JP2023154438A - electromagnetic brake device - Google Patents

Abstract

To provide an electromagnetic brake device for preventing the occurrence of abnormal sound during abutment between a brake hub and a locking member while enabling the entry suppression of foreign matters.SOLUTION: An electromagnetic brake device 10 includes a brake stator 31, a rotary shaft 15 rotatable with respect to the brake stator 31, a brake hub 34 fitted to the rotary shaft 15 and movable in the direction of an axial center P of the rotary shaft 15, a brake plate 35 fitted to the brake hub 34 in an integrally rotatable manner, and provided movable in the direction of the axial center P of the rotary shaft 15, and a locking member 52 provided on the rotary shaft 15 for preventing the come-off of the brake hub 34 from the rotary shaft 15. Between the brake hub 34 and the locking member 52, a buffer member 57 is laid.SELECTED DRAWING: Figure 2

Description

The present invention relates to an electromagnetic brake device.

As a conventional technique of an electromagnetic brake device, for example, a non-excited electromagnetic brake device disclosed in Patent Document 1 is known. The non-excitation electromagnetic brake device disclosed in Patent Document 1 includes a movable iron core, a rotating disk, a center hub, a rotating shaft, and a connecting member. The movable iron core is movable only in the axial direction in which it is attracted by an electromagnet to release the brake and is pushed by a brake spring to apply the brake. A rotating disk is arranged between the movable iron core and the brake plate. The center hub is movably coupled to this rotating disk only in the axial direction. The rotating shaft is fixed to this center hub and supported by a bearing. The connecting member ensures the mutual position of the fixed core of the electromagnet and the brake plate.

Further, the non-excited electromagnetic brake device of Patent Document 1 is arranged between a center hub or a rotating shaft and a rotating disk so that the moving distance of the rotating disk from the braking position to the releasing direction is the same as that of the movable iron core from the braking position to the releasing position. It includes a movement restricting means for restricting the movement to a position smaller than the gap, and an urging means whose force for urging the rotating disk in the releasing direction is smaller than the force of the brake spring.

According to the non-excited electromagnetic brake device of Patent Document 1, the rotating disk that is rotating after the brake is released is moved between the movable iron core in the released position and the brake plate by the movement regulating means and the urging means. The directional position is fixed, neither the movable iron core nor the brake plate slides, and there is no sliding noise.

Japanese Patent Application Publication No. 7-35175

By the way, some electromagnetic brake devices are equipped with a brake hub (center hub) that is slidable in the axial direction with respect to the rotating shaft. In this case, the end of the rotating shaft is provided with a retaining member for preventing the brake hub from coming off the rotating shaft. When the rotating shaft rotates, which is a non-braking time, the brake hub may slide in the axial direction and repeatedly come into contact with the retaining member. For this reason, there is a problem in that an abnormal noise is generated when the brake hub and the retaining member come into contact with each other, and foreign matter is likely to enter between the brake hub and the rotating shaft. When metal powder (foreign matter) enters between the brake hub and the rotating shaft, wear at the sliding portion between the brake hub and the rotating shaft is accelerated.

In the non-excited electromagnetic brake device of Patent Document 1, the moving distance of the rotary disk in the release direction only restricts the sliding of the movable iron core and the brake plate to suppress the generation of sliding noise, and the distance traveled by the rotating disk in the release direction is limited to the brake hub and the brake hub. This is not a technology that suppresses abnormal noise when coming into contact with the retaining member.

The present invention has been made in view of the above problems, and an object of the present invention is to prevent the generation of abnormal noise when the brake hub and the retaining member come into contact with each other, and to suppress the entry of foreign objects. The objective is to provide an electromagnetic brake device.

In order to solve the above problems, the present invention includes a brake stator, a rotating shaft rotatable with respect to the brake stator, and a brake fitted with the rotating shaft and movable in the axial direction of the rotating shaft. a hub, a brake plate fitted to the brake hub so as to be integrally rotatable and movable in the axial direction of the rotating shaft; and a brake plate provided on the rotating shaft and capable of removing the brake hub from the rotating shaft. In the electromagnetic brake device, the electromagnetic brake device has a retaining member that prevents the brake from coming off, wherein a buffer member is interposed between the brake hub and the retaining member.

