Hub motor

Abstract

The utility model relates to the technical field of motors for electric vehicles, and particularly discloses a hub motor which is characterized in that a planetary support is fixedly sleeved on a motor shaft, an inner ring of a planetary bearing is fixedly connected to a connecting shaft, an outer ring of the planetary bearing is fixedly connected to a planetary gear, and a sun gear is sleeved on a stator and is rotatably connected to the motor shaft. A plurality of permanent magnets are fixedly arranged along the inner circumferential face of the sun gear, the outer gear ring is fixedly connected to the inner wall of the hub, and the planetary gears are meshed with the outer gear ring and the sun gear at the same time. The planetary assembly, the sun gear and the outer gear ring form a planetary speed reduction structure, the stator generates electromagnetic force to drive the permanent magnet to drive the sun gear to rotate, and the sun gear can drive the outer gear ring to operate and finally drive the hub to rotate through meshing transmission with the planetary gears. Therefore, the stator part does not need to be greatly superposed, the torque can be increased by several times on the aspect of power, and the light weight and the torque maximization of the hub motor are realized.

Description

Technical Field

[0001] The utility model relates to the technical field of motors for electric vehicles, in particular to a hub motor. Background Art

[0002] With the development and popularization of transportation, electric vehicles play an increasingly important role in people's daily travel. As the most commonly used drive motor for electric vehicles, the hub motor does not require any transmission system. The driving force acts directly on the wheels of the electric vehicle. It has the characteristics of high driving efficiency, compact structure and high reliability.

[0003] The wheel hub motors of existing electric vehicles usually adopt a direct drive method of outer rotor plus stator in structure. This method does not have a transmission mechanism. Although the structure is simple, its power is only directly output through the outer rotor, and its torque performance cannot be maximized. The direct drive motor has limited adaptability to loads, especially in large load and large torque situations. The performance is not as good as the motor with a transmission structure. If the direct drive hub motor of an electric vehicle wants to maximize the climbing performance, that is, maximize the torque, it can only increase the motor power by increasing the stator stack length to achieve maximum torque, but this method will further increase the size and weight of the motor. Utility Model Content

[0004] The utility model aims to provide a wheel hub motor, which can improve the torque of the wheel hub motor of an electric vehicle and reduce the overall weight of the wheel hub motor of the electric vehicle.

[0005] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0006] The utility model provides a hub motor, comprising:

[0007] Wheel hub;

[0008] A first end cover and a second end cover, wherein the first end cover, the second end cover and the wheel hub surround and form a first accommodating cavity;

[0009] A motor shaft, wherein the motor shaft passes through the first end cover and the second end cover;

[0010] A stator, the stator is disposed in the first accommodating cavity and fixedly sleeved on the motor shaft;

[0011] A planetary assembly, the planetary assembly comprising a planetary support, a plurality of planetary gears, and a plurality of planetary bearings corresponding to the plurality of planetary gears one by one, the planetary support being fixedly sleeved on the motor shaft, and the planetary support being convexly provided with a plurality of connecting shafts corresponding to the plurality of planetary gears one by one, the inner ring of the planetary bearing being fixedly connected to the connecting shaft, and the outer ring of the planetary bearing being fixedly connected to the planetary gears;

[0012] A sun gear, the sun gear is sleeved on the stator and rotatably connected to the motor shaft, and a plurality of permanent magnets are fixedly arranged along the inner circumference of the sun gear;

[0013] An outer gear ring is fixedly connected to the inner wall of the wheel hub, and a plurality of planetary gears are meshed with the outer gear ring and the sun gear at the same time.

[0014] As a preferred technical solution of the above-mentioned hub motor, the planetary bracket includes an inner bracket and an outer bracket, the inner bracket is fixedly sleeved on the motor shaft, the outer bracket is sleeved on the inner bracket, and the outer bracket and the inner bracket are spaced apart to form a raceway, the planetary assembly also includes a plurality of rollers, the plurality of rollers are arranged in the raceway, and can all roll against the inner wall of the raceway, the inner wall of the raceway is provided with a plurality of slots corresponding to the plurality of rollers, and the rollers can be snapped into the slots to limit the rotation of the outer bracket relative to the inner bracket.

[0015] As a preferred technical solution of the above-mentioned hub motor, the planetary assembly also includes a limiter, which is fixedly connected to the inner bracket or the outer bracket and can abut against the plurality of rollers to limit the axial movement of the plurality of rollers.

