Hub motor with double-planetary speed reduction structure
By adopting a dual planetary deceleration structure in the hub motor and using the continuous deceleration of the two planetary deceleration units, the problem of small maximum output torque of the existing hub motor is solved, and a higher power output is achieved.
Patent Information
- Application Number
- CN202422171176.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-04
- Publication Date
- 2025-06-20
- Estimated Expiration
- 2034-09-04
AI Technical Summary
The existing hub motors adopt a single-stage planetary arrangement, resulting in a small maximum output torque, which cannot meet certain power needs.
The in-wheel motor design adopts a dual-planetary deceleration structure, including the first planetary deceleration unit and the second planetary deceleration unit, forms a larger transmission ratio through the continuous deceleration of the two planetary deceleration units, thereby increasing the maximum output torque.
Through the dual planetary deceleration structure, the hub motor can form a larger transmission ratio between the motor assembly and the hub shell, significantly improving the maximum output torque and meeting higher power needs.
Smart Images
Figure CN223007429U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the technical field of in-wheel motors, and particularly to an in-wheel motor with a double planetary reduction structure. Background Art
[0002] An in-wheel motor is a motor disposed inside a wheel hub and capable of driving a wheel connected to the wheel hub to rotate.
[0003] Existing in-wheel motors generally include a wheel hub housing, a central shaft, a motor assembly, and a reduction assembly. Both ends of the central shaft are used to connect to a vehicle. The wheel hub housing is sleeved on the middle part of the central shaft. The motor assembly includes a stator and a rotor. Both the stator and the rotor are disposed inside the wheel hub housing. The stator can drive the rotor to rotate around the central shaft. The reduction assembly is disposed between the rotor and the wheel hub housing and can reduce the power output by the rotor and transmit it to the wheel hub housing.
[0004] However, since existing reduction and torque-increasing assemblies generally adopt a single-stage planetary gear set structure, the single-stage speed ratio of this planetary gear set structure can basically only reach within 5, resulting in a relatively small maximum output torque of the in-wheel motor.
[0005] In view of this, there is a need to provide an in-wheel motor with a double planetary reduction structure. Summary of the Utility Model
[0006] In order to solve the problem that existing in-wheel motors generally adopt a single-stage planetary gear set structure, resulting in a relatively small maximum output torque of the in-wheel motor, this application provides an in-wheel motor with a double planetary reduction structure.
[0007] This application provides an in-wheel motor with a double planetary reduction structure, adopting the following technical solution: including a wheel hub housing, a central shaft, a motor assembly, and a planetary reduction assembly. A rotation through hole is opened on the wheel hub housing along its rotation axis, and the central shaft passes through the rotation through hole;
[0008] The motor assembly is disposed on the central shaft;
[0009] The planetary reduction assembly includes a first planetary reduction unit and a second planetary reduction unit. The power input end of the first planetary reduction unit is connected to the output shaft of the motor assembly. The power output end of the first planetary reduction unit is connected to the power input end of the second planetary reduction unit. The power output end of the second planetary reduction unit is connected to the wheel hub housing.
[0010] By adopting the above technical solution, the motor assembly can input power to the power input end of the first planetary reduction unit, and the first planetary reduction unit can reduce the received power and transmit it to the second planetary reduction unit, and then the second planetary reduction unit further reduces and transmits this part of the power to the hub housing, so as to form a large transmission ratio between the motor assembly and the hub housing, thereby enabling the hub motor with a double planetary reduction structure to have a large maximum output torque.
[0011] Specifically, the motor assembly includes a rotor and a stator. The rotor is rotatably connected to the central shaft, and a permanent magnet is provided on the outer side of the rotor.
[0012] The stator is arranged on the outer side of the rotor and fixedly connected to the central shaft, and a coil corresponding to the permanent magnet is provided on the inner side of the stator.
[0013] By adopting the above technical solution, the stator can drive the rotor to rotate around the rotating shaft through the coil, so as to output power through the rotor.
[0014] Furthermore, the motor assembly further includes a power cord. A wiring hole leading to the inside of the hub housing is provided on the shaft body of the central shaft extending outside the hub housing. One end of the power cord is provided with a plug, and the other end of the power cord passes through the wiring hole and is connected to the stator.
[0015] By adopting the above technical solution, the hub motor with a double planetary reduction structure can be connected to a power supply device through the plug on the power cord, so that the power supply device can provide power for the motor assembly through this power cord.
[0016] Furthermore, the first planetary reduction unit includes an internal gear, a first sun gear and a first planet carrier. The internal gear is connected to the stator, the first sun gear is connected to the rotor, and a plurality of first planet gears are provided on the first planet carrier. Each of the first planet gears is located between the tooth surfaces of the first sun gear and the internal gear and meshes with both the first sun gear and the internal gear at the same time.
