JP2004052902A - Electromagnetic brake - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electromagnetic brake capable of checking the degree of abrasion of a brake plate and a brake disc without disassembling it. <P>SOLUTION: The electromagnetic brake which is interposed between a fixing housing and a rotating member, includes a multiple disc brake mechanism, a ring-like core member fixed in the housing, an annular excitation coil stored in an annular groove of the core member, and a ring-like armature member which has a larger diameter than the diameter of the core member, and is arranged opposing to the annular groove of the core member. The electromagnetic brake additionally includes a cylindrical pressing member and a check hole. The cylindrical pressing member is fixed to the outer periphery of the armature at one end and engaged with a multiple disc brake mechanism at another end. The cylindrical pressing member is externally fitted to the core member so as to be able to move in the pressing direction of the multiple disc brake mechanism. The check hole is provided on the housing at the opposite side of the core member to the armature member, and can measure the amount of gap between the armature and the core member. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an electromagnetic brake and a driving force distribution device for a vehicle using the electromagnetic brake.
[0002]
[Prior art]
The differential is located in the vehicle's power train so that the outer wheels rotate faster than the inner wheels when turning, while maintaining equal torque distribution for the left and right wheels, ensuring smooth turning. Is to be obtained.
[0003]
The main function of the differential is to make it possible to turn a curve smoothly. For example, what happens when one wheel slips on a muddy road on a rough road?
[0004]
The drag on the muddy wheel is small, and most of the rotational force is transmitted to the slipping wheel, and no driving force is transmitted to the other wheel. As a result, the driving force is insufficient as a whole, and it is impossible to escape from the mud. This is a drawback of common differentials.
[0005]
This disadvantage is prevented by a differential device having a differential limiting mechanism, which has a function of compensating for the above-mentioned basic disadvantage of the differential device. This differential is referred to as a limited slip differential (LSD).
[0006]
Conventional differentials are generally planetary gear type differentials. A planetary gear type differential gear assembly provided with a differential limiting mechanism comprising an electromagnetic clutch and a multi-plate clutch is disclosed in Japanese Patent Application Laid-Open No. Hei 6-33997. ing.
[0007]
This differential gear assembly applies a suction force between a solenoid and an armature of an electromagnetic clutch to a multi-plate clutch to press it, thereby selectively controlling the engagement force of the multi-plate clutch.
[0008]
A connecting member including a plurality of legs is disposed between the pressure plate and the armature of the multi-plate clutch. One end of these legs is fixed to the pressure plate of the multi-plate clutch, and the other end contacts the inner peripheral portion of the armature when the solenoid is operated.
[0009]
In the differential gear assembly described above, the plurality of legs are fixed to the pressure plate and extend in a direction substantially perpendicular to the pressure plate. Therefore, when some of these legs are attached to the pressure plate while being inclined, there is a problem that the pressing force of the armature sucked by the solenoid may not be uniformly transmitted to the pressure plate of the multi-plate clutch. .
[0010]
Further, in the differential gear assembly described in the above publication, the engaging force of the multi-plate clutch is controlled by the electromagnetic clutch, so that the plurality of legs as the pressing members are arranged so as to correspond to the inner peripheral portion of the armature. Have been.
[0011]
However, in the multi-plate brake structure, the brake plate and the brake disk are generally arranged on the outer peripheral side in view of the device configuration. Therefore, it is difficult to apply the structure disclosed in the above-mentioned publication that operatively connects the armature and the multiple disc clutch on the inner peripheral side to the multiple disc brake structure as it is.
[0012]
Further, in a conventional electromagnetic brake using an excitation coil, a control is performed such that a small current is supplied to the excitation coil to make the clearance between the brake plate and the brake disk always close to 0 in order to improve responsiveness.
[0013]
Furthermore, although it is used in a form having a predetermined air gap between the armature and the core, a constant value of current is applied to the exciting coil even when adjusting the clearance of the multi-plate brake mechanism, while the gap between the brake plate and the brake disc is maintained. You need to adjust the clearance.
[0014]
[Problems to be solved by the invention]
However, energizing the excitation coil at all times to improve responsiveness is not preferable because of problems such as an increase in power consumption and heat generation of the excitation coil. Further, since the excitation coil needs to be energized when assembling the electromagnetic brake (when adjusting the clearance between the brake plate and the brake disk), the cost of the assembling apparatus is increased, and the cost and time are also required for current management.
