CN107339339B

CN107339339B - Brake and motor

Info

Publication number: CN107339339B
Application number: CN201710566242.0A
Authority: CN
Inventors: 杨�一; 陈世国; 尚文海; 彭玉礼; 肖胜宇; 钟成堡
Original assignee: Gree Green Refrigeration Technology Center Co Ltd of Zhuhai
Current assignee: Gree Green Refrigeration Technology Center Co Ltd of Zhuhai
Priority date: 2017-07-12
Filing date: 2017-07-12
Publication date: 2023-07-14
Anticipated expiration: 2037-07-12
Also published as: CN107339339A

Abstract

The invention provides a brake and a motor. The brake comprises a braking stator (1), a driving mechanism and friction plates (2), wherein the friction plates (2) are movably arranged relative to the braking stator (1) along the radial direction of the braking stator (1), and the driving mechanism is in driving connection with the friction plates (2) so as to enable the friction plates (2) to be positioned at a first radial position for braking along the radial direction and a second radial position for releasing the braking. According to the brake, the axial height of the brake can be effectively reduced, and the motor miniaturization is facilitated.

Description

Brake and motor

Technical Field

The invention belongs to the technical field of motor equipment, and particularly relates to a brake and a motor.

Background

The electromagnetic brake is an important basic component, integrates mechanical, electric and electronic technologies, and is mainly used for precisely controlling and braking a rotating mechanism (such as a motor device and the like).

As shown in fig. 1, a conventional brake generally includes a stator 1', an armature 2', a friction plate 3', a square wheel 4', a column sleeve 5', a baffle 6', etc., wherein the square wheel 4 'is mounted on the friction plate 3', and the square wheel 4 'is used for being connected with an external rotating shaft so as to be driven by the external rotating shaft to drive the friction plate 3' to rotate together. The baffle 6' is positioned at one side of the friction plate 3' and is fixedly connected with the stator 1 '. The baffle 6' is used to limit the friction plate 3' and to provide support for the friction plate 3' during braking.

The stator 1', the armature 2', the friction plate 3 'and the baffle 6' of the brake are sequentially arranged along the axial direction of the stator 1', and the rotating shaft brake is realized through the square wheel 4'. Since the respective components of the brake are disposed in the axial direction, the axial height of the brake is increased, thereby increasing the volume of the brake, which is disadvantageous in achieving miniaturization of the motor.

Disclosure of Invention

Therefore, the technical problem to be solved by the invention is to provide the brake and the motor, which can effectively reduce the axial height of the brake and facilitate the miniaturization of the motor.

In order to solve the above-mentioned problems, the present invention provides a brake including a brake stator, a driving mechanism, and a friction plate movably disposed with respect to the brake stator in a radial direction of the brake stator, the driving mechanism being drivingly connected to the friction plate so that the friction plate is located at a first radial position where braking is performed in a radial direction and a second radial position where braking is released.

Preferably, the braking stator comprises an axial through hole, the driving mechanism and the friction plate are sequentially arranged from outside to inside along the radial direction of the axial through hole, and the friction plate is arranged in the axial through hole.

Preferably, the drive mechanism includes a coil, an armature and a return member for providing opposing radial forces to the friction plate when the coil is energized.

Preferably, the plurality of groups of friction plates are arranged at intervals along the circumferential direction, the armatures are fixedly connected with the friction plates, and the coils, the armatures and the friction plates of each group are arranged in one-to-one correspondence.

Preferably, the number of friction plates is 3 to 5 groups.

Preferably, the return member is a spring provided radially on an inner peripheral side of the braking stator, one end of the spring is pressed against the braking stator, the other end of the spring is pressed against an outer peripheral side of the armature, and when the coil is energized, the armature receives a magnetic force that moves toward the outer peripheral side to press the spring.

Preferably, the return member is a spring disposed radially on an inner peripheral side of the braking stator, one end of the spring is fixedly connected to the braking stator, the other end of the spring is fixedly connected to the armature and provides a tensioning force to the armature, and when the coil is energized, the armature is subjected to a magnetic force moving toward a central axis of the braking stator to stretch the spring.

Preferably, the two ends of the armature are provided with radially outwardly extending lugs, each end is provided with two oppositely arranged lugs, the two lugs at each end are respectively located at two axial ends of the braking stator, a guide post is connected between the two lugs at each end, the braking stator is provided with a guide hole, and the guide post is arranged in the guide hole and enables the lugs to move radially relative to the braking stator.

