EMB motor assembly and braking system

Abstract

The utility model discloses an EMB motor assembly and a braking system, and relates to the technical field of vehicle braking. The EMB motor assembly comprises a motor main body, a planetary gear set and a control circuit board, the motor main body comprises a shell, a stator assembly and a rotor assembly, the stator assembly comprises a stator coil and a busbar electrically connected with the stator coil, the stator coil comprises a first three-phase winding and a second three-phase winding which have a spatial phase difference, and the first three-phase winding and the second three-phase winding are arranged in the shell. The rotor assembly comprises a rotor body and a rotor shaft which are coaxially connected, the rotor body is rotatably arranged in the shell, the rotor shaft penetrates through the front end face of the shell and extends out of the shell, and the front end face is concaved inwards to form a fixing groove. The planetary gear set is fixedly arranged in the fixing groove to reduce speed and increase torque. The control circuit board is arranged on the side, facing the front end face, of the shell, the control circuit board and the output gear are arranged at intervals, and the busbar penetrates through the front end face and is electrically connected with the control circuit board. According to the EMB motor assembly, the axial size is greatly reduced, the space occupied by the EMB motor assembly can be reduced, and the structure is simplified.

Description

Technical Field

[0001] This utility model relates to the field of vehicle braking technology, and in particular to an EMB motor assembly and braking system. Background Technology

[0002] With the rapid development of electrification and intelligence in the automotive industry, there is an increasing number of drive-by-wire products for automobiles. In order to adapt to autonomous driving technology and improve the response speed of the braking system, the braking system of automobiles has begun to shift from hydraulic electronic braking system (EHB) to mechanical electronic braking system (EMB) powered by EMB motor assembly.

[0003] However, due to the low voltage level of the vehicle's voltage platform, a large drive current is required to achieve the required power, which can easily cause overheating. To ensure safety, the EMB motor assembly has a thicker wire diameter and is paired with a planetary gear set for speed reduction and torque amplification. Under the premise of a certain power, the axial dimension of the EMB motor assembly is large, which encroaches on the chassis space. Utility Model Content

[0004] The purpose of this invention is to propose an EMB motor assembly and braking system that significantly reduces the axial dimension of the EMB motor assembly, thereby reducing the space occupied by the EMB motor assembly and simplifying the structure.

[0005] To achieve this objective, the present invention adopts the following technical solution:

[0006] An EMB motor assembly, comprising:

[0007] The motor body includes a housing, a stator assembly, and a rotor assembly. The stator assembly includes stator coils and a busbar electrically connected to the stator coils. The rotor assembly includes a rotor body and a rotor shaft coaxially connected. The rotor body is rotatably disposed within the housing, and the rotor shaft passes through the front end face of the housing and extends out of the housing. The front end face is recessed to form a fixing groove.

[0008] A planetary gear set, comprising a sun gear, multiple planet gears, a planet carrier, and an external gear ring. The external gear ring is fixedly disposed in the fixed slot. The sun gear is connected to the rotor shaft. The planet carrier is rotatably disposed within the external gear ring. The multiple planet gears are rotatably disposed on the planet carrier, and the multiple planet gears mesh with both the sun gear and the external gear ring. An output gear is disposed at the end of the planet carrier away from the front end face.

[0009] A control circuit board is disposed on the front side of the housing facing away from the output gear, and the busbar passes through the front side and is electrically connected to the control circuit board.

[0010] As an optional solution for the above-mentioned EMB motor assembly, the stator assembly includes a first three-phase winding and a second three-phase winding, and there is a spatial phase difference between the first three-phase winding and the second three-phase winding.

[0011] As an optional solution for the above-mentioned EMB motor assembly, the EMB motor assembly further includes an angle detection component, which includes a magnet and a sensor chip. The rotor shaft passes through the planetary carrier, the magnet is disposed at the end of the rotor shaft facing the control circuit board, and the sensor chip is disposed on the control circuit board. The sensor chip can detect the rotation angle of the rotor shaft according to the magnetic field direction of the magnet.

