Wheel-side electric drive axle

Abstract

The utility model provides a wheel-side electric drive axle which comprises an axle body and a motor reducer integrated structure, and the axle body is sequentially provided with a plate spring mounting seat and a reduction gearbox connecting seat from the middle to the two sides; the motor and speed reducer integrated structure comprises a shared shell, a motor cavity is formed in one side of the shared shell, a speed reducer cavity is formed in the other side of the shared shell, a speed reducer assembly is arranged in the speed reducer cavity, a motor assembly is arranged in the motor cavity, and a motor shaft of the motor assembly is coaxially connected with an input shaft of the speed reducer assembly; the axle body is connected with the shared shell through the reduction gearbox connecting base, and the plate spring mounting base is located between the two motor reducer integrated structures. The wheels are independently driven through the motor reducer integrated structures at the two ends of the axle body, a transmission half shaft of the axle body is omitted, a transmission chain is shortened, the mechanical transmission structure is greatly simplified, the weight is reduced, the efficiency loss of a mechanical differential mechanism is reduced, and meanwhile the dynamic response to wheel control is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of electric drive axles, and particularly relates to a wheel side electric drive axle. Background Art

[0002] At present, the structure of the electric drive axle on the market is as Figure 1 shown. Basically, the drive motor A is assembled with the rear drive axle B, and the transmission route is: drive motor - reduction gearbox - transmission shaft - rear axle main reducer - differential - half shaft - wheel. The longer the power transmission chain is, the greater the energy loss is, which affects the economy of the whole vehicle. Secondly, due to the need to install the main reducer and differential in the middle of the rear drive axle body B, a raised axle housing needs to be added at the axle body. Therefore, for a light truck using the rear drive axle B, in order to avoid the axle housing, the height of the cargo platform must be raised (refer to Figure 2 ), resulting in difficulty in meeting the design requirements of a low ground clearance for the whole vehicle. Content of the Utility Model

[0003] Based on this, the purpose of the utility model is to provide a wheel side electric drive axle to solve the technical problems mentioned in the above background art.

[0004] The utility model provides a wheel side electric drive axle, which includes an axle body and an integrated structure of a motor and a reducer. The axle body is sequentially provided with leaf spring mounting seats and reducer connection seats from the middle to both sides;

[0005] The integrated structure of the motor and the reducer includes a common housing. One side of the common housing is provided with a motor chamber, and the other side is provided with a reducer chamber. A reducer assembly is arranged in the reducer chamber, a motor assembly is arranged in the motor chamber, and the motor shaft of the motor assembly is coaxially connected with the input shaft of the reducer assembly;

[0006] The axle body is connected to the common housing through the reducer connection seat, and the leaf spring mounting seats are located between two integrated structures of the motor and the reducer.

[0007] Further, for the wheel side electric drive axle, the integrated structure of the motor and the reducer further includes a motor rear housing. The common housing and the axle body are integrally formed by casting with cast iron or cast steel, and the motor rear housing is made of aluminum.

[0008] Further, for the wheel side electric drive axle, the reducer connection seat includes an arc-shaped enclosing plate matching the contour of the common housing. An arc-shaped mounting plate is arranged at the edge of the common housing. A plurality of mounting holes are arranged along the arc direction on the arc-shaped mounting plate. Threaded holes corresponding to the mounting holes are arranged on the arc-shaped enclosing plate. The mounting holes are used to penetrate bolts to connect the threaded holes, so that the common housing is fixed in the mounting area enclosed by the arc-shaped enclosing plate.

[0009] Further, for the in-wheel motor drive axle, the central angle of the arc-shaped enclosing plate is an obtuse angle.

[0010] Further, for the in-wheel motor drive axle, the shared housing includes a bottom plate. On one side of the bottom plate, there are a motor inner-ring side wall and a motor outer-ring side wall. The space between the motor inner-ring side wall and the motor outer-ring side wall forms the motor chamber. On the other side of the bottom plate, there is a reducer side wall. The inner side of the reducer side wall forms the reducer chamber. The arc-shaped mounting plate is arranged on the motor outer-ring side wall.

[0011] Further, for the in-wheel motor drive axle, reinforcing ribs are arranged between the arc-shaped mounting plate and the motor outer-ring side wall and / or the reducer side wall.

[0012] Further, for the in-wheel motor drive axle, the motor rear shell is connected to the motor outer-ring side wall to enclose the motor chamber. In the motor chamber, there is a first stator fixedly connected to the bottom plate, and a second stator fixedly connected to the motor rear shell. A rotor is arranged between the first stator and the second stator, and the rotor is fixedly connected to the motor shaft.

