Dual motor powertrain and electric vehicle with protection against bearing galvanic corrosion

Abstract

The application provides a dual-motor power assembly and an electric vehicle. The power assembly comprises two driving motors arranged adjacently. The housing of the power assembly comprises a middle partition plate, and each of the two end faces of the middle partition plate comprises a bearing groove and an oil guide structure. Each bearing groove is used for fixing a motor shaft of a driving motor through a motor bearing. Two ends of each oil guide structure are respectively used for fixedly connecting the groove bottom of a bearing groove and for conveying cooling liquid or lubricating oil along the axial hole of a motor shaft into the power assembly. A gap exists between the outer circumferential surface of each oil guide structure and the inner circumferential surface of the axial hole of a motor shaft, and is used for accommodating an annular conductive structure. Each conductive structure is used for electrically connecting a motor shaft and an oil guide structure. The power assembly provided by the application uses the structure that the middle partition plate supplies oil to the axial hole of the motor shaft on both sides to conduct the shaft current to the housing ground to protect the motor bearing.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electric vehicles, in particular to a double-motor power assembly for preventing bearing electric corrosion and an electric vehicle. BACKGROUND

[0002] During the operation of the double-motor power assembly, the shaft voltage of the motor shaft can break through the oil film of the motor bearing to cause bearing electric corrosion, so that the contact surface of the motor bearing is locally molten and uneven. The bearing electric corrosion not only reduces the performance of the bearing, but also causes the motor shaft bearing to fail prematurely, thereby reducing the overall life of the power assembly. SUMMARY

[0003] The present application provides a double-motor power assembly for preventing bearing electric corrosion and an electric vehicle. The structure of the middle partition plate of the power assembly supplies oil to the shaft hole of the motor shaft, which conducts the shaft current of the motor shaft to the shell ground to protect the motor bearing.

[0004] In a first aspect, the present application provides a double-motor power assembly for preventing bearing electric corrosion. The power assembly includes two drive motors arranged adjacent to each other along the axial direction of the power assembly. The shell of the power assembly includes a middle partition plate, which includes two end faces opposite to each other along the axial direction of the power assembly. Each end face includes a bearing groove and an oil guide structure. Each bearing groove is used to fix the motor shaft of a drive motor through the motor bearing. One end of each oil guide structure is used to fixedly connect the groove bottom of the bearing groove, and the other end of each oil guide structure is used to extend into the shaft hole of the motor shaft along the axial direction of the power assembly and deliver cooling liquid or lubricating oil to the shaft hole. There is a gap between the outer circumferential surface of each oil guide structure and the inner circumferential surface of the shaft hole of the motor shaft, and the gap is used to accommodate an annular conductive structure. Each conductive structure is used to electrically connect the motor shaft and an oil guide structure.

[0005] The double-motor power assembly for preventing bearing electric corrosion provided by the present application forms two bearing grooves through the middle partition plate, and the openings of the two bearing grooves are opposite to each other along the axial direction of the power assembly. The groove wall of each bearing groove is used to fix the motor bearing and drive connect the motor shaft of a drive motor through the motor bearing. The groove bottom of each bearing groove is used to fix an oil guide structure, and the extension directions of the two oil guide structures along the axial direction of the power assembly are opposite to each other. Each oil guide structure is used to extend into the shaft hole of the motor shaft and deliver lubricating oil or cooling liquid towards the shaft hole.

[0006] The power assembly provided by the application also uses the gap between the oil guide structure and the shaft hole of the motor shaft to fix an electrically conductive structure. The electrically conductive structure is used to conduct the electrical connection between the outer circumferential surface of the oil guide structure and the inner circumferential surface of the shaft hole, so as to conduct the shaft end current of the motor shaft to the middle partition plate to achieve grounding, thereby avoiding the shaft end current of the motor shaft flowing through the motor bearing to cause the motor bearing to fail. The power assembly provided by the application reasonably uses the internal space of the shaft holes of the two motor shafts to respectively achieve the electrical connection between the two motor shafts and the shell. The motor bearing is effectively protected, and the service life of the power assembly is prolonged.

