Hub motor for electric bicycle

Abstract

The utility model provides a hub motor for an electric bicycle, and relates to the technical field of electric bicycle motors. The cycloidal-pin gear speed reducer comprises a hub shell, a center shaft, a motor assembly and a cycloidal-pin gear speed reducing assembly, a mounting hole is formed in the hub shell along a rotating shaft of the hub shell, and the center shaft is inserted into the mounting hole and connected with the motor assembly; an output shaft of the motor assembly is in transmission connection with the power input end of the cycloidal-pin wheel speed reduction assembly, and the power output end of the cycloidal-pin wheel speed reduction assembly is in transmission connection with the hub shell and can drive the hub shell to rotate around the center shaft. The engine has the advantage of being large in maximum output torque.

Description

Technical Field

[0001] The present application relates to the technical field of electric vehicle motors, and in particular to a hub motor for an electric bicycle. Background Art

[0002] A hub motor is a motor installed inside the wheel hub.

[0003] Existing wheel hub motors generally include a wheel hub shell, a center shaft, a motor assembly and a speed reduction and torque increase assembly. The two ends of the center shaft are used to connect to the vehicle frame. The wheel hub shell is sleeved on the middle of the center shaft. The motor assembly includes a stator and a rotor. Both the stator and the rotor are arranged in the wheel hub shell. The stator is connected to the center shaft and can drive the rotor to rotate around the center shaft. The rotor is connected to the input side of the speed reduction and torque increase assembly, and the output end of the speed reduction and torque increase assembly is connected to the wheel hub shell to be able to drive the wheel hub shell to rotate.

[0004] However, since the existing speed reduction and torque increase components generally adopt a planetary gear structure, and the internal space of the hub of the electric bicycle wheel is relatively small, the single-stage speed ratio of the planetary gear structure can basically only be within 5, which makes the maximum output torque of the hub motor relatively small, and then the electric bicycle using this hub motor has difficulty climbing.

[0005] In view of this, it is necessary to provide a hub motor for an electric bicycle. Utility Model Content

[0006] In order to solve the problem that the maximum output torque of the existing hub motor is small, so that the electric bicycle using the hub motor is unable to climb hills, the present application provides a hub motor for an electric bicycle.

[0007] The present application provides a hub motor for an electric bicycle, which adopts the following technical solution: comprising a hub shell, a central shaft, a motor assembly and a cycloidal pinwheel reduction assembly, wherein a mounting hole is provided on the hub shell along its rotation axis, and the central shaft is inserted into the mounting hole and connected to the motor assembly;

[0008] The output shaft of the motor assembly is drivingly connected to the power input end of the cycloid pinwheel reduction assembly, and the power output end of the cycloid pinwheel reduction assembly is drivingly connected to the hub shell and can drive the hub shell to rotate around the central axis.

[0009] By adopting the above technical solution, the motor assembly can input power to the power input end of the cycloid pinwheel reduction assembly, and the cycloid pinwheel reduction assembly applies the principle of planetary transmission with small tooth difference, which not only occupies a smaller space as a whole, but also can achieve a larger speed ratio of 20 to 40 between its own power input end and power output end, so that the hub motor for the electric bicycle can achieve a larger output torque and realize transmission reversal without self-locking, thereby realizing that the electric bicycle using this hub motor has speed on flat roads, torque on climbing roads, and the motor has the advantages of small size, light weight and low energy consumption.

[0010] Specifically, the motor assembly includes a rotor, a stator and a Hall plate, the rotor is rotatably connected to the central shaft through a bearing, and a magnetic steel is provided on the outer side of the rotor;

[0011] The stator is sleeved on the rotor and fixedly connected to the central shaft, and a coil matched with the magnetic steel is provided on the stator;

[0012] The Hall plate is arranged on the stator and can be electrically connected to a controller of the electric bicycle.

[0013] By adopting the above technical solution, the stator can drive the rotor to rotate around the shaft through the coil, so that power can be output outward through the rotor; the Hall plate can detect the position and speed of the rotor, so that the controller of the electric bicycle can control the hub motor of the electric bicycle.

[0014] Furthermore, the motor assembly also includes a power cord, and a wiring hole leading to the interior of the hub shell is provided on the shaft body on the central axis extending outside the hub shell, one end of the power cord is provided with a plug, and the other end of the power cord passes through the wiring hole to be connected to the stator and the Hall plate.