Preferably, the guide post is in interference fit with the guide hole, the lug plate is provided with a connecting hole, and the guide post is arranged in the connecting hole in a penetrating way and is in clearance fit with the connecting hole; or, the guide post is in clearance fit with the guide hole, the lug plate is provided with a connecting hole, and the guide post is arranged in the connecting hole in a penetrating way and in interference fit with the connecting hole.

Preferably, the braking stator is integrally formed or laminated.

Preferably, the brake further comprises an insulating framework, the insulating framework is fixedly arranged at two axial ends of the brake stator, and the coil is wound on the insulating framework.

Preferably, the insulating framework is in interference fit or adhesive fixation with the braking stator.

Preferably, the brake further comprises a brake column disposed in the axial through hole and located on an inner peripheral side of the friction plate, and when the friction plate is located at the second radial position, a radial gap is provided between an outer periphery of the brake column and an inner periphery of the friction plate.

Preferably, the gap is 0.15mm to 0.2mm.

Preferably, the outer peripheral wall surface of the brake post is rugged.

Preferably, the outer peripheral wall surface of the brake post has a texture.

According to another aspect of the present invention, there is provided an electric motor comprising a brake as described above.

Preferably, the motor further comprises a motor stator and a magnetism isolating ring, wherein the magnetism isolating ring is made of non-magnetic conductive materials, and the motor stator, the magnetism isolating ring and the braking stator are sequentially arranged and fixedly connected along the axial direction of the braking stator.

Preferably, the shape of the magnetism isolating ring is consistent with the shape of the motor stator.

Preferably, the magnetism isolating ring is laminated.

The invention provides a brake, which comprises a braking stator, a driving mechanism and a friction plate, wherein the friction plate is movably arranged relative to the braking stator along the radial direction of the braking stator, and the driving mechanism is in driving connection with the friction plate so that the friction plate is positioned at a first radial position for braking along the radial direction and a second radial position for releasing the braking. The brake brakes by controlling the radial and radial positions of the friction plates, so that the friction plates can move along the radial direction of the braking stator, the friction plates and other structures are not required to be arranged along the axial direction of the braking stator, the axial height of the brake can be reduced, the whole length of the motor is shortened, and the motor is miniaturized. In addition, because the friction plate carries out friction braking through the ring surface, the braking friction area of the friction plate can be effectively increased, so that the volume of the brake can be reduced as a whole, the effective braking capability of the brake can still be ensured, and the motor miniaturization can be realized more conveniently.

Drawings

FIG. 1 is a cross-sectional structural view of a prior art brake;

FIG. 2 is a cross-sectional block diagram of a brake according to an embodiment of the present invention;

FIG. 3 is an assembled block diagram of a brake stator, armature and friction plate of a brake in accordance with an embodiment of the present invention;

fig. 4 is a perspective view of a magnetism isolation ring of a motor according to an embodiment of the present invention;

FIG. 5 is an assembled block diagram of the motor of the embodiment of the invention with the motor shaft removed from the brake, magnetism isolating ring and motor stator;

FIG. 6 is a block diagram of the assembly of a brake post and a motor shaft of a motor according to an embodiment of the present invention;

fig. 7 is an assembly structure diagram of a brake, a magnetism blocking ring, and a motor stator of a motor according to an embodiment of the present invention.

The reference numerals are expressed as:

1. braking the stator; 2. a friction plate; 3. an axial through hole; 4. a coil; 5. an armature; 6. a return piece; 7. ear plates; 8. a guide post; 9. a connection hole; 10. an insulating skeleton; 11. a brake column; 12. a motor stator; 13. a magnetism isolating ring; 14. a motor shaft; 15. and a connection key.

Detailed Description

Referring to fig. 2 to 7 in combination, according to an embodiment of the present invention, a brake includes a brake stator 1, a driving mechanism, and a friction plate 2, the friction plate 2 being movably disposed with respect to the brake stator 1 in a radial direction of the brake stator 1, the driving mechanism being drivingly connected to the friction plate 2 so that the friction plate 2 is located at a first radial position where braking is performed in a radial direction and a second radial position where braking is released.

