Hub motor with electromagnetic brake

Abstract

The utility model discloses a hub motor with an electromagnetic brake, and belongs to the field of hub motors. The motor mainly comprises a hub and a motor shaft, the motor shaft is provided with a rotor, the rotor is provided with a central shaft sleeve, a stator assembly surrounds the outer side of the central shaft sleeve, the central shaft sleeve is sleeved with a first fixing piece and a second fixing piece, the first fixing piece is fixed to the central shaft sleeve through screws, and a brake pad is arranged between the first fixing piece and the second fixing piece; a fixed cover is mounted on the hub through a bearing, the fixed cover is provided with an annular groove, and an electromagnetic coil is mounted in the annular groove; the fixing cover is provided with a pushing part which is powered on / off through the electromagnetic coil and suitable for controlling the second fixing piece to move front and back. According to the hub motor with the electromagnetic brake, the braking function is integrated between the fixing pieces of the rotor and the stator, internal space occupation is reduced, the second fixing piece is driven to drive the brake pad to make contact with or be separated from the first fixing piece through power-on or power-off of the electromagnetic coil, and braking is achieved.

Description

Technical Field

[0001] This utility model relates to the field of hub motor technology, and in particular to a hub motor with an electromagnetic brake. Background Technology

[0002] Hub motors, also known as electric wheels, are motors that integrate power, transmission, and braking devices all within the hub. They generally consist of the motor body (including stator and rotor; the stator is usually composed of stacked silicon steel sheets and windings, which generate a magnetic field when energized; the rotor has embedded permanent magnets or conductor bars that rotate under the influence of the magnetic field), a controller (which receives signals and regulates operating parameters such as motor voltage and current), and a reducer (some models have this feature, used to adjust speed and torque).

[0003] However, to meet braking requirements, traditional solutions require an additional independent brake disc. This component not only occupies the limited internal space of the hub motor but also necessitates component adaptation design (such as coaxiality calibration with the shaft and brake pads, and gap adjustment). This process not only increases assembly complexity but also increases the overall size and axial width of the hub motor. Furthermore, the traditional design commonly uses pull clips and their associated connectors and fasteners, forming a multi-level mechanical linkage structure. This structure involves a large number of parts and a complex assembly process. Therefore, a hub motor with an electromagnetic brake is needed.

[0004] It should be noted that the information disclosed in this background section is only for understanding the background technology of this application concept, and therefore may include information that does not constitute prior art. Utility Model Content

[0005] This utility model provides a hub motor with an electromagnetic brake to solve the problems of traditional hub motors requiring an additional independent brake disc for braking, which takes up space, increases assembly complexity and volume, and has many structural parts such as pull clips, making assembly cumbersome.

[0006] The present invention adopts the following technical solution: a hub motor with an electromagnetic brake, comprising a hub and a motor shaft, wherein a rotor is disposed on the motor shaft, the rotor having a central bushing, and a stator assembly surrounding the outer side of the central bushing, the stator assembly comprising a stator support and a stator core, the stator core being cylindrically sleeved on the outer side of the stator support and circumferentially positioned by a limiting pin, characterized in that: a first fixing plate and a second fixing plate are sleeved on the central bushing, the first fixing plate being fixed to the end face of the central bushing by screws, and a brake pad being disposed between the first fixing plate and the second fixing plate; a fixing cover is rotatably mounted on the hub via a bearing, the fixing cover having an annular groove, and an electromagnetic coil being installed in the annular groove; the fixing cover is provided with a pushing part adapted to control the back-and-forth movement of the second fixing plate by energizing / de-energizing the electromagnetic coil, so as to push the brake pad against the first fixing plate and drive the rotor to brake.

[0007] Preferably, the fixing cover has multiple sets of recessed holes on the side near the stator support. The pushing part includes springs installed in the recessed holes. One end of each set of springs is connected to a suction cup. The suction cup is connected to the second fixing plate through a stud through the stator support. At least two sets of studs are provided. The suction cup is magnetically connected to the electromagnetic coil.

[0008] Preferably, the wheel hub has a first outer shell and a second outer shell that cover both sides of the hub. The second outer shell consists of a plastic cover and an aluminum alloy cover. The aluminum alloy cover is fixed to the side of the wheel hub by screws. The fixing cover is installed inside the plastic cover. The aluminum alloy cover is used to support the bearing.