[0012] As an optional solution for the above-mentioned EMB motor assembly, the planetary carrier is provided with a central hole, a third bearing is embedded in the central hole, and the rotor shaft passes through the central hole and is rotatably disposed in the third bearing.

[0013] As an optional solution for the above-mentioned EMB motor assembly, the planetary gear set further includes a fixed housing, which is fastened to the external gear ring to form a receiving cavity between the fixed housing and the external gear ring, and the sun gear, the planet gears and part of the planet carrier are all disposed in the receiving cavity.

[0014] As an optional solution for the above-mentioned EMB motor assembly, the outer periphery of the fixed housing is provided with a limiting protrusion, the outer shell is provided with a bayonet, the fixed housing is disposed in the fixed groove and is limited and abuts against the inner wall of the fixed groove, and the limiting protrusion is engaged with the bayonet and is interference-fitted with the bayonet.

[0015] As an optional solution for the above-mentioned EMB motor assembly, the housing includes a main housing and an inner housing. The main housing has an open structure with a main cavity. The inner housing is fixedly disposed at the opening of the main housing. A notch is provided on the outer periphery of the inner housing. The side of the inner housing facing the control circuit board is the front end face. The busbar passes through the front end face through the notch.

[0016] As an optional embodiment of the aforementioned EMB motor assembly, the main housing is provided with a first bearing groove, a first bearing is fixedly disposed in the first bearing groove, and the rotor shaft passes through the first bearing; and / or,

[0017] The bottom surface of the fixing groove of the inner shell is recessed to form a second bearing groove, and a second bearing is fixedly installed in the second bearing groove. The rotor shaft passes through the second bearing.

[0018] As an optional solution for the above-mentioned EMB motor assembly, the planetary carrier is coaxially provided with at least two of the output gears, and the transmission ratio and / or outer diameter of the at least two output gears are different.

[0019] A braking system includes the aforementioned EMB motor assembly, and further includes a brake pedal and a brake caliper, wherein the brake pedal is communicatively connected to the control circuit board, and the brake caliper is drive-connected to the output gear.

[0020] The beneficial effects of this utility model are:

[0021] This invention provides an EMB motor assembly and braking system. In this EMB motor assembly, the motor body is energized by the stator coil, driving the rotor shaft of the rotor assembly to rotate. After speed reduction and torque amplification through a planetary gear set, the power is output to the outside through the output gear. Since the stator coil has a dual three-phase structure, the control circuit board can provide drive current to the motor body through six-phase lines, which can significantly reduce the current of each phase, thereby reducing heat generation. This allows the use of smaller wire harnesses, reducing the size of the stator coil, enabling the front end face to be recessed to form a fixing groove, and allowing the planetary gear set to be embedded in the motor body. This significantly reduces the axial dimension of the EMB motor assembly, which is beneficial to the overall vehicle layout. Since there is no other structure at the front end of the output gear, the control circuit board is placed on the side of the front face of the housing and spaced apart from the output gear, which can further reduce the space occupied by the EMB motor assembly. Moreover, the busbar can be directly connected to the circuit board without bending, simplifying the structure. Attached Figure Description

[0022] Figure 1 This is a side view of the EMB motor assembly provided by this utility model;

[0023] Figure 2 This is a cross-sectional view of the EMB motor assembly provided by this utility model;

[0024] Figure 3 This is an exploded view of the EMB motor assembly provided by this utility model;

[0025] Figure 4 This is a schematic diagram of the structure of the outer shell provided by this utility model;

[0026] Figure 5 This is a schematic diagram of the external gear ring and the fixed housing provided by this utility model.

[0027] In the picture:

[0028] 1. Motor body; 11. Housing; 111. Main housing; 1111. First bearing groove; 112. Inner housing; 1121. Front end face; 1122. Fixing groove; 1123. Bayonet; 1124. Notch; 1125. Second bearing groove; 12. Stator assembly; 121. Stator coil; 122. Busbar; 13. Rotor assembly; 131. Rotor body; 132. Rotor shaft; 14. First bearing; 15. Second bearing;

[0029] 2. Planetary gear set; 21. Sun gear; 22. Planet gears; 23. Planet carrier; 231. Support body; 232. Extending shaft; 233. Protrusion; 234. Center hole; 24. External gear ring; 25. Output gear; 26. Third bearing; 27. Fixed housing; 271. Output hole; 272. Limiting ring; 273. Limiting protrusion;

[0030] 3. Control circuit board;

[0031] 41. Magnet; 42. Sensor chip. Detailed Implementation

[0032] The embodiments of this utility model are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this utility model, and should not be construed as limiting this utility model.