[0015]
In the past, the measurement of the air gap between the armature and the core was performed at the time of assembling the electromagnetic brake, but after assembly, the air gap could not be measured without disassembly, so the brake wear could not be easily checked. was there.
[0016]
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an electromagnetic brake capable of measuring an air gap between a core and an armature without disassembling the brake, and checking a degree of wear of a brake plate and a brake disk.
[0017]
Another object of the present invention is to provide an electromagnetic brake that can keep the clearance between the brake plate and the brake disc close to zero at all times without requiring the excitation coil to be energized.
[0018]
[Means for Solving the Problems]
According to the first aspect of the present invention, there is provided an electromagnetic brake interposed between a fixed housing and a rotating member at least partially housed in the fixed housing.
[0019]
The electromagnetic brake includes a multi-plate brake mechanism having a plurality of brake plates mounted on a fixed housing, and a plurality of brake disks mounted on a rotating member so as to be alternately arranged with the brake plates; A ring-shaped core member fixed in the housing, an annular exciting coil housed in an annular groove of the core member, and a second outer diameter larger than the first outer diameter. And a ring-shaped armature member disposed to face the annular groove of the core member.
[0020]
The electromagnetic brake further has a first end and a second end, the first end being fixed to the outer peripheral portion of the armature member, the second end being engaged with the multi-plate brake mechanism, and in a pressing direction of the multi-plate brake mechanism. A cylindrical pressing member externally fitted to the core member so as to be movable, and a gap amount between the armature member and the core member provided on the housing opposite to the core member with respect to the armature member can be measured. Includes check holes.
[0021]
In an electromagnetic brake having a multi-plate brake mechanism, when the gap (air gap) between the ring-shaped core member and the ring-shaped armature member changes, the suction force of the ring-shaped core member and, consequently, the cylindrical pressing member against the multi-plate brake mechanism. Since the pressing force changes, high precision is required for air gap management.
[0022]
This air gap changes due to manufacturing variations and aging (wear) of a plurality of brake plates and brake disks of the multi-plate brake mechanism.
[0023]
According to the first aspect of the present invention, since the housing is provided with the check hole for measuring the gap amount between the armature member and the core member, the gap amount can be reduced without disassembling the electromagnetic brake during inspection or the like. It can be measured and thus the degree of wear of the brake plate and brake disc can be checked externally without disassembly.
[0024]
According to the second aspect of the present invention, since the elastic means for urging the armature member in the pressing direction of the pressing member is provided between the housing and the armature member, the energizing coil does not need to be energized at all times. The clearance between the brake plate and the brake disk can be kept close to 0 by the urging force of the means, and the responsiveness of the electromagnetic brake can be improved.
[0025]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic configuration diagram of a front engine / front drive (FF) vehicle to which a driving force distribution device having an electromagnetic brake according to the present invention is applied.
[0026]
The driving force of the engine 2 is transmitted via a transmission 4 to a driving force distribution device 6 having an electromagnetic brake of the present invention. The driving force distributed right and left by the driving force distribution device 6 drives the left and right front wheels 12 and 14 via the front axles 8 and 10.
[0027]
FIG. 2 is a schematic configuration diagram of a four-wheel drive vehicle to which the driving force distribution device provided with the electromagnetic brake of the present invention is applied. The driving force of the engine 2 drives the left and right front wheels 12 and 14 via the transmission 4 and the front axles 8 and 10, and also includes the electromagnetic brake of the present invention disposed on the rear wheel side via the propeller shaft 18. The power is transmitted to the force distribution device 20.
[0028]
The driving force distribution device 20 has substantially the same configuration as the driving force distribution device 6 of FIG. The right and left rear wheels 26 and 28 are driven via the rear axles 22 and 24 by the driving force distributed by the driving force distribution device 20 at a predetermined ratio.
[0029]
As will be described in detail later, the driving force can be arbitrarily distributed to the left and right rear wheels 26 and 28 by controlling the braking force of a pair of electromagnetic brakes built in the driving force distribution device 20. In the case where the rear wheels 26, 28 are idling, etc., all the driving force of the engine 2 can be supplied to the left and right front wheels 12, 14. In this case, the four-wheel drive vehicle is an FF vehicle.
[0030]
Referring to FIG. 3, a sectional view of the driving force distribution device 20 according to the embodiment of the present invention is shown. Reference numeral 30 denotes a fixed housing, which includes a central housing 30a, left and right side housings 30b and 30c, and an intermediate housing 30d.