[0013] Further, for the in-wheel motor drive axle, the integrated reducer structure further includes a reducer front shell. The reducer front shell is connected to the reducer side wall to enclose the reducer chamber. The reducer assembly includes a sun gear, planet gears, a planet carrier, and a ring gear. The sun gear is integrally formed on the input shaft. The ring gear is arranged on the inner wall of the reducer side wall. The planet carrier is rotatably arranged around the input shaft in the reducer chamber. The planet gears are rotatably arranged on the planet carrier and mesh with the sun gear and the ring gear at the same time.

[0014] Further, for the in-wheel motor drive axle, a plurality of fixing holes are arranged on the leaf spring mounting seat.

[0015] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0016] 1. By independently driving the wheels through the integrated motor-reducer structures at both ends of the axle, the drive half shafts of the axle are cancelled, the transmission chain is shortened, the mechanical transmission structure is greatly simplified, the weight is reduced, the efficiency loss of the mechanical differential is saved, and at the same time, the dynamic response of the wheel control is improved.

[0017] 2. The shared housing loads the motor and the reducer at the same time, making the overall structure very compact, saving the installation space. And because the motor shaft arranged in the motor chamber is coaxially connected with the input shaft of the reducer assembly, it helps to reduce the overall height (radial dimension) of the entire integrated motor-reducer structure, which is beneficial to meeting the design requirements of a low ground clearance for the vehicle. Description of the Drawings

[0018] Figure 1 is a structural schematic diagram of an electric drive axle in the prior art;

[0019] Figure 2 is a structural schematic diagram of a light truck using an electric drive axle of the prior art;

[0020] Figure 3 is a perspective view of a wheel-side electric drive axle in the present invention;

[0021] Figure 4 is a top view of a wheel-side electric drive axle in the present invention;

[0022] Figure 5 is a side view of a wheel-side electric drive axle in the present invention;

[0023] Figure 6 is a specific structural schematic diagram of a shared housing in the present invention;

[0024] Figure 7 is a cross-sectional view of an integrated structure of a motor and a reducer in the present invention;

[0025] Figure 8 is an assembly drawing of a wheel-side electric drive axle on a frame girder in the present invention;

[0026] Figure 9 is a structural schematic diagram of a light truck using the wheel-side electric drive axle of the present invention;

[0027] Main element symbol description:

[0028] 11. Axle body; 12. Arc-shaped enclosing plate;

[0029] 20. Shared housing; 21. Bottom plate; 22. Inner side wall of the motor; 23. Outer side wall of the motor; 24. Side wall of the reducer;

[0030] 31. Arc-shaped mounting plate; 32. Mounting hole; 33. Bolt; 34. Reinforcing rib;

[0031] 40. Motor rear housing; 41. First stator; 42. Second stator; 43. Rotor; 44. Motor shaft;

[0032] 50. Reducer front housing; 51. Sun gear; 52. Planet gear; 53. Planet carrier; 54. Ring gear; 55. Input shaft;

[0033] 60. Fixed hole position;

[0034] 71. Leaf spring suspension; 72. Frame girder;

[0035] 80. Hydraulic drum brake;

[0036] 90. Controller housing;

[0037] 100, Leaf spring mounting seat; 200, Reducer connection seat.

[0038] The following specific embodiments will further illustrate the present invention in conjunction with the above-mentioned drawings. Specific Embodiments

[0039] For ease of understanding of the present invention, the present invention will be described more comprehensively below with reference to the relevant drawings. Several embodiments of the present invention are shown in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided so that the disclosure of the present invention is more thorough and comprehensive.

[0040] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly on the other element or there can also be an intermediate element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

[0041] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0042] Please refer to Figures 3 to 7 , the in-wheel motor drive axle in the present invention includes a bridge body 11 and an integrated motor and reducer structure. The bridge body 11 is sequentially provided with a leaf spring mounting seat 100 and a reducer connection seat 200 from the middle to both sides; the integrated motor and reducer structure includes a common housing 20. One side of the common housing 20 is provided with a motor chamber, and the other side is provided with a reducer chamber. A reducer assembly is provided in the reducer chamber, and a motor assembly is provided in the motor chamber. The motor shaft 44 of the motor assembly is coaxially connected to the input shaft 55 of the reducer assembly;

[0043] The bridge body is connected to the common housing 20 through the reducer connection seat 200, and the leaf spring mounting seat 100 is located between two integrated motor and reducer structures.