[0033] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The terms "first position" and "second position" refer to two different positions.

[0034] Unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing" should be interpreted broadly. For example, they can refer to fixed connections or detachable connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and connections within two components or interactions between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0035] Unless otherwise expressly specified and limited, "above" or "below" a second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of a second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" of a second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0036] The technical solution of this utility model will be further described below with reference to the accompanying drawings and specific embodiments.

[0037] This embodiment provides a braking system for braking a vehicle. The braking system includes a power structure, a brake pedal, and brake calipers. The power structure operates according to the travel of the brake pedal and reduces speed and increases torque through a reduction gear system, thereby controlling the movement of the brake calipers. This causes the brake calipers to drive the friction pads to press against the brake disc, thus generating parking braking force.

[0038] In this embodiment, the braking system is a mechanical electronic braking system (EMB). EMB systems offer advantages such as faster response times and better compatibility with autonomous driving technologies. Correspondingly, its power structure is an EMB motor assembly, which controls the braking force of the brake calipers via the displacement signal of the brake pedal, thereby achieving the purpose of decelerating the vehicle.

[0039] like Figures 1-4 As shown, this embodiment also provides an EMB motor assembly, which includes a motor body 1 and a control circuit board 3. The motor body 1 includes a housing 11, a stator assembly 12, and a rotor assembly 13. The stator assembly 12 includes a stator coil 121 and a busbar 122 electrically connected to the stator coil 121. The rotor assembly 13 includes a rotor body 131 and a rotor shaft 132 coaxially connected. The rotor body 131 is rotatably disposed inside the housing 11, and the rotor shaft 132 passes through the front end face 1121 of the housing 11 and extends out of the housing 11. The brake pedal is communicatively connected to the control circuit board 3, and the busbar 122 is electrically connected to the control circuit board 3.

[0040] The control circuit board 3 can receive the displacement signal of the brake pedal and control the magnitude and direction of the current in the stator coil 121 through the busbar 122, thereby establishing a changing magnetic field. The rotor body 131 is equipped with a permanent magnet 41, and the rotor body 131 can be rotated by controlling the change of the magnetic field.

[0041] like Figure 2 and Figure 3 As shown, the reduction gear system of the braking system is a planetary gear set 2, which includes a sun gear 21, multiple planet gears 22, a planet carrier 23 and an external gear ring 24. The sun gear 21 is connected to the rotor shaft 132. The planet carrier 23 is rotatably disposed in the external gear ring 24. The multiple planet gears 22 are rotatably disposed on the planet carrier 23, and the multiple planet gears 22 mesh with both the sun gear 21 and the external gear ring 24. An output gear 25 is provided at the end of the planet carrier 23 away from the front end face 1121.

[0042] In this EMB motor assembly, the motor body 1 is energized by the stator coil 121, driving the rotor shaft 132 of the rotor assembly 13 to rotate, and driving the planetary gears 22 to rotate through the sun gear 21. Since the external gear ring 24 is fixedly connected to the outer casing 11 of the motor body 1, the planetary gears 22 drive the planet carrier 23 to rotate by rotating along the external gear ring 24, and provide power to the outside through the output gear 25 of the planet carrier 23. The planetary gear set 2 has a compact structure, saves space, and has high power density. Multiple planetary gears 22 share the load simultaneously, which significantly improves the load-bearing capacity of the planetary gear set 2. At the same time, the load distribution of the planetary gear set 2 is uniform. Multiple planetary gears 22 mesh simultaneously, and the load is evenly distributed to multiple gears, reducing the wear of individual gears and extending their service life.