In the present invention, since the buffer member is interposed between the brake hub and the stopper member, the buffer member does not come into contact with the brake hub or the stopper member, and the generation of abnormal noise due to the contact is prevented. Further, the buffer member interposed between the brake hub and the retaining member can prevent foreign matter from entering the sliding portion between the brake hub and the rotating shaft.

Further, in the electromagnetic brake device described above, the buffer member may be fixed to an end face of the retaining member facing the brake hub, and a gap may be formed between the buffer member and the brake hub.
In this case, the buffer member is fixed to the end surface of the retaining member that faces the brake hub, and a gap is formed between the buffer member and the brake hub. Therefore, even if the brake hub rattles in the circumferential direction with respect to the rotating shaft, the presence of the gap can suppress sliding contact between the buffer member and the brake hub.

Further, in the above electromagnetic brake device, the buffer member may be fixed to an end face of the brake hub that faces the retaining member, and a gap may be formed between the buffer member and the retainer. .
In this case, the buffer member is fixed to the end surface of the brake hub that faces the retaining member, and a gap is formed between the buffer member and the retaining member. Therefore, even if the brake hub rattles in the circumferential direction with respect to the rotating shaft, the existence of a gap between the buffer member and the retaining member prevents the sliding contact between the buffer member and the retainer member. Can be suppressed.

Further, in the electromagnetic brake device described above, the buffer member may be formed in a ring shape and arranged coaxially with the rotating shaft.
In this case, since the buffer member is formed into a ring shape and is arranged coaxially with the rotating shaft, the buffer member surrounds the rotating shaft. Therefore, it is possible to further prevent foreign matter from entering the sliding portion between the brake hub and the rotating shaft.

Further, in the electromagnetic brake device described above, the buffer member may be formed of a rubber-based material or a spongy body.
Since the buffer member is made of a rubber-based material or a spongy body, even if abrasion powder from the buffer member enters the sliding part between the brake hub and the rotating shaft as a foreign object, the sliding part between the brake hub and the rotating shaft will be prevented. The moving parts are hardly affected by wear particles.

According to the present invention, it is possible to provide an electromagnetic brake device that can prevent the generation of abnormal noise when the brake hub and the retaining member come into contact with each other, and can also suppress the entry of foreign objects.

FIG. 2 is a partially cutaway side view showing the electromagnetic brake device and electric motor according to the first embodiment. FIG. 2 is a longitudinal cross-sectional view of main parts of the electromagnetic brake device according to the first embodiment. FIG. 3 is a perspective view of a retaining member and a buffer member of the electromagnetic brake device. FIG. 7 is a longitudinal cross-sectional view of main parts of an electromagnetic brake device according to a second embodiment.

(First embodiment)
Hereinafter, an electromagnetic brake device according to a first embodiment will be described with reference to the drawings. The electromagnetic brake device of this embodiment is a non-excitation braking type electromagnetic brake device that enters a braking state in a non-excitation state. Further, the electromagnetic brake device of this embodiment is an electromagnetic brake device provided in a traveling electric motor mounted on a vehicle, and the vehicle is a forklift as an industrial vehicle.

As shown in FIG. 1, the electromagnetic brake device 10 of this embodiment is provided in an electric motor 11. First, the electric motor 11 will be explained. The electric motor 11 includes a rotor 12 and a stator 13. The rotor 12 has a rotor core 14 and a rotating shaft 15 fixedly extending through the rotor core 14. The rotating shaft 15 protrudes from both ends of the rotor 12. The stator 13 includes a cylindrical stator core 16 and a stator coil 17. Coil ends 18 of the stator coil 17 are formed at both ends of the stator core 16 . In FIG. 1, the coil end 18 at one end is not shown, and only the coil end 18 at the other end is shown. Note that a screw hole 20 is formed in the center of the end of the rotating shaft 15 on the electromagnetic brake device 10 side.

