Hub electric drive assembly and vehicle

Abstract

The invention relates to a hub electric drive assembly and a vehicle, solves the problem that in the prior art, power cannot be cut off under the reverse dragging working condition, so that a system is damaged, efficient integration of a motor and a speed reducer is achieved through structure optimization, and the reliability of power transmission and the compactness of the system are improved. In the hub electric drive assembly, an output shaft of a drive motor is provided with an axial blind hole, and an elastic pushing mechanism is installed in the axial blind hole; the planetary reducer comprises a sun gear shaft, one end of the sun gear shaft is inserted into the axial blind hole to make contact with the elastic pushing mechanism, the other end of the sun gear shaft is provided with sun gear teeth, and the sun gear shaft is slidably connected with the axial blind hole through a spline pair; the first-stage planet row is selectively meshed with the sun gear, and a limiting structure for limiting the axial position of the sun gear shaft is installed in the first-stage planet row; an output power part of the first-stage planet row is shunted to the second-stage planet row; and the other part of output power of the first-stage planet row is converged with the output power of the first-stage planet row and then is connected into the output structure.

Description

Technical Field

[0001] The present invention relates to the field of vehicle drive, and in particular to a wheel hub electric drive assembly and a vehicle. Background Art

[0002] In the traditional sprocket wheel type wheel hub electric drive system under high-speed trailer working conditions, the reverse towing speed will be transmitted reversely to the motor and the reducer through the transmission chain, resulting in the high-speed idling of the motor rotor, which may damage the motor bearing, rotor or the reducer gear system. To protect the motor system, therefore, the reduction ratio of the reducer cannot be made larger and cannot match the characteristics of the sprocket vehicle with low speed and large torque.

[0003] Most of the existing wheel hub drive structures adopt a reducer and a motor with a fixed connection, and cannot actively cut off the power transmission path during reverse towing, resulting in energy loss and mechanical wear. The integration degree of the motor and the reducer is insufficient, and there are problems such as many connection links, loose structure and poor rigidity, which affect the power transmission efficiency and system stability. Summary of the Invention

[0004] The present invention provides a wheel hub electric drive assembly and a vehicle, which solve the problem of system damage caused by the inability to disconnect power under reverse towing conditions in the prior art, and at the same time realize the efficient integration of the motor and the reducer through structural optimization, improving the reliability of power transmission and the compactness of the system.

[0005] The technical solution of the present invention is as follows: The present application provides a wheel hub electric drive assembly, including a drive motor and a planetary reducer. An axial blind hole is provided on the output shaft of the drive motor, and an elastic pushing mechanism is installed in the axial blind hole; The planetary reducer includes: A sun gear shaft, one end of which is inserted into the axial blind hole to contact the elastic pushing mechanism, the other end is provided with sun gear teeth, and the sun gear shaft is slidably connected to the axial blind hole through a spline pair; A first-stage planetary gear set, which is selectively engaged with the sun gear teeth, and a limiting structure for limiting the axial position of the sun gear shaft is installed in the first-stage planetary gear set; A first-stage planetary gear set, and a part of the output power of the first-stage planetary gear set is shunted to the first-stage planetary gear set; An output structure, and the other part of the output power of the first-stage planetary gear set is joined with the output power of the first-stage planetary gear set and then connected to the output structure; In the driving state, the sun gear teeth are engaged with the first-stage planetary gear set, and the drive motor, the first-stage planetary gear set, the first-stage planetary gear set and the output structure form a complete power transmission path; In the reverse towing state, the axial position limit of the sun gear shaft by the limiting structure is released, so that the elastic pushing mechanism pushes the sun gear shaft away from the first planetary gear set, cutting off the power transmission path, and the first planetary gear set and the first planetary gear set rotate idly.

[0006] Preferably, the length of the spline pair between the sun gear shaft and the axial blind hole is greater than the gear meshing length between the sun gear teeth and the first planetary gear set.

[0007] Preferably, the first planetary gear set includes: A first planetary gear that selectively meshes with the sun gear teeth; A first planetary carrier that is fixedly connected to the first planetary gear; A first ring gear, one end of the first ring gear meshes with the first planetary gear, and the other end is fixedly connected to the first planetary gear set.

[0008] Preferably, the first planetary gear set includes: A second sun gear that is fixedly connected to the other end of the first ring gear; A second planetary carrier that is fixedly connected to the stator housing of the drive motor through a spline support disk; A second planetary gear that meshes with the second sun gear; A second ring gear, the second planetary gear passes through the second planetary carrier and meshes with the second ring gear, and the second ring gear is fixedly connected to the first planetary carrier.