[0043] In this embodiment, the outer periphery of the rotor shaft 132 is provided with gear teeth to form the sun gear 21. That is to say, the sun gear 21 and the rotor shaft 132 are an integral structure, which is convenient for processing and reduces costs.

[0044] In this embodiment, the stator assembly 12 includes a first three-phase winding and a second three-phase winding, with a spatial phase difference between them. That is, the motor body 1 is a six-phase motor with a dual three-phase structure, having two sets of three-phase pins (U / V / W). During normal operation, the controller can simultaneously supply current to the motor through all six pins, significantly reducing the controller's drive current and thus the current magnitude of each phase, thereby reducing heat generation. This allows for the use of smaller diameter wire harnesses, improving heat dissipation and assembly manufacturability. Due to the reduced heat generation, the planetary gear set 2 can be made of more economical materials, contributing to cost reduction and improving product durability.

[0045] Moreover, the six-phase motor can reduce the current of each phase while ensuring output capacity, thereby reducing the size of the busbar 122 terminals, thus making room for the planetary gear set 2, improving the design of the planetary gear set 2, increasing the transmission ratio of the planetary gear set 2, and thus providing higher transmission torque, which is beneficial to the size optimization of the assembly product.

[0046] However, since the EMB motor assembly needs to achieve the function of speed reduction and torque increase through the planetary gear set 2, the motor body 1 and the planetary gear set 2 are axially arranged, resulting in a large axial dimension of the EMB motor assembly under the premise that the power is constant, that is, the size of the motor body 1 and the planetary gear set 2 remains unchanged, which encroaches on the chassis space.

[0047] like Figures 2-4 As shown, in order to solve the above problems, in the EMB motor assembly provided in this embodiment, the front end face 1121 of the outer shell 11 of the motor body 1 is recessed to form a fixing groove 1122, the outer gear ring 24 is fixedly disposed in the fixing groove 1122, and the control circuit board 3 is disposed on the side facing the front end face 1121 of the outer shell 11 and spaced apart from the output gear 25. The busbar 122 passes through the front end face 1121 and is electrically connected to the control circuit board 3.

[0048] The front end face 1121 of the motor body 1 is recessed to form a fixing groove 1122, which allows the planetary gear set 2 to be embedded in the motor body 1. This allows full utilization of the axial space of the motor body 1 without changing the structure of the stator assembly 12 and the rotor assembly 13, thereby significantly reducing the axial dimension of the EMB motor assembly. Since there is no other structure at the front end of the output gear 25, the control circuit board 3 is set on the side facing the front end face 1121 of the housing 11 and spaced apart from the output gear 25. This further reduces the space occupied by the EMB motor assembly, and the busbar 122 can be directly connected to the circuit board without bending, simplifying the structure.

[0049] like Figures 2-5 As shown, the planetary gear set 2 also includes a fixed housing 27, which is fastened to the external gear ring 24 to form a receiving cavity between the fixed housing 27 and the external gear ring 24. The sun gear 21, planet gears 22, and part of the planet carrier 23 are all disposed within the receiving cavity. The fastening of the fixed housing 27 and the external gear ring 24 makes the entire planetary gear set 2 a single module, ensuring the stability of the planetary gear set 2 during operation, facilitating the installation and disassembly of the planetary gear set 2, and reducing production and material costs.

[0050] Furthermore, the outer periphery of the fixed housing 27 is provided with a limiting protrusion 273, and the outer shell 11 is provided with a bayonet 1123. The fixed housing 27 is disposed in the fixing groove 1122 and is limited and abuts against the inner wall of the fixing groove 1122. The limiting protrusion 273 is engaged with the bayonet 1123 and is interference-fitted with the bayonet 1123. The inner wall of the fixing groove 1122 can provide radial limiting for the fixed housing 27, and the interference fit between the limiting protrusion 273 and the bayonet 1123 can provide axial and circumferential angular limiting for the fixed housing 27, thereby ensuring the relative stability between the fixed housing 27 and the outer shell 11 of the motor body 1 during the operation of the EMB motor assembly.