The electric motor 11 includes an output side bracket 19 attached to one end of the stator 13 and a brake side bracket 21 attached to the other end of the stator 13 on the electromagnetic brake device 10 side. The output side bracket 19 rotatably supports the vicinity of one end of the rotating shaft 15 via a bearing (not shown). The brake-side bracket 21 rotatably supports the vicinity of the other end of the rotating shaft 15 via a bearing 22 . The output side bracket 19 and the brake side bracket 21 are connected by a through bolt (not shown). A portion of the rotating shaft 15 protrudes from the output side bracket 19 as an output shaft 23. Further, the electromagnetic brake device 10 is attached to the other end of the brake side bracket 21. Details of the electromagnetic brake device 10 will be described later.

A terminal block 24 is provided on the brake side bracket 21. A lead wire 25 is drawn out from the other coil end 18 of the stator coil 17, and the drawn out lead wire 25 is drawn into the terminal block 24. The terminal block 24 is connected to the lead wire 25 and has a terminal portion (not shown) that is connectable to external wiring that connects to an external device (for example, an inverter). The lead wire 25 is wiring for supplying power to the electric motor 11.

Next, the electromagnetic brake device 10 that can brake the rotation of the rotor 12 will be described. As shown in FIG. 2, the electromagnetic brake device 10 includes a brake stator 31, a brake armature 32, a fixed plate 33, a brake hub 34, a brake plate 35, and a brake cover 36.

As shown in FIG. 2, the brake stator 31 has a ring-shaped stator body 37 and a circular hole 38 at the center of the stator body 37. One end surface of the stator main body portion 37 abuts against the brake side bracket 21 . The other end of the rotating shaft 15 and a portion of the brake hub 34 are accommodated in the circular hole 38 . The stator main body 37 has a built-in annular electromagnetic coil 39 as a suction mechanism. The electromagnetic coil 39 excites the brake stator 31 when energized, and de-energizes the brake stator 31 when the energization is stopped.

The stator main body 37 has a through hole 42 through which a bolt 41 for fixing the electromagnetic brake device 10 to the electric motor 11 is inserted. A screw hole 43 is provided to allow screw insertion. Brake stator 31 is fixed to brake side bracket 21 by screwing bolts 41 inserted into through holes 42 into screw holes 43 . The plurality of bolts 41 pass through the brake armature 32 and the fixing plate 33, respectively, and fix the brake stator 31 to the electric motor 11.

The stator main body portion 37 has a plurality of bottomed holes 44 located on the inner circumferential side than the electromagnetic coil 39 . The plurality of bottomed holes 44 are arranged at equal intervals in the circumferential direction of the stator main body portion 37. A coil spring 45 is built into the bottomed hole 44 . The center axis of each coil spring 45 is along the axis P of the rotating shaft 15. The coil spring 45 is a biasing member that biases the brake armature 32.

The brake armature 32 faces the brake stator 31 in the direction of the axis P of the rotating shaft 15. The brake armature 32 has a disc shape, and the rotating shaft 15 and the brake hub 34 pass through the center thereof. The brake armature 32 is movable in the direction of the axis P of the rotating shaft 15. Further, one end of the coil spring 45 built in the brake stator 31 in the direction of the axis P contacts the brake stator 31, and the other end in the direction of the axis P that protrudes from the brake stator 31 contacts the brake armature 32. Coil spring 45 urges brake armature 32 in a direction away from brake stator 31 along the axial direction of rotating shaft 15 .

When the brake stator 31 is excited by energizing the electromagnetic coil 39, the brake armature 32 is attracted to the brake stator 31 against the urging force of the coil spring 45. When the electromagnetic coil 39 is not energized and the brake stator 31 is de-energized, the brake armature 32 moves in a direction away from the brake stator 31 under the urging force of the coil spring 45.