The radial position of the friction plate 2 is controlled to brake the motor shaft 14, so that the friction plate 2 can move along the radial direction of the braking stator 1, the friction plate 2 and other structures are not required to be arranged along the axial direction of the braking stator 1, the axial height of the brake can be reduced, the whole length of the motor is shortened, and the motor is miniaturized. In addition, because friction plate 2 carries out friction braking to motor shaft 14 through the anchor ring, can effectively increase friction plate 2 to the braking friction area of motor shaft 14, consequently can reduce the volume of stopper on the whole, still can guarantee the effective braking ability of stopper, be favorable to realizing the miniaturization of motor more.

The brake can brake the motor shaft by radial movement of the friction plate 2 in an electromagnetic braking mode, and can brake the motor shaft by radial movement of the friction plate 2 in other mechanical braking modes, so long as the original axial friction braking of the friction plate 2 can be adjusted to radial friction braking in the invention, and the brake belongs to the protection scope of the application.

Preferably, the braking stator 1 comprises an axial through hole 3, the driving mechanism and the friction plate 2 are sequentially arranged from outside to inside along the radial direction of the axial through hole 3, and the friction plate 2 is arranged in the axial through hole 3. The braking stator 1 is provided with the axial through hole 3, and the driving mechanism and the friction plate are arranged in the axial through hole 3, so that the inner space of the braking stator 1 can be more effectively utilized, the whole length of the brake is prevented from being increased along the axial direction, the whole length of the motor is more favorably shortened, and the miniaturization and the light-weight of the motor are realized. Because actuating mechanism and friction disc 2 set gradually in axial through-hole 3 along the radial direction from outside to inside, consequently can make actuating mechanism more convenient follow radial to friction disc 2 drive, realize the operation to the braking of motor shaft 14 or release the braking, structural arrangement is simple and convenient more, and the cost is lower, and space utilization is higher.

Preferably, in this embodiment, the braking is performed by electromagnetic braking, and the driving mechanism includes a coil 4, an armature 5 and a return member 6, where the armature 5 and the return member 6 are configured to provide opposite radial forces to the friction plate 2 when the coil 4 is energized. When the coil 4 is energized, an electromagnetic force can be applied to the armature 5 such that the armature 5 moves in the radial direction of the brake stator 1, in which case the armature 5 can drive the friction plate 2 toward the first radial position or the second radial position. Be provided with the wrapping post on braking stator 1, the circumference both sides of wrapping post all are provided with the winding hole, and coil 4 twines outside the wrapping post from the winding hole department, realizes the installation of coil 4.

For example, when the coil 4 is energized, the armature 5 moves against the force of the return 6 toward the first radial position, at which time the armature 5 drives the friction plate 2 toward the first radial position, such that the friction plate 2 reaches the braking position, braking the motor shaft 14. When the coil is deenergized, the armature 5 is no longer subjected to electromagnetic force, and under the restoring action of the restoring piece 6, the friction plate 2 returns to the second radial position, and the braking of the motor shaft 14 is released.

For another example, when the coil 4 is energized, the armature 5 moves against the force of the return 6 toward the second radial position, at which time the armature 5 drives the friction plate 2 toward the second radial position, such that the friction plate 2 reaches the brake release position, releasing the brake to the motor shaft 14. When the coil 4 is de-energized, the armature 5 is no longer subjected to electromagnetic forces, and the friction plate 2 returns to the first radial position under the return action of the return member 6, braking the motor shaft 14.

In this embodiment, the armature 5 drives the friction plate 2 to brake when the coil 4 is energized, and the friction plate 2 releases the braking mode under the recovery action of the recovery piece 6 when the coil 4 loses electricity, so that the power supply and the power loss of the coil 4 are consistent with those of the motor, and the motor shaft 14 can be effectively braked under the condition of power loss after the motor loses electricity or fails, thereby improving the safety and the reliability of the motor operation.