[0009] Preferably, an installation hole is provided on the first planetary carrier, the installation hole is opposite to the sun gear shaft, and the limiting structure is movably installed in the installation hole; In the driving state, the limiting structure presses the sun gear shaft, so that the sun gear teeth and the first planetary gear mesh; In the reverse towing state, the limiting structure is moved outwards, so that the sun gear shaft moves towards the side of the limiting structure under the action of the elastic pushing mechanism until the sun gear teeth are disengaged from the first planetary gear.

[0010] Preferably, the output structure includes: A bearing seat, which is fixedly connected to the second ring gear and is supported on the stator housing of the drive motor through a support bearing; A sprocket disk, which is fixedly connected to the bearing seat.

[0011] Preferably, an oil seal is provided between the bearing seat and the stator housing of the drive motor.

[0012] Preferably, the first planetary carrier, the second ring gear, and the bearing seat are sequentially connected to jointly form the housing of the planetary reducer.

[0013] Preferably, the elastic pushing mechanism includes: A spring, one end of which is fixedly connected to the bottom of the axial blind hole; A top block, which is fixedly connected to the other end of the spring, and the top block contacts one end of the sun gear shaft.

[0014] The present application also provides a vehicle, including the above-mentioned hub electric drive assembly.

[0015] The beneficial effects of the present invention are: When anti-dragging is required, by manually adjusting the position of the limit structure, the axial limit of the sun gear shaft by the limit structure is released. The sun gear shaft moves axially under the action of the elastic pushing mechanism, and then disengages from the first-stage planetary gear set, realizing the physical disconnection of the motor and the transmission chain. The rotor of the drive motor and the sun gear shaft both remain stationary, avoiding damage to the motor bearings / rotors caused by the anti-dragging speed and wear of the reducer gears, solving the problem that the traditional system cannot use a large reduction ratio reducer due to anti-dragging restrictions, and can meet the low-speed and high-torque requirements of the vehicle. Description of the Drawings

[0016] Figure 1 It is a schematic structural diagram of the hub electric drive assembly in the driving state in the embodiment of the present application; Figure 2 It is a schematic structural diagram of the hub electric drive assembly in the anti-dragging state in the embodiment of the present application; Figure 3 It is a schematic diagram of the structural cooperation between the sun gear shaft and both ends in the embodiment of the present application. Detailed Embodiments

[0017] For the convenience of understanding by those skilled in the art, the following further describes the present invention through the drawings. The description is relatively detailed and complete, but it should not be construed as a limitation on the scope of the present invention. Obvious deformations and replacement forms of the following examples are within the protection scope of the present patent.

[0018] Referring to Figure 1 and Figure 2 , the embodiment of the present application provides a hub electric drive assembly, including a drive motor and a planetary reducer. An axial blind hole 211 is provided on the output shaft 21 of the drive motor, and an elastic pushing mechanism 212 is installed in the axial blind hole 211; The planetary reducer includes: A sun gear shaft 11, one end of which is inserted into the axial blind hole 211 to contact the elastic pushing mechanism 212, the other end is provided with sun gear teeth 111, and the sun gear shaft 11 is slidably connected to the axial blind hole 211 through a spline pair; The first planetary gear set 12 is selectively meshed with the sun gear tooth 111, and a limiting structure 13 for limiting the axial position of the sun gear shaft 11 is installed in the first planetary gear set 12; The second planetary gear set 14, and the output power part of the first planetary gear set 12 is shunted to the second planetary gear set 14; The output structure 15, and the other part of the output power of the first planetary gear set 12 and the output power of the second planetary gear set 14 are converged and then connected to the output structure 15; In the driving state, the sun gear tooth 111 is meshed with the first planetary gear set 12, and the driving motor, the first planetary gear set 12, the second planetary gear set 14 and the output structure 15 form a complete power transmission path; In the counter-dragging state, the axial position limit of the sun gear shaft 11 by the limiting structure 13 is released, so that the elastic pushing mechanism 212 pushes the sun gear shaft 11 and the first planetary gear set 12 apart, cutting off the power transmission path, and the first planetary gear set 12 and the second planetary gear set 14 rotate idly.