The electromagnetic brake device 10 includes a disk-shaped fixing plate 33 fixed to a brake cover 36. The fixed plate 33 is located at a certain distance from the brake stator 31 along the axial direction of the rotating shaft 15. The brake stator 31 and the fixed plate 33 are arranged side by side in the direction of the axis P of the rotating shaft 15. The fixing plate 33 is fixed to the brake cover 36 by fastening bolts (not shown) passing through the fixing plate 33 to the brake cover 36. The brake armature 32 is disposed between the brake stator 31 and the fixed plate 33 in the axial direction of the rotating shaft 15.

The electromagnetic brake device 10 includes a brake hub 34 that rotates integrally with the rotating shaft 15. The brake hub 34 is key-fitted to the rotating shaft 15 and cannot rotate in the circumferential direction with respect to the rotating shaft 15, but is slidable in the direction of the axis P of the rotating shaft 15. That is, the brake hub 34 is movable in the direction of the axis P of the rotating shaft 15. A key groove (not shown) is formed in the axial direction on the outer circumferential surface of the rotating shaft 15 and the inner circumferential surface of the brake hub 34, and key fitting is achieved by inserting a key (not shown) into the key groove. . In FIG. 2, a sliding portion S is shown as a sliding portion between the brake hub 34 and the rotary shaft 15 through key-fitting. The brake hub 34 is equipped with a brake plate 35. The brake plate 35 is disc-shaped, and is disposed between the brake armature 32 and the fixed plate 33 in the direction of the axis P of the rotating shaft 15, and is fitted to the brake hub 34 so as to be able to rotate integrally with the rotating shaft. It is movable in the direction of the axis P of 15. The plate surface of the brake plate 35 includes a friction material 46 that contacts the brake armature 32 in a braking state, and a friction material 47 that contacts the fixed plate 33 in a braking state.

Next, the brake cover 36 will be explained. The brake cover 36 includes a cover main body 48 fixed to the fixing plate 33, a side wall 49 extending from the periphery of the cover main body 48 to the brake stator 31, and a protrusion 50 projecting from the cover main body 48 in the axial direction. It is equipped with. A through hole 48A through which the bolt 41 is inserted is provided near the outer periphery of the cover main body portion 48. The side wall portion 49 is a cylindrical portion that covers the outer circumferences of the brake armature 32, brake plate 35, and fixed plate 33. A space 51 is formed inside the protrusion 50 in which the end of the rotating shaft 15 is accommodated.

In the electromagnetic brake device 10 configured in this way, when the electromagnetic coil 39 is excited, the brake armature 32 is attracted to the brake stator 31, the brake armature 32 is separated from the brake plate 35, and the fixing plate 33 of the brake plate 35 is separated from the brake plate 35. The pressure on is released. As a result, the rotating shaft 15 is released from the braking state and can freely rotate without being restricted.

On the other hand, when the electromagnetic coil 39 is not excited, the brake armature 32 is pressed toward the brake plate 35 by the urging force of the coil spring 45, and the brake plate 35 is pressed against the fixed plate 33. Therefore, the brake plate 35 is sandwiched between the brake armature 32 and the fixed plate 33. As a result, the rotating shaft 15 enters a braking state due to the frictional force generated between the brake armature 32 and the brake plate 35. In other words, the parking brake is activated.

By the way, the brake hub 34 is key-fitted to the rotating shaft 15 and is slidable in the direction of the axis P. A retaining member 52 that prevents the brake hub 34 from coming off from the rotating shaft 15 is fixed to the other end of the rotating shaft 15 with a bolt 53 . The retaining member 52 is a disk having an outer circumferential diameter larger than the outer circumferential diameter of the end of the rotating shaft 15 . A through hole 54 is formed in the center of the retaining member 52, into which the shaft of the bolt 53 is inserted.

One end surface 55 of the retaining member 52 faces the end surface of the brake hub 34 , and the other end surface 56 faces the protrusion 50 of the brake cover 36 . A ring-shaped buffer member 57 is fixed to one end surface 55 of the retaining member 52 . That is, the buffer member 57 is interposed between the brake hub 34 and the retaining member 52. The buffer member 57 is made of an elastically deformable rubber material. Note that the rubber material is preferably a material that has not only wear resistance but also resistance to humidity and salt. The buffer member 57 is fixed to the retaining member 52 using adhesive, double-sided tape, or the like.