[0016] As a preferred technical solution of the above-mentioned hub motor, the hub motor also includes a third end cover and a fourth end cover, the third end cover and the fourth end cover are both rotatably connected to the motor shaft, the third end cover and the fourth end cover are both fixedly connected to the sun gear, and the third end cover, the fourth end cover and the sun gear surround and form a second accommodating cavity, and the stator is located in the second accommodating cavity.

[0017] As a preferred technical solution for the above-mentioned hub motor, the connecting shaft includes a first section and a second section, the second section is fixedly connected between the first section and the planetary bracket, the shaft diameter of the first section is smaller than the shaft diameter of the second section, and the inner ring of the planetary bearing is fixedly sleeved on the first section and abuts against the second section.

[0018] As a preferred technical solution of the above-mentioned hub motor, the planetary assembly also includes a plurality of retaining springs, and the plurality of retaining springs are arranged in a one-to-one correspondence with the plurality of planetary bearings. The retaining springs are fixedly sleeved on the first section and abut against the inner ring of the planetary bearing.

[0019] As a preferred technical solution of the above-mentioned hub motor, the hub motor also includes a first oil seal ring and a second oil seal ring. The first oil seal ring is fixedly sleeved on the motor shaft and has an interference fit with the first end cover. The second oil seal ring is fixedly sleeved on the motor shaft and has an interference fit with the second end cover.

[0020] As a preferred technical solution of the above-mentioned hub motor, the hub motor further includes a dust cover, which is fixedly sleeved on the motor shaft and covers the first oil seal ring.

[0021] As a preferred technical solution of the above-mentioned hub motor, the hub motor further includes a magnetic conductive ring, which is arranged on the inner circumference of the sun gear and is integrally formed with the sun gear.

[0022] As a preferred technical solution of the above-mentioned hub motor, the planetary gear is made of plastic steel material.

[0023] The beneficial effects of the utility model are:

[0024] The utility model provides a wheel hub motor, which comprises: a wheel hub, a first end cover, a second end cover, a motor shaft, a stator, a planetary assembly, a sun gear and an outer gear ring, the first end cover, the second end cover and the wheel hub are surrounded and form a first accommodating cavity, the motor shaft passes through the first end cover and the second end cover, the stator is arranged in the first accommodating cavity and is fixedly sleeved on the motor shaft, the planetary assembly comprises a planetary bracket, a plurality of planetary gears, and a plurality of planetary bearings corresponding to the plurality of planetary gears one by one, the planetary bracket is fixedly sleeved on the motor shaft, and a plurality of connecting shafts corresponding to the plurality of planetary gears one by one are convexly provided on the planetary bracket, the inner ring of the planetary bearing is fixedly connected to the connecting shaft, the outer ring of the planetary bearing is fixedly connected to the planetary gear, the sun gear is sleeved on the stator and is rotatably connected to the motor shaft, a plurality of permanent magnets are fixedly arranged along the inner circumferential surface of the sun gear, the outer gear ring is fixedly connected to the inner wall of the wheel hub, and the plurality of planetary gears are meshed with the outer gear ring and the sun gear at the same time. With this arrangement, the planetary assembly, the sun gear and the outer gear ring form a planetary reduction structure. When the hub motor is operating normally, the winding coil begins to be energized, and the stator generates electromagnetic force to drive the permanent magnet to drive the sun gear to rotate. Since the planetary bracket is fixedly sleeved on the motor shaft, the sun gear can drive the outer gear ring to operate by meshing with several planetary gears, and finally drive the hub to rotate. Since the planetary reduction structure has several times the reduction ratio, the stator part does not need to be greatly superimposed, and the hub motor can achieve several times the torque increase in power. It can effectively reduce the overall weight of the hub motor, achieve lightweight and maximize torque of the hub motor, and improve the power density of the hub motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A cross-sectional view of the hub motor provided by the utility model;

[0026] Figure 2 A schematic diagram of the structure of the planetary assembly, sun gear and outer gear ring provided by the utility model;

[0027] Figure 3 The structure diagram of the planetary bracket provided by the utility model Figure 1 ;

[0028] Figure 4 The structure diagram of the planetary bracket provided by the utility model Figure 2 ;

[0029] Figure 5 for Figure 4 Sectional view along the AA direction;

[0030] Figure 6 The structure diagram of the planetary bracket provided by the utility model Figure 3 .