[0019] When high-speed counter-dragging is required, the position of the limiting structure 13 is manually adjusted to release the axial limit of the sun gear shaft 11. The sun gear shaft 11 moves axially under the action of the elastic pushing mechanism 212, and then disengages from the first planetary gear set 12, realizing the physical disconnection of the driving motor and the transmission chain, so that the rotor 22 of the driving motor and the sun gear shaft 11 both remain stationary, avoiding damage to the motor bearing and rotor 22 caused by the counter-dragging speed and wear of the sun shaft tooth 111 of the reducer, solving the problem that the traditional system cannot use a large reduction ratio reducer due to counter-dragging restrictions, and can match the low-speed and high-torque requirements of the vehicle.

[0020] Refer to Figure 1 and Figure 2 , an axial blind hole 211 is provided at the end of the output shaft 21 of the driving motor, and the inner diameter of the axial blind hole 211 matches the outer diameter of the sun gear shaft 11 to achieve the plug-in connection of the sun gear shaft 11.

[0021] The elastic pushing mechanism 212 installed in the blind hole is used to apply an elastic force to the sun gear shaft 11 axially. Refer to Figure 1 and Figure 2 , in the embodiment of the present application, the elastic pushing mechanism 212 includes, for example, a spring 2121 and a top block 2122. One end of the spring 2121 is fixed at the bottom of the blind hole, and the other end is connected to the oil seal 2122. The top block 2122 contacts the sun gear shaft 11. The spring 2121, the top block 2122 and the long spline are meshed and designed, taking into account both the power transmission stability and the anti-impact ability. By inserting one end of the sun gear shaft 11 into the axial blind hole 211 and contacting the top block 2122 of the elastic pushing mechanism 212, the axial floating connection of the sun gear shaft 11 is realized.

[0022] Referring to Figure 1 and Figure 2 , the first-stage planetary gear set 12 in the embodiment of the present application includes: A first-stage planetary gear 121, which is selectively meshed with the sun gear tooth 111; A first-stage planetary carrier 122, which is fixedly connected to the first-stage planetary gear 121; A first-stage ring gear 123, one end of the first-stage ring gear 123 meshes with the first-stage planetary gear 121, and the other end is fixedly connected to the second-stage planetary gear set 14.

[0023] Specifically, the first-stage planetary gear 121 is positioned on the first pin 125 through the first bearing 124, and the first pin 125 is fixed on the first-stage planetary carrier 122.

[0024] Referring to Figure 1 and Figure 2 , in the embodiment of the present application, the second-stage planetary gear set 14 includes: A second-stage sun gear 141, which is fixedly connected to the other end of the first-stage ring gear 123; A second-stage planetary carrier 142, which is fixedly connected to the stator housing 24 of the drive motor through the spline support disk 28; A second-stage planetary gear 143, which meshes with the second-stage sun gear 141; A second-stage ring gear 144, the second-stage planetary gear 143 passes through the second-stage planetary carrier 142 and meshes with the second-stage ring gear 144, and the second-stage ring gear 144 is fixedly connected to the first-stage planetary carrier 122.

[0025] Among them, the second-stage planetary gear 143 is positioned on the second pin 146 through the second bearing 145, and the second pin 146 is fixed on the second-stage planetary carrier 142. The second-stage planetary carrier 142 is fixedly connected to the spline support disk 28 through a spline pair, and the spline support disk 28 is fixedly connected to the stator housing 24 of the drive motor by means of screws 29 or pins, etc., so as to realize that the second-stage planetary carrier 142 is fixed and does not rotate while having a radial floating function. The drive motor in the embodiment of the present application is an inner-rotor motor. A stator housing 24 is arranged outside the stator 23 of the motor. The stator housing is fixedly connected to the motor housing 25, and a bearing 26 is arranged between the motor housing 25 and the output shaft 21. The stator housing 24 of the drive motor is fixedly connected to the second-stage planetary carrier 142 through the spline support disk 28 to form a rigid whole.

[0026] In the embodiment of the present application, the length of the spline pair between the sun gear shaft 11 and the axial blind hole 211 is greater than the effective meshing length of the sun gear tooth 111 and the first-stage planetary gear 121, ensuring that the spline connection between the sun gear shaft 11 and the axial blind hole 211 does not come off and ensuring the stability of power transmission.

[0027] Referring to Figure 1 and Figure 2 In the embodiment of the present application, the output structure 15 includes: a bearing seat 151, which is fixedly connected to the secondary gear ring 144 and is supported on the stator housing 24 of the drive motor through a support bearing 16; a sprocket disc 152, which is fixedly connected to the bearing seat 151. The sprocket disc 152 directly outputs power, reducing the intermediate transmission link and improving the efficiency.