An end surface 57A of the buffer member 57 is an adhesive surface, and an end surface 57B opposite to the end surface 57A faces the brake hub 34. As shown in FIG. 3, the buffer member 57 is a ring-shaped member, and is arranged coaxially with the axis P of the rotating shaft 15. As shown in FIG. The diameter of the inner circumferential surface 57C of the buffer member 57 is larger than the outer circumferential diameter of the other end of the rotating shaft 15, and the diameter of the outer circumferential surface 57D of the buffer member 57 is smaller than the outer circumferential diameter of the brake hub 34 (see FIG. 2). reference). The cross-sectional shape of the buffer member 57 is rectangular. The thickness of the buffer member 57 in the direction of the axis P is set to such a value that a slight gap G is formed between the buffer member 57 and the end surface of the brake hub 34 .

When the rotary shaft 15 rotates in a non-braking state, the brake hub 34 may move in the direction of the axis P with respect to the rotary shaft 15 and come into contact with the buffer member 57 . Even if the buffer member 57 comes into contact with the brake hub 34, it absorbs the shock caused by the contact with the brake hub 34, thereby preventing the generation of abnormal noise due to the contact. In other words, the buffer member 57 has a function of preventing abnormal noise. Furthermore, since the gap G between the buffer member 57 and the end surface of the brake hub 34 is small, the buffer member 57 has the function of preventing foreign matter from entering the sliding portion S between the rotating shaft 15 and the brake hub 34 .

Next, the operation of the electromagnetic brake device 10 of this embodiment will be explained. First, a case in which the electromagnetic brake device 10 operates from a braking state to a non-braking state will be described. When the electromagnetic brake device 10 is in a braking state, the electromagnetic coil 39 is in a demagnetized state. Therefore, the brake armature 32 is pressed against the brake plate 35 by the urging force of the coil spring 45. Braking force of the electromagnetic brake device 10 is generated by the brake plate 35 being pressed between the brake armature 32 and the fixed plate 33.

When releasing the braking state of the electromagnetic brake device 10, the electromagnetic coil 39 is energized. When the electromagnetic coil 39 is excited by the energization of the electromagnetic coil 39, the brake armature 32 is drawn toward the brake stator 31 by the attractive force of the magnetic force against the urging force of the coil spring 45, and is separated from the brake plate 35. Then, the brake armature 32 is attracted to the brake stator 31.

When the electromagnetic brake device 10 is in a non-braking state, the rotor 12 of the electric motor 11 is rotatable. When the rotor 12 rotates, the rotating shaft 15 and the brake hub 34 are rotated together. Further, the retaining member 52 and the buffer member 57 rotate integrally with the rotating shaft 15. When the rotating shaft 15 and the brake hub 34 are rotated together, the brake hub 34 may slide in the direction of the axis P with respect to the rotating shaft 15 due to vibration or the like. When the brake hub 34 slides in the direction of the axis P toward the retaining member 52, the brake hub 34 comes into contact with the buffer member 57. Even if the brake hub 34 comes into contact with the buffer member 57, no abnormal noise is generated due to the contact due to the elastic deformation of the buffer member 57. Furthermore, the brake hub 34 comes into contact with the buffer member 57, thereby eliminating the gap G and preventing foreign matter from entering the sliding portion S between the rotating shaft 15 and the brake hub 34. Even if the brake hub 34 slides in the direction away from the buffer member 57, the gap G is so small that foreign matter is unlikely to enter the sliding portion S between the rotating shaft 15 and the brake hub 34.

Next, a case in which the electromagnetic brake device 10 operates from a non-braking state to a braking state will be described. When the electromagnetic brake device 10 is in a non-braking state, the electromagnetic coil 39 is in an excited state. Therefore, the brake armature 32 is attracted to the brake stator 31 against the urging force of the coil spring 45. Since the brake armature 32 is attracted to the brake stator 31, no braking force is generated in the electromagnetic brake device 10.

