brake

Abstract

This utility model provides a brake, belonging to the field of mechanical braking technology, comprising: a stator with a limiting step on its inner circumference, the limiting step forming a limiting space on the inner circumference of the stator; an armature with a third end face and a fourth end face, and a mounting ear on its outer circumference, the mounting ear protruding radially from the outer circumference of the stator; a coil disposed within the stator; an elastic element disposed within the stator; a friction disc disposed within the limiting space; a movable plate disposed within the limiting space; and an assembly fixedly connected to the armature and the movable plate; wherein the brake is fixedly connected to the target equipment through the mounting ear, and is optionally disposed adjacent to the mounting surface of the target equipment through either the third end face or the fourth end face. The mounting ear is far from the friction pair, which avoids contamination of the friction pair, resulting in higher braking reliability. Furthermore, the radial dimension of the mounting ear is larger than the outer diameter of the stator, allowing it to accommodate larger installation requirements without the need for an additional mounting plate for auxiliary installation.

Description

Technical Field

[0001] This utility model belongs to the field of mechanical braking technology, and specifically relates to a brake. Background Technology

[0002] Existing brakes include various structural types. One type of brake structure includes a stator, armature, coil, elastic element, friction disc, movable plate, assembly parts, and mounting parts. Both the friction disc and movable plate are located inside the stator, with the friction disc positioned between the stator's limiting step and the movable plate. The armature is adjacent to one axial end face of the stator, near the limiting step. The movable plate and armature are connected by an assembly part, allowing them to move as a single unit. When energized, a magnetic field is generated around the coil, creating a magnetic force between the stator and armature. This magnetic force overcomes the elastic force of the elastic element, attracting the armature. Simultaneously, the movable plate releases the friction disc, allowing it to rotate with the drive shaft. When de-energized, the magnetic force on the armature disappears, and the elastic force of the elastic element pushes the armature until the movable plate presses against the friction disc, preventing rotation and thus achieving braking.

[0003] The specific method for installing the brake onto the target equipment is as follows: Mounting holes are made on the stator, and holes are made on the armature to allow clearance from the mounting components. The mounting components pass through the mounting holes and are locked onto the mounting surface of the target equipment. The end face of the stator away from the armature is in contact with the mounting surface. Threadlocker is typically applied to the mounting components or the holes on the mounting surface to prevent loosening. The mounting holes on the stator are located close to the friction pair (the friction disc and the surface of the moving plate in contact with the friction disc, and the surface of the stator). Liquid threadlocker requires a certain amount of time to fully cure. If the threadlocker is not cured, it may seep into the friction pair through gaps in the brake, contaminating the friction pair and causing brake failure. Furthermore, the seeping threadlocker, after curing, can cause the brake to seize up, preventing the friction disc from rotating freely when energized.

[0004] Furthermore, due to the size limitation of the stator, the mounting hole distribution circle cannot be adapted to a larger mounting hole distribution circle. In some applications, it is necessary to fix it to the mounting surface of the target equipment through a mounting plate. The brake is fixed to the mounting plate through the mounting holes, and then the mounting plate is fixed to the target equipment. This makes the brake adapt to a mounting hole distribution circle that is larger than its own size, resulting in a heavier brake. Utility Model Content

[0005] The purpose of this utility model is to provide a brake that addresses the technical problems of existing brakes, which are fixed to the target equipment by opening mounting holes on the stator and armature and passing a mounting piece through the mounting holes. These problems include the risk of thread adhesive seeping into the friction pair and causing brake failure, the limited distribution of mounting holes making it unsuitable for larger mounting hole distributions, and the increased overall weight due to the addition of a mounting plate.

[0006] To achieve the above objectives, the technical solution adopted by this utility model is as follows: This utility model provides a brake, comprising: a stator having a first end face and a second end face in an axial direction, the inner circumference of the stator having a limiting step, the limiting step forming a limiting space facing the first end face on the inner circumference of the stator; an armature disposed adjacent to the second end face, the armature having a third end face close to the second end face and a fourth end face away from the second end face, the outer circumference of the armature having a mounting ear, the mounting ear protruding radially from the outer circumference of the stator; a coil disposed within the stator; and an elastic element disposed within the stator. The device includes: a friction disc disposed within the limiting space; a movable plate disposed within the limiting space, with the friction disc located between the movable plate and the limiting step; and an assembly fixedly connected to the armature and the movable plate. The brake is fixedly connected to the target device via the mounting ear, and is optionally disposed adjacent to the mounting surface of the target device via either the third end face or the fourth end face. During braking, the armature and the movable plate do not move relative to the mounting surface; instead, the stator moves axially relative to the mounting surface.