[0028] The limit structure 13 in the embodiment of the present application is, for example, a limit ring. The limit ring is, for example, fitted with the internal thread in the mounting hole 1221 of the first-stage planetary carrier 122 through an external thread, and the thread length is greater than the effective meshing length of the sun gear teeth 111 and the first-stage planetary gear train 12, ensuring the limit accuracy of the sun gear shaft 11. In the driving state, the limit structure 13 presses the sun gear shaft 11 to make the sun gear teeth 111 mesh with the first-stage planetary gear 121; in the counter-dragging state, the limit structure 13 is moved outwards to make the sun gear shaft 11 move towards the limit structure 13 under the action of the elastic pushing mechanism 212 until the sun gear teeth 111 are disengaged from the first-stage planetary gear 121.

[0029] In the embodiment of the present application, the first-stage planetary carrier 122, the secondary gear ring 144, and the bearing seat 151 are sequentially connected to jointly form the housing 24 of the planetary reducer.

[0030] By fixedly connecting the stator housing 24 of the drive motor with the spline support disc 28, and the spline support disc 28 is fixedly connected to the secondary planetary carrier 142 through a spline pair. The bearing seat 151 is rigidly connected to the stator housing 24 of the drive motor through a support bearing 16 and a oil seal 17. Combining with the direct output design of the sprocket disc 152, the multi-link connection of the traditional structure is eliminated, the space occupation is reduced by more than 30%, the torsional rigidity of the system is increased by 25%, and the power transmission efficiency is increased to more than 95%.

[0031] In addition, in the embodiment of the present application, as Figure 3 , both ends of the sun gear shaft 11 are hemispherical ball top structures 112, thereby realizing the floating of the sun gear shaft 11.

[0032] The ball top structure 112 at one end of the sun gear shaft 11 is designed to cooperate with the long spline in the axial blind hole 211. Combining with the oil seals 2121 and 2122 built in the axial blind hole 211, more than 20% of the axial impact can be absorbed, ensuring the stability of power transmission; the limit structure 13 realizes the axial positioning accuracy of ±0.1 mm level through threaded connection with the first-stage planetary carrier 122; and, by combining with the oil seal 17 structure, lubrication leakage is avoided and the system life is prolonged.

[0033] Meanwhile, the ball top structure 112 at the other end of the sun gear shaft 11 cooperates with the limit structure 13, and the floating of the sun gear shaft 11 is realized through the ball top structures 112 at both ends. Although the relative rotational speed between the arc vertex of the ball top structure 112 and the limit structure 13 is very high, the relative linear speed is low, thereby ensuring that the wear is within a controllable range.

[0034] Through the combined transmission of the first-stage planetary gear 121 and the second-stage planetary gear 143, while maintaining a compact structure, a wide range of speed ratio adjustment from 8 to 25:1 can be achieved, meeting the driving requirements of different vehicle models, and the applicable scenario is expanded by 50% compared with the traditional fixed-speed ratio reducer.

[0035] It should be noted that each embodiment in this specification is described in a progressive manner. The key point of each embodiment is to illustrate the differences from other embodiments. The same or similar parts among the embodiments can be referred to each other.

[0036] Although the preferred embodiments of the embodiments of the present invention have been described, those skilled in the art can make additional changes and modifications once they know the basic creative concept. Therefore, the appended claims are intended to be construed as including the preferred embodiments and all changes and modifications falling within the scope of the embodiments of the present invention.

[0037] It should also be noted that in this article, the orientation or positional relationship indicated by terms such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or component referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. In addition, relational terms such as "first" and "second" are used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations, nor can they be understood as indicating or implying relative importance. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or terminal device including a series of elements does not include those elements, but also includes other elements not expressly listed, or elements inherent to such process, method, article or terminal device. Without further limitation, an element defined by the statement "including a..." does not exclude the existence of additional identical elements in the process, method, article or terminal device including the element.

[0038] The above has introduced the technical solution provided by the present invention in detail. Specific examples are used herein to elaborate on the principle and implementation manner of the present invention. The description of the above embodiments is only for helping to understand the present invention, and the content of this specification should not be construed as a limitation to the present invention. At the same time, for those of ordinary skill in the art, according to the present invention, there will be various changes in the specific implementation manner and application scope. It is not necessary and impossible to enumerate all the implementation manners here, and the obvious changes or variations derived therefrom still fall within the protection scope of the present invention.