[0031] in:

[0032] 1. Wheel hub; 2. First end cover; 3. Second end cover; 4. First accommodating chamber; 5. Motor shaft; 6. Stator;

[0033] 7. Planetary bracket; 71. Inner bracket; 72. Outer bracket;

[0034] 8. Planetary gears; 9. Planetary bearings; 10. Connecting shaft; 101. First section; 102. Second section; 11. Sun gear; 12. Permanent magnet; 13. Outer gear ring; 14. Raceway; 15. Roller; 16. Slot; 17. Limiting member; 18. Third end cover; 19. Fourth end cover; 20. Second accommodating chamber; 21. Retaining spring; 22. First oil seal ring; 23. Second oil seal ring; 24. Dust cover. DETAILED DESCRIPTION

[0035] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0036] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance. Among them, the terms "first position" and "second position" are two different positions.

[0037] Unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this utility model can be understood according to specific circumstances.

[0038] Unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include the first feature being in direct contact with the second feature, or may include the first feature being in contact with the second feature through another feature between them instead of being in direct contact. Moreover, a first feature being "above", "above" and "above" a second feature includes the first feature being directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes the first feature being directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0039] The technical solution of the utility model is further explained below with reference to the accompanying drawings and through specific implementation methods.

[0040] like Figures 1 to 6As shown, this embodiment provides a hub motor, which includes: a hub 1, a first end cover 2, a second end cover 3, a motor shaft 5, a stator 6, a planetary assembly, a sun gear 11 and an outer gear ring 13, the first end cover 2, the second end cover 3 and the hub 1 are surrounded and form a first accommodating cavity 4, the motor shaft 5 passes through the first end cover 2 and the second end cover 3, the stator 6 is arranged in the first accommodating cavity 4, and is fixedly sleeved on the motor shaft 5, the planetary assembly includes a planetary bracket 7, a plurality of planetary gears 8, and a plurality of planetary gears corresponding to the plurality of planetary gears 8. The planetary bearing 9 and the planetary support 7 are fixedly sleeved on the motor shaft 5, and the planetary support 7 is provided with a plurality of connecting shafts 10 corresponding to the plurality of planetary gears 8 one by one. The inner ring of the planetary bearing 9 is fixedly connected to the connecting shaft 10, and the outer ring of the planetary bearing 9 is fixedly connected to the planetary gear 8. The sun gear 11 is sleeved on the stator 6 and rotatably connected to the motor shaft 5. A plurality of permanent magnets 12 are fixedly arranged along the inner circumference of the sun gear 11, and the outer gear ring 13 is fixedly connected to the inner wall of the wheel hub 1. The plurality of planetary gears 8 are meshed with the outer gear ring 13 and the sun gear 11 at the same time. It should be noted that the stator 6 includes an iron core and a winding coil, and the winding coil is wound around the iron core. In this arrangement, the planetary assembly, the sun gear 11 and the outer ring gear 13 form a planetary reduction structure. When the hub motor is operating normally, the winding coil starts to be energized, and the stator 6 generates an electromagnetic force to drive the permanent magnet 12 to drive the sun gear 11 to rotate. Since the planetary bracket 7 is fixedly sleeved on the motor shaft 5, the sun gear 11 can drive the outer ring gear 13 to operate by meshing with a number of planetary gears 8, and finally drive the hub 1 to rotate. Since the planetary reduction structure has several times the reduction ratio, the stator 6 part does not need to be greatly superimposed, and the hub motor can achieve several times the torque increase in power. It can effectively reduce the overall weight of the hub motor, achieve lightweight and maximize torque of the hub motor, and improve the power density of the hub motor.

[0041] In this embodiment, the number of the planetary gears 8 is three, and they are evenly arranged on the outer surface of the planetary bracket 7. Of course, in other embodiments, the number of the planetary gears 8 can also be set according to actual needs, and no further limitation is made here.

[0042] Optionally, bearings are provided between the first end cover 2 and the second end cover 3 and the motor shaft 5 , the inner ring of the bearing is fixedly connected to the motor shaft 5 , and the outer ring of the bearing is fixedly connected to the corresponding first end cover 2 or second end cover 3 .