[0007] In an implementation manner, the middle partition plate comprises an internal oil channel, and the internal oil channel is used to deliver the cooling liquid or lubricating oil to the oil guide structures of the two end surfaces.

[0008] In the implementation manner, the two sides of the middle partition plate along the axial direction of the power assembly are respectively arranged with a driving motor. The internal oil channel in the middle partition plate is used to extend along the radial direction of the power assembly, so as to reduce the axial size of the power assembly. The middle partition plate is connected to the two oil guide structures through the internal oil channel, so as to simplify the internal structure of the middle partition plate.

[0009] In an implementation manner, each gap comprises two gaps with different radial sizes, and the two gaps are arranged in sequence along the direction in which each oil guide structure extends into the shaft hole. The radial size of one of the two gaps is greater than the radial size of the other gap, and the radial size of the other gap is less than the radial size of the electrically conductive structure.

[0010] In the implementation manner, near the opening region of each shaft hole, the radial size of one of the gaps between each oil guide structure and the shaft hole is relatively large, so as to provide sufficient installation space for the two electrically conductive structures. In the internal region of the shaft hole, the radial size of the other gap between each oil guide structure and the shaft hole is relatively small, so as to reduce the amount of oil leakage of the cooling liquid or lubricating oil delivered into the shaft hole towards the opening of the shaft hole, thereby delivering more cooling liquid or lubricating oil towards the driving motor and the speed reducer.

[0011] In an implementation manner, each oil guide structure comprises an axial protrusion. One end of each axial protrusion is used to fixedly connect the bottom of the bearing groove, and the other end of each axial protrusion is used to extend into the shaft hole of the motor shaft along the axial direction of the power assembly. The end surface of the other end of each axial protrusion comprises a through hole, and the through hole is used to deliver the cooling liquid or lubricating oil to the shaft hole of the motor shaft.

[0012] In the implementation manner, each oil guide structure is used to extend into the shaft hole of the motor shaft along the axial direction of the power assembly through the axial protrusion. The other end of each axial protrusion extending into the shaft hole is used to deliver the cooling liquid or lubricating oil to the shaft hole through the through hole. Each through hole is used to communicate with the internal oil channel of the middle partition plate.

[0013] In an implementation, the axes of the two axially protruding through holes coincide.

[0014] In the present implementation, the internal oil passage of the partition plate extends in the radial direction of the power assembly, and the two through holes are symmetrically located on the partition plate. The oil amount of the cooling liquid or lubricating oil flowing into the two through holes from the internal oil passage is relatively uniform, which can ensure that the cooling effect or lubricating effect of the two drive motors on both sides of the partition plate is similar.

[0015] In an implementation, each axial protrusion includes a first protrusion and a second protrusion, and the first protrusion and the second protrusion are arranged in sequence in the direction in which each oil guide structure extends into the shaft hole. The outer diameter of the first protrusion is greater than the outer diameter of the second protrusion, and the first protrusion is used to sleeve the conductive structure.

[0016] In the present implementation, the first protrusion of each axial protrusion has a larger outer diameter to stably support the conductive structure, and the second protrusion has a smaller outer diameter to facilitate the extension into the shaft hole, which is conducive to reducing the inner diameter size of the deep shaft hole and thus improving the structural stability of the motor shaft.

[0017] In an implementation, the outer peripheral surface of each first protrusion includes one or more limiting structures in the axial direction of the power assembly. Wherein in the radial direction of the power assembly, the radial dimension of each limiting structure in each first protrusion is different from the outer diameter of the remaining part of each first protrusion.

[0018] In the present implementation, the one or more limiting structures are used to increase the contact area of the first protrusion with the conductive structure and enhance the conductive effect of the axial protrusion with the conductive structure.

[0019] In an implementation, the one or more limiting structures in each first protrusion are used to fix and electrically connect the inner ring of the conductive structure, and the outer ring of the conductive structure is used to contact and electrically connect the inner peripheral surface of the shaft hole.

[0020] In the present implementation, the one or more limiting structures are used to form a positioning groove in the first protrusion. The groove bottom of the positioning groove is used to fix the conductive structure to limit the axial displacement of the conductive structure in the power assembly. The groove bottom of the positioning groove is used to fit the inner peripheral surface of the conductive structure to enhance the conductive effect.

