Drive mechanism of an electrically assisted bicycle and electrically assisted bicycle

Abstract

The utility model belongs to the technical field of moped, disclose a kind of drive mechanism and electric moped of electric power-assisted bicycle of electric power-assisted bicycle.The drive mechanism includes middle shaft, motor module, disc brake pad, transmission module, tower base torque sensor and controller, the both ends of middle shaft are used to connect the rear fork of electric power-assisted bicycle, motor module includes motor casing, stator assembly and rotor assembly, stator assembly is connected with middle shaft, rotor assembly is set in stator assembly, the end of stator assembly projects motor casing setting, disc brake pad is installed in motor casing, one end of controller is connected with the end of stator assembly projecting motor casing, the other end of controller is provided with radiating fin, tower base torque sensor is set in middle shaft, and is connected with motor casing.The heat dissipation efficiency of the drive mechanism is higher, and the heat dissipation effect is better, and structure is relatively simple.

Description

Technical Field

[0001] This utility model relates to the field of electric bicycle technology, and in particular to a drive mechanism for an electric-assisted bicycle and an electric-assisted bicycle. Background Technology

[0002] The rear drive motor of an electric-assist bicycle is a drive technology that highly integrates the power, transmission, and braking systems within the wheel hub. This technology integrates components such as the motor, reducer, clutch, torque sensor, and freehub into the wheel hub, eliminating the need for traditional mechanical transmission structures and saving space. However, due to the enclosed environment and compact internal structure of the rear drive motor, it is prone to heat accumulation and poor heat dissipation. Utility Model Content

[0003] The first objective of this invention is to provide a drive mechanism for an electric-assisted bicycle, which has high heat dissipation efficiency, good heat dissipation effect, and a relatively simple structure.

[0004] The second objective of this invention is to provide an electric-assisted bicycle with a drive mechanism that has good heat dissipation, high reliability, and low failure rate.

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

[0006] This utility model discloses a drive mechanism for an electric-assist bicycle, comprising: a bottom bracket, both ends of which are used to connect to the rear fork of the electric-assist bicycle; a motor module, the motor module including a motor housing, a stator assembly, and a rotor assembly, the stator assembly being connected to the bottom bracket, the rotor assembly being sleeved on the stator assembly, and one end of the stator assembly extending out of the motor housing; a disc brake pad, the disc brake pad being installed on the motor housing; a transmission module, the power output end of the transmission module being connected to the motor housing, and the power input end of the transmission module being connected to the rotor assembly; a controller, one end of the controller being connected to the end of the stator assembly extending out of the motor housing, the other end of the controller being provided with heat dissipation fins, and the controller being electrically connected to the motor module; and a freehub torque sensor, the freehub torque sensor being sleeved on the bottom bracket and connected to the motor housing, the rotating part of the freehub torque sensor being used to connect to the chainring of the electric-assist bicycle, and the fixing control part of the freehub torque sensor being electrically connected to the motor module.

[0007] In some embodiments, the motor module further includes a desiccant box, which is installed in the stator assembly and located inside the motor housing, and the outer wall of the desiccant box is provided with a plurality of vent holes.

[0008] In some embodiments, the bottom bracket has a through mounting hole, and a fixing bolt passes through the rear fork and the mounting hole and is locked by a fixing nut to fix the bottom bracket to the rear fork.

[0009] In some embodiments, the stator assembly includes a stator bracket and a stator winding. The stator bracket is an aluminum bracket with an integrally formed wire passage hole. The motor wires of the motor module pass through the wire passage hole and are connected to the controller.

[0010] In some embodiments, the central shaft is provided with a wire guide groove, through which the lead wire of the tower base torque sensor passes and is connected to the welding wire portion of the stator assembly, and part of the lead wire is fixed to the wire guide groove by sealant.

[0011] In some embodiments, the motor housing includes a housing body and an end cap, one end of the housing body is open, the end cap is fastened to the open end of the housing body, and the side of the housing body opposite to the end cap is connected to the rotating part of the tower base torque sensor.