[0044] The wheels are independently driven by the integrated structure of the motor speed reducers at both ends of the axle housing 11, eliminating the drive half shafts of the axle housing 11, shortening the transmission chain, greatly simplifying the mechanical transmission structure, reducing the weight, saving the efficiency loss of the mechanical differential, and at the same time improving the dynamic response of the wheel control. Secondly, the shared housing 20 houses the motor and the speed reducer at the same time, making the overall structure very compact, saving the installation space, and since the motor shaft 44 provided in the motor chamber is coaxially connected to the input shaft 55 of the speed reducer assembly, it helps to reduce the overall height (radial dimension) of the entire integrated structure of the motor speed reducer, which is beneficial to meeting the design requirements of a low ground clearance for the vehicle.

[0045] Refer to Figures 3 to 5 , the reduction gearbox connection seat 200 includes an arc-shaped enclosure plate 12 that matches the contour of the shared housing 20. An arc-shaped mounting plate 31 is provided at the edge of the shared housing 20. A plurality of mounting holes 32 are arranged along the arc direction on the arc-shaped mounting plate 31. Threaded holes corresponding to the mounting holes 32 are provided on the arc-shaped enclosure plate 12. The mounting holes 32 are used to insert bolts 33 to connect to the threaded holes, so that the shared housing 20 is fixed within the installation area enclosed by the arc-shaped enclosure plate 12.

[0046] In this embodiment, the central angle of the arc-shaped enclosure plate 12 is an obtuse angle, aiming to provide a wider installation space and facilitating the installation of the integrated structure of the motor speed reducer. Specifically, refer to Figure 1 , in this embodiment, a controller housing 90 is integrated on the edge side of the shared housing 20. When the integrated structure of the motor speed reducer is installed on the arc-shaped enclosure plate 12, the controller housing 90 protruding outward from the periphery of the shared housing 20 can be located in the open area, avoiding interference with the arc-shaped enclosure plate 12 during installation.

[0047] Refer to Figure 6 and Figure 7 , the shared housing 20 includes a bottom plate 21. On one side of the bottom plate 21, there are a motor inner ring side wall 22 and a motor outer ring side wall 23. The motor chamber is formed between the motor inner ring side wall 22 and the motor outer ring side wall 23. On the other side of the bottom plate 21, there is a speed reducer side wall 24. The inner side of the speed reducer side wall 24 forms the speed reducer chamber. The arc-shaped mounting plate 31 is arranged on the motor outer ring side wall 23.

[0048] Specifically, in this embodiment, both the shared housing 20 and the axle housing 11 are integrally cast from cast iron or cast steel, having high structural strength and being able to adapt to various complex and harsh working conditions, while the motor rear housing 40 is made of aluminum, which can reduce the overall weight of the integrated structure of the motor speed reducer.

[0049] Further, reinforcing ribs 34 are provided between the arc-shaped mounting plate 31 and the side wall 23 of the motor outer ring and / or the side wall 24 of the reducer, so as to improve the structural strength of the arc-shaped mounting plate 31 and ensure the installation stability of the motor reducer integrated structure on the arc-shaped enclosure 12.

[0050] Referring to Figure 7 , the motor reducer integrated structure further includes a motor rear housing 40. The motor rear housing 40 is connected to the side wall 23 of the motor outer ring to enclose the motor chamber. A first stator 41 fixedly connected to the bottom plate 21 and a second stator 42 fixedly connected to the motor rear housing 40 are arranged in the motor chamber. A rotor 43 is provided between the first stator 41 and the second stator 42, and the rotor 43 is fixedly connected to the motor shaft 44. It can be seen that in this embodiment, the motor assembly on one side of the shared housing 20 is an axial flux motor, which is light in weight, small in size and flat in structure, greatly reducing the overall axial dimension of the motor reducer integrated structure, thereby reducing its occupation of the vehicle cargo box space and improving the utilization rate of the whole vehicle cargo box space.

[0051] Furthermore, the reducer integrated structure further includes a reducer front housing 50. The reducer front housing 50 is connected to the side wall 24 of the reducer to enclose the reducer chamber. The reducer assembly includes a sun gear 51, a planetary gear 52, a planet carrier 53 and a ring gear 54. The sun gear 51 is integrally formed on the input shaft 55, the ring gear 54 is arranged on the inner wall of the side wall 24 of the reducer, the planet carrier 53 is rotatably arranged in the reducer chamber around the input shaft 55, and the planetary gear 52 is rotatably arranged on the planet carrier 53 and meshes with the sun gear 51 and the ring gear 54 at the same time. It can be seen that in this embodiment, the reducer assembly on the other side of the shared housing 20 is a planetary reducer, which cooperates with the axial flux motor, making the overall axial dimension of the motor reducer integrated structure compressed to the extreme, greatly saving the space occupation and providing convenience for the design of a large cargo box space.