[0007] In some possible implementations, the mounting ear has a mounting hole, and the brake further includes a mounting member passing through the mounting hole.

[0008] In some possible implementations, the mounting hole is one of a smooth through hole, a countersunk hole, or a threaded hole.

[0009] In some possible implementations, the mounting hole is a countersunk hole, which includes a head hole and a rod hole that are connected to each other; the head hole is located on the third end face, and the fourth end face is configured to be adjacent to the mounting surface of the target device; or, the head hole is located on the fourth end face, and the third end face is configured to be adjacent to the mounting surface of the target device.

[0010] In some possible implementations, the mounting lug is integrally formed with the armature, or the mounting lug and the armature are fixedly connected together.

[0011] In some possible implementations, the mounting ears are provided in multiples, and the multiple mounting ears are evenly distributed on the outer periphery of the armature.

[0012] In some possible implementations, the brake further includes a bushing, the friction disc is sleeved on the outer periphery of the bushing, and a spring is provided between the friction disc and the bushing, the spring having a preload force away from the center of the bushing.

[0013] In some possible implementations, the bushing has a plurality of alternating first teeth and second teeth, the width of the second teeth being greater than or equal to the width of the first teeth, and a plurality of spring pieces being respectively clamped on both sides of the plurality of second teeth.

[0014] In some possible implementations, several second teeth are provided with fixing holes, and the fixing holes and the spring are located on different second teeth.

[0015] In some possible implementations, there are N friction discs and N movable plates, where N is an integer greater than or equal to 1. The N movable plates and N friction discs are arranged alternately, with the Nth movable plate adjacent to the Nth friction disc. The Nth friction disc is adjacent to the limiting step. The first movable plate is fixedly connected to the armature through the assembly. In the axial direction, the Nth friction disc can abut against the Nth movable plate and the limiting step, and each of the remaining friction discs can abut against two adjacent movable plates.

[0016] Compared with the prior art, the brake provided by this utility model has at least the following technical advantages: In the above-mentioned brake technical solution, a mounting ear is provided on the outer periphery of the armature. The mounting ear protrudes radially from the outer periphery of the stator. The brake is fixedly connected to the target equipment through the mounting ear, and can be selectively arranged adjacent to the mounting surface of the target equipment through the third end face or the fourth end face of the armature. During braking, the armature and the movable plate will not move relative to the mounting surface, but the stator moves axially relative to the mounting surface. With this arrangement, the stator does not need to be machined with the hole structure of the corresponding fitting, reducing machining steps and production costs. Since the mounting ear is located outside the stator, it is far away from the friction pair, which can avoid contaminating the friction pair and improve braking reliability. Furthermore, the radial dimension of the mounting ear is larger than the outer diameter of the stator, which can be adapted to larger size installation requirements without the need to add a mounting plate for auxiliary installation, thus reducing the overall weight. It also provides greater size adaptation space for drilling, welding, snap-fit, and other methods of installation. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the structure of a brake provided in an embodiment of the present invention; Figure 2 for Figure 1A schematic diagram of the brake from another angle; Figure 3 for Figure 2 The diagram shows a cross-sectional view of the brake at section AA. Figure 4 for Figure 1 The diagram shows the structure of the armature used in the brake. Figure 5 This is a schematic diagram of the structure of a brake provided in another embodiment of the present invention; Figure 6 This is a schematic diagram showing the brake installed on the target device according to an embodiment of the present invention; Figure 7 for Figure 6 A schematic diagram of the structure shown from another angle; Figure 8 for Figure 7 The diagram shows a cross-sectional view of the structure at section BB. Figure 9 A schematic diagram of the armature structure used in a brake according to another embodiment of the present utility model; Figure 10 for Figure 1 The diagram shows the brake after it has been installed on the target device. Figure 11 for Figure 5 The diagram shows the brake after it has been installed on the target device. Figure 12 A schematic diagram of the friction disc and bushing used in a brake according to an embodiment of the present invention; Figure 13 for Figure 12 The diagram shows a cross-sectional view of the structure at section CC.