[0012] In some specific embodiments, the rotating part of the tower base torque sensor is provided with a first fixed protrusion ring, one end of the shell body is provided with a second fixed protrusion ring, the rotating part passes through the second fixed protrusion ring, and the first fixed protrusion ring and the second fixed protrusion ring are connected by a connector.

[0013] In some embodiments, the transmission module includes: a planetary carrier connected to the central shaft; a sun gear rotatably mounted on the planetary carrier and connected to the rotor assembly; a plurality of planetary gears rotatably mounted on the planetary carrier and arranged around the sun gear, the plurality of planetary gears meshing with the sun gear respectively; and an internal gear ring meshing with the plurality of planetary gears and connected to the motor housing.

[0014] In some specific embodiments, the central shaft and the planet carrier are connected by a connecting key to prevent the planet carrier from rotating relative to the central shaft, and a retaining spring is provided on the central shaft, which abuts against one side of the planet carrier.

[0015] This utility model also discloses an electric-assisted bicycle, including a frame and the drive mechanism of the electric-assisted bicycle described above.

[0016] The beneficial effects of the drive mechanism of this electric-assist bicycle are as follows: Since one end of the stator assembly extends directly out of the motor housing and disc brake pads and is connected to the controller, which is equipped with heat dissipation fins, the heat generated by the stator core and stator windings of the stator assembly can be transferred to the controller through the stator support during actual operation, and then dissipated by the heat dissipation fins, resulting in good heat dissipation efficiency and effect. Because the controller is located outside the motor module, the heat generated during controller operation will not affect the motor module, further ensuring the reliability of the motor module. Furthermore, this drive mechanism does not have structures such as fans or coolant circulation structures, making the structure of the drive mechanism in this embodiment very simple and more compact.

[0017] The beneficial effects of this electric-assisted bicycle are as follows: due to the drive mechanism described above, the drive mechanism of this electric-assisted bicycle has better heat dissipation, higher operational reliability, and a lower failure rate.

[0018] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0019] Figure 1 This is an exploded structural diagram of the drive mechanism of the electric-assisted bicycle according to an embodiment of the present invention.

[0020] Figure 2 This is a cross-sectional view of the drive mechanism of an electric-assisted bicycle according to an embodiment of the present utility model;

[0021] Figure 3 This is a schematic diagram of the stator support structure according to an embodiment of the present invention.

[0022] Figure label:

[0023] 100, Bottom shaft; 110, Mounting hole; 120, Cable guide groove; 200, Motor module; 201, Motor cable; 210, Motor housing; 211, Housing body; 2111, Second fixing convex ring; 212, End cap; 220, Stator assembly; 221, Stator bracket; 2211, Cable guide hole; 230, Rotor assembly; 300, Disc brake pad; 400, Transmission module; 410, Planetary carrier; 420, Sun gear; 421, Connecting flange; 430, Planetary gear; 440, Internal gear ring; 500, Controller; 510, Heat sink fins; 600, Tower base torque sensor; 610, First fixing convex ring; 620, Lead wire; 700, Desiccant box; 800, Snap ring; 910, First bearing; 920, Second bearing; 930, Third bearing; 10, Rear fork; 20, Fixing bolt. Detailed Implementation

[0024] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, not the entire structure.

[0025] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0026] In the description of this embodiment, the terms "upper," "lower," "left," "right," "front," and "rear," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, 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. Therefore, they should not be construed as limitations on this utility model. In addition, the terms "first" and "second" are only used for distinction in description and have no special meaning.