[0015] By adopting the above technical solution, the hub motor for an electric bicycle can be connected to a power supply device and a controller on the electric bicycle through a plug on a power cord, so that the power supply device can provide power to the stator and the Hall plate through the power cord, and the controller can be electrically connected to the Hall plate through the power cord.

[0016] Furthermore, the cycloid pinwheel reduction assembly comprises an eccentric sleeve, an external gear, an internal gear and an output ring, the eccentric sleeve is sleeved on the central shaft, and the rotor is connected to the eccentric sleeve and can drive the eccentric sleeve to rotate;

[0017] The outer gear is sleeved on the eccentric shaft sleeve, and a bearing is provided between the outer gear and the eccentric shaft sleeve, and the inner gear is sleeved on the outer gear and fixedly connected to the stator;

[0018] The output ring is sleeved on the central shaft, the output ring is connected to the hub shell, a bearing is arranged between the inner ring of the output ring and the central shaft, a transmission hole is opened on the external gear, a transmission shaft is arranged on the annular surface of the output ring, the shaft body of the transmission shaft is inserted into the transmission hole and is slidably connected with an annular sleeve, and the annular sleeve can abut against the hole wall of the transmission hole;

[0019] The inner teeth of the inner gear mesh with the outer teeth of the outer gear, and the eccentric sleeve can drive the outer gear to perform planetary rotation around the central axis through rotation, so that the outer gear drives the output ring and the hub shell to rotate around the central axis through the transmission shaft.

[0020] By adopting the above technical solution, the rotor can drive the eccentric sleeve to rotate around the central axis, so that the eccentric sleeve drives the external gear to perform orbital motion around the central axis, and when the external gear performs orbital motion in a clockwise or counterclockwise direction, the internal teeth of the internal gear will mesh with the external teeth of the external gear and drive the external gear to perform self-rotation motion around its own rotation axis. The rotation direction of the self-rotation motion is opposite to the rotation direction of the orbital motion, so that the eccentric sleeve drives the external gear to perform planetary motion around the central axis, and drives the output ring to rotate through the cooperation of the transmission hole and the transmission shaft, thereby driving the hub shell to rotate around the central axis.

[0021] Furthermore, a clutch is provided between the output ring and the hub shell.

[0022] By adopting the above technical solution, the setting of the clutch can control the power transmission between the output ring and the hub shell.

[0023] Furthermore, a pair of eccentric circle segments are formed on the outer wall of the eccentric sleeve, and the eccentric distances of the pair of eccentric circle segments are equal and the phase difference is 180°;

[0024] The cycloid pinwheel reduction assembly comprises a pair of external gears, each of which is sleeved on the corresponding eccentric circle segment, and an annular spacer is arranged between the pair of external gears.

[0025] By adopting the above technical solution, since the eccentric distances of the two eccentric circle segments are equal and the phase difference is 180°, the eccentric torque of the eccentric sleeve is 0, so that the eccentric sleeve will not generate eccentric force when driving a pair of external gears to rotate, thereby making it difficult for the cycloidal pinwheel reduction assembly to vibrate on the center axis due to the influence of eccentric force during operation.

[0026] Specifically, both ends of the central shaft are provided with chamfered threaded sections for connecting to the frame of the electric bicycle.

[0027] By adopting the above technical solution, the central shaft can be threadedly connected to the frame of the electric bicycle through the chamfered thread section, so as to improve the stability of the connection between the central shaft and the frame.

[0028] Specifically, a disc brake fixing end cover for installing a disc brake is provided on one side of the wheel hub shell.

[0029] By adopting the above technical solution, the disc brake fixed end cover can be used to install the disc brake, so that the wheel installed with the disc brake can be braked by the disc brake.