[0017] The second planetary reduction unit includes a second sun gear, a second planet carrier and an output ring. The second sun gear is connected to the first planet carrier, a plurality of second planet gears are provided on the second planet carrier. Each of the second planet gears is located between the tooth surfaces of the second sun gear and the internal gear and meshes with both the second sun gear and the internal gear at the same time. The output ring is rotatably sleeved on the central shaft, and both the second planet carrier and the hub housing are connected to the output ring.
[0018] By adopting the above technical solution, the rotor of the motor assembly can drive the first sun gear to rotate together, and the first sun gear can cooperate with the internal gear and multiple first planet gears to drive the first planet carrier to rotate, and then the first planet carrier drives the second sun gear to rotate, so that the second sun gear can cooperate with the internal gear and multiple second planet gears to drive the second planet carrier to rotate, and then the second planet carrier drives the output ring and the hub housing to rotate.
[0019] Furthermore, a clutch is provided between the output ring and the inner wall of the hub housing.
[0020] By adopting the above technical solution, setting the clutch can control the power transmission between the output ring and the hub housing.
[0021] Specifically, it further includes a tower base which is rotatably connected to the central shaft, and the tower base is connected to a side end cover of the hub housing.
[0022] By adopting the above technical solution, a sprocket adapted to the chain can be provided on the tower base, so that the vehicle can drive the sprocket and the tower base to rotate via the chain by pedaling, and then drive the hub housing to rotate through the tower base.
[0023] Furthermore, the side end cover of the hub housing far from the tower base is a disc brake fixed end cover for installing a disc brake.
[0024] By adopting the above technical solution, the disc brake fixed end cover can be used to install a disc brake, so as to brake the wheel on which it is installed through the disc brake.
[0025] Specifically, both ends of the central shaft are provided with tapered thread sections for connecting with the vehicle.
[0026] By adopting the above technical solution, the central shaft can be threadedly connected to the vehicle through the tapered thread section, so as to improve the connection stability between the central shaft and the vehicle.
[0027] In summary, the present application includes the following beneficial technical effects:
[0028] It includes a wheel hub housing, a central shaft, a motor assembly, and a planetary reduction assembly. A rotation through hole is provided along the rotation axis on the wheel hub housing, the central shaft passes through the rotation through hole, the motor assembly is arranged on the central shaft, the planetary reduction assembly includes a first planetary reduction unit and a second planetary reduction unit. The power input end of the first planetary reduction unit is connected to the output shaft of the motor assembly, the power output end of the first planetary reduction unit is connected to the power input end of the second planetary reduction unit, and the power output end of the second planetary reduction unit is connected to the wheel hub housing. In this way, power can be input to the power input end of the first planetary reduction unit through the motor assembly, and the first planetary reduction unit can reduce the received power and transmit it to the second planetary reduction unit. Then, this part of the power is further reduced and transmitted to the wheel hub housing through the second planetary reduction unit, so as to form a large transmission ratio between the motor assembly and the wheel hub housing, thereby enabling the in-wheel motor with a double planetary reduction structure to have a sufficiently large maximum output torque. Description of the Drawings
[0029] Figure 1 is a perspective view of an in-wheel motor with a double planetary reduction structure according to the present application;
[0030] Figure 2 is a schematic cross-sectional view taken along the central axis of the central shaft of an in-wheel motor with a double planetary reduction structure according to the present application;
[0031] Figure 3 is an exploded view of the planetary reduction assembly of an in-wheel motor with a double planetary reduction structure according to the present application.
[0032] Reference Numerals: 1, wheel hub housing; 11, disc brake fixed end cover; 2, central shaft; 21, tapered thread section; 3, motor assembly; 31, rotor; 32, stator; 33, power cord; 331, plug; 4, planetary reduction assembly; 41, first planetary reduction unit; 411, internal gear; 412, first sun gear; 413, first planetary carrier; 42, second planetary reduction unit; 421, second sun gear; 422, second planetary carrier; 423, output ring; 5, clutch; 6, bottom bracket. Detailed Description of the Embodiment
[0033] Figure 1 is a perspective view of an in-wheel motor with a double planetary reduction structure according to the present application, Figure 2 is a schematic cross-sectional view taken along the central axis of the central shaft of an in-wheel motor with a double planetary reduction structure according to the present application. Refer to Figure 1 and Figure 2, a hub motor with a double planetary reduction structure provided by the present application includes: a hub housing 1, a central shaft 2, a motor assembly 3, and a planetary reduction assembly 4. A rotation through hole is provided on the hub housing 1 along its rotation axis, and the central shaft 2 passes through the rotation through hole. The motor assembly 3 includes a rotor 31, a stator 32, and a power cord 33. The rotor 31 is rotatably connected to the central shaft 2 through a bearing, and a permanent magnet is provided on the outer side of the rotor 31. The stator 32 is provided on the outer side of the rotor 31 and fixedly connected to the central shaft 2, and a coil corresponding to the permanent magnet is provided on the inner side of the stator 32, so that the stator 32 can drive the rotor 31 to rotate around the rotation axis through the coil, thereby being able to output power outward through the rotor 31. The motor assembly 3 further includes a power cord 33. A wiring hole leading to the inside of the hub housing 1 is provided on the shaft body of the central shaft 2 extending outside the hub housing 1. One end of the power cord 33 is provided with a plug 331, and the other end of the power cord 33 passes through the wiring hole and is connected to the stator 32, so that the hub motor with a double planetary reduction structure can be connected to a power supply device through the plug 331 on the power cord 33, thereby enabling the power supply device to supply power to the motor assembly 3 through the power cord 33.