[0019] Explanation of reference numerals in the attached figures: 1. Brake; 10. Stator; 11. First end face; 12. Second end face; 13. Limiting step; 131. Limiting space; 20. Armature; 21. Third end face; 22. Fourth end face; 23. Mounting ear; 231. Mounting hole; 30. Coil; 40. Elastic element; 50. Friction disc; 60. Movable plate; 70. Assembly part; 80. Mounting part; 90. Bushing; 91. First tooth; 92. Second tooth; 93. Fixing hole; 100. Spring; 2. Target equipment. Detailed Implementation

[0020] To make the technical problems, technical solutions, and beneficial effects of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0021] It should be noted that when an element is referred to as "fixed to," "fixed," "connected to," "connected to," "set on," "set on," or "fixed to" another element, an intervening element may or may not be present. Furthermore, when an element is referred to as "connected to" or "connected to" another element, it can be interpreted, according to the conventional understanding of those skilled in the art, as a mechanical connection, electrical connection, communication connection, etc. In this document, "multiple" refers to two or more items; "several" refers to one or more items.

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0023] Please refer to the following: Figures 1 to 13 The brake provided in the embodiments of this utility model will now be described.

[0024] Please see Figures 1 to 4 , Figure 10 and Figure 11 This utility model provides a brake 1, comprising: a stator 10 having a first end face 11 and a second end face 12 in the axial direction, and a limiting step 13 on the inner periphery of the stator 10, the limiting step 13 forming a limiting space 131 on the inner periphery of the stator 10 facing the first end face 11; an armature 20, disposed adjacent to the second end face 12, the armature 20 having a third end face 21 close to the second end face 12 and a fourth end face 22 away from the second end face 12, and a mounting ear 23 on the outer periphery of the armature 20 protruding radially from the outer periphery of the stator 10; and a coil 30 disposed inside the stator 10. The system includes: an elastic element 40 located within the stator 10; a friction disc 50 located within the limiting space 131; a movable plate 60 located within the limiting space 131, with the friction disc 50 positioned between the movable plate 60 and the limiting step 13; and an assembly 70 fixedly connected to the armature 20 and the movable plate 60. The brake 1 is fixedly connected to the target device 2 via a mounting ear 23, and is optionally adjacent to the mounting surface of the target device 2 via either a third end face 21 or a fourth end face 22. During braking, the armature 20 and the movable plate 60 do not move relative to the mounting surface; instead, the stator 10 moves axially relative to the mounting surface.

[0025] It should be noted that the number of coils 30, the number of elastic elements 40, and the number of mounting ears 23 can all be one or more. For example... Figure 10 As shown, the third end face 21 of the armature 20 is adjacent to the mounting surface of the target device 2, the stator 10 is entirely housed within the internal space of the target device 2, and the brake 1 protrudes only slightly from the target device 2, with the protrusion being only the thickness of the armature 20; Figure 11As shown, the fourth end face 22 of the armature 20 is adjacent to the mounting surface of the target device 2, and the stator 10 protrudes entirely from the target device 2.

[0026] It is understandable that the mounting ear 23 can be fixedly connected to the target device 2 through methods such as drilling to set the connection structure, welding, snap-fitting, riveting, or gluing, without specific restrictions. In practical applications, the installation method can be determined according to the specific installation environment.

[0027] The brake 1 provided in this embodiment of the present invention has at least the following technical effects compared with the prior art: In the above-mentioned brake 1 technical solution, a mounting ear 23 is arranged on the outer periphery of the armature 20. The mounting ear 23 protrudes radially from the outer periphery of the stator 10. The brake 1 is fixedly connected to the target device 2 through the mounting ear 23, and can be optionally arranged adjacent to the mounting surface of the target device 2 through the third end face 21 or the fourth end face 22 of the armature 20. During braking, the armature 20 and the movable plate 60 will not move relative to the mounting surface, but the stator 10 will move relative to the mounting surface. With the surface moving axially, the stator 10 does not need to be machined with the corresponding hole structure of the fitting 70, reducing machining steps and production costs. Since the mounting ear 23 is located outside the stator 10, it is far away from the friction pair, which can avoid contaminating the friction pair and improve braking reliability. Furthermore, the radial dimension of the mounting ear 23 is larger than the outer diameter of the stator 10, which can accommodate larger installation requirements without the need for additional mounting plates, thus reducing the overall weight. It also provides greater dimensional adaptability for methods such as drilling, welding, and snap-fit.