[0031]
The side housing 30b and the intermediate housing 30d are fastened to the central housing 30a by screws 32 and 34, and the side housing 30c is fastened to the central housing 30a by screws 36.
[0032]
In the housing 30, the left rear axle 22 is rotatably supported by a pair of bearings 38, 40, and similarly, the right rear axle 24 is rotatably supported by a pair of bearings 42, 44. The left rear axle 22 is connected to a left rear wheel 26, and the right rear axle 24 is connected to a right rear wheel 28.
[0033]
Reference numeral 46 denotes a companion flange, which is fastened to the propeller shaft 18 shown in FIG. 2 by a screw (not shown). The input shaft 50 is rotatably supported in the housing 30 by a pair of needle bearings 52 and 54. The input shaft 50 is connected to the companion flange 46 by a spline 48. A bevel gear 56 is formed at the tip of the input shaft 50.
[0034]
A planetary gear assembly 58A is interposed between the input shaft 50 and the left rear axle 22, and a planetary gear assembly 58B is interposed between the input shaft 50 and the right rear axle 24.
[0035]
Since the planetary gear assembly 58A and the planetary gear assembly 58B have substantially the same structure, the same reference numerals are given to the respective components, and mainly the left planetary gear assembly 58A will be described.
[0036]
A bevel gear 60 is engaged with a bevel gear 56 of the input shaft 50, and a ring gear 62 is fastened to the bevel gear 60 by a screw 63. The ring gear 62 is a ring gear common to the left and right planetary gear assemblies 58A, 58B.
[0037]
The planetary carrier 64 of the planetary gear assembly 58A is fixed to the left rear axle 22 by splines 66. The sun gear 68 is rotatably mounted around the left rear axle 22 by a needle bearing 70. A plurality of planet gears 72 (only one is shown) carried by the planetary carrier 64 mesh with the sun gear 68 and the ring gear 62.
[0038]
Reference numeral 74 denotes a wet-type multi-plate brake mechanism. The wet-type multi-plate brake mechanism 74 is attached to a plurality of brake plates 76 attached to the housing 30 and to a sun gear 68 so as to be arranged alternately with the brake plates 76. And a plurality of brake disks 78 provided.
[0039]
Each brake plate 76 is axially movable and non-rotatably attached to the housing 30, and each brake disk 78 is axially movable and non-rotatably attached to the sun gear 68.
[0040]
A snap ring 80 is attached to the housing 30, and the snap ring 80 positions one end (right end) of the multi-plate brake mechanism 74. Fine adjustment of the positioning is performed by the thickness of the end plates 82 and 84.
[0041]
Reference numeral 90 denotes a ring-shaped core member formed of a magnetic material, and has an annular groove 96 having a first outer diameter and a rectangular cross section. As shown in FIG. 4A, the ring-shaped core member 90 has a center hole 91 and three fastening portions 94 separated from each other. Each fastening portion 94 has a hole 95 into which a screw is inserted.
[0042]
As best shown in FIG. 4B, an exciting coil 98 is accommodated in the annular groove 96. The core member 90 is divided into an inner peripheral portion 90a and an outer peripheral portion 90b by an annular groove 96, and the cross-sectional area of the inner peripheral portion 90a and the cross-sectional area of the outer peripheral portion 90b at the exciting coil 98 are substantially equal.
[0043]
The ring-shaped core member 90 has an outer tapered end surface 97 inclined at a first angle with respect to a center axis formed outside the annular groove 96, and a center axis formed inside the annular groove 96 at an inner side. An inner peripheral side tapered end surface 99 inclined at a second angle is provided. In the present embodiment, the taper angle (first angle) of the outer peripheral side tapered end surface 97 and the taper angle (second angle) of the inner peripheral side tapered end surface 99 are substantially equal.
[0044]
As shown in FIG. 4A, the core member 90 has an insertion portion 104 of the excitation coil terminal 108 and a search coil terminal insertion portion 106 which are separated from each other by 90 °.
[0045]
As can be seen in FIG. 3, a search coil 100 is mounted in groove 96 adjacent to excitation coil 98. The intensity of the magnetic flux when the exciting coil 98 is energized by the search coil 100 is detected, and the current applied to the exciting coil 98 is feedback-controlled based on the detected intensity of the magnetic flux.
[0046]
Each of the fastening portions 94 of the ring-shaped core member 90 is brought into contact with a receiving portion (not shown) of the side housing 30b, and a screw 92 is screwed into a tap hole (not shown) of the side housing 30b through the hole 95 of the fastening portion 94. 90 is fixed to the side housing 30b.