[0021] In an implementation, each shaft hole includes a first shaft hole, a second shaft hole, and a third shaft hole, and the first shaft hole, the second shaft hole, and the third shaft hole are arranged in sequence in the direction in which each oil guide structure extends into the shaft hole. Wherein the inner diameter of the first shaft hole is greater than the inner diameter of the second shaft hole, and the inner diameter of the second shaft hole is greater than the inner diameter of the third shaft hole. The length of the first shaft hole is greater than the length of the second shaft hole, and the length of the first shaft hole is less than the length of the third shaft hole.

[0022] In the present embodiment, the inner diameter of the first section of the shaft hole is larger to accommodate and secure the conductive structure. The inner diameter of the third section of the shaft hole is smaller to receive the cooling liquid or lubricating oil delivered by the axial protrusion and to reduce the leakage of the cooling liquid or lubricating oil towards the conductive structure. The second section of the shaft hole is to connect the first section of the shaft hole and the third section of the shaft hole, and the end surface of the second section of the shaft hole towards the first section of the shaft hole is to limit the axial displacement of the conductive structure.

[0023] In an embodiment, a step surface is formed between the second section of the shaft hole and the third section of the shaft hole, the step surface towards the conductive structure along the axial direction of the power assembly, and the distance between the step surface and the conductive structure is smaller than the distance between the bottom of the bearing groove and the conductive structure.

[0024] In the present embodiment, the smaller the distance between the step surface and the conductive structure along the axial direction of the power assembly, the longer the length of the axial protrusion extending into the third section of the shaft hole. Because the gap between the third section of the shaft hole and the axial protrusion is small in radial dimension, the cooling liquid or lubricating oil flows from the third section of the shaft hole to the first section of the shaft hole for a longer distance, which can reduce the contact between the conductive structure and the cooling liquid or lubricating oil.

[0025] In an embodiment, the inner circumferential surface of each first section of the shaft hole comprises one or more annular grooves. Wherein along the radial direction of the power assembly, the inner diameter of each first section of the shaft hole at the one or more annular grooves is larger than the inner diameter of the rest of each first section of the shaft hole.

[0026] In the present embodiment, the one or more annular grooves are to increase the contact area between the first section of the shaft hole and the conductive structure, and to enhance the conductive effect between the first section of the shaft hole and the conductive structure.

[0027] In an embodiment, each annular groove is to accommodate a portion of the outer ring of the conductive structure.

[0028] In the present embodiment, the bottom of the annular groove is to secure the conductive structure to limit the axial displacement of the conductive structure along the axial direction of the power assembly. The bottom of the annular groove is to fit the outer circumferential surface of the conductive structure to enhance the conductive effect.

[0029] In an embodiment, the outer circumferential surface of the motor shaft along the axial direction of the power assembly comprises a first section of the outer circumferential surface and a second section of the outer circumferential surface connected to each other. Wherein along the radial direction of the power assembly, the outer diameter of the first section of the outer circumferential surface is smaller than the outer diameter of the second section of the outer circumferential surface and is larger than or equal to the inner diameter of the motor bearing.

[0030] In the present embodiment, the first section of the outer circumferential surface of the motor shaft is to be embedded in the inner hole of the motor bearing. The motor shaft forms another step surface through the first section of the outer circumferential surface and the second section of the outer circumferential surface. The other step surface is towards the bottom of the bearing groove along the axial direction of the power assembly. The other step surface is to abut the side surface of the motor bearing to limit the axial displacement of the motor bearing relative to the motor shaft.

[0031] In an implementation, the length of the first section of the outer circumferential surface is greater than the sum of the lengths of the first section of the shaft hole and the second section of the shaft hole along the axial direction of the power assembly.

[0032] In the implementation, the other stepped surface coincides with the third section of the shaft hole along the axial direction of the power assembly. That is, the other stepped surface is aligned with the third section of the shaft hole along the axial direction of the power assembly. The other stepped surface has higher structural stability in the motor shaft and can better limit the axial displacement of the motor bearing relative to the motor shaft.