[0052] Regarding the transmission path of the motor reducer integrated structure, the input shaft 55 is driven to rotate by the motor shaft 44, so that the sun gear 51 drives the planetary gear 52 to rotate, and at the same time the planetary gear 52 meshes with the ring gear 54. The planetary gear 52 rotates around its own axis and also revolves, and finally the power is output from the planet carrier 53 to the wheel.

[0053] In this embodiment, the motor reducer integrated structure independently controls the left and right wheel speeds and torque, and eliminates the traditional central differential structure, secondary reducer assembly, transmission half shaft and other components compared to the central layout space of the traditional electric drive axle, effectively reducing the middle height space of the drive axle, so that the cargo platform plane of the cargo box falls between the two motor reducer integrated structures. On the one hand, the axial spacing between the two motor reducer integrated structures is ≥1350mm, ensuring the minimum passing spacing of the cargo box is ≥1250mm, and the standard shelf can pass; on the other hand, the ground clearance of the lowest point of the bridge body 11 is ≥200mm, ensuring the passability in the urban logistics terminal scenario. The height of the cargo platform of the comprehensive light truck van logistics vehicle can be reduced to about 550mm, and the empty height in the cargo box can be increased by about 400mm, which is convenient for terminal users to save unloading / loading time, reduce the work intensity and efficiency of handling goods, and improve the efficiency of personnel use; the height of the cargo box is increased by 400mm, and the loading volume is increased by 3.5m 3 , increasing the loading space by 20%, facilitating the transportation of large goods, and having a wider range of applicable scenarios. At the same time, it increases the amount of cargo in a single trip, allowing less running and more carrying, greatly improving the utilization and efficiency of personnel.

[0054] In addition, the motor-reducer integrated structure independently drives the wheels, with fast torque response and even motor torque control power distribution. The motor torque gradient is designed to be 360N.m / 450N.m / 500N.m, which can adapt to the needs of different usage scenarios. For example, when a wheel is suddenly suspended in the air, the overall stability and power of the vehicle will not be significantly affected, thereby improving the vehicle's passability in extreme environments. Or in high-speed conditions, such as when one of the front wheels has a flat tire, the system can also quickly adjust the body by adjusting the speed and torque of each motor to ensure that the vehicle continues to move forward stably without deviation.

[0055] See also Figure 4 The bridge body 11 is provided with a plurality of fixing holes 60 in the area adjacent to the arc-shaped enclosure plate 12. The fixing holes 60 are used to connect the leaf spring suspension 71 and are fixed to the frame beam 72 through the leaf spring suspension 71. When the bridge body 11 is fixedly connected to the frame beam 72, the motor reducer integrated structure is arranged on the outside of the two beams, and the distance between the motor rear housing 40 and the inner side of the cargo box and the leaf spring suspension 71 is specifically referred to Figure 8 , the height of the upper wing surface of the beam from the ground can be achieved at a full load height of about 525mm, and the height of the rear cargo platform after the customized van cargo box of 4200mm×2100mm×2500mm is about 550mm from the ground. In addition, it should be noted that the cargo platform plane of the electric drive axle structure of this embodiment needs to be specially shaped to avoid the arrangement and jumping of the tires. For details, please refer to Figure 9 .

[0056] See also Figure 3, a hydraulic drum brake 80 is connected to the outside of the motor reduction integrated structure, with a specification of φ314mm×75mm, which is integrated for both running and parking, and the wheel-side parking meets the braking requirements of a 6.5T vehicle. Regarding the drum brake, it should be noted that it includes two parts: a brake drum and a rear baffle assembly. Among them, the brake drum is connected to the axle, and the rear baffle assembly is connected to the vehicle chassis. There are structures such as brake shoes and springs in the rear baffle assembly. When the brake pedal is depressed, the hydraulic brake pushes the brake oil to flow out of the master cylinder and through the oil pipe, and then transmits the pressure from the brake pedal to the drum brake. At this time, the two brake shoes will open and contact the inner surface of the brake drum to generate frictional force, causing the brake drum to stop rotating immediately and realizing the braking of the wheel.