[0027] This utility model discloses a drive mechanism for an electric-assisted bicycle (hereinafter referred to as the drive mechanism for ease of description), see reference. Figure 1 and Figure 2 The drive mechanism includes a bottom bracket 100, a motor module 200, a disc brake pad 300, a transmission module 400, a freehub torque sensor 600, and a controller 500. The two ends of the bottom bracket 100 are used to connect to the rear fork 10 of the electric bicycle. The motor module 200 includes a motor housing 210, a stator assembly 220, and a rotor assembly 230. The stator assembly 220 is connected to the bottom bracket 100, and the rotor assembly 230 is fitted onto the stator assembly 220. One end of the stator assembly 220 extends out of the motor housing 210. The disc brake pad 300 is installed in the motor housing 210. The transmission module 400 provides power to the... The output end is connected to the motor housing 210, the power input end of the transmission module 400 is connected to the rotor assembly 230, one end of the controller 500 is connected to the end of the stator assembly 220 that extends out of the motor housing 210, the other end of the controller 500 is provided with heat dissipation fins 510, the controller 500 is electrically connected to the motor module 200, the base torque sensor 600 is sleeved on the central shaft 100 and connected to the motor housing 210, the rotating part of the base torque sensor 600 is used to connect to the chainring of the electric bicycle, and the fixed control part of the base torque sensor 600 is electrically connected to the motor module 200.

[0028] First, it should be noted that the specific structure of the freehub torque sensor 600 is existing technology. The rotating part of the freehub torque sensor 600 can be connected to the chainring or freewheel via a chain, and the connection method is existing technology. The fixed control part of the freehub torque sensor 600 is usually an integrated strain gauge or magnetic sensor, fixed to the hub shaft. The driving principle of the drive mechanism in this embodiment is that after the motor module 200 is started, the rotor assembly 230 drives the motor housing 210 to rotate, and the motor housing 210 drives the drive part of the freehub torque sensor 600 to rotate, thereby driving the chainring of the electric-assist bicycle to rotate.

[0029] It is understandable that in existing electric bicycles, the main heat source of the rear drive motor, the stator core and windings, are heavily encased, making it difficult for heat to dissipate. This leads to increased temperature, reduced motor efficiency, and in severe cases, demagnetization of the magnets and insulation failure of the enameled wires. The drive mechanism disclosed in this invention, however, has a stator assembly 220 that extends directly from the motor housing 210 and the disc brake pad 300, and is connected to the controller 500. The controller 500 is equipped with heat dissipation fins 510. During actual operation, the heat generated by the stator core and windings of the stator assembly 220 can be transferred to the controller 500 through the stator support 221, and then dissipated by the heat dissipation fins 510, resulting in better heat dissipation efficiency and effect. Since the controller 500 is located outside the motor module 200, the heat generated during the controller 500's operation does not affect the motor module 200, further ensuring the reliability of the motor module 200. Furthermore, the drive mechanism of this embodiment does not have structures such as fans or coolant circulation structures, making the structure of the drive mechanism in this embodiment very simple and more compact.

[0030] Optionally, the stator support 221 of the stator assembly 220 is connected to the controller 500 by screws. This improves the connection strength and simplifies the assembly process. Of course, in other embodiments of this invention, the stator support 221 can also be bonded to the controller 500 with thermally conductive adhesive, and is not limited to the above description.

[0031] Optionally, the disc brake pad 300 and the motor housing 210 can be connected by screws, pins or other connectors, or by snap-fit ​​connections. No limitation is made on the connection method between the disc brake pad 300 and the motor housing 210.

[0032] refer to Figure 2As shown, the motor module 200 also includes a desiccant box 700, which is installed on the stator assembly 220 and located inside the motor housing 210. The outer wall of the desiccant box 700 has multiple ventilation holes. It is understood that the desiccant box 700 on the stator assembly 220 absorbs moisture inside the motor housing 210, preventing the motor module 200 from rusting. It should be noted that in embodiments of this invention, the desiccant box 700 can be fixed to the stator assembly 220 in various ways, such as adhesive bonding, screw connection, or snap-fit ​​connection, etc., depending on actual needs.

[0033] refer to Figure 2 As shown, the bottom bracket 100 has a through mounting hole 110. A fixing bolt 20 passes through the rear fork 10 and the mounting hole 110 and is locked in place by a fixing nut to secure the bottom bracket 100 to the rear fork 10. First, it should be noted that traditional electric power-assisted rear drive motors have a threaded section at the end of the shaft, with a flattened portion milled onto the threaded section, and are then fixed to the rear fork 10 with a nut. The flattened portion reduces the effective contact area of ​​the threads, making them prone to stripping, requiring replacement of the entire motor after stripping. In this embodiment, however, the bottom bracket 100 has a through mounting hole 110, and is locked in place by the fixing bolt 20 and fixing nut. This not only makes installation and disassembly very convenient but also eliminates the need for thread machining on the bottom bracket 100, avoiding the problem of needing to replace the entire motor after thread stripping. Furthermore, designing the bottom bracket 100 as a hollow shaft reduces weight, making the entire drive mechanism lighter and easier to transport and assemble.