[0028] The following example illustrates the specific structure of the mounting ear 23, but is not limited to the following embodiments.

[0029] Please see Figures 1 to 11 In some embodiments, the mounting ear 23 has a mounting hole 231, and the brake 1 also includes a mounting member 80 passing through the mounting hole 231. In this embodiment, the mounting ear 23 is fixedly connected to the target device 2 by drilling. The mounting hole 231 is provided on the mounting ear 23, and the diameter of the distribution circle of the mounting hole 231 is larger than the outer diameter of the stator 10, which can adapt to the installation requirements of larger sizes. The mounting member 80 can be a connection structure such as a screw, bolt, or rivet. The mounting member 80 is located outside the stator 10. When thread-locking adhesive is applied to the mounting member 80 or the hole in the mounting surface, the thread-locking adhesive does not easily penetrate into the friction pair, which can avoid contaminating the friction pair and ensure braking reliability.

[0030] There are no specific limitations on the shape of the mounting hole 231. For example, the mounting hole 231 can be one of a smooth through hole, a countersunk hole, or a threaded hole. Figure 4As shown, mounting hole 231 is a countersunk hole, specifically a tapered countersunk hole, a cylindrical countersunk hole, a hexagonal countersunk hole, etc., in which case the head of the mounting part 80 can be partially or completely accommodated in the countersunk hole. The countersunk hole includes a head hole and a rod hole that connect with each other; such as... Figure 5 and Figure 11 As shown, the head hole is located on the third end face 21, and the fourth end face 22 is configured to be adjacent to the mounting surface of the target device 2. The mounting member 80 passes through the mounting hole 231 and is locked onto the mounting surface of the target device 2, or, as shown... Figures 1 to 3 , Figure 10 As shown, the head hole is located on the fourth end face 22, and the third end face 21 is configured to be adjacent to the mounting surface of the target device 2. The mounting member 80 passes through the mounting hole 231 and is locked onto the mounting surface of the target device 2.

[0031] like Figures 6 to 8 As shown, the mounting hole 231 is a threaded hole. Either the third end face 21 or the fourth end face 22 of the armature 20 is optionally adjacent to the mounting surface of the target device 2. The mounting member 80 passes through the mounting surface of the target device 2 and is locked within the mounting hole 231. Figure 9 As shown, the mounting hole 231 is a smooth through hole, and the third end face 21 or the fourth end face 22 of the armature 20 is optionally arranged adjacent to the mounting surface of the target device 2. The mounting part 80 passes through the mounting hole 231 and is locked on the mounting surface of the target device 2.

[0032] In some embodiments, the mounting ear 23 is integrally formed with the armature 20, or the mounting ear 23 and the armature 20 are fixedly connected together. Specifically, the mounting ear 23 may be integrally formed with the armature 20 by means of stamping, cutting, casting, etc., or the mounting ear 23 and the armature 20 may be made separately and fixedly connected together by means of welding, snap-fitting, bonding, riveting, etc.

[0033] Please see Figure 4 and Figure 9 In some embodiments, multiple mounting ears 23 are provided, and the multiple mounting ears 23 are evenly distributed on the outer periphery of the armature 20. In this embodiment, in order to improve the installation reliability of the brake 1, multiple mounting ears 23 are evenly arranged on the outer periphery of the armature 20 to ensure force balance.

[0034] The following example illustrates the connection structure between the brake 1 and the drive shaft of the target device 2, but is not limited to the following embodiments.