Claims

1. A wheel hub electric drive assembly, comprising a drive motor and a planetary reducer, characterized in that, The output shaft (21) of the drive motor is provided with an axial blind hole (211), and an elastic pushing mechanism (212) is installed in the axial blind hole (211); The planetary reducer includes: A sun gear shaft (11), one end of which is inserted into the axial blind hole (211) to contact the elastic pushing mechanism (212), the other end is provided with sun gear teeth (111), and the sun gear shaft (11) is slidably connected to the axial blind hole (211) through a spline pair; A first-stage planetary gear set (12), which is selectively meshed with the sun gear teeth (111), and a limiting structure (13) for limiting the axial position of the sun gear shaft (11) is installed in the first-stage planetary gear set (12); A second-stage planetary gear set (14), and the output power part of the first-stage planetary gear set (12) is shunted to the second-stage planetary gear set (14); An output structure (15), and the other part of the output power of the first-stage planetary gear set (12) is joined with the output power of the second-stage planetary gear set (14) and then connected to the output structure (15); In the driving state, the sun gear teeth (111) are meshed with the first-stage planetary gear set (12), and the drive motor, the first-stage planetary gear set (12), the second-stage planetary gear set (14) and the output structure (15) form a complete power transmission path; In the back-dragging state, the axial position limit of the sun gear shaft (11) by the limiting structure (13) is released, so that the elastic pushing mechanism (212) pushes the sun gear shaft (11) and the first-stage planetary gear set (12) to disengage, cutting off the power transmission path, and the first-stage planetary gear set (12) and the second-stage planetary gear set (14) rotate idly.

2. The hub electric drive assembly according to claim 1, wherein The length of the spline pair between the sun gear shaft (11) and the axial blind hole (211) is greater than the gear meshing length between the sun gear teeth (111) and the first-stage planetary gear set (12).

3. The hub electric drive assembly according to claim 1, wherein, The first-stage planetary gear set (12) includes: A first-stage planetary gear (121), which is selectively meshed with the sun gear teeth (111); A first-stage planetary carrier (122), which is fixedly connected to the first-stage planetary gear (121); A first-stage ring gear (123), one end of the first-stage ring gear (123) is meshed with the first-stage planetary gear (121), and the other end is fixedly connected to the second-stage planetary gear set (14).

4. The hub electric drive assembly according to claim 3, characterized in that, The second-stage planetary gear set (14) includes: A second-stage sun gear (141), which is fixedly connected to the other end of the first-stage ring gear (123); A second-stage planetary carrier (142), which is fixedly connected to the stator housing (24) of the drive motor through a spline support disk (28); A second-stage planetary gear (143), which is meshed with the second-stage sun gear (141); A second-stage ring gear (144), the second-stage planetary gear (143) passes through the second-stage planetary carrier (142) and is meshed with the second-stage ring gear (144), and the second-stage ring gear (144) is fixedly connected to the first-stage planetary carrier (122).

5. The hub electric drive assembly according to claim 3, wherein, An installation hole (1221) is provided on the first-stage planet carrier (122), the installation hole (1221) faces the sun gear shaft (11), and the limiting structure (13) is movably installed in the installation hole (1221); In the driving state, the limiting structure (13) presses against the sun gear shaft (11) to make the sun gear teeth (111) mesh with the first-stage planet gear (121); In the counter-dragging power state, the limiting structure (13) is moved outwards, so that the sun gear shaft (11) moves towards the side of the limiting structure (13) under the action of the elastic pushing mechanism (212) until the sun gear teeth (111) are disengaged from the first-stage planet gear (121).

6. The wheel hub electric drive assembly according to claim 4, characterized in that, The output structure (15) includes: A bearing seat (151), which is fixedly connected to the second-stage gear ring (144) and is supported on the stator housing (24) of the drive motor through a support bearing (16); A sprocket disc (152), which is fixedly connected to the bearing seat (151).

7. The wheel hub electric drive assembly according to claim 6, wherein, An oil seal (17) is provided between the bearing seat (151) and the stator housing (24) of the drive motor.

8. The hub electric drive assembly according to claim 6, characterized in that, The first-stage planet carrier (122), the second-stage gear ring (144), and the bearing seat (151) are sequentially connected to jointly form the housing (24) of the planetary reducer.

9. The hub electric drive assembly according to claim 1, wherein, The elastic pushing mechanism (212) includes: A spring (2121), one end of which is fixedly connected to the bottom of the axial blind hole (211); A top block (2122), which is fixedly connected to the other end of the spring (2121), and the top block (2122) contacts one end of the sun gear shaft (11).

10. A vehicle, characterized in that, It includes a hub electric drive assembly according to any one of claims 1-9.

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