[0034] refer to Figures 2-3 As shown, the stator assembly 220 includes a stator bracket 221 and stator windings. The stator bracket 221 is an aluminum bracket with an integrally formed wire-passing hole 2211. The motor wires 201 of the motor module 200 pass through the wire-passing hole 2211 and connect to the controller 500. It is understood that in the prior art, the wire-passing hole needs to be post-processed on the stator bracket for wire passage. In this embodiment, the stator bracket 221 is made of aluminum, and the wire-passing hole 2211 can be integrally formed with the entire stator bracket 221. No drilling is required during the assembly of the motor module 200, simplifying the assembly process of the entire drive mechanism. The aluminum bracket 221 also has good thermal conductivity, enabling rapid transfer of the working heat of the motor module 200 to the controller 500, which is beneficial for further improving the heat dissipation efficiency and effect of the drive mechanism.

[0035] refer to Figure 2As shown, a wire guide groove 120 is provided on the central shaft 100. The lead wire 620 of the tower base torque sensor 600 passes through the wire guide groove 120 and connects to the welding part of the stator assembly 220. Part of the lead wire 620 is fixed to the wire guide groove 120 with sealant. It is understandable that since the tower base torque sensor 600 is located at the end of the central shaft 100, providing a wire guide groove 120 on the central shaft 100 facilitates the lead wire 620's exit, and fixing the lead wire 620 with sealant prevents it from coming loose. The shape and length of the wire guide groove 120 can be selected according to the wiring requirements; therefore, no specific shape or size parameters of the wire guide groove 120 are limited here.

[0036] refer to Figure 2 As shown, the motor housing 210 includes a housing body 211 and an end cover 212. One end of the housing body 211 is open, and the end cover 212 is fastened to the open end of the housing body 211. The side of the housing body 211 facing away from the end cover 212 is connected to the rotating part of the tower base torque sensor 600. It is understood that separating the motor housing 210 into two parts allows for easy disassembly of the motor housing 210, thereby facilitating the inspection and cleaning of the stator assembly 220 or the rotor assembly 230. It should be noted that the housing body 211 and the end cover 212 can be connected by screws or other fasteners, or by snap-fit ​​connections; the specific connection method between the housing body 211 and the end cover 212 is not limited here.

[0037] Optional, see reference Figure 2 As shown, the rotating part of the tower base torque sensor 600 is provided with a first fixing protrusion ring 610, and one end of the housing body 211 is provided with a second fixing protrusion ring 2111. The rotating part passes through the second fixing protrusion ring 2111, and the first fixing protrusion ring 610 and the second fixing protrusion ring 2111 are connected by a connector. It can be understood that in the actual assembly process, the tower base torque sensor 600 is pushed outward from the inside of the housing body 211, so that the first fixing protrusion ring 610 abuts against the inner sidewall of the second fixing protrusion ring 2111. Then, the connector is passed through the second fixing protrusion ring 2111 and connected to the first fixing protrusion ring 610 from the outside of the housing body 211. This facilitates the connection and improves the connection stability between the rotating part and the housing body 211.

[0038] Optional, see reference Figure 2 As shown, there is a first bearing 910 between the end cover 212 and the stator assembly 220. The first bearing 910 can support the end cover 212 well, ensure the stable rotation of the entire motor housing 210, reduce the friction between the end cover 212 and the stator assembly 220, reduce the wear of the stator assembly 220, and extend the service life of the stator assembly 220.

[0039] Optional, see reference Figure 2As shown, a second bearing 920 is provided between the central shaft 100 and the rotor assembly 230. The second bearing 920 can better support the rotor assembly 230, ensure the stable rotation of the entire rotor assembly 230, reduce the friction between the central shaft 100 and the rotor assembly 230, reduce the wear of the rotor assembly 230, and extend the service life of the rotor assembly 230.