[0030] In summary, this application includes the following beneficial technical effects:

[0031] The invention comprises a wheel hub shell, a central shaft, a motor assembly and a cycloidal pinwheel reduction assembly. A mounting hole is provided on the wheel hub shell along its rotation axis, the central shaft is inserted into the mounting hole and connected to the motor assembly; the output shaft of the motor assembly is transmission-connected with the power input end of the cycloidal pinwheel reduction assembly, the power output end of the cycloidal pinwheel reduction assembly is transmission-connected with the wheel hub shell and can drive the wheel hub shell to rotate around the central shaft. Since the cycloidal pinwheel reduction assembly adopts the principle of planetary transmission with a small tooth difference, not only is the overall space occupied smaller, but also a larger speed ratio of 20 to 40 can be achieved between its own power input end and power output end, so that the wheel hub motor for the electric bicycle can achieve a larger output torque and realize transmission reversal without self-locking, so that the electric bicycle adopting the wheel hub motor has a high speed on a flat road section and a high torque on a climbing road section, and the motor has the advantages of small size, light weight and low energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a three-dimensional diagram of a hub motor for an electric bicycle of the present application;

[0033] Figure 2 is along Figure 1 A schematic cross-sectional view taken along the central axis of the central axis;

[0034] Figure 3 It is an exploded view of a hub motor for an electric bicycle of the present application, showing a cycloid pinwheel reduction assembly and a central shaft.

[0035] Figure numerals: 1. wheel hub shell; 11. disc brake fixed end cover; 2. center axis; 21. chamfered threaded section; 3. motor assembly; 31. rotor; 32. stator; 33. Hall plate; 34. power cord; 4. cycloid pinwheel reduction assembly; 41. eccentric bushing; 411. eccentric circle segment; 42. outer gear; 421. annular spacer; 43. inner gear; 44. output ring; 441. transmission shaft; 442. annular bushing; 5. clutch. DETAILED DESCRIPTION

[0036] Figure 1 This is a stereoscopic diagram of a hub motor for an electric bicycle of the present application. Figure 2 is along Figure 1 A schematic cross-sectional view of the central axis of the central axis. Figure 1 and Figure 2 A hub motor for an electric bicycle provided in the present application comprises: a hub shell 1, a central shaft 2, a motor assembly 3 and a cycloidal pinwheel reduction assembly 4. A mounting hole is provided on the hub shell 1 along its rotation axis; the middle portion of the central shaft 2 passes through the mounting hole and is inserted into the interior of the hub shell 1 and is connected to the motor assembly 3; both ends of the central shaft 2 are provided with chamfered threaded sections 21 for connecting to the frame of the electric bicycle, so that the stability of the connection between the central shaft 2 and the frame can be improved by the chamfered threaded sections; a disc brake fixing end cover 11 for installing a disc brake is provided on one side of the hub shell 1, so that the wheel installed on the hub shell 1 can be braked by the disc brake.

[0037] See also Figure 1 and Figure 2 The motor assembly 3 includes a rotor 31, a stator 32, a Hall plate 33 and a power cord 34. The rotor 31 is rotatably connected to the central shaft 2 through a bearing, and a magnet is provided on the outer side of the rotor 31; the stator 32 is sleeved on the rotor 31 and fixedly connected to the central shaft 2, and a coil adapted to the magnet is provided on the stator 32, so that the rotor 31 can be driven to rotate around the rotating shaft through the coil, so that power can be output outward through the rotor 31; the Hall plate 33 is provided on the stator 32 and can detect the position and speed of the rotor 31; a wiring hole leading to the inside of the hub shell 1 is provided on the shaft body of the central shaft 2 extending out of the hub shell 1, and a plug is provided at one end of the power cord 34, and the other end of the power cord 34 passes through the wiring hole and is connected to the stator 32 and the Hall plate 33. Through the above design, the hub motor for the electric bicycle can be connected to the power supply device and the controller on the electric bicycle through the plug on the power cord 34, so that the power supply device can provide power to the stator 32 and the Hall plate 33 through the power cord 34, and the controller of the electric bicycle can be electrically connected to the Hall plate 33 through the power cord 34, so that the controller can control the hub motor for the electric bicycle.

[0038] Figure 3 : is an exploded view of a hub motor for an electric bicycle of the present application, which shows a cycloid pinwheel reduction assembly and a central shaft. Figure 2 and Figure 3The cycloid pinwheel reduction assembly 4 includes an eccentric sleeve 41, an outer gear 42, an inner gear 43 and an output ring 44. The eccentric sleeve 41 is sleeved on the central shaft 2. The rotor 31 is connected to the eccentric sleeve 41 and can drive the eccentric sleeve 41 to rotate; the outer gear 42 is sleeved on the eccentric sleeve 41, and a bearing is provided between the outer gear 42 and the eccentric sleeve 41. The inner gear 43 is sleeved on the outer gear 42 and fixedly connected to the stator 32; the output ring 44 is sleeved on the central shaft 2, the output ring 44 is connected to the hub shell 1, and the inner ring of the output ring 44 A bearing is provided between the inner gear 43 and the central axis 2, a transmission hole is provided on the outer gear 42, a transmission shaft 441 is provided on the annular surface of the output ring 44, the shaft body of the transmission shaft 441 is inserted into the transmission hole and is slidably connected with an annular sleeve 442, and the annular sleeve 442 can abut against the hole wall of the transmission hole; the inner teeth of the inner gear 43 are meshed with the outer teeth of the outer gear 42, and the eccentric sleeve 41 can drive the outer gear 42 to perform planetary rotation around the central axis 2 through rotation, so that the outer gear 42 drives the output ring 44 and the hub shell 1 to rotate around the central axis 2 via the transmission shaft 441.