[0057] In summary, for the wheel-side electric drive axle in the above embodiments of the present invention, the wheels are independently driven by the motor reducer integrated structures at both ends of the axle housing 11, the drive half shafts of the axle housing 11 are cancelled, the transmission chain is shortened, the mechanical transmission structure is greatly simplified, the weight is reduced, the efficiency loss of the mechanical differential is saved, and at the same time, the dynamic response of the wheel control is improved. Secondly, the common housing 20 simultaneously houses the motor and the reducer, making the overall structure very compact, saving the installation space, and since the motor shaft 44 provided in the motor chamber is coaxially connected to the input shaft 55 of the reducer assembly, it helps to reduce the overall height (radial dimension) of the entire motor reducer integrated structure, which is beneficial to meeting the design requirements of a low ground clearance for the vehicle.

[0058] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0059] The above-described embodiments only represent several implementation manners of the present invention, and their descriptions are relatively specific and detailed, but should not be construed as limiting the scope of the patent of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention should be subject to the appended claims.

Claims

1. A wheel-end electric drive axle, characterized in that, It includes a bridge body (11) and an integrated structure of a motor and a speed reducer. The bridge body (11) is successively provided with a leaf spring mounting seat (100) and a speed reducer connecting seat (200) from the middle to both sides. The integrated structure of the motor and the speed reducer includes a common housing (20). A motor chamber is arranged on one side of the common housing (20), and a speed reducer chamber is arranged on the other side. A speed reducer assembly is arranged in the speed reducer chamber, and a motor assembly is arranged in the motor chamber. The motor shaft (44) of the motor assembly is coaxially connected with the input shaft (55) of the speed reducer assembly. The bridge body is connected to the common housing (20) through the speed reducer connecting seat (200), and the leaf spring mounting seat (100) is located between two integrated structures of the motor and the speed reducer.

2. The wheel-end electric drive axle according to claim 1, wherein, The integrated structure of the motor and the speed reducer further includes a motor rear housing (40). The common housing (20) and the bridge body (11) are integrally cast by cast iron or cast steel, and the motor rear housing (40) is made of aluminum.

3. The wheel-end electric drive axle according to claim 2, wherein, The speed reducer connecting seat (200) includes an arc-shaped enclosing plate (12) matching the contour of the common housing (20). An arc-shaped mounting plate (31) is arranged at the edge of the common housing (20). A plurality of mounting holes (32) are arranged along the arc direction on the arc-shaped mounting plate (31). Threaded holes corresponding to the mounting holes (32) are arranged on the arc-shaped enclosing plate (12). The mounting holes (32) are used to penetrate bolts (33) to connect the threaded holes, so that the common housing (20) is fixed in the mounting area enclosed by the arc-shaped enclosing plate (12).

4. The wheel hub motor drive axle according to claim 3, wherein, The central angle of the arc-shaped enclosing plate (12) is an obtuse angle.

5. The wheel-end electric drive axle according to claim 3, characterized in that, The common housing (20) includes a bottom plate (21). A motor inner ring side wall (22) and a motor outer ring side wall (23) are arranged on one side of the bottom plate (21). The motor chamber is formed between the motor inner ring side wall (22) and the motor outer ring side wall (23). A speed reducer side wall (24) is arranged on the other side of the bottom plate (21). The inner side of the speed reducer side wall (24) forms the speed reducer chamber. The arc-shaped mounting plate (31) is arranged on the motor outer ring side wall (23).

6. The wheel-end electric drive axle according to claim 5, characterized in that Reinforcing ribs (34) are arranged between the arc-shaped mounting plate (31) and the motor outer ring side wall (23) and / or the speed reducer side wall (24).

7. The wheel-end electric drive axle according to claim 5, wherein The motor rear housing (40) is connected to the motor outer ring side wall (23) to close the motor chamber. A first stator (41) fixedly connected to the bottom plate (21) and a second stator (42) fixedly connected to the motor rear housing (40) are arranged in the motor chamber. A rotor (43) is arranged between the first stator (41) and the second stator (42). The rotor (43) is fixedly connected to the motor shaft (44).

8. The wheel-end electric drive axle according to claim 5, wherein, The speed reducer integrated structure further includes a speed reducer front housing (50), the speed reducer front housing (50) is connected to the speed reducer side wall (24) to enclose the speed reducer chamber, the speed reducer assembly includes a sun gear (51), a planet gear (52), a planet carrier (53) and a ring gear (54), the sun gear (51) is integrally formed on the input shaft (55), the ring gear (54) is arranged on the inner wall of the speed reducer side wall (24), the planet carrier (53) is rotatably arranged in the speed reducer chamber around the input shaft (55), and the planet gear (52) is rotatably arranged on the planet carrier (53) and meshes with the sun gear (51) and the ring gear (54) at the same time.

9. The wheel hub motor drive axle according to claim 3, characterized in that, A plurality of fixing holes (60) are provided on the leaf spring mounting seat.

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