Preferably, the friction plates 2 are circumferentially arranged at intervals, the armature 5 is fixedly connected with the friction plates 2, and the coil 4, the armature 5 and the friction plates 2 of each group are arranged in a one-to-one correspondence. The armature 5 and the friction plate 2 can be fixed by gluing, for example, station street fixing is performed by anaerobic glue, and the armature 5 is machined by adopting soft magnetic materials. The friction plates 2 are arranged at intervals along the circumferential direction, so that the friction plates 2 can be ensured not to interfere with each other when moving along the radial direction, and the normal and effective braking and releasing braking of the friction plates 2 can be ensured. Because multiunit friction disc 2 sets up along circumference interval, consequently can follow the circumference a plurality of positions of motor shaft 14 and carry out friction braking to motor shaft 14, the precision requirement to friction disc 2 is lower, and effective friction area when friction disc 2 brakes motor shaft 14 is bigger, and circumference friction force distributes more evenly, and the friction effect is better. In addition, the coil 4, the armature 5 and each group of friction plates 2 are arranged in a one-to-one correspondence mode, so that motion control of the friction plates 2 can be effectively guaranteed, materials consumption is less, control is more convenient and effective, and control efficiency is higher. The number of the friction plates 2 in each group may be one or a plurality, and may be specifically selected as required.

Because friction disc 2 and armature 5 all adopt the block type structure, and be fixed connection as an organic whole between friction disc 2 and the armature 5, consequently can improve the structural strength of friction disc 2, improve the whole reliability of stopper. In addition, since the friction plate 2 is fixedly connected with the armature 5, when the brake is in a brake release state, the friction plate 2 can be always separated from the motor shaft 14 through the armature 5 for braking, so that the motor shaft 14 cannot generate direct or indirect friction with the friction plate 2 in the rotating process, and friction noise cannot be generated.

The number of the braking stators 1 may be determined according to the number of the friction plates 2, and the braking stators 1 may include a plurality of stator blocks fixedly arranged along the circumferential direction to form an annular braking stator 1. The braking stator 1 may also be of unitary construction. Adjacent stator blocks can be fixed through welding, so that the structural strength of the braking stator 1 is improved.

The braking stator 1 may be integrally formed or laminated. When the brake stator 1 is laminated and formed, the brake stator 1 can be laminated by self-adhesive silicon steel sheets, and at the moment, the brake stator 1 can be laminated by adopting the same process as the motor stator 12, so that the machining process can be omitted, and the machining cost can be reduced. The braking stator 1 can be made of electrical pure iron or No. 10 steel and other soft magnetic materials.

Preferably, the number of friction plates 2 is 3 to 5 groups. When the number of the friction plates 2 is too small, the processing precision requirement on the friction plates 2 is high, so that the friction plates 2 have enough effective friction area when the motor shaft 14 is braked, and the processing cost is increased; when the number of the friction plates 2 is too large, the friction plates 2 are inconvenient to install, the efficiency of installing and detaching is low, the assembly of the brake is not facilitated, and the assembly efficiency of the brake is reduced.

Preferably, the restoring member 6 is a spring provided radially on the inner peripheral side of the braking stator 1, one end of the spring being pressed against the braking stator 1, the other end of the spring being pressed against the outer peripheral side of the armature 5, the armature 5 being subjected to a magnetic force which moves to the outer peripheral side to press the spring when the coil 4 is energized. A spring hole is provided on the inner peripheral side of the brake stator 1, and a spring is provided in the spring hole. Preferably, two spring holes are arranged in each winding column and are arranged along the axial direction of the braking stator 1 at intervals, so that more balanced and stable pressing force can be provided for the friction plate 2, and the friction force provided by the friction plate 2 for the motor shaft 14 is more stable and balanced, and the braking effect is better. When the brake works, the coil 4 is electrified, the armature 5 is subjected to magnetic force of the coil, and the elastic force of the spring is overcome, so that the friction plate 2 is driven to move towards the second radial position, and the brake releasing operation of the motor shaft 14 is completed. When the coil 4 is powered off, the armature 5 drives the friction plate 2 to move towards the first radial position under the action of the elastic force of the spring, so that the motor shaft 14 is braked.

In another embodiment, not shown in the drawings, the return member 6 is a spring provided radially on the inner peripheral side of the braking stator 1, one end of the spring being fixedly connected to the braking stator 1, the other end of the spring being fixedly connected to the armature 5 and providing a tightening force to the armature 5, the armature 5 being subjected to a magnetic force moving toward the center axis of the braking stator 1 to stretch the spring when the coil 4 is energized. In this embodiment, when the brake is operated, the coil 4 is energized, the armature 5 is subjected to the magnetic force of the coil, and overcomes the tension of the spring, so as to drive the friction plate 2 to move toward the first radial position, and complete the braking operation of the motor shaft 14. When the coil 4 is powered off, the armature 5 drives the friction plate 2 to move towards the second radial position under the action of the tension of the spring, so that the brake of the motor shaft 14 is released.