[0043] Optionally, see Figures 4 to 6As shown, the planetary bracket 7 includes an inner bracket 71 and an outer bracket 72. The inner bracket 71 is fixedly sleeved on the motor shaft 5, and the outer bracket 72 is sleeved on the inner bracket 71. The outer bracket 72 and the inner bracket 71 are spaced apart to form a raceway 14. The planetary assembly also includes a plurality of rollers 15. The plurality of rollers 15 are arranged in the raceway 14 and can roll against the inner wall of the raceway 14. The inner wall of the raceway 14 is provided with a plurality of slots 16 corresponding to the plurality of rollers 15. The rollers 15 can be snapped into the slots 16 to limit the rotation of the outer bracket 72 relative to the inner bracket 71. With such an arrangement, when the hub motor is running, when the power is output from the sun gear 11 to the planetary gear 8, an extrusion meshing is formed between the rollers 15 and the corresponding slots 16. At this time, the planetary assembly is a fixed mechanism, which plays a one-way "close" role, and the power is transmitted and conducted;

[0044] When the hub motor has no power output and is in a gliding state, the hub 1 rotates, and the outer gear ring 13 also rotates with the hub 1. The roller 15 and the slot 16 are in a disengaged, free, unidirectional rotation state. At this time, the functions of the inner bracket 71 and the outer bracket 72 are equivalent to "bearings", and their resistance is much smaller than the resistance of the meshing rotation of the outer gear ring 13 and the planetary gear 8. Therefore, the outer bracket 72 drives the planetary assembly to rotate with the outer gear ring 13, playing a unidirectional "disengagement" role. At this time, the resistance of the hub motor during gliding is small, which can extend the gliding distance and increase the cruising range of the electric vehicle.

[0045] Optionally, in order to prevent the rollers 15 in the raceway 14 from axial movement, the planetary assembly further includes a stopper 17, which is fixedly connected to the inner bracket 71 or the outer bracket 72 and can abut against the rollers 15 to limit the axial movement of the rollers 15. In this embodiment, the stopper 17 is a cover plate, which is fixedly connected to the outer bracket 72 by a plurality of locking bolts.

[0046] Optionally, the hub motor further includes a third end cover 18 and a fourth end cover 19, the third end cover 18 and the fourth end cover 19 are both rotatably connected to the motor shaft 5, the third end cover 18 and the fourth end cover 19 are both fixedly connected to the sun gear 11, and the third end cover 18, the fourth end cover 19 and the sun gear 11 surround and form a second accommodating cavity 20, and the stator 6 is located in the second accommodating cavity 20. Further, a bearing is provided between the third end cover 18 and the fourth end cover 19 and the motor shaft 5, the inner ring of the bearing is fixedly connected to the motor shaft 5, and the outer ring of the bearing is fixedly connected to the corresponding third end cover 18 or the fourth end cover 19.

[0047] Optionally, see Figure 3As shown, the connecting shaft 10 includes a first section 101 and a second section 102, the second section 102 is fixedly connected between the first section 101 and the planetary bracket 7, the shaft diameter of the first section 101 is smaller than the shaft diameter of the second section 102, and the inner ring of the planetary bearing 9 is fixedly sleeved on the first section 101 and abuts against the second section 102. Such a configuration can facilitate the assembly of the planetary bearing 9 and can prevent the planetary bearing 9 from axial movement to a certain extent.

[0048] Optionally, in order to further prevent the planetary bearing 9 from axial movement, the planetary assembly also includes a plurality of retaining springs 21 , and the plurality of retaining springs 21 are arranged one-to-one corresponding to the plurality of planetary bearings 9 , and the retaining springs 21 are fixedly sleeved on the first section 101 and abut against the inner ring of the planetary bearing 9 .

[0049] Optionally, the wheel hub motor further includes a first oil seal ring 22 and a second oil seal ring 23, wherein the first oil seal ring 22 is fixedly sleeved on the motor shaft 5 and is interference fit with the first end cover 2, and the second oil seal ring 23 is fixedly sleeved on the motor shaft 5 and is interference fit with the second end cover 3. Further, the wheel hub motor further includes a dust cover 24, which is fixedly sleeved on the motor shaft 5 and covers the first oil seal ring 22. In this way, the first oil seal ring 22, the second oil seal ring 23 and the dust cover 24 form a sealing structure of the wheel hub motor as a whole, which can greatly slow down the aging speed and extend its service life.

[0050] Optionally, the hub motor further includes a magnetic conductive ring, which is arranged on the inner circumference of the sun gear 11 and is integrally formed with the sun gear 11 .

[0051] Optionally, in order to further reduce the overall weight of the planetary assembly and make the hub motor lightweight, the planetary gear 8 is made of plastic steel material.