When releasing the non-braking state of the electromagnetic brake device 10, the power to the electromagnetic coil 39 is cut off. When the electromagnetic coil 39 is demagnetized by cutting off the power to the electromagnetic coil 39, the brake armature 32 is separated from the brake stator 31 and pressed against the brake plate 35 by the urging force of the coil spring 45. Then, the brake plate 35 is compressed by the brake armature 32 and the fixed plate 33. The electromagnetic brake device 10 is in a braking state.

The electromagnetic brake device 10 according to this embodiment has the following effects.
(1) Since the buffer member 57 is interposed between the brake hub 34 and the retaining member 52, the buffer member 57 does not come into contact with the brake hub 34, and the occurrence of abnormal noise due to the contact is prevented. Further, the buffer member 57 interposed between the brake hub 34 and the retaining member 52 can prevent foreign matter from entering the sliding portion S between the brake hub 34 and the rotating shaft 15. That is, it is possible to prevent the occurrence of abnormal noise due to the contact between the brake hub 34 and the retaining member 52, and to suppress the entry of foreign matter into the sliding portion S between the brake hub 34 and the rotating shaft 15. Furthermore, since the brake hub 34 and the retaining member 52 do not come into contact with each other, wear caused by contact between the brake hub 34 and the retaining member 52 can be prevented.

(2) The buffer member 57 is fixed to an end face 55 of the retaining member 52 that faces the end face of the brake hub 34, and a gap G is formed between the buffer member 57 and the brake hub 34. Therefore, even if the brake hub 34 rattles in the circumferential direction with respect to the rotating shaft 15, the gap G between the buffer member 57 and the retaining member 52 exists, so that the buffer member 57 and the brake Sliding contact with the hub 34 can be suppressed.

(3) The buffer member 57 is formed in a ring shape and is arranged coaxially with the rotating shaft 15. Therefore, the buffer member 57 surrounds the rotating shaft 15 and can further prevent foreign matter from entering the sliding portion S between the brake hub 34 and the rotating shaft 15.

(4) The buffer member 57 is made of a rubber material. Therefore, even if the abrasion powder of the buffer member 57 enters the sliding part S between the brake hub 34 and the rotating shaft 15 as a foreign object, the abrasion powder of the buffer member 57 is sufficiently soft compared to metal, and the brake hub 34 The sliding portion S between the rotary shaft 15 and the rotary shaft 15 is hardly affected by the abrasion powder of the buffer member 57. Furthermore, manufacturing costs can be reduced by using a relatively inexpensive rubber-based material for the buffer member 57.

(5) Since it is only necessary to fix the ring-shaped buffer member 57 to the retaining member 52, it is possible to reduce the number of parts necessary for preventing abnormal noise and suppressing the entry of foreign objects, as well as for electromagnetic The work of assembling the brake device 10 is also relatively easy.

(Second embodiment)
Next, an electromagnetic brake device according to a second embodiment will be described. The electromagnetic brake device according to the second embodiment differs from the first embodiment in that a buffer member is attached to the rotor hub. In this embodiment, the description of the first embodiment is used for the same configuration as in the first embodiment, and the same reference numerals are used.

As shown in FIG. 4, in the electromagnetic brake device 60 of this embodiment, a buffer member 61 is fixed to the end surface of the brake hub 34 facing the end surface 55 of the retaining member 52 with adhesive or double-sided tape. The shape of the buffer member 61 is the same as the buffer member 57 of the first embodiment. Therefore, the buffer member 61 includes an end surface 61A facing the retaining member 52, an end surface 61B which is an adhesive surface on the opposite side of the end surface 61A, an inner circumferential surface 61C, and an outer circumferential surface 61D. The material of the buffer member 61 is a synthetic sponge obtained by foaming synthetic resin. In other words, the buffer member 61 is a spongy body. A slight gap G is formed between the buffer member 61 and the retaining member 52.

According to this embodiment, effects equivalent to effects (1) and (3) of the first embodiment are achieved. Further, a buffer member 61 is fixed to an end surface of the brake hub 34 facing the retaining member 52, and a gap G is formed between the buffer member 61 and the retaining member 52. Therefore, even if the brake hub 34 rattles in the circumferential direction with respect to the rotating shaft 15, the existence of the gap G suppresses the sliding contact between the buffer member 61 and the retaining member 52. I can do it.