Preferably, the two ends of the armature 5 are provided with radially outwardly extending lugs 7, each end has two oppositely disposed lugs 7, the two lugs 7 of each end are respectively located at two axial ends of the braking stator 1, a guide post 8 is connected between the two lugs 7 of each end, the braking stator 1 has a guide hole, the guide post 8 is disposed in the guide hole, and the lugs 7 are radially movable relative to the braking stator 1. The cooperation of guiding hole, guide post 8 and otic placode 7 can make otic placode 7 take place radial position for braking stator 1 to make armature 5 can take place radial displacement for braking stator 1, and then can drive friction disc 2 through armature 5 and accomplish the operation to the braking of motor shaft 14 and release the braking, simple structure easily realizes, is difficult to appear armature 5 for the dead phenomenon of card of braking stator 1, has guaranteed the effectiveness and the security of braking of stopper braking and release.

In one embodiment, the guide post 8 is in interference fit with the guide hole, the lug plate 7 is provided with a connecting hole 9, and the guide post 8 is arranged in the connecting hole 9 in a penetrating way and is in clearance fit with the connecting hole 9. In this embodiment, the guide post 8 is in interference fit with the guide hole, and the laminated braking stator 1 can be guided during assembly through the guide post 8, so that the rapid and accurate assembly of the braking stator 1 is ensured, and the assembly efficiency of the braking stator 1 is improved. Because the guide post 8 is in clearance fit with the connecting hole 9, enough movement clearance can be provided for radial displacement of the armature 5 through the connecting hole 9, and the armature 5 can be ensured to smoothly drive the friction plate 2 to finish braking and braking releasing operation.

In another embodiment, the guide post 8 is in clearance fit with the guide hole, the lug plate 7 is provided with a connecting hole 9, and the guide post 8 is arranged in the connecting hole 9 in a penetrating way and is in interference fit with the connecting hole 9. In this embodiment, the guide post 8 is in excessively hard fit with the connecting hole 9, and the guide post 8 is in clearance fit with the guide hole on the braking stator 1, so that the armature 5 drives the friction plate 2 to complete braking and braking releasing operations through radial displacement of the guide post 8 relative to the braking stator 1.

Preferably, the brake further comprises two insulating bobbins 10, the two insulating bobbins 10 are fixedly arranged at two axial ends of the brake stator 1, and the coil 4 is wound on the insulating bobbins 10. The insulating framework 10 can provide an installation position for the installation of the coil 4, and can ensure the accuracy of the winding position of the coil 4 and improve the electromagnetic performance of the coil 4.

Preferably, the insulating framework 10 is in interference fit or glued fixation with the braking stator 1, and when the insulating framework 10 and the braking stator 1 are glued and fixed, the insulating framework 10 and the braking stator 1 can be fixed on the braking stator 1 through anaerobic glue. When the insulating framework 10 is in interference fit with the braking stator 1, an axial protrusion can be arranged on the braking stator 1 at a position corresponding to the inner peripheral side or the outer peripheral side of the insulating framework 10, so that the insulating framework 10 is sleeved on the axial protrusion of the braking stator 1, and interference fit of the insulating framework and the braking stator is realized.

Preferably, the brake further comprises a brake post 11, the brake post 11 being arranged in the axial through hole 3 and being located at the inner circumferential side of the friction plate 2, the outer circumference of the brake post 11 having a radial clearance with the inner circumference of the friction plate 2 when the friction plate 2 is located at the second radial position. The brake column 11 is fixedly connected with the motor shaft 14 in the circumferential direction, so that the brake column 11 and the motor shaft 14 cannot rotate in the circumferential direction, when the friction plate 2 brakes, the friction plate is tightly held on the outer circumferential side of the brake column 11 and forms larger friction with the brake column 11, and therefore the brake column 11 brakes, and because the brake column 11 is fixedly connected with the motor shaft 14 in the circumferential direction, the brake column 11 can brake the motor shaft 14, and therefore the motor shaft 14 brakes. Because the friction braking of the friction plate 2 directly acts on the braking column 11 rather than directly acts on the motor shaft 14, the abrasion damage of the motor shaft 14 caused by the direct friction between the friction plate 2 and the motor shaft 14 can be avoided, and the service life of the motor shaft 14 can be effectively prolonged. In addition, the brake post 11 can be made of wear-resistant materials, and a friction-increasing structure can be arranged on the periphery of the brake post 11, so that braking of the motor shaft 14 is easier to achieve, the friction braking effect is better, the cost is lower, and the braking performance of the brake is better. After the friction of the brake column 11 fails, the brake column 11 can be directly replaced without replacing the motor shaft 14, so that the use cost of the motor shaft 14 is reduced. The brake post 11 and the motor shaft 14 can be connected by a connecting key 15, so that circumferential transmission is realized.