[0035] Please see Figure 1 , Figure 5 , Figure 6 , Figures 10 to 13In some embodiments, the brake 1 further includes a bushing 90, a friction disc 50 fitted around the outer periphery of the bushing 90, and a spring piece 100 between the friction disc 50 and the bushing 90, the spring piece 100 having a preload force away from the center of the bushing 90. With this configuration, during installation, the friction disc 50 is fitted around the outer periphery of the bushing 90, and the spring piece 100 automatically abuts against the inner circumferential surface of the friction disc 50, achieving a stable fit between the friction disc 50 and the bushing 90, reducing the hysteresis effect of the friction disc 50, and achieving a noise reduction effect.

[0036] Of course, in other embodiments, the friction disc 50 may not use the bushing 90 for transitional fit, but may be directly adapted to the drive shaft, and there are no specific restrictions on this.

[0037] Please see Figure 12 and Figure 13 In some specific embodiments, the bushing 90 has a plurality of alternating first teeth 91 and second teeth 92, the tooth width of the second teeth 92 being greater than or equal to the tooth width of the first teeth 91, and a plurality of spring pieces 100 respectively clamping on both sides of the plurality of second teeth 92. In this embodiment, the number of spring pieces 100 can be one or more, and they are arranged on the corresponding second teeth 92 according to actual design requirements.

[0038] The second tooth 92 can be a regular tooth or a non-standard tooth. If a single tooth is large enough, a portion of its top can be shaved off to form a non-standard tooth. If a single tooth is small, multiple teeth can be connected and a portion of their tops can be shaved off to form a non-standard tooth. The non-standard tooth provides an installation position for the spring 100, allowing the spring 100 to be more stably clamped on both sides of the non-standard tooth along its axial direction, making it less prone to positional displacement.

[0039] Please see Figure 12 and Figure 13In some specific embodiments, several second teeth 92 are provided with fixing holes 93 and spring slots. The fixing holes 93 and spring slots are located on different second teeth 92. The spring slots are used to install springs 100. It can be understood that the fixing holes 93 and springs 100 are located on different second teeth 92. In this embodiment, the number of fixing holes 93 can be one or more, and they are set on the corresponding second teeth 92 according to the actual design requirements. The fixing holes 93 are used to connect the bushing 90 and the drive shaft. In order to avoid physical contact interference, the fixing holes 93 and spring slots are set on different second teeth 92. The second teeth 92 used to set the fixing holes 93 can be ordinary teeth or irregular teeth. When using irregular teeth, space can be provided for the fixing holes 93 when the radial width of the bushing 90 is small. The two ends of the fixing holes 93 have U-shaped grooves, and the two ends of the central hole of the bushing 90 have countersunk holes, which communicate with the U-shaped grooves. The spring slot is used to install the spring 100. When the radial width of the bushing 90 is small, to avoid a thin wall forming between the spring slot and the central hole of the bushing 90, the spring slot can be extended to communicate with the central hole of the bushing 90, such as... Figure 13 As shown, the cross-sectional shape of the spring slot is an isosceles trapezoid.

[0040] Furthermore, the brake 1 provided in this embodiment of the present invention may also include multiple friction discs 50 and multiple movable plates 60. In combination with the above-mentioned case where only one friction disc 50 and one movable plate 60 are provided, in summary, in the brake 1 provided in this embodiment of the present invention, there are N friction discs 50 and N movable plates 60, where N is an integer greater than or equal to 1. The N movable plates 60 and the N friction discs 50 are alternately arranged. The Nth movable plate 60 is arranged adjacent to the Nth friction disc 50. The Nth friction disc 50 is arranged adjacent to the limiting step 13. The first movable plate 60 is fixedly connected to the armature 20 through the fitting 70. In the axial direction, the Nth friction disc 50 can abut against the Nth movable plate 60 and the limiting step 13, and each of the remaining friction discs 50 can abut against two adjacent movable plates 60.

[0041] Specifically, the first movable plate 60 is the one furthest from the armature 20. The first movable plate 60 is fixedly connected to the armature 20 through the fitting 70. The remaining movable plates 60 are not connected to the armature 20. The N friction discs 50 and the remaining movable plates 60 are alternately arranged between the first movable plate 60 and the limiting step 13. After the brake 1 is installed on the target device 2, the N friction discs 50 are adapted to the drive shaft of the target device 2 through the bushing 90.