[0052] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation methods of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all implementation methods here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. A hub motor, characterized in that: include: Wheel hub (1); A first end cover (2) and a second end cover (3), wherein the first end cover (2), the second end cover (3) and the wheel hub (1) surround and form a first accommodating cavity (4); A motor shaft (5), wherein the motor shaft (5) passes through the first end cover (2) and the second end cover (3); A stator (6), the stator (6) being arranged in the first accommodating cavity (4) and fixedly sleeved on the motor shaft (5); A planetary assembly, the planetary assembly comprising a planetary support (7), a plurality of planetary gears (8), and a plurality of planetary bearings (9) corresponding one-to-one to the plurality of planetary gears (8), the planetary support (7) being fixedly sleeved on the motor shaft (5), and the planetary support (7) being convexly provided with a plurality of connecting shafts (10) corresponding one-to-one to the plurality of planetary gears (8), the inner ring of the planetary bearing (9) being fixedly connected to the connecting shaft (10), and the outer ring of the planetary bearing (9) being fixedly connected to the planetary gear (8); A sun gear (11), the sun gear (11) being sleeved on the stator (6) and rotatably connected to the motor shaft (5), and a plurality of permanent magnets (12) being fixedly arranged along the inner circumference of the sun gear (11); An outer gear ring (13) is fixedly connected to the inner wall of the wheel hub (1), and a plurality of planetary gears (8) are meshed with the outer gear ring (13) and the sun gear (11) at the same time.

2. The wheel hub motor according to claim 1, characterized in that: The planetary bracket (7) comprises an inner bracket (71) and an outer bracket (72), wherein the inner bracket (71) is fixedly sleeved on the motor shaft (5), and the outer bracket (72) is sleeved on the inner bracket (71), and the outer bracket (72) and the inner bracket (71) are spaced apart to form a raceway (14), and the planetary assembly further comprises a plurality of rollers (15), wherein the plurality of rollers (15) are arranged in the raceway (14) and can roll against the inner wall of the raceway (14), and the inner wall of the raceway (14) is provided with a plurality of slots (16) corresponding to the plurality of rollers (15), and the rollers (15) can be snapped into the slots (16) to limit the outer bracket (72) from rotating relative to the inner bracket (71).

3. The wheel hub motor according to claim 2, characterized in that: The planetary assembly further comprises a limiting member (17), wherein the limiting member (17) is fixedly connected to the inner bracket (71) or the outer bracket (72) and is capable of abutting against a plurality of the rollers (15) to limit the axial movement of the plurality of the rollers (15).

4. The hub motor according to any one of claims 1 to 3, characterized in that: The hub motor further comprises a third end cover (18) and a fourth end cover (19), wherein the third end cover (18) and the fourth end cover (19) are both rotatably connected to the motor shaft (5), and the third end cover (18) and the fourth end cover (19) are both fixedly connected to the sun gear (11), and the third end cover (18), the fourth end cover (19) and the sun gear (11) surround and form a second accommodating cavity (20), and the stator (6) is located in the second accommodating cavity (20).

5. The wheel hub motor according to any one of claims 1 to 3, characterized in that: The connecting shaft (10) comprises a first section (101) and a second section (102); the second section (102) is fixedly connected between the first section (101) and the planetary bracket (7); the shaft diameter of the first section (101) is smaller than the shaft diameter of the second section (102); and the inner ring of the planetary bearing (9) is fixedly sleeved on the first section (101) and abuts against the second section (102).

6. The wheel hub motor according to claim 5, characterized in that: The planetary assembly further comprises a plurality of retaining springs (21), the plurality of retaining springs (21) being arranged in one-to-one correspondence with the plurality of planetary bearings (9), the retaining springs (21) being fixedly sleeved on the first section (101) and abutting against the inner ring of the planetary bearing (9).

7. The wheel hub motor according to any one of claims 1 to 3, characterized in that: The hub motor further comprises a first oil seal ring (22) and a second oil seal ring (23); the first oil seal ring (22) is fixedly sleeved on the motor shaft (5) and is interference fit with the first end cover (2); the second oil seal ring (23) is fixedly sleeved on the motor shaft (5) and is interference fit with the second end cover (3).

8. The wheel hub motor according to claim 7, characterized in that: The hub motor further comprises a dust cover (24), wherein the dust cover (24) is fixedly sleeved on the motor shaft (5) and covers the first oil seal ring (22).

9. The wheel hub motor according to any one of claims 1 to 3, characterized in that: The wheel hub motor also includes a magnetic conductive ring, which is arranged on the inner peripheral surface of the sun gear (11) and is integrally formed with the sun gear (11).

10. The hub motor according to any one of claims 1 to 3, characterized in that: The planetary gear (8) is made of plastic steel material.

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