[0047]
A ring-shaped armature member 110 made of a magnetic material is arranged facing the annular groove 96 of the core member 90. The armature member 110 has a second outer diameter larger than the first outer diameter of the core member 90, as shown in FIG.
[0048]
The armature member 110 further has an inner peripheral side tapered end surface 111, an outer peripheral side tapered end surface 113, an annular mounting groove 112 formed in the inner peripheral portion, and an annular mounting groove 114 formed in the outer peripheral portion. I have.
[0049]
The inner peripheral side tapered end surface 111 has a shape complementary to the inner peripheral side tapered end surface 99 of the ring-shaped core member 90. That is, the inner peripheral side tapered end surface 111 is inclined at the second angle with respect to the central axis.
[0050]
The outer peripheral side tapered end surface 113 of the armature member 110 has a shape complementary to the outer peripheral side tapered end surface 97 of the ring-shaped core member 90. That is, the outer peripheral side tapered end surface 113 is inclined at the first angle with respect to the central axis.
[0051]
One end (left end) of a cylindrical slider (cylindrical guide member) 116 shown in FIG. 6 is press-fitted and fixed to the annular mounting groove 112 of the armature member 110. By this press-fitting, the cylindrical slider 116 is fixed so as to be parallel to the central axis of the ring-shaped core member 110.
[0052]
As shown in FIGS. 3 and 9, the first end (left end) of the cylindrical pressing member 120 is mounted in the annular mounting groove 114 of the ring-shaped armature member 110. The second end (right end) of the cylindrical pressing member 120 is in contact with the end plate 82.
[0053]
As shown in FIGS. 7A and 7B, the cylindrical pressing member 120 has three notches 122 into which the fastening portions 94 of the core member 90 are inserted.
[0054]
FIG. 8 shows a left end view of the electromagnetic brake of the present invention, and FIG. 9 shows a longitudinal sectional view thereof. In FIG. 9, the left rear axle 22 and the left planetary gear assembly 58A shown in FIG. 3 are omitted.
[0055]
Referring to FIG. 9, three bosses (projections) 128 (only one is shown) are integrally formed on the side housing 30b and are spaced apart by 120 degrees in the circumferential direction. As best shown in the enlarged view of FIG. 10, the boss 128 has a through hole 130. The through hole 130 of the boss 128 is closed by a sealing bolt 134 with the packing 136 interposed therebetween.
[0056]
A coil spring 132 is mounted between the step portion 128b of the boss 128 and the ring-shaped armature member 110. By this coil spring 132, the ring-shaped armature member 110 is urged in the pressing direction of the cylindrical pressing member 120, and as a result, the brake plate 76 and the brake disc 78 of the multi-plate brake mechanism 74 are pressed through the cylindrical pressing member 120. The clearance between them is kept close to zero.
[0057]
Referring again to FIG. 9, reference numeral 138 denotes a lubricating oil passage, one end of which is closed by a bolt 140 with a packing 142 interposed therebetween. Reference numeral 144 denotes an annular oil seal that seals the lubricating oil of the ball bearing 38.
[0058]
The excitation coil terminal 108 is inserted into the insertion portion 104 of the core member 90 and fixed to the side housing 30b with a screw 109. The search coil terminal 146 shown in FIG. 8 is inserted into the insertion portion 106 of the core member 90 and fixed to the side housing 30b with a screw.
[0059]
As is apparent from FIG. 8, three sealing bolts 134 are attached to the side housing 30b at a circumferential distance of 120 degrees.
[0060]
As described above, the inner peripheral portion 90a is formed wider than the outer peripheral portion 90b so that the inner peripheral portion 90a and the outer peripheral portion 90b of the ring-shaped core member 90 have substantially the same cross-sectional area. With this configuration, when the excitation coil 98 is energized, the ring-shaped armature member 110 can be attracted with a uniform force from the inner circumference to the outer circumference.
[0061]
When the excitation coil 98 is energized, a predetermined air gap is formed between the ring-shaped core member 90 and the ring-shaped armature member 110 to prevent metal contact between the core member 90 and the armature member 110.
[0062]
When the gap (air gap) between the core member 90 and the armature member 110 changes, the suction force of the core member 90 and, consequently, the pressing force of the cylindrical pressing member 120 against the multi-plate brake mechanism 74 change. High accuracy is required.