[0039] Through the above design, the rotor 31 can drive the eccentric sleeve 41 to rotate around the central axis 2, so that the eccentric sleeve 41 drives the external gear 42 to perform orbital motion around the central axis 2, and when the external gear 42 performs orbital motion in a clockwise or counterclockwise direction, the internal teeth of the internal gear 43 will mesh with the external teeth of the external gear 42 and drive the external gear 42 to perform self-rotation motion around its own rotation axis, and the rotation direction of the self-rotation motion is opposite to the rotation direction of the orbital motion, so that the eccentric sleeve 41 drives the external gear 42 to perform planetary motion around the central axis 2, and drives the output ring 44 to rotate through the cooperation of the transmission hole and the transmission shaft 441, thereby being able to drive the hub shell 1 to rotate around the central axis 2.

[0040] Take the example that the number of internal teeth of the internal gear 43 is 25 and the number of external teeth of the external gear 42 is 24. Through the above design, the motor assembly 3 can input power to the power input end of the cycloid pinwheel reduction assembly 4, and the cycloid pinwheel reduction assembly 4 applies the principle of planetary transmission with small tooth difference. Compared with the conventional hub motor with a single-stage planetary gear structure and a speed ratio of less than 5, it not only occupies a smaller space size as a whole and has a low energy transmission loss rate, but also can achieve a large speed ratio of 25:1 between its own power input end (i.e., the eccentric shaft sleeve 41) and the power output end (i.e., the output ring 44), so that the hub motor for the electric bicycle can achieve a larger output torque, and realize the reverse transmission without self-locking, so that the electric bicycle using this hub motor has speed on a gentle road section, has torque on a climbing road section, and has the advantages of small motor size, light weight and low energy consumption.

[0041] See also Figure 2 and Figure 3A clutch 5 is provided between the output ring 44 and the hub shell 1, and the clutch 5 can be a wedge-type one-way clutch to control the power transmission between the output ring 44 and the hub shell 1; a pair of eccentric circle segments 411 are formed on the outer wall of the eccentric sleeve 41, and the eccentric distances of the pair of eccentric circle segments 411 are equal and the phase difference is 180°; the cycloid pinwheel reduction assembly 4 includes a pair of external gears 42, each external gear 42 is sleeved on the corresponding eccentric circle segment 411, and an annular spacer 421 is provided between the external gears 42 and between the external gear 42 and the rotor 31, so that the external gear 42 can be limited by the annular spacer 421, so that the external gear 42 is not easily offset along the axial direction of the central axis 2. Through the above design, since the eccentric distances of the two eccentric circle segments 411 are equal and the phase difference is 180°, the eccentric torque of the eccentric sleeve 41 is 0, so that the eccentric sleeve 41 will not generate eccentric force when driving a pair of external gears 42 to rotate, thereby making it difficult for the cycloidal pinwheel reduction assembly 4 to vibrate on the central shaft 2 due to the influence of the eccentric force during operation.

[0042] The working principle of a hub motor for an electric bicycle in the present application when in use is as follows:

[0043] After the motor assembly 3 is turned on, the stator 32 can drive the rotor 31 to drive the eccentric sleeve 41 to rotate around the central axis 2, so that the eccentric sleeve 41 drives the outer gear 42 to revolve around the central axis 2, and when the outer gear 42 revolves in a clockwise or counterclockwise direction, the inner teeth of the inner gear 43 will mesh with the outer teeth of the outer gear 42 and drive the outer gear 42 to rotate around its own rotation axis. The rotation direction of the rotation motion is opposite to the rotation direction of the revolution motion, so that the eccentric sleeve 41 drives the outer gear 42 to perform planetary motion around the central axis 2, and drives the output ring 44 to rotate through the cooperation of the transmission hole and the transmission shaft 441, thereby driving the hub shell 1 to drive the wheel to rotate, so that the electric bicycle can actively drive.