[0033] In an implementation, each conductive structure includes two opposite end surfaces along the axial direction of the power assembly, one of the end surfaces is arranged between the other end surface and the groove bottom of the bearing groove, and the distance between one end of the axial protrusion and one of the end surfaces is less than the distance between the other end of the axial protrusion and the other end surface.

[0034] In the implementation, the conductive structure is closer to the groove bottom of the bearing groove and farther from the oil nozzle of the axial protrusion for conveying lubricating oil or cooling liquid along the axial direction of the power assembly, which can reduce the contact of the conductive structure with the cooling liquid or the lubricating oil and avoid the premature failure of the conductive structure due to excessive immersion in the cooling liquid or the lubricating oil.

[0035] In an implementation, each conductive structure includes a conductive bearing and one or more conductive rubber rings.

[0036] In the implementation, the conductive bearing and the conductive rubber ring have different stiffness. The conductive bearing has higher stiffness, which can improve the overall structural stability of the conductive structure. The conductive rubber ring has lower stiffness, which is used to offset the wear of the conductive structure through elastic deformation to ensure the reliability of the electrical connection.

[0037] In an implementation, the inner ring of the conductive bearing is used to fix the outer circumferential surface of the oil guide structure, and the outer ring of the conductive bearing is used to fix one or more conductive rubber rings.

[0038] In the implementation, the oil guide structure is a fixed structure on the partition plate, which facilitates the assembly of the conductive bearing.

[0039] In an implementation, the size of the conductive rubber ring along the axial direction of the power assembly is smaller than the size of the inner ring or the outer ring of the conductive bearing.

[0040] In the implementation, the conductive rubber ring has a smaller width along the axial direction of the power assembly, which facilitates the enhancement of the conductive effect by cooperating multiple conductive rubber rings with the conductive bearing.

[0041] In an implementation, each conductive structure comprises two conductive rubber rings. The two conductive rubber rings are arranged in an interval along the axial direction of the power assembly, and the interval between the two conductive rubber rings and the sum of the widths of the two conductive rubber rings are less than or equal to the length of the conductive bearing.

[0042] In the implementation, the two conductive rubber rings arranged in an interval along the axial direction of the power assembly can more evenly distribute the impact force of the radial movement of the motor shaft to the conductive bearing, thereby improving the internal stress condition of the conductive structure to prolong the service life of the conductive structure.

[0043] In an implementation, the elastic modulus of one conductive rubber ring in each oil guide structure is less than that of the other conductive rubber ring.

[0044] In the implementation, by differentiating the elastic modulus of the materials of the two conductive rubber rings, the elastic force of the two conductive rubber rings along the radial direction of the power assembly is differentiated. After the power assembly provided in the application is used for a long time, the wear amount of the two conductive rubber rings is different, and the conductive rubber ring with a smaller wear amount can compensate for the wear amount of the other conductive rubber ring through elastic deformation.

[0045] In an implementation, along the direction in which each oil guide structure extends into the shaft hole, the one conductive rubber ring and the other conductive rubber ring are arranged in an interval in sequence.

[0046] In the implementation, the other conductive rubber ring with a smaller elastic modulus is closer to the other section of the shaft hole along the axial direction of the power assembly. The radial movement of the motor shaft causes the other conductive rubber ring to be compressed more, thereby forming a certain sealing effect on the one conductive rubber ring, reducing the contact of the one conductive rubber ring with the cooling liquid or lubricating oil, and protecting the one conductive rubber ring.

[0047] In an implementation, the conductive structure comprises an axial sleeve. The conductive structure is fixed to the outer circumferential surface of the axial protrusion through the axial sleeve, and the outer circumferential surface of the conductive structure is coated with a wear-resistant conductive coating.

[0048] In the implementation, the axial sleeve is used to extend along the axial direction of the power assembly to increase the contact area of the conductive structure and the axial protrusion, thereby fixing the conductive structure to the outer circumferential surface of the axial protrusion. During the operation of the driving motor, the inner circumferential surface of the shaft hole of the motor shaft continuously rotates and rubs against the outer circumferential surface of the conductive structure. The wear-resistant conductive coating coated on the outer circumferential surface of the conductive structure is used to reduce the wear of the outer circumferential surface of the conductive structure and to conduct the electrical connection between the outer circumferential surface of the conductive structure and the inner circumferential surface of the shaft hole of the motor shaft.