[0063]
The air gap changes due to manufacturing variations and aging (wear) of the brake plate 76 and the brake disk 78 of the multi-plate brake mechanism 74.
[0064]
As described above, in the conventional electromagnetic brake, a small current is always supplied to the exciting coil in order to improve the responsiveness, and the clearance between the brake plate and the brake disk of the multi-plate brake mechanism is always maintained near zero. I was
[0065]
In the present embodiment, the coil spring 132 having a constant load is provided between the side housing 30b and the ring-shaped armature member 110 to urge the armature member 110 in the pressing direction of the cylindrical pressing member 120. , The clearance between the brake plate 76 and the brake disk 78 can always be maintained at about zero, and the responsiveness of the electromagnetic brake can be improved.
[0066]
A method for setting the predetermined air gap G will be described with reference to FIGS. First, the distance L between the end surface 128a of the boss 128 and the flat surface 110a of the ring-shaped armature member 110 is measured with the air gap G being zero.
[0067]
That is, the coil spring 132, the ring-shaped armature member 110, the ring-shaped core member 90, the exciting coil 98, the cylindrical slider 116, and the cylindrical pressing member 120 are inserted into the side housing 30b. Fastened to the side housing 30b.
[0068]
In this state, since the multi-plate brake mechanism 74 is not mounted, the ring-shaped armature member 110 is pushed by the coil spring 132 and contacts the core member 90, and the air gap G becomes zero. Therefore, the distance L is measured in this state and is set to L1.
[0069]
Next, the distance L is measured by incorporating the brake plate 76, the brake disk 78, and the end plates 82 and 84 of the multi-plate brake mechanism 74, and is set to L2. The distance L is measured using, for example, a dial gauge.
[0070]
The thickness of the end plates 82 and 84 is adjusted so that L1−L2 becomes the air gap G and the specified air gap G is obtained. When the specified air gap G is obtained, the through hole 130 is sealed with the sealing bolt 134 with the packing 136 interposed between the boss 128 and the assembly is completed.
[0071]
In this embodiment, since the coil spring 132 is mounted between the boss 128 having the through hole 130 and the ring-shaped armature member 110, if the L2 dimension is recorded at the time of assembling, the bolt 134 is removed at the time of inspection or the like to remove the distance. By measuring L, the air gap G can be checked, and the degree of wear of the brake plate 76 and the brake disc 78 of the multiple disc brake mechanism 74 can be checked without disassembling.
[0072]
When it is determined that the air gap G has become small and the multi-plate brake mechanism 74 has been worn, the thicker end plates 82 and 84 can be incorporated to adjust the air gap G to a specified value. .
[0073]
Hereinafter, the operation of the present embodiment will be described.
[0074]
When the electromagnetic brakes 150A and 150B are turned off without energizing the exciting coils 98 of the left and right electromagnetic brakes 150A and 150B, the sun gear 68 of the planetary gear assemblies 58A and 58B is left and right because the multiple disc brake mechanisms 74 are not engaged. Idle around the rear axles 22, 24, respectively.
[0075]
Therefore, the driving force (torque) of the input shaft 50 is not transmitted to the left and right rear axles 22 and 24 at all. In this case, the rear wheels 26 and 28 idle, and all the driving force is directed to the front wheels 12 and 14 to form a two-wheel drive vehicle.
[0076]
When a predetermined amount of current is applied to the exciting coils 98 of the left and right electromagnetic brakes 150A and 150B to completely engage both the multi-plate brake mechanisms 74 via the cylindrical pressing member 120, the planetary gear assemblies 58A and 58B Are fixed to the housing 30, and the driving force of the input shaft 50 is transmitted to the left and right rear axles 22, 24 via the ring gear 62, the planet gear 72, and the planet carrier 64.
[0077]
Therefore, the driving force of the input shaft 50 is equally divided and transmitted to the left and right rear axles 22 and 24. As a result, the four-wheel drive vehicle shown in FIG. 2 enters the four-wheel drive mode and travels straight. In the case of a front engine / rear drive (FR) vehicle, the driving force is divided equally between the left and right rear wheels, and the vehicle goes straight.
[0078]
Also, when the vehicle turns or escapes from mud, etc., the driving force of the input shaft 50 is applied to the left and right rear axles 22 and 24 by controlling the current value flowing through the exciting coils 98 of the left and right electromagnetic brakes 150A and 150B. It can be distributed arbitrarily, and realizes optimal turning control and / or facilitation of muddy escape.