[0009] Preferably, a trigger body is sleeved on the motor shaft, with one end of the trigger body passing through the plastic cover. The plastic cover has an opening groove for the trigger body to move axially along the motor shaft. The trigger body is mounted on the fixed cover by a fastening unit. The fixed cover has multiple sets of steel balls on the side near the trigger body. The fixed cover has a steel ball recess that matches the diameter of the steel balls. At the same time, the trigger body has a steel ball hole that matches the steel balls. The depth of the steel ball recess is greater than the depth of the steel ball hole.

[0010] Preferably, the fastening unit includes a first screw that passes through the fixed cover. The fixed cover has a through hole through which the first screw passes. One end of the first screw is connected to a nut by a thread. The trigger body is fitted onto the first screw, and after the nut is tightened, it fits tightly against the side of the fixed cover, forming a positioning connection that can slide slightly axially.

[0011] In the initial state, when the electromagnetic coil is de-energized, the trigger body is initially connected to the fixing cover through the first screw and nut. The steel ball is embedded in the steel ball pit. Due to the difference in pit depth, part of the steel ball's volume is located in the steel ball hole, thus forming a mechanical lock and restricting the axial movement of the trigger body along the motor shaft. The fixing cover is connected to the second fixing plate through a suction cup plate. The second fixing plate presses against the brake pad to be in a braking state.

[0012] If manual release of the brake is required, the trigger body is manually pulled, and the trigger hole slides out of the steel ball. The steel ball is adapted to use the difference in the depth of the pit to push the trigger body out a distance of 0.5-5mm. The trigger body is adapted to drive the first screw to pull the suction cup plate, and the suction cup plate in turn drives the second fixing plate away from the brake pad, thereby realizing the release of the brake.

[0013] The trigger body is adapted to be pulled in the opposite direction to drive the steel ball back into the steel ball hole, and the second fixing plate presses the brake pad under the action of the spring to restore the braking state.

[0014] Preferably, a tire is mounted on the wheel hub.

[0015] The above-mentioned at least one technical solution adopted in this utility model embodiment can achieve the following beneficial effects: This hub motor with electromagnetic brake integrates the braking function between the rotor and the stator fixed plate, eliminating the need for a separate brake disc, reducing the internal space occupied, making the overall structure easy to assemble, and driving the second fixed plate to contact or separate the brake pad from the first fixed plate by energizing or de-energizing the electromagnetic coil, thereby achieving braking. Attached Figure Description

[0016] The accompanying drawings, which are provided to further illustrate the present invention and constitute a part of the present invention, illustrate exemplary embodiments of the present invention and are used to explain the present invention, but do not constitute an undue limitation of the present invention.

[0017] In the attached diagram:

[0018] Figure 1 This is an overall schematic diagram of a hub motor with an electromagnetic brake according to this application;

[0019] Figure 2 for Figure 1 A sectional view;

[0020] Figure 3 for Figure 2 A sectional view;

[0021] Figure 4 for Figure 1 A partial structural diagram;

[0022] Figure 5 for Figure 4A partial structural diagram;

[0023] Figure label:

[0024] 1. Hub; 2. Tire; 3. First housing; 4. Second housing; 41. Plastic cover; 42. Aluminum alloy cover; 5. Motor shaft; 6. Rotor; 61. Central bushing; 7. First fixing plate; 8. Brake pad; 9. Second fixing plate; 10. Stator assembly; 11. Electromagnetic coil; 12. Suction cup plate; 13. Stud; 14. Spring; 15. Trigger body; 16. Fixing cover; 17. Bearing; 18. Steel ball; 19. First screw; 110. Nut; 111. Stator core; 112. Steel ball hole; 113. Stator bracket. Detailed Implementation

[0025] To further illustrate the technical means and effects adopted by this utility model in order to achieve the intended utility model purpose, the following detailed description of the specific implementation methods, structure, features and effects of this utility model is provided in conjunction with the accompanying drawings and preferred embodiments.

[0026] The technical solutions provided by the various embodiments of this utility model are described in detail below with reference to the accompanying drawings.

[0027] Reference Figures 1 to 5 As shown, this utility model embodiment provides a hub motor with an electromagnetic brake, including a hub 1 and a motor shaft 5. The hub 1 serves as the basic frame of the motor. The motor shaft 5 is disposed in the inner hole of the hub 1 with an interference fit. A rotor 6 is disposed on the motor shaft 5. The rotor 6 has a central bushing 61. The rotor 6 is interference-fitted with the motor shaft 5 through its central bushing 61. A stator assembly 10 is surrounded on the outside of the central bushing 61. The stator assembly 10 consists of a stator bracket 113 and a stator core 111. The stator core 111 is cylindrical and sleeved on the outside of the stator bracket 113, and is circumferentially positioned by a limiting pin.