Preferably, the gap is 0.15 mm-0.2 mm, so that the brake can be ensured to brake rapidly, and meanwhile, the friction plate 2 and the brake column 11 are prevented from being contacted when the brake is released, and noise is prevented from being generated.

Preferably, the outer circumferential wall surface of the brake column 11 is rugged, so that the rotational friction between the friction plate 2 and the brake column 11 can be increased, and the braking effect can be improved.

In this embodiment, the outer peripheral wall surface of the brake column 11 has a reticulation, so that the distribution of the friction structure on the outer peripheral side of the brake column 11 is more uniform, the friction force distribution is more uniform, the holding force between the friction plate 2 and the brake column 11 is larger, and the braking performance is better. Of course, other friction-increasing structures, such as a boss structure, etc., may be provided on the outer peripheral wall surface of the brake post 11.

According to an embodiment of the invention, the motor comprises a brake, which is the brake described above.

Preferably, the motor further comprises a motor stator 12 and a magnetism isolating ring 13, wherein the magnetism isolating ring 13 is made of a non-magnetic conductive material, and the motor stator 12, the magnetism isolating ring 13 and the braking stator 1 are sequentially arranged and fixedly connected along the axial direction of the braking stator 1. The braking stator 1 is fixedly arranged on the motor stator 12 through the magnetism isolating ring 13 and is combined with the motor stator 12 into a whole, the structure is simpler, the matching structure of the braking stator 1 and a motor end cover is not required, the installation step is simpler, the reliability is high, and the processing cost can be reduced. The magnetism isolating ring 13 can isolate the cross influence of the magnetic circuits of the braking stator 1 and the motor stator 12, so that the respective magnetic effect is ensured, the effective working performance of the brake is ensured, the normal operation of the motor stator 12 is ensured, and the stability and the reliability of the motor structure are improved. The motor stator 12, the magnetism isolating ring 13 and the braking stator 1 can be fixedly connected together by welding or bolting.

Preferably, the shape of the magnetism isolating ring 13 is consistent with that of the motor stator 12, so that the magnetism isolating ring 13 can be manufactured by adopting the same process as that of the motor stator 12, the processing cost of the magnetism isolating ring 13 is reduced, and the processing efficiency of the magnetism isolating ring is improved.

Preferably, in this embodiment, the magnetism blocking rings 13 are laminated. The magnetism isolating ring 13 is formed by stacking non-magnetic conductive material sheets, and the blocking type magnetism isolating blocks are enclosed into a ring shape through a tool and then fixed through a welding machine. The non-magnetic material is, for example, austenite, stainless steel 304, aluminum, plastic, or the like.

It will be readily appreciated by those skilled in the art that the above advantageous ways can be freely combined and superimposed without conflict.

The foregoing description of the preferred embodiments of the invention is not intended to be limiting, but rather is intended to cover all modifications, equivalents, and alternatives falling within the spirit and principles of the invention. The foregoing is merely a preferred embodiment of the present invention, and it should be noted that it will be apparent to those skilled in the art that modifications and variations can be made without departing from the technical principles of the present invention, and these modifications and variations should also be regarded as the scope of the invention.