[0079]
In the above description, the example in which the driving force distribution device 20 is provided on the rear wheel side has been described. However, the driving force distribution device 6 similar to the front wheel side of the FF vehicle shown in FIG. 1 may be provided.
[0080]
Further, when the driving force distribution device 20 is provided on the rear wheel side, the driving force distribution device 20 is not limited to the four-wheel drive vehicle shown in FIG. May be.
[0081]
In the above description, an example in which the electromagnetic brake of the present invention is applied to the driving force distribution device 20 has been described, but the present invention is not limited to this, and is interposed between the fixed housing and the rotating member. It is applicable to any mechanism or device having an electromagnetic brake.
[0082]
【The invention's effect】
According to the first aspect of the present invention, a check hole capable of measuring a gap amount between the armature member and the core member is provided in the housing opposite to the core member with respect to the armature member. Through this check hole, the gap amount between the armature member and the core member can be measured without disassembling the brake. As a result, it is possible to check the degree of wear of the brake plate and the brake disc of the multiple disc brake mechanism based on the measured gap amount.
[0083]
According to the second aspect of the present invention, the elastic means for urging the armature member in the pressing direction of the pressing member is provided between the housing and the armature member. The clearance between the brake plate and the brake disk can be maintained at approximately zero, and the responsiveness of the electromagnetic brake can be improved. Since it is not necessary to always energize the excitation coil, power consumption and heat generation of the excitation coil can be suppressed.
[Brief description of the drawings]
FIG. 1 is a schematic view of an FF vehicle equipped with a driving force distribution device of the present invention.
FIG. 2 is a schematic view of a four-wheel drive vehicle equipped with the driving force distribution device of the present invention.
FIG. 3 is a sectional view of the driving force distribution device according to the embodiment of the present invention.
FIG. 4A is a front view of a link-shaped core member, and FIG. 4B is a cross-sectional view taken along line 4B-4B in FIG. 4A.
FIG. 5 is a cross-sectional view of the ring-shaped armature member with the cylindrical slider fitted therein.
FIG. 6 is a longitudinal sectional view of a cylindrical slider.
7 (A) is a front view of a cylindrical pressing member, and FIG. 7 (B) is a sectional view taken along line 7B-7B of FIG. 7 (A).
FIG. 8 is an end view of the electromagnetic brake according to the embodiment of the present invention.
FIG. 9 is a longitudinal sectional view of the electromagnetic brake according to the embodiment of the present invention.
FIG. 10 is an enlarged sectional view showing a main part of the electromagnetic brake of the embodiment.
[Explanation of symbols]
2 Engine 12, 14 Front wheel 18 Propeller shaft 20 Driving force distribution device 22, 24 Rear axle 26, 28 Rear wheel 30 Housing 50 Input shaft 58A, 58B Planetary gear assembly 62 Ring gear 64 Planetary carrier 68 Sun gear 72 Planet gear 74 Multi-plate brake mechanism 90 Ring-shaped core member 98 Exciting coil 110 Ring-shaped armature member 116 Cylindrical slider 120 Cylindrical pressing member 128 Boss 130 Through-hole 132 Coil spring 150A, 150B Electromagnetic brake

Claims (2)

An electromagnetic brake interposed between a fixed housing and a rotating member at least partially contained within the fixed housing,
A multi-plate brake mechanism having a plurality of brake plates attached to the fixed housing and a plurality of brake disks attached to the rotating member so as to be alternately arranged with the brake plates;
A ring-shaped core member having an annular groove and a first outer diameter, fixed in the housing;
An annular exciting coil housed in the annular groove of the core member,
A ring-shaped armature member having a second outer diameter larger than the first outer diameter and disposed to face the annular groove of the core member;
It has a first end and a second end, the first end is fixed to the outer peripheral portion of the armature member, and the second end is engaged with the multi-plate brake mechanism, in a pressing direction of the multi-plate brake mechanism. A cylindrical pressing member externally fitted to the core member so as to be movable;
A check hole provided in the housing on the side opposite to the core member with respect to the armature member, capable of measuring a gap amount between the armature member and the core member,
An electromagnetic brake comprising: Elastic means for urging the armature member in a pressing direction of the pressing member provided between the housing and the armature member,
A boss for regulating the position of the elastic means formed integrally with the housing,
The electromagnetic brake according to claim 1, wherein the check hole is formed through the boss.

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