[0028] The central bushing 61 is fitted with a first fixing plate 7 and a second fixing plate 9. The first fixing plate 7 is fixed to the end face of the central bushing 61 by screws. A brake plate 8 is provided between the first fixing plate 7 and the second fixing plate 9. The first fixing plate 7 and the second fixing plate 9 are located in the central through hole of the stator bracket 113.

[0029] A fixed cover 16 is rotatably mounted on the hub 1 via a bearing 17. The fixed cover 16 has an annular groove in which an electromagnetic coil 11 is installed.

[0030] The fixed cover 16 is provided with a pushing part that controls the back-and-forth movement of the second fixed plate 9 by turning on / off the electromagnetic coil 11, so as to push the brake plate 8 against the first fixed plate 7 to drive the rotor 6 for braking.

[0031] Specifically, multiple sets of recessed holes are provided on the side of the fixed cover 16 near the stator support 113. The pushing part includes springs 14 installed in the recessed holes. One end of each set of springs 14 is connected to a suction cup plate 12. The suction cup plate 12 passes through the stator support 113 and is connected to the second fixed plate 9 by studs 13. There are three sets of studs 13. The suction cup plate 12 is magnetically connected to the electromagnetic coil 11.

[0032] When the electromagnetic coil 11 is energized, the motor enters normal operation. The specific process is as follows:

[0033] When the electromagnetic coil 11 is energized, it generates a magnetic field, which in turn generates an electromagnetic force. Since the suction cup 12 is magnetically connected to the electromagnetic coil 11, the electromagnetic force will attract the suction cup 12 towards the direction of the electromagnetic coil 11. At this time, the spring 14 in the recess on the fixing cover 16 is compressed because the electromagnetic force is greater than the elastic force of the spring 14.

[0034] The suction cup 12 is connected to the second fixing plate 9 through the stud 13. So when the suction cup 12 is attracted, it will drive the second fixing plate 9 to move backward together. After the second fixing plate 9 moves backward, the brake pad 8, which was originally located between the first fixing plate 7 and the second fixing plate 9, is separated from the first fixing plate 7, and the friction between the two disappears.

[0035] Specifically, the hub 1 has a first outer shell 3 and a second outer shell 4 covering both sides. The second outer shell 4 is composed of a plastic cover 41 and an aluminum alloy cover 42. The aluminum alloy cover 42 is fixed to the side of the hub 1 by screws. The fixing cover 16 is installed inside the plastic cover 41. The aluminum alloy cover 42 is used to support the bearing 17 and also to protect the internal components of the hub 1 to ensure the stability of the overall structure of the motor.

[0036] Specifically, a trigger body 15 is sleeved on the motor shaft 5. One end of the trigger body 15 passes through the plastic cover 41. The plastic cover 41 has an opening groove (not shown in the figure) for the trigger body 15 to move axially along the motor shaft 5. The trigger body 15 is mounted on the fixed cover 16 by a fastening unit. The fixed cover 16 has multiple sets of steel balls 18 on the side near the trigger body 15. The fixed cover 16 has a steel ball recess (not shown in the figure) that matches the diameter of the steel ball 18. The trigger body 15 has a steel ball hole 112 that matches the steel ball 18. The depth of the steel ball recess is greater than the depth of the steel ball hole 112.

[0037] Specifically, the fastening unit includes a first screw 19 that passes through the fixed cover 16. The fixed cover 16 has a through hole through which the first screw 19 passes. One end of the first screw 19 is connected to the nut 110 by a thread. The trigger body 15 is fitted onto the first screw 19, and after the nut 110 is tightened, it fits tightly against the side of the fixed cover 16, forming a positioning connection that can slide slightly axially.

[0038] In the initial state, when the electromagnetic coil 11 is de-energized, the trigger body 15 is initially connected to the fixed cover 16 through the first screw 19 and nut 110. The steel ball 18 is simultaneously embedded in the steel ball pit of the fixed cover 16, which has a larger depth, and the steel ball hole 112 of the trigger body 15, which has a shallower depth. Due to the difference in pit depth, part of the steel ball 18 is located in the steel ball hole 112, forming a mechanical lock and restricting the trigger body 15 from moving axially along the motor shaft 5. The fixed cover 16 is connected to the second fixed plate 9 through the suction cup plate 12. The second fixed plate 9 presses the brake plate 8, which is in a braking state.