[0044] It should be noted that the above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, all equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A hub motor for an electric bicycle, characterized in that: The invention comprises a wheel hub shell (1), a central shaft (2), a motor assembly (3) and a cycloidal pinwheel reduction assembly (4); the wheel hub shell (1) is provided with a mounting hole along its rotation axis, the central shaft (2) is inserted into the mounting hole and connected to the motor assembly (3); The output shaft of the motor assembly (3) is drivingly connected to the power input end of the cycloid pinwheel reduction assembly (4), and the power output end of the cycloid pinwheel reduction assembly (4) is drivingly connected to the wheel hub shell (1) and is capable of driving the wheel hub shell (1) to rotate around the central axis (2).

2. The hub motor for an electric bicycle according to claim 1, characterized in that: The motor assembly (3) comprises a rotor (31), a stator (32) and a Hall plate (33); the rotor (31) is rotatably connected to the central shaft (2) via a bearing, and a magnetic steel is provided on the outer side of the rotor (31); The stator (32) is sleeved on the rotor (31) and fixedly connected to the central shaft (2), and a coil matched with the magnetic steel is provided on the stator (32); The Hall plate (33) is arranged on the stator (32) and can be electrically connected to a controller of the electric bicycle.

3. The hub motor for an electric bicycle according to claim 2, characterized in that: The motor assembly (3) also includes a power cord (34); a shaft on the central shaft (2) extending outside the hub shell (1) is provided with a wiring hole leading to the interior of the hub shell (1); one end of the power cord (34) is provided with a plug; the other end of the power cord (34) passes through the wiring hole and is connected to the stator (32) and the Hall plate (33).

4. The hub motor for an electric bicycle according to claim 2, characterized in that: The cycloid pinwheel reduction assembly (4) comprises an eccentric shaft sleeve (41), an external gear (42), an internal gear (43) and an output ring (44); the eccentric shaft sleeve (41) is sleeved on the central shaft (2); the rotor (31) is connected to the eccentric shaft sleeve (41) and is capable of driving the eccentric shaft sleeve (41) to rotate; The external gear (42) is sleeved on the eccentric shaft sleeve (41), and a bearing is provided between the external gear (42) and the eccentric shaft sleeve (41); the internal gear (43) is sleeved on the external gear (42) and fixedly connected to the stator (32); The output ring (44) is sleeved on the central shaft (2), the output ring (44) is connected to the hub shell (1), a bearing is provided between the inner ring of the output ring (44) and the central shaft (2), a transmission hole is provided on the outer gear (42), a transmission shaft (441) is provided on the annular surface of the output ring (44), the shaft body of the transmission shaft (441) is inserted into the transmission hole and is slidably connected to an annular sleeve (442), and the annular sleeve (442) can abut against the hole wall of the transmission hole; The inner teeth of the inner gear (43) mesh with the outer teeth of the outer gear (42), and the eccentric sleeve (41) can drive the outer gear (42) to perform planetary rotation around the central axis (2) through rotation, so that the outer gear (42) drives the output ring (44) and the hub shell (1) to rotate around the central axis (2) via the transmission shaft (441).

5. The hub motor for an electric bicycle according to claim 4, characterized in that: A clutch (5) is provided between the output ring (44) and the wheel hub shell (1).

6. The hub motor for an electric bicycle according to claim 4, characterized in that: A pair of eccentric circular segments (411) are formed on the outer wall of the eccentric shaft sleeve (41), and the eccentric distances of the pair of eccentric circular segments (411) are equal and the phase difference is 180°; The cycloid pinwheel reduction assembly (4) comprises a pair of external gears (42), each of the external gears (42) being sleeved on a corresponding eccentric circle segment (411), and an annular spacer (421) being provided between the pair of external gears (42).

7. The hub motor for an electric bicycle according to claim 1, characterized in that: Both ends of the central shaft (2) are provided with chamfered threaded sections (21) for connecting to the frame of an electric bicycle.

8. The hub motor for an electric bicycle according to claim 1, characterized in that: A disc brake fixing end cover (11) for mounting a disc brake is provided on one side of the wheel hub shell (1).

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