[0040] refer to Figures 1-2 As shown, the transmission module 400 includes a planetary carrier 410, a sun gear 420, multiple planetary gears 430, and an internal gear ring 440. The planetary carrier 410 is connected to the central shaft 100. The sun gear 420 is rotatably mounted on the planetary carrier 410 and connected to the rotor assembly 230. The multiple planetary gears 430 are rotatably mounted on the planetary carrier 410 and arranged around the sun gear 420. The multiple planetary gears 430 mesh with the sun gear 420 respectively. The internal gear ring 440 meshes with the multiple planetary gears 430 and is connected to the motor housing 210. It can be understood that during the transmission process, when the rotor assembly 230 drives the sun gear 420 to rotate, the multiple planetary gears 430 rotate under the drive of the sun gear 420. Since the planetary carrier 410 is fixed on the central shaft 100, the rotating planetary gears 430 can drive the internal gear ring 440 to rotate, thereby driving the motor housing 210 to rotate. In this embodiment, planetary gears 430 are used as the transmission module 400, which ensures a large transmission ratio while reducing size and improving structural compactness. In this embodiment, there are four planetary gears 430. Of course, in other embodiments of this utility model, the number of planetary gears 430 can be two, three, or more than four, depending on actual needs.

[0041] Optionally, the sun gear 420 is provided with a connecting flange 421, which is fixed to the rotor assembly 230 by screws. This facilitates the connection stability between the sun gear 420 and the rotor assembly 230.

[0042] Optionally, a third bearing 930 is provided between the planetary gear 430 and the planet carrier 410. This ensures smooth rotation of the planetary gear 430 and reduces wear on both the planetary gear 430 and the planet carrier 410, thus extending the service life of the transmission components.

[0043] refer to Figure 2As shown, the central shaft 100 and the planetary carrier 410 are connected by a connecting key to prevent the planetary carrier 410 from rotating relative to the central shaft 100. A retaining circlip 800 is provided on the central shaft 100, which abuts against one side of the planetary carrier 410. It can be understood that the connection between the central shaft 100 and the planetary carrier 410 via the connecting key not only improves the connection strength but also facilitates assembly. The retaining circlip 800 restricts the axial movement of the planetary carrier 410 relative to the central shaft 100, thereby ensuring the stable operation of the transmission module 400.

[0044] The advantages of the drive mechanism of this utility model are as follows:

[0045] First, by using an aluminum stator bracket 221 that extends outside the motor housing 210 and connects to the controller 500, the heat inside the motor module 200 can be dissipated, reducing the overheating failure rate of the motor module 200.

[0046] Second: Using the stator bracket 221 for wiring, the motor wire 201 passes through the wire hole 2211 integrally formed on the stator bracket 221, avoiding the drilling process required in the stator assembly 220 assembly process in the prior art, which helps to simplify the assembly.

[0047] Third: The central shaft 100 has a through mounting hole 110, which is then locked in place by a fixing bolt 20 and a fixing nut. This makes installation and disassembly very convenient, and eliminates the need for thread machining on the central shaft 100, thus avoiding the problem of having to replace the entire motor if the threads strip.

[0048] Fourth: A desiccant box 700 is installed inside the motor to absorb moisture inside the motor module 200 and prevent the motor module 200 from rusting.

[0049] This utility model also discloses an electric-assisted bicycle, including a frame and the aforementioned drive mechanism. Due to the aforementioned drive mechanism, the electric-assisted bicycle's drive mechanism has better heat dissipation, higher operational reliability, and a lower failure rate.