[0042] The brake 1 is fixedly connected to the target device 2 via the mounting lug 23 of the armature 20. When the target device 2 does not need to be braked, the coil 30 generates a magnetic field when energized, causing the stator 10 to overcome the elastic force of the elastic member 40 and move towards the armature 20, increasing the distance between the first movable plate 60 and the limiting step 13, thereby releasing the pressure of the N movable plates 60 on the N friction discs 50.

[0043] When the target device 2 needs to be braked, the coil 30 is de-energized. Under the elastic force of the elastic element 40, the stator 10 moves away from the armature 20, reducing the distance between the first movable plate 60 and the limiting step 13. The clamping force is transmitted through the stator 10 to each friction disc 50 and the movable plate 60, thereby achieving the clamping of N movable plates 60 on N friction discs 50.

[0044] In this embodiment of the utility model, when both friction disc 50 and movable plate 60 are provided, friction disc 50 achieves a pressing effect by relying on movable plate 60 and limiting step 13. When both friction disc 50 and movable plate 60 are provided in multiple ways, multiple friction discs 50 achieve a pressing effect by relying on adjacent movable plate 60 and limiting step 13.

[0045] It is understood that the parts in the above embodiments can be freely combined or deleted to form different combined embodiments. The specific contents of each combined embodiment will not be repeated here. After this description, it can be considered that the specification has recorded each combined embodiment and can support different combined embodiments.

[0046] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A brake, characterized in that, include: The stator has a first end face and a second end face in the axial direction, and the inner periphery of the stator has a limiting step, which makes the inner periphery of the stator form a limiting space facing the first end face; An armature is disposed adjacent to the second end face. The armature has a third end face close to the second end face and a fourth end face away from the second end face. The outer periphery of the armature has a mounting lug that protrudes radially from the outer periphery of the stator. The coil is located within the stator; An elastic element is disposed within the stator; A friction disc is disposed within the aforementioned limiting space; A movable plate is disposed within the limiting space, and the friction disc is located between the movable plate and the limiting step; and The assembly is fixedly connected to the armature and the movable plate; The brake is fixedly connected to the target device via the mounting ear, and is optionally arranged adjacent to the mounting surface of the target device via the third end face or the fourth end face. During braking, the armature and the movable plate do not move relative to the mounting surface, but the stator moves axially relative to the mounting surface.

2. The brake according to claim 1, characterized in that, The mounting ear has a mounting hole, and the brake also includes a mounting member that passes through the mounting hole.

3. The brake according to claim 2, characterized in that, The mounting hole is one of the following: a smooth through hole, a countersunk hole, or a threaded hole.

4. The brake according to claim 3, characterized in that, The mounting hole is a countersunk hole, which includes a head hole and a rod hole that are connected to each other; the head hole is located on the third end face, and the fourth end face is configured to be adjacent to the mounting surface of the target device, or the head hole is located on the fourth end face, and the third end face is configured to be adjacent to the mounting surface of the target device.

5. The brake according to claim 1, characterized in that, The mounting lug is integrally formed with the armature, or the mounting lug and the armature are fixedly connected together.

6. The brake according to claim 1, characterized in that, The mounting ears are provided in multiple ways, and the multiple mounting ears are evenly distributed on the outer periphery of the armature.

7. The brake according to claim 1, characterized in that, The brake also includes a bushing, the friction disc is sleeved on the outer periphery of the bushing, and a spring is provided between the friction disc and the bushing, the spring having a preload force away from the center of the bushing.

8. The brake according to claim 7, characterized in that, The bushing has a plurality of alternating first teeth and second teeth, the width of the second teeth being greater than or equal to the width of the first teeth, and a plurality of spring pieces being respectively clamped on both sides of the plurality of second teeth.

9. The brake according to claim 8, characterized in that, Several second teeth are provided with fixing holes, and the fixing holes and the spring piece are located on different second teeth.

10. The brake according to any one of claims 1 to 9, characterized in that, Both the friction disc and the movable plate are provided in N units, where N is an integer greater than or equal to 1. The N movable plates and the N friction discs are arranged alternately. The Nth movable plate is arranged adjacent to the Nth friction disc. The Nth friction disc is arranged adjacent to the limiting step. The first movable plate is fixedly connected to the armature through the assembly. In the axial direction, the Nth friction disc can abut against the Nth movable plate and the limiting step, and each of the remaining friction discs can abut against two adjacent movable plates.

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