Claims

1. A brake, characterized by comprising a braking stator (1), a drive mechanism and a friction plate (2), the friction plate (2) being arranged movably relative to the braking stator (1) in a radial direction of the braking stator (1), the drive mechanism being in driving connection with the friction plate (2) so that the friction plate (2) is in a first radial position for braking in a radial direction and in a second radial position for releasing braking;

the driving mechanism comprises a coil (4), an armature (5) and a restoring piece (6), wherein when the coil (4) is electrified, the armature (5) and the restoring piece (6) are used for providing radial acting forces with opposite directions for the friction plate (2);

the two ends of the armature (5) are respectively provided with a lug plate (7) extending radially outwards, each end is provided with two lug plates (7) which are oppositely arranged, the two lug plates (7) at each end are respectively positioned at the two axial ends of the braking stator (1), a guide post (8) is connected between the two lug plates (7) at each end, the braking stator (1) is provided with a guide hole, and the guide post (8) is arranged in the guide hole and enables the lug plates (7) to be radially movable relative to the braking stator (1).

2. Brake according to claim 1, characterized in that the brake stator (1) comprises an axial through-hole (3), the drive mechanism and the friction plate (2) being arranged in sequence from outside to inside in the radial direction of the axial through-hole, the friction plate (2) being arranged in the axial through-hole (3), the friction plate (2) having an annular surface facing away from the inner surface of the axial through-hole (3).

3. The brake according to claim 2, wherein a plurality of groups of friction plates (2) are arranged at intervals along the circumferential direction, the armature (5) is fixedly connected with the friction plates (2), and the coil (4), the armature (5) and the friction plates (2) of each group are arranged in a one-to-one correspondence.

4. A brake according to claim 3, characterized in that the number of friction plates (2) is 3 to 5 groups.

5. A brake according to claim 2, characterized in that the return member (6) is a spring arranged radially on the inner circumferential side of the brake stator (1), one end of the spring being pressed against the brake stator (1), the other end of the spring being pressed against the outer circumferential side of the armature (5), the armature (5) being subjected to a magnetic force which presses the spring in a movement towards the outer circumferential side when the coil (4) is energized.

6. A brake according to claim 2, characterized in that the return member (6) is a spring arranged radially on the inner circumferential side of the brake stator (1), one end of the spring being fixedly connected to the brake stator (1), the other end of the spring being fixedly connected to the armature (5) and providing a tightening force to the armature (5), the armature (5) being subjected to a magnetic force which moves towards the central axis of the brake stator (1) to stretch the spring when the coil (4) is energized.

7. Brake according to claim 1, characterized in that the guide post (8) is in interference fit with the guide hole, the lug plate (7) is provided with a connecting hole (9), and the guide post (8) is arranged in the connecting hole (9) in a penetrating way and is in clearance fit with the connecting hole (9); or, the guide post (8) is in clearance fit with the guide hole, the lug plate (7) is provided with a connecting hole (9), and the guide post (8) is arranged in the connecting hole (9) in a penetrating way and in interference fit with the connecting hole (9).

8. Brake according to any of claims 1 to 7, characterized in that the brake stator (1) is integrally formed or laminated.

9. Brake according to any one of claims 2 to 7, further comprising an insulating skeleton (10), the insulating skeleton (10) being fixedly arranged at both axial ends of the brake stator (1), the coil (4) being wound on the insulating skeleton (10).

10. Brake according to claim 9, characterized in that the insulating skeleton (10) is interference fit or adhesively fixed with the brake stator (1).

11. Brake according to any one of claims 2 to 7, 10, further comprising a brake post (11), said brake post (11) being arranged in said axial through hole (3) and being located on the inner circumferential side of said friction plate (2), the outer circumference of said brake post (11) having a radial clearance with the inner circumference of said friction plate (2) when said friction plate (2) is in the second radial position.

12. The brake of claim 11, wherein the gap is 0.15mm to 0.2mm.

13. Brake according to claim 11, characterized in that the outer circumferential wall surface of the brake column (11) is rugged.

14. Brake according to claim 13, characterized in that the outer circumferential wall surface of the brake column (11) has a reticulation.

15. An electric machine comprising a brake, characterized in that the brake is a brake as claimed in any one of claims 1 to 14.

16. The motor according to claim 15, further comprising a motor stator (12) and a magnetism isolating ring (13), wherein the magnetism isolating ring (13) is made of a non-magnetic conductive material, and the motor stator (12), the magnetism isolating ring (13) and the braking stator (1) are sequentially arranged and fixedly connected along the axial direction of the braking stator (1).

17. The electric machine according to claim 16, characterized in that the shape of the magnetism isolating ring (13) corresponds to the shape of the electric machine stator (12).

18. An electric machine according to claim 17, characterized in that the magnetism isolating ring (13) is laminated.