[0034] Figure 3 is an exploded view of the planetary reduction assembly of a hub motor with a double planetary reduction structure according to the present application. Refer to Figure 2 and Figure 3 , the planetary reduction assembly 4 includes a first planetary reduction unit 41 and a second planetary reduction unit 42. The first planetary reduction unit 41 includes an internal gear 411, a first sun gear 412, and a first planetary carrier 413. The internal gear 411 is connected to the stator 32, the first sun gear 412 is connected to the rotor 31, and four first planetary gears are provided on the first planetary carrier 413. Each first planetary gear is located between the tooth surfaces of the first sun gear 412 and the internal gear 411 and meshes with both the first sun gear 412 and the internal gear 411 at the same time. The second planetary reduction unit 42 includes a second sun gear 421, a second planetary carrier 422, and an output ring 423. The second sun gear 421 is connected to the first planetary carrier 413, four second planetary gears are provided on the second planetary carrier 422. Each second planetary gear is located between the tooth surfaces of the second sun gear 421 and the internal gear 411 and meshes with both the second sun gear 421 and the internal gear 411 at the same time. The output ring 423 is rotatably sleeved on the central shaft 2, and both the second planetary carrier 422 and the hub housing 1 are connected to the output ring 423.
[0035] With the above settings, the rotor 31 of the motor assembly 3 can drive the first sun gear 412 to rotate together, and the first sun gear 412 can cooperate with the internal gear 411 and multiple first planet gears to drive the first planet carrier 413 to rotate. Subsequently, the first planet carrier 413 drives the second sun gear 421 to rotate, so that the second sun gear 421 can cooperate with the internal gear 411 and multiple second planet gears to drive the second planet carrier 422 to rotate. Subsequently, the second planet carrier 422 drives the output ring 423 and the hub housing 1 to rotate, so that the motor assembly 3 can input power to the power input end of the first planetary reduction unit 41, and the first planetary reduction unit 41 can reduce the received power and transmit it to the second planetary reduction unit 42. Subsequently, this part of the power is further reduced and transmitted to the hub housing 1 through the second planetary reduction unit 42, so as to form a relatively large transmission ratio of 15-20 between the motor assembly 3 and the hub housing 1, thereby enabling the hub motor with a double planetary reduction structure to have a sufficiently large maximum output torque.
[0036] See Figure 2 and Figure 3 , it should be noted that since the first planetary reduction unit 41 and the second planetary reduction unit 42 share an internal gear 411, by reducing the dimensions of the first sun gear 412, the first planet gears, the second sun gear 421, and the second planet gears in the axial direction of the central shaft 2, the overall dimensions of the planetary reduction assembly 4 can be reduced, and the utilization rate of the internal space of the profile housing can be improved.
[0037] See Figure 2 and Figure 3 , specifically, a clutch 5 can be provided between the output ring 423 and the inner wall of the hub housing 1. The clutch 5 can be a wedge-type one-way bearing, so as to be able to control the power transmission between the output ring 423 and the hub housing 1 through the wedge-type one-way bearing. Threaded sections 21 for connection with the vehicle can also be provided at both ends of the central shaft 2, so that the central shaft 2 can be threadedly connected to the vehicle through the threaded sections 21, thereby improving the connection stability between the central shaft 2 and the vehicle.
[0038] See Figure 1 and Figure 2 , a hub motor with a double planetary reduction structure further includes a bottom bracket 6. The bottom bracket 6 is rotatably connected to the central shaft 2 through a bearing, and the bottom bracket 6 is fixedly connected to one end cover of the hub housing 1. A sprocket adapted to the chain can be provided on the bottom bracket 6, so that the vehicle can drive the sprocket and the bottom bracket 6 to rotate via the chain by pedaling, and then drive the hub housing 1 to rotate through the bottom bracket 6; One end cover of the hub housing 1 far from the bottom bracket 6 is a disc brake fixed end cover 11 for installing a disc brake, so as to be able to brake the wheel on which it is installed through the disc brake.