[0051] like Figures 2-4 As shown, the outer casing 11 includes a main casing 111 and an inner casing 112. The main casing 111 has an open structure with a main cavity, and the inner casing 112 is fixedly disposed in the opening of the main casing 111. This structure facilitates the disassembly and installation of the motor body 1, thereby placing the stator assembly 12 and the rotor assembly 13 in the main cavity of the main casing 111. The inner casing 112 is used to seal the opening to prevent the stator assembly 12 and the rotor assembly 13 from coming out of the main cavity.

[0052] The rotor shaft 132 of the rotor assembly 13 extends out of the outer shell 11 through the inner shell 112 to output power. Therefore, the side of the inner shell 112 facing the control circuit board 3 is the front end face 1121. In other words, the fixing groove 1122 is formed by the inner shell 112 recessed inward towards the inside of the main cavity. The planetary gear set 2 is disposed on the inner shell 112, and the outer periphery of the inner shell 112 is provided with a notch 1124. The busbar 122 passes through the notch 1124 and passes through the front end face 1121 to be electrically connected to the control circuit board 3.

[0053] like Figure 2 and Figure 4 As shown, the outer casing 11 is provided with a first bearing groove 1111, and a first bearing 14 is fixedly installed in the first bearing groove 1111. The rotor shaft 132 passes through the first bearing 14. The first bearing groove 1111 is used to fix the first bearing 14, so that the first bearing 14 can greatly reduce the friction generated by the rotation of the rotor shaft 132, which can improve its service life and make the rotor shaft 132 rotate stably. Similarly, the outer casing 11 is also provided with a second bearing groove 1125, and a second bearing 15 is fixedly installed in the second bearing groove 1125. The rotor shaft 132 passes through the second bearing 15.

[0054] To ensure smooth rotation of the rotor shaft 132, the first bearing 14 and the second bearing 15 are located at opposite ends of the rotor body 131 along the axial direction. Therefore, the first bearing groove 1111 can be provided on the bottom surface of the main housing 111. However, to avoid the rotor shaft 132 needing to protrude through the bottom surface of the main housing 111, the first bearing groove 1111 is formed by the outward protrusion of the bottom surface of the main housing 111, and the first bearing 14 is located inside the main cavity.

[0055] It is worth noting that the bottom surface of the main housing 111 is concave to form a clearance groove from the outside of the main housing 111, and then the bottom surface of the clearance groove protrudes outward, thereby forming a first bearing groove 1111 in the main cavity. This structure can reduce the size of the first bearing groove 1111 protruding outward from the main housing 111, thereby reducing the axial dimension of the motor body 1.

[0056] In this embodiment, the bottom surface of the fixing groove 1122 of the inner housing 112 is recessed to form the second bearing groove 1125. With this structure, the rotor shaft 132 needs to pass through the inner housing 112 to pass through the second bearing 15. However, since the rotor shaft 132 itself needs to pass through the inner housing 112 to output power, no additional sealing requirements are imposed on the motor body 1. Moreover, since the second bearing groove 1125 is formed by further recessing the bottom surface of the fixing groove 1122, the inner housing 112 can be formed in one step by stamping or casting during molding, greatly reducing costs.

[0057] like Figure 2 As shown, the planetary carrier 23 includes a support body 231, a protrusion 233, and multiple extension shafts 232. The support body 231 is rotatably disposed within the external gear ring 24. The multiple extension shafts 232 are connected to the support body 231 and extend toward the front end face 1121. The planetary gear 22 is rotatably disposed on the extension shaft 232. The protrusion 233 is disposed on the support body 231 and located at one end away from the extension shaft 232. The output gear 25 is disposed on the protrusion 233.

[0058] The bracket body 231 is located on the side of the planetary gear 22 away from the front end face 1121, so that the bracket body plays the role of a cover, preventing the planetary gear 22 from being exposed to the external environment and easily absorbing dust or debris particles, which would cause unnecessary wear, extend its service life, and also ensure the normal operation of the planetary gear set 2.