[0050] In the description of this specification, references to terms such as "some embodiments," "other embodiments," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0051] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating the present utility model, and are not intended to limit the implementation of the present utility model. Those skilled in the art can make various obvious changes, readjustments, and substitutions without departing from the protection scope of this utility model. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. A drive mechanism for an electric-assisted bicycle, characterized in that, include: A central axle (100), the two ends of which are used to connect the rear fork (10) of an electric-assist bicycle; A motor module (200) includes a motor housing (210), a stator assembly (220), and a rotor assembly (230). The stator assembly (220) is connected to the central shaft (100), and the rotor assembly (230) is sleeved on the stator assembly (220). One end of the stator assembly (220) extends out of the motor housing (210). Disc brake pad (300), the disc brake pad (300) is mounted on the motor housing (210); A transmission module (400) is provided, wherein the power output end of the transmission module (400) is connected to the motor housing (210), and the power input end of the transmission module (400) is connected to the rotor assembly (230). A controller (500) is provided with a heat dissipation fin (510) at one end connected to the end of the stator assembly (220) extending out of the motor housing (210), and the other end of the controller (500) is provided with a heat dissipation fin (510). The controller (500) is electrically connected to the motor module (200). A base torque sensor (600) is sleeved on the central shaft (100) and connected to the motor housing (210). The rotating part of the base torque sensor (600) is used to connect to the chainring of the electric bicycle. The fixing control part of the base torque sensor (600) is electrically connected to the motor module (200).

2. The drive mechanism of the electric-assisted bicycle according to claim 1, characterized in that, The motor module (200) also includes a desiccant box (700), which is installed in the stator assembly (220) and located inside the motor housing (210). The outer wall of the desiccant box (700) is provided with a plurality of vent holes.

3. The drive mechanism of the electric-assisted bicycle according to claim 1, characterized in that, The bottom bracket (100) has a through mounting hole (110), and a fixing bolt (20) passes through the rear fork (10) and the mounting hole (110) and is locked by a fixing nut to fix the bottom bracket (100) to the rear fork (10).

4. The drive mechanism of the electric-assisted bicycle according to claim 1, characterized in that, The stator assembly (220) includes a stator bracket (221) and a stator winding. The stator bracket (221) is an aluminum bracket with an integrally formed wire hole (2211). The motor wire (201) of the motor module (200) passes through the wire hole (2211) and is connected to the controller (500).

5. The drive mechanism of the electric-assisted bicycle according to claim 1, characterized in that, The central shaft (100) is provided with a wire passage groove (120), and the lead wire (620) of the tower base torque sensor (600) passes through the wire passage groove (120) and is connected to the welding part of the stator assembly (220). A portion of the lead wire (620) is fixed to the wire passage groove (120) with sealant.

6. The drive mechanism of the electric-assisted bicycle according to any one of claims 1-5, characterized in that, The motor housing (210) includes a housing body (211) and an end cap (212). One end of the housing body (211) is open, and the end cap (212) is fastened to the open end of the housing body (211). The side of the housing body (211) facing away from the end cap (212) is connected to the rotating part of the tower base torque sensor (600).

7. The drive mechanism of the electric-assisted bicycle according to claim 6, characterized in that, The rotating part of the tower base torque sensor (600) is provided with a first fixed protrusion ring (610), and one end of the shell body (211) is provided with a second fixed protrusion ring (2111). The rotating part passes through the second fixed protrusion ring (2111), and the first fixed protrusion ring (610) and the second fixed protrusion ring (2111) are connected by a connector.

8. The drive mechanism of the electric-assisted bicycle according to any one of claims 1-5, characterized in that, The transmission module (400) includes: Planetary carrier (410), which is connected to the central axis (100); A sun gear (420) is rotatably mounted on the planet carrier (410) and connected to the rotor assembly (230); A plurality of planetary gears (430) are rotatably mounted on the planet carrier (410) and arranged around the sun gear (420), and the plurality of planetary gears (430) respectively mesh with the sun gear (420); An internal gear ring (440) meshes with a plurality of planetary gears (430) and is connected to the motor housing (210).

9. The drive mechanism of the electric-assisted bicycle according to claim 8, characterized in that, The central shaft (100) and the planet carrier (410) are connected by a connecting key to prevent the planet carrier (410) from rotating relative to the central shaft (100), and the central shaft (100) is provided with a retaining ring (800), which abuts against one side of the planet carrier (410).

10. An electric-assisted bicycle, characterized in that, Includes the vehicle body and the drive mechanism of the electric-assisted bicycle as described in any one of claims 1-9.

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