[0039] The working principle of a hub motor with a double planetary reduction structure of the present application during use is specifically as follows:
[0040] It includes a hub housing 1, a central shaft 2, a motor assembly 3, and a planetary reduction assembly 4. A rotary through-hole is provided on the hub housing 1 along its rotation axis, the central shaft 2 passes through the rotary through-hole, the motor assembly 3 is arranged on the central shaft 2, the planetary reduction assembly 4 includes a first planetary reduction unit 41 and a second planetary reduction unit 42. The power input end of the first planetary reduction unit 41 is connected to the output shaft of the motor assembly 3, the power output end of the first planetary reduction unit 41 is connected to the power input end of the second planetary reduction unit 42, and the power output end of the second planetary reduction unit 42 is connected to the hub housing 1, so as to be able to input power to the power input end of the first planetary reduction unit 41 through the motor assembly 3, and the first planetary reduction unit 41 can reduce the received power and transmit it to the second planetary reduction unit 42, and then the second planetary reduction unit 42 reduces this part of the power again and transmits it to the hub housing 1, so as to be able to form a large transmission ratio between the motor assembly 3 and the hub housing 1, thereby enabling the hub motor with a double planetary reduction structure to have a sufficiently large maximum output torque.
[0041] 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 thereby. Therefore, all equivalent changes made according to the structure, shape, and principle of the present application should be covered within the protection scope of the present application.
Claims
1. A hub motor with a double planetary reduction structure, characterized in that: It comprises a wheel hub shell (1), a central shaft (2), a motor assembly (3) and a planetary reduction assembly (4); the wheel hub shell (1) is provided with a rotating through hole along its rotating axis, and the central shaft (2) passes through the rotating through hole; The motor assembly (3) is arranged on the central shaft (2); The planetary reduction assembly (4) comprises a first planetary reduction unit (41) and a second planetary reduction unit (42), wherein a power input end of the first planetary reduction unit (41) is connected to an output shaft of the motor assembly (3), a power output end of the first planetary reduction unit (41) is connected to a power input end of the second planetary reduction unit (42), and a power output end of the second planetary reduction unit (42) is connected to the wheel hub housing (1).
2. The hub motor with a double planetary reduction structure according to claim 1, characterized in that: The motor assembly (3) comprises a rotor (31) and a stator (32); the rotor (31) is rotatably connected to the central shaft (2), and a magnetic steel is provided on the outer side of the rotor (31); The stator (32) is arranged on the outside of the rotor (31) and is fixedly connected to the central shaft (2), and a coil corresponding to the magnetic steel is arranged on the inside of the stator (32).
3. The hub motor with a double planetary reduction structure according to claim 2, characterized in that: The motor assembly (3) further comprises a power cord (33); a wiring hole leading to the interior of the hub shell (1) is provided on the shaft body of the central shaft (2) extending outside the hub shell (1); a plug (331) is provided at one end of the power cord (33); and the other end of the power cord (33) passes through the wiring hole and is connected to the stator (32).
4. The hub motor with a double planetary reduction structure according to claim 2, characterized in that: The first planetary reduction unit (41) comprises an internal gear (411), a first sun gear (412) and a first planet carrier (413), the internal gear (411) being connected to the stator (32), the first sun gear (412) being connected to the rotor (31), and the first planet carrier (413) being provided with a plurality of first planetary gears, each of the first planetary gears being located between the tooth surfaces of the first sun gear (412) and the internal gear (411) and meshing with the first sun gear (412) and the internal gear (411) at the same time; The second planetary reduction unit (42) comprises a second sun gear (421), a second planet carrier (422) and an output ring (423); the second sun gear (421) is connected to the first planet carrier (413); a plurality of second planet gears are arranged on the second planet carrier (422); each of the second planet gears is located between the tooth surfaces of the second sun gear (421) and the internal gear (411) and is meshed with the second sun gear (421) and the internal gear (411); the output ring (423) is rotatably sleeved on the central shaft (2); the second planet carrier (422) and the hub housing (1) are both connected to the output ring (423).
5. The hub motor with a double planetary reduction structure according to claim 4, characterized in that: A clutch (5) is provided between the output ring (423) and the inner wall of the hub shell (1).
6. The hub motor with a double planetary reduction structure according to claim 1, characterized in that: It also includes a freewheel base (6), which is rotatably connected to the central shaft (2), and the freewheel base (6) is connected to a side end cover of the hub shell (1).
7. The hub motor with a double planetary reduction structure according to claim 6, characterized in that: The end cover on one side of the wheel hub shell (1) away from the tower base (6) is a disc brake fixing end cover (11) for installing a disc brake.
8. The hub motor with a double planetary reduction structure according to claim 1, characterized in that: Both ends of the central shaft (2) are provided with chamfered thread sections (21) for connecting to a vehicle.