[0049] In an implementation, the conductive structure is fixed to the inner circumferential surface of the shaft hole through the axial sleeve, and the inner circumferential surface of the conductive structure is coated with a wear-resistant conductive coating.

[0050] In the present embodiment, the axial sleeve is used to increase the contact area between the electrically conductive structure and the shaft hole of the motor shaft along the axial direction of the power assembly, so as to fix the electrically conductive structure to the inner circumferential surface of the shaft hole of the motor shaft. During the operation of the driving motor, the electrically conductive structure is used to rotate with the motor shaft in the housing, and the inner circumferential surface of the electrically conductive structure continuously rotates and rubs the outer circumferential surface of the axial protrusion. The wear-resistant conductive coating coated on the inner circumferential surface of the electrically conductive structure is used to reduce the wear of the inner circumferential surface of the electrically conductive structure, and to conduct the electrical connection between the inner circumferential surface of the electrically conductive structure and the outer circumferential surface of the axial protrusion.

[0051] In an embodiment, the axial sleeve extends along the axial direction of the power assembly towards the direction away from the groove bottom of the bearing groove.

[0052] In the present embodiment, the axial sleeve is relatively close to the third segment shaft hole of the motor shaft along the axial direction of the power assembly. The electrically conductive structure is used to conduct the electrical connection between the inner circumferential surface of the first segment shaft hole and the outer circumferential surface of the axial protrusion on the side close to the groove bottom of the bearing groove. The electrically conductive structure is relatively away from the part used to conduct and realize the electrical connection, and the third segment shaft hole, so as to reduce the contact between the electrically conductive structure and the cooling liquid or lubricating oil, thereby prolonging the service life of the electrically conductive structure.

[0053] In an embodiment, the electrically conductive structure includes a radial protrusion. The electrically conductive structure is used to conduct the electrical connection between the outer circumferential surface of the axial protrusion and the inner circumferential surface of the shaft hole through the radial protrusion. The radial protrusion is used to be fixed to one end of the axial sleeve close to the groove bottom of the bearing groove along the axial direction of the power assembly.

[0054] In a second aspect, the present application provides an electric vehicle. The electric vehicle includes a wheel and the power assembly provided by any one of the embodiments of the first aspect, and the power assembly is used to drive the wheel of the electric vehicle.

[0055] The electric vehicle provided by the present application adopts the above-mentioned power assembly, and the structure of the electric vehicle is more compact and has a longer service life. BRIEF DESCRIPTION OF DRAWINGS

[0056] Figure 1 A schematic diagram of the appearance of the electric vehicle provided by the embodiment of the present application;

[0057] Figure 2 A schematic diagram of the transmission of the electric vehicle provided by the embodiment of the present application;

[0058] Figure 3 A schematic diagram of the cross section of the driving motor provided by the embodiment of the present application;

[0059] Figure 4 A schematic diagram of the cross section of the power assembly provided by the embodiment of the present application;

[0060] Figure 5 A schematic diagram of the partial enlargement of the power assembly provided by the embodiment of the present application;

[0061] Figure 6 Another partial enlarged view of the power assembly provided by the embodiment of the present application;

[0062] Figure 7 Another exploded view of the power assembly provided by the embodiment of the present application;

[0063] Figure 8 Another exploded view of the power assembly provided by the embodiment of the present application;

[0064] Figure 9 Another cross-sectional view of the power assembly provided by the embodiment of the present application;

[0065] Figure 10 Another cross-sectional view of the power assembly provided by the embodiment of the present application;

[0066] Figure 11 Another exploded view of the power assembly provided by the embodiment of the present application;

[0067] Figure 12 Another cross-sectional view of the power assembly provided by the embodiment of the present application;

[0068] Figure 13 Another cross-sectional view of the power assembly provided by the embodiment of the present application;

[0069] Figure 14 Another exploded view of the power assembly provided by the embodiment of the present application;