[0039] When the electromagnetic coil 11 is energized, it generates magnetic force, which drives the trigger body 15 to move axially along the motor shaft 5. At this time, the steel ball hole 112 and the steel ball 18 gradually separate, and the steel ball 18 falls completely into the steel ball pit of the fixed cover 16 (because the pit is deeper). The steel ball 18 no longer restricts the movement of the trigger. The trigger drives the fixed cover 16, the suction cup plate 12 and the second fixed plate 9 to move to the left in sync. The second fixed plate 9 disengages from the brake plate 8, the braking friction disappears, and the motor shaft 5 can rotate freely.

[0040] The opening slot of the second housing 4 provides space for the trigger body 15 to move to the left, thus avoiding interference with the housing;

[0041] When manual release of the brake is required, an external force pulls the trigger body 15 to move axially along the motor shaft 5. One end of the trigger body 15 passes through the opening slot of the second housing 4. This opening slot provides clearance space for the left and right movement of the trigger body 15 to avoid interference with the housing. At the same time, the pulling force overcomes the friction between the steel ball 18 and the steel ball hole 112. The steel ball 18 slides out of the steel ball hole 112. Because the steel ball pit is deeper, the steel ball 18 tilts towards the pit side and falls into the steel ball pit, thereby pushing the trigger body 15 to move 0.7-1mm. The trigger body 15 pulls the suction cup plate 12 through the first screw 19. The suction cup plate 12 drives the second fixing plate 9 to disengage from the brake plate 8 through the stud 13, thus releasing the brake.

[0042] When the trigger body 15 is released, the second fixing plate 9 presses the brake pad 8 under the action of the return spring 14, restoring the braking state. At the same time, the trigger body 15, with the help of the first screw 19 and nut 110, drives the steel ball 18 to re-embed into the steel ball hole 112 and the steel ball recess.

[0043] The first screw 19 and nut 110 are not completely rigidly fixed, but allow a small axial sliding between the trigger body 15 and the fixed cover 16, which, together with the "pull out" action of the steel ball 18, realizes displacement transmission.

[0044] Specifically, the tire 2 mounted on the hub 1 is the final actuator for the motor's power output. When the electromagnetic coil 11 is energized, the stator assembly 10 generates a rotating magnetic field, driving the rotor 6 (which is interference-fitted with the motor shaft 5 via the central bushing 61) to rotate. The torque of the rotor 6 is transmitted to the tire 2 through the following path:

[0045] The wheel hub 1 serves as the mounting base for the tire 2, and is fixedly connected to the tire 2 by bolts or slots. When the wheel hub 1 rotates, it directly drives the tire 2 to rotate, using the friction between the tire 2 and the ground to propel the vehicle forward or backward.

[0046] Working principle: The vehicle is electrically driven for braking. When the electromagnetic coil 11 is energized, its magnetic field generates an electromagnetic force that overcomes the spring force of the spring 14, attracting the suction cup 12 towards the electromagnetic coil 11. The suction cup 12, through three sets of studs 13, moves the second fixing plate 9 backward, causing the brake pad 8 to separate from the first fixing plate 7, eliminating friction. Simultaneously, the stator assembly 10 is energized, generating a rotating magnetic field that drives the rotor 6 to rotate the motor shaft 5 via the central bushing 61. This, in turn, through an interference fit, rotates the wheel hub 1, the first outer shell 3, the second outer shell 4, and the tire 2, enabling the vehicle to move.

[0047] When the electromagnetic coil 11 is de-energized, the electromagnetic force disappears, the compressed spring 14 returns to its original position, pushing the suction cup 12 forward. Through the stud 13, the second fixing plate 9 presses the brake pad 8 against the first fixing plate 7. Since the first fixing plate is rigidly connected to the central shaft sleeve 61 and the motor shaft 5, the friction between the brake pad 8 and the first fixing plate hinders the rotation of the rotor 6. This friction is transmitted to the wheel hub 1 through the motor shaft 5, causing the tire 2 to stop and achieving braking.

[0048] Simultaneously, when the electromagnet is energized and the brake is released, the operator can pull the trigger body 15, which moves axially along the motor shaft 5 (the opening slot of the second housing 4 provides the space for movement). The steel ball hole 112 on the trigger body 15 separates from the steel ball 18 in the fixing cover 16. Due to the difference in the depth of the recess, the steel ball 18 pushes the trigger body 15 to move by 0.7-1mm. Through the first screw 19, it pulls the suction cup plate 12 to overcome the force of the spring 14 and move backward, driving the second fixing plate 9 to disengage the brake plate 8 from the first fixing plate 7, thus releasing the brake.