Further, the buffer member 61 is made of synthetic sponge. Therefore, even if the abrasion powder of the buffer member 61 enters the sliding part S between the brake hub 34 and the rotating shaft 15 as a foreign object, the abrasion powder of the buffer member 61 is sufficiently soft compared to metal, and the brake hub 34 The sliding portion S between the rotating shaft 15 and the rotating shaft 15 is hardly affected by the abrasion powder of the buffer member 61. In addition, since it is only necessary to fix the ring-shaped buffer member 61 to the retaining member 52, the number of parts required for preventing abnormal noise and suppressing the entry of foreign matter can be reduced as much as possible, and the electromagnetic brake The assembly work of the device 60 is also relatively easy. Furthermore, since the buffer member 61 is made of synthetic sponge, it can absorb moisture and prevent moisture from entering the sliding portion S.

The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the invention. For example, the following modifications may be made.

In the embodiments described above, a gap was formed between the buffer member and the brake hub or the retaining member, but the gap is not limited thereto. For example, the buffer member and the brake hub or the retaining member may be in contact with each other without any gap.
In the above embodiment, the buffer member has a complete ring shape, but is not limited to this. For example, a notch may be formed in the circumferential direction of the buffer member to break the buffer member in the radial direction. Alternatively, the buffer member may be divided into a plurality of parts, and the plurality of divided buffer members may be arranged in the circumferential direction.
In the embodiments described above, the cross-sectional shape of the buffer member is rectangular, but it is not limited to this. The cross-sectional shape may be, for example, circular or oval, and may be set to any shape.
In the above embodiment, the rotating shaft and the brake hub are key-fitted, but the invention is not limited to this. The brake hub may be spline-fitted to the rotating shaft, for example. In this case, spline teeth may be formed in the axial direction on the outer peripheral surface of the rotating shaft, spline holes may be formed in the axial direction in the brake hub, and the spline teeth may be inserted into the spline holes.
In the above embodiment, the retaining member is fixed to the rotating shaft by fastening the bolt, but the securing member to the rotating shaft is not limited to the bolt. The retaining member may be fixed to the rotating shaft using, for example, a snap ring, and the means for fixing the retaining member to the rotating shaft is not particularly limited.

10, 60 Electromagnetic brake device 11 Electric motor 12 Rotor 13 Stator 15 Rotating shaft 19 Output side bracket 21 Brake side bracket 31 Brake stator 32 Brake armature 33 Fixed plate 34 Brake hub 35 Brake plate 36 Brake cover 37 Stator main body 39 Electromagnetic coil 41 Bolt 45 Coil spring 52 Retaining member 53 Bolts 57, 61 Buffer member G Gap P Axial center S Sliding part

Claims (5)

brake stator and
a rotating shaft rotatable relative to the brake stator;
a brake hub fitted with the rotating shaft and movable in the axial direction of the rotating shaft;
a brake plate that is integrally rotatably fitted to the brake hub and is movable in the axial direction of the rotating shaft;
An electromagnetic brake device comprising: a retaining member that is provided on the rotating shaft and prevents the brake hub from coming off from the rotating shaft,
An electromagnetic brake device characterized in that a buffer member is interposed between the brake hub and the retaining member. The buffer member is fixed to an end surface of the retaining member facing the brake hub,
The electromagnetic brake device according to claim 1, wherein a gap is formed between the buffer member and the brake hub. The buffer member is fixed to an end surface of the brake hub that faces the retaining member,
The electromagnetic brake device according to claim 1, wherein a gap is formed between the buffer member and the retaining member. The electromagnetic brake device according to any one of claims 1 to 3, wherein the buffer member is formed in a ring shape and is arranged coaxially with the rotating shaft. The electromagnetic brake device according to any one of claims 1 to 3, wherein the buffer member is made of a rubber-based material or a spongy body.

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