[0059] Specifically, the fixed housing 27 has an output hole 271, and a limiting ring 272 is provided on the inner wall of the output hole 271. The support body 231 is located on the side of the limiting ring 272 facing the front end face 1121 and slides against the limiting ring 272. The extension shaft 232 extends out of the output hole 271 to output power. The limiting ring 272 can both limit the axial movement of the planetary carrier 23 and abut against the support body to prevent external dust or debris particles from entering the planetary gear set 2.

[0060] In this embodiment, the planetary carrier 23 is coaxially provided with at least two output gears 25, and the transmission ratio and / or outer diameter of the at least two output gears 25 are different. That is to say, the motor body 1 can drive the movement of the car's calipers through different transmission ratios, thereby improving the adjustability of braking force and braking time during braking.

[0061] It is worth noting that for the mechanical electronic braking system (EMB), it is necessary to monitor the angular position of the rotor shaft 132 in the rotor assembly 13 at all times to ensure that the rotation angle of the rotor shaft 132 is accurate when the control circuit board 3 controls the rotation of the rotor shaft 132, so as to provide the appropriate braking force for the car.

[0062] like Figures 1-3As shown, to achieve the above objectives, the EMB motor assembly also includes an angle detection component, which includes a magnet 41 and a sensor chip 42. The rotor shaft 132 passes through the planetary carrier 23, the magnet 41 is located at the end of the rotor shaft 132 facing the control circuit board 3, and the sensor chip 42 is located on the control circuit board 3. The sensor chip 42 can detect the rotation angle of the rotor shaft 132 according to the magnetic field direction of the magnet 41.

[0063] Understandably, magnet 41 has its own magnetic field, and sensor chip 42 can determine the angular position of rotor shaft 132 by detecting the direction of the magnetic field. Furthermore, when rotor shaft 132 rotates, the magnetic field of magnet 41 also rotates accordingly, ensuring the accuracy of the angular position detection of rotor shaft 132. It is worth noting that the N-S poles of magnet 41 point perpendicular to the axial direction of rotor shaft 132.

[0064] Specifically, the planetary carrier 23 is provided with a central hole 234, through which the rotor shaft 132 passes to allow the end magnet 41 to approach the sensor chip 42. It is understandable that, after the reduction speed of the planetary gear set 2, the rotor shaft 132 and the planetary carrier 23 rotate at different speeds, resulting in relative rotation between them. To ensure stable rotation of the rotor shaft 132, the planetary carrier 23 needs to slide against the rotor shaft 132, which can easily lead to friction between the rotor shaft 132 and the planetary carrier 23, affecting the output torque and service life.

[0065] like Figure 2 and Figure 3 As shown, to solve the above problems, a third bearing 26 is embedded in the central hole 234, and the rotor shaft 132 passes through the central hole 234 and is rotatably mounted in the third bearing 26. The third bearing 26 can provide radial restraint on the rotor shaft 132 near the end of the rotor shaft 132 close to the magnet 41, thereby ensuring the stability of the position of the magnet 41 and ensuring that the change in magnetic field sensed by the sensor chip 42 is entirely caused by the rotation of the magnet 41, thus improving the monitoring accuracy. At the same time, it can also significantly reduce the friction between the rotor shaft 132 and the support body during relative rotation.

[0066] In this embodiment, the third bearing 26 is a sliding bearing, which is interference-fitted into the central hole 234 and has a polymer coating embedded on its inner surface to provide lubrication and reduce friction.

[0067] The above description is only a preferred embodiment of this utility model. For those skilled in the art, there will be changes in the specific implementation method and application scope based on the idea of ​​this utility model. The content of this specification should not be construed as a limitation of this utility model.

Claims

1. An EMB motor assembly, characterized in that, include: The motor body (1) includes a housing (11), a stator assembly (12), and a rotor assembly (13). The stator assembly (12) includes a stator coil (121) and a busbar (122) electrically connected to the stator coil (121). The stator coil includes a first three-phase winding and a second three-phase winding. There is a spatial phase difference between the first three-phase winding and the second three-phase winding. The rotor assembly (13) includes a rotor body (131) and a rotor shaft (132) coaxially connected. The rotor body (131) is rotatably disposed inside the housing (11). The rotor shaft (132) passes through the front end face (1121) of the housing (11) and extends out of the housing (11). The front end face (1121) is recessed to form a fixing groove (1122). The planetary gear set (2) is fixedly installed in the fixed groove (1122). The planetary gear set (2) is connected to the rotor shaft (132) for transmission to reduce speed and increase torque, and outputs power through the output gear (25). The control circuit board (3) is disposed on the side facing the front end face (1121) of the housing (11) and spaced apart from the output gear (25). The busbar (122) passes through the front end face (1121) and is electrically connected to the control circuit board (3).