[0049] Pulling the trigger body 15 in the opposite direction causes the steel ball 18 to re-enter the ball hole 112, stopping the pull on the first screw 19. The spring 14 pushes the suction cup plate 12 forward, which, through the stud 13, drives the second fixing plate 9 to press the brake plate 8 against the first fixing plate 7, locking the rotor 6 using friction to achieve manual braking.

[0050] In summary, compared to the traditional solution which requires an additional independent brake disc and faces problems such as large space occupation and relatively complex assembly, this solution integrates the braking function between the rotor 6 and the fixed plate of the stator assembly 10, eliminating the need for an independent brake disc, reducing internal space occupation, and making the overall structure easier to assemble. In terms of braking drive method, a simple structure is adopted in which the suction cup plate 12 and the stud 13 directly connect the fixed plate, reducing the number of parts and assembly steps.

[0051] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Although the present utility model has been disclosed above with reference to a preferred embodiment, it is not intended to limit the present utility model. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present utility model. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present utility model without departing from the scope of the present utility model shall still fall within the scope of the present utility model.

Claims

1. A hub motor with an electromagnetic brake, comprising a hub (1) and a motor shaft (5), wherein a rotor (6) is disposed on the motor shaft (5), the rotor (6) having a central bushing (61), a stator assembly (10) surrounding the outer side of the central bushing (61), the stator assembly (10) comprising a stator support (113) and a stator core (111), the stator core (111) being cylindrically sleeved on the outer side of the stator support (113), and circumferentially positioned by a limiting pin, characterized in that: The central bushing (61) is fitted with a first fixing plate (7) and a second fixing plate (9). The first fixing plate (7) is fixed to the end face of the central bushing (61) by screws. A brake plate (8) is provided between the first fixing plate (7) and the second fixing plate (9). A fixed cover (16) is rotatably mounted on the hub (1) via a bearing (17). The fixed cover (16) has an annular groove, and an electromagnetic coil (11) is installed in the annular groove. The fixed cover (16) is provided with a pusher that is energized by an electromagnetic coil (11) to control the back-and-forth movement of the second fixed plate (9), so as to push the brake plate (8) against the first fixed plate (7) and drive the rotor (6) to brake.

2. A hub motor with an electromagnetic brake according to claim 1, characterized in that: Multiple sets of recessed holes are provided on the side of the fixed cover (16) near the stator support (113). The pushing part includes springs (14) installed in the recessed holes. One end of the multiple sets of springs (14) is connected to a suction cup (12). The suction cup (12) passes through the stator support (113) and is connected to the second fixed plate (9) through a stud (13). At least two sets of studs (13) are provided. The suction cup (12) is magnetically connected to the electromagnetic coil (11).

3. A hub motor with an electromagnetic brake according to claim 2, characterized in that: The hub (1) has a first outer shell (3) and a second outer shell (4) covering its two sides. The second outer shell (4) is composed of a plastic cover (41) and an aluminum alloy cover (42). The aluminum alloy cover (42) is fixed to the side of the hub (1) by screws. The fixing cover (16) is installed inside the plastic cover (41). The aluminum alloy cover (42) is used to support the bearing (17).

4. A hub motor with an electromagnetic brake according to claim 3, characterized in that: A trigger body (15) is sleeved on the motor shaft (5). One end of the trigger body (15) passes through the plastic cover (41). The plastic cover (41) has an opening groove for the trigger body (15) to move along the axial direction of the motor shaft (5). The trigger body (15) is mounted on the fixing cover (16) by a fastening unit. Multiple sets of steel balls (18) are provided on the side of the fixing cover (16) near the trigger body (15). The fixing cover (16) has a steel ball recess that matches the diameter of the steel ball (18). At the same time, a steel ball hole (112) that matches the steel ball (18) is provided on the trigger body (15). The depth of the steel ball recess is higher than the depth of the steel ball hole (112).

5. A hub motor with an electromagnetic brake according to claim 4, characterized in that: The fastening unit includes a first screw (19) that passes through the fixed cover (16). The fixed cover (16) has a through hole through which the first screw (19) passes. One end of the first screw (19) is connected to a nut (110) by a thread. The trigger body (15) is fitted onto the first screw (19), and after the nut (110) is tightened, it fits tightly against the side of the fixed cover (16), forming a positioning connection that can slide slightly axially.

6. A hub motor with an electromagnetic brake according to claim 1, characterized in that: A tire (2) is mounted on the hub (1).

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