integral or
multi-part, or split, shrinking disk. This results in the
capability to move the rotor on the shaft during fitting, in order
to allow exact positioning. Once the clamping element has been
released, the rotor can be removed again. The clamping element can,
for example, be clamped and released from the side of the rotor
facing away from the motor bearing. By way of example, it can be
clamped and released by means of screws distributed around the
shaft.
[0081] If the clamping element comprises a two-part shrinking disk,
the two parts may have conical areas which face one another, with
the inner surface, facing the shaft, being cylindrical. In this
case, the rotor is provided in the area of the shaft with a hub
which has a cylindrical surface area on the side remote from the
shaft.
[0082] The natural weight of the rotor is supported by the shaft.
The rotor can thus be pushed into the motor by means of a simple
apparatus which is attached to the motor shaft via threaded rods
and a pressure plate. The exact guidance by means of the shaft
prevents the rotor from touching the stator.
[0083] The described electric motor is particularly suitable for
elevators whose cab is connected via supporting means to a
counterweight, for example as in the case of traction drive
elevators.
[0084] As explained, the clamping element is preferably formed by
at least one shrinking disk. It is possible to provide for one
shrinking disk to be arranged at each of the two axial ends on the
rotor hub.
[0085] The rotor is typically mounted on the shaft with a rotor
hub, with the shaft being cylindrical in the area of the rotor hub.
The rotor hub may have an outer area which is conical.
[0086] The proposed electric motor can be used in conjunction with
an elevator drive as described above. In addition, the electric
motor may have the features as explained above of the electric
motor as claimed in any one of claims 16 to 26, and a braking
device as claimed in claim 35.
[0087] The rotor according to the invention is used in such an
electric motor.
[0088] The described elevator drive is designed such that the rotor
is mounted in a floating manner on the shaft. The shaft is
cylindrical in the area of the rotor hub. When the rotor is being
fitted, the shaft has already been finally fitted in its two
bearings, and has therefore been stabilized in the radial
direction.
[0089] The rotor is mounted on the shaft with the rotor hub, whose
surface facing the shaft is likewise cylindrical. To this end, the
hub may have an outer area which is in the form of a cone or is
conical. Alternatively, a ring is arranged on a hub which is
likewise cylindrical on the outside, with the external contour of
the ring being conical. The connection between the rotor hub and
the motor shaft is made via the clamping element, which is likewise
conical on its side facing the shaft and either is directly on the
hub surface or, together with the first ring, forms a so-called
shrinking disk.
[0090] By way of example, the shrinking disk is arranged on that
surface of the hub which is remote from the shaft and, during
tightening, the outer cone, which is formed on a clamping element,
is drawn in the axial direction over the inner conical ring, which
is arranged on the hub, and thus compresses the hub. The stress can
in this case be applied with the aid of screws which are arranged
all around the shaft.
[0091] A shrinking disk can be arranged at each of the two axial
ends on the hub, and these disks are drawn toward one another by
the screws. Alternatively, only one shrinking disk is provided, and
is drawn against the hub disk with the aid of the screws.
[0092] Until the screws have been correctly tightened, the rotor
can be moved on the shaft and can thus be moved to the desired
exact position. Once the clamping element has been released, the
rotor can be removed again.
[0093] It should be noted that, during the insertion of the rotor
into the stator and the exact axial position with respect to the
stator, the natural weight of the rotor is already supported by the
shaft, which is arranged in its bearings. The precise guidance of
the shaft prevents the rotor from touching the stator. Particularly
in the case of large rotors with a natural weight of several
hundred kilograms, it is advantageous to push the rotor into the
motor, or to safely pull it out of the motor again during removal,
with the aid of a simple apparatus with a pressure plate which is
attached to the end face of the motor shaft via threaded rods.
[0094] Further advantages and refinements of the invention will
become evident form the description and the attached drawing.
[0095] It is self-evident that the features mentioned above and
those which are still to be explained in the following text can be
used not only in the respectively stated combination but also in
other combinations or on their own without departing from the scope
of the present invention.
[0096] The invention will be described in detail in the following
text with reference to the drawing, which schematically illustrates
exemplary embodiments.
[0097] FIG. 1 shows a detail of one embodiment of the stator
according to the invention.
[0098] FIG. 2 shows in schematic manner the subdivision of a stator
into a plurality of segments.
[0099] FIG. 3 shows one embodiment of the electric motor according
to the invention, illustrated in a simplified form in order to show
a terminal arrangement.
[0100] FIG. 4 shows a simplified illustration of an electric motor,
in the form of a plan view.
[0101] FIG. 5 shows a schematic illustration of a brake with
hydraulic brake ventilation.
[0102] FIG. 6 shows a rotor mounting according to the
invention.
[0103] FIG. 1 shows a detail of a stator which is annotated overall
with the reference number 10. The illustrated detail shows, within
a frame, a first segment 12 and a second segment 14. In this case,
a first converter 16 is associated with the first segment 12, and a
second converter 18 is associated with the second segment 14.