2. The EMB motor assembly according to claim 1, characterized in that, The planetary gear set (2) includes a sun gear (21), multiple planet gears (22), a planet carrier (23), and an external gear ring (24). The external gear ring (24) is fixedly disposed in the fixed groove (1122). The sun gear (21) is connected to the rotor shaft (132). The planet carrier (23) is rotatably disposed in the external gear ring (24). The multiple planet gears (22) are rotatably disposed on the planet carrier (23), and the multiple planet gears (22) mesh with both the sun gear (21) and the external gear ring (24). The output gear (25) is disposed at the end of the planet carrier (23) away from the front end face (1121).

3. The EMB motor assembly according to claim 2, characterized in that, The EMB motor assembly also includes an angle detection component, which includes a magnet (41) and a sensor chip (42). The rotor shaft (132) passes through the planetary carrier (23). The magnet (41) is located at one end of the rotor shaft (132) facing the control circuit board (3). The sensor chip (42) is located on the control circuit board (3). The sensor chip (42) can detect the rotation angle of the rotor shaft (132) according to the magnetic field direction of the magnet (41).

4. The EMB motor assembly according to claim 3, characterized in that, The planetary carrier (23) is provided with a central hole (234), and a third bearing (26) is embedded in the central hole (234). The rotor shaft (132) passes through the central hole (234) and is rotatably disposed in the third bearing (26).

5. The EMB motor assembly according to claim 2, characterized in that, The planetary gear set (2) also includes a fixed housing (27), which is fastened to the external gear ring (24) to form a receiving cavity between the fixed housing (27) and the external gear ring (24). The sun gear (21), the planet gears (22) and part of the planet carrier (23) are all disposed in the receiving cavity.

6. The EMB motor assembly according to claim 5, characterized in that, The outer periphery of the fixed housing (27) is provided with a limiting protrusion (273), the outer shell (11) is provided with a bayonet (1123), the fixed housing (27) is disposed in the fixed groove (1122) and is limited and abutted against the inner wall of the fixed groove (1122), the limiting protrusion (273) is inserted into the bayonet (1123) and is interference-fitted with the bayonet (1123).

7. The EMB motor assembly according to claim 1, characterized in that, The outer casing (11) includes a main casing (111) and an inner casing (112). The main casing (111) has an open structure with a main cavity. The inner casing (112) is fixedly disposed in the opening of the main casing (111). A notch (1124) is provided on the outer periphery of the inner casing (112). The side of the inner casing (112) facing the control circuit board (3) is the front end face (1121). The busbar (122) passes through the front end face (1121) through the notch (1124).

8. The EMB motor assembly according to claim 7, characterized in that, The main housing (111) is provided with a first bearing groove (1111), and a first bearing (14) is fixedly disposed in the first bearing groove (1111). The rotor shaft (132) passes through the first bearing (14); and / or, The bottom surface of the fixing groove (1122) of the inner housing (112) is recessed to form a second bearing groove (1125), and a second bearing (15) is fixedly installed in the second bearing groove (1125), and the rotor shaft (132) passes through the second bearing (15).

9. The EMB motor assembly according to claim 2, characterized in that, The planetary carrier (23) is coaxially provided with at least two of the output gears (25), and the transmission ratio and / or outer diameter of the at least two output gears (25) are different.

10. A braking system, characterized in that, The EMB motor assembly included in any one of claims 1 to 9 further includes a brake pedal and a brake caliper, wherein the brake pedal is communicatively connected to the control circuit board (3) and the brake caliper is drively connected to the output gear (25).

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