[0104] In the first segment 12, pole shoes 20, magnets 24, stator
teeth 26 and coils 28 can be seen. These coils are, for example,
formed with a concentrated winding as a so-called single-tooth
winding. The illustration also shows a stator slot 30.
[0105] The first segment 12 is connected via six cables to the
first converter 16, with cable 32 carrying phase one, cable 34
carrying phase 2, and cable 36 carrying phase 3. The first
converter 16 is connected via a first connection 38 to the elevator
control system, and the second converter 18 is connected in the
same way via a second connection 40 to the elevator control
system.
[0106] The second segment 14 is a very small motor segment with
three phases, and in each case one coil for one phase. However, it
is possible to implement different splits of the windings into
segments and different interconnection options for the segments to
one another. For example, one phase may comprise a plurality of
stator teeth or else a plurality of very small segments may be
associated with one converter.
[0107] FIG. 2 illustrates the principle of the splitting according
to the invention of a stator winding into segments, and the
association of segments with converters. This shows a schematically
illustrated stator 50, which is subdivided into eight segments 52.
Each of these segments 52 is associated with one converter 54, with
only three converters 54 being shown in the illustration, for
clarity reasons.
[0108] FIG. 3 shows a simplified illustration of an electric motor
60. The illustration shows a machine frame 62, a stator housing 64,
a rotor cover 66 and a traction sheave 68 with a brake disk 70.
[0109] Furthermore, two ribs 72 are illustrated, in which
attachment points 74 for a cover are located.
[0110] Furthermore, FIG. 3 shows four terminals 76 which are
arranged between the two ribs 72 and are preferably each provided
for one segment. Motor connecting cables 78 connect the terminal 76
to the converters.
[0111] Aperture holes 80 are provided in the stator housing 64 for
the cabling of the coils. The cables of the coils are passed
through these aperture holes 80.
[0112] FIG. 4 shows a simplified illustration of an electric motor
for an elevator drive, which is annotated overall with the
reference number 90. The electric motor 90 comprises a rotor 92 and
a stator 94, a motor housing 96 and a machine frame 98. The rotor
92 is mounted, in the form of an internal rotor, in the stator 94
such that it can rotate.
[0113] Ribs or supporting ribs 100 are arranged on the motor
housing 96, with terminals 102 being provided between the ribs 100.
A terminal area cover 104 having attachment points 106 is located
above this. Motor connecting cables 108 are the cables for
connecting the terminals 102 to the converters.
[0114] FIG. 5 shows, schematically, a brake 120 with hydraulic
brake ventilation, with the brake 120 being illustrated in the
braking state during operation in the upper half and in the
ventilated state in the lower half.
[0115] The illustration shows a brake disk 122, a brake lining 124,
a pressure plate 126, a spring 128, an oil line 130 for feeding in
and feeding out, an inlet flow 132 for a pressure medium 134, for
example a hydraulic oil, a piston 136 with a piston surface 138, an
oil-pressure monitor 140, a housing 142 and a pushrod 144.
[0116] In the upper half of the illustration, the brake lining 124
is resting on the brake disk 122. The spring 128 is in the released
state. No braking is taking place in the lower half, and the spring
128 is in the biased state.
[0117] In order to monitor the brake 120, a device 146 is provided
in order to monitor the time profile of the oil pressure. This
device 146 can likewise read and evaluate the signal of a limit
position switch 148. In the upper half, the switch is open 152, and
in the lower half it is closed 152. A check is now carried out in
this position to determine whether the amount of force required to
reach the limit position corresponds to a predetermined value.
[0118] FIG. 6 shows a simplified illustration of a rotor mounting
according to the invention. The illustration shows a rotor 160
mounted in a floating manner, a stator 162, a motor housing 164, a
drive-end bearing 166, a traction sheave with a brake disk 168, a
non-drive-end bearing 170 and a shaft 172 on which the rotor 160 is
mounted. While being fitted, the rotor 160 is pushed onto the shaft
172 in the horizontal direction, and can then be positioned
exactly, held by the shaft 172.
[0119] The rotor hub 174 of the rotor 160 surrounds the shaft 172,
wherein the rotor can be braced by means of a clamping element 176
with clamping screws 178 and can therefore be firmly mounted on the
shaft 172. Once the clamping element 176 has been released, the
rotor 160 can be moved along the shaft 172 and can thus be
positioned or removed, with the dead weight of the rotor 160 being
held by the shaft 172.
[0120] The traction sheave 168 can likewise be mounted on the shaft
by means of clamping elements 190 and 192. This makes it possible
to easily fit and remove the traction sheave 168, in the same way
as the rotor 160. The present application therefore describes an
electric motor in which the rotor 160 and the traction sheave 168
can be attached by means of clamping elements, which may be in the
form of an integral, two-part or split shrinking disk.
[0121] An electric motor is also disclosed in which only the
traction sheave can be attached by means of a clamping element, for
example by means of at least one shrinking disk.
* * * * *