[0070] Figure 15 Another cross-sectional view of the power assembly provided by the embodiment of the present application;

[0071] Figure 16 Another cross-sectional view of the power assembly provided by the embodiment of the present application;

[0072] Figure 17 Another cross-sectional view of the power assembly provided by the embodiment of the present application;

[0073] Figure 18 Another view of the power assembly provided by the embodiment of the present application;

[0074] Figure 19 Another cross-sectional view of the power assembly provided by the embodiment of the present application. DETAILED DESCRIPTION

[0075] With reference to the drawings of the embodiments of the present application, the technical solutions in the embodiments of the present application will be described. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort belong to the scope of the present application.

[0076] The present application provides a double-motor power assembly for preventing bearing electric corrosion. The power assembly comprises two driving motors, and the two driving motors are arranged adjacent to each other along an axial direction of the power assembly. A housing of the power assembly comprises a middle partition plate, and the middle partition plate comprises two end faces opposite to each other along the axial direction of the power assembly, each of the end faces comprises a bearing groove and an oil guide structure. Each of the bearing grooves is configured to fix a motor shaft of a driving motor by a motor bearing, and one end of each of the oil guide structures is configured to be fixedly connected to a groove bottom of a bearing groove, and the other end of each of the oil guide structures is configured to extend into an axial hole of a motor shaft along the axial direction of the power assembly and deliver cooling liquid or lubricating oil to the axial hole. A gap is formed between an outer circumferential surface of each of the oil guide structures and an inner circumferential surface of the axial hole of the motor shaft, and the gap is configured to accommodate an annular conductive structure, and each of the conductive structures is configured to electrically connect the motor shaft and the oil guide structure.

[0077] The present application provides an electric vehicle. The electric vehicle comprises a wheel and the power assembly provided by the present application, and the power assembly is configured to drive the wheel of the electric vehicle. The electric vehicle provided by the embodiments of the present application adopts the power assembly provided by the embodiments of the present application, and the structure of the electric vehicle is more compact, and the service life of the electric vehicle is longer.

[0078] Figure 1 A schematic diagram of an external shape of the electric vehicle 200 provided by the embodiments of the present application is shown in FIG. 1. As shown in FIG. 1, the electric vehicle 200 comprises a battery 101, a wheel 102 and a power assembly 100. The battery 101 is configured to supply power for the power assembly 100. The power assembly 100 is configured to drive the wheel 102 to rotate to provide power for the electric vehicle 200. Figure 1

[0079] Figure 2 A schematic diagram of a transmission of the electric vehicle 200 provided by the embodiments of the present application is shown in FIG. 2. Figure 3 A schematic diagram of a cross section of the power assembly 100 provided by the embodiments of the present application is shown in FIG. 3.

[0080] The double-motor power assembly 100 for preventing bearing electric corrosion provided by the present application comprises two driving motors 20, and the two driving motors 20 are arranged adjacent to each other along an axial direction of the power assembly 100. A housing 10 of the power assembly 100 comprises a middle partition plate 12.

[0081] ​In an embodiment, the housing 10 comprises a first axial housing, a circumferential housing and a second axial housing arranged in sequence along the axial direction of the power assembly 100. The circumferential housing comprises the partition plate 12 and two inner cavities arranged on two sides of the partition plate 12 along the circumferential direction of the power assembly 100, and the two inner cavities penetrate the circumferential housing towards the direction away from the partition plate 12. The first axial housing and the second axial housing along the axial direction of the power assembly 100 are respectively arranged on two sides of the circumferential housing to respectively enclose two accommodating cavities. The two accommodating cavities are respectively used for accommodating two driving motors 20.

[0082] In an embodiment, each driving motor 20 comprises a motor shaft 211, a motor rotor 21 and a motor stator 22. Please refer to Figure 4 A schematic cross-sectional view of the driving motor 20 provided by the embodiment of the application is shown.

[0083] In Figure 4 In the driving motor 20 shown, the motor stator 22 of the driving motor 20 is fixedly connected with the housing 10 of the power assembly 100, the motor stator 22 is coaxially sleeved on the periphery of the motor rotor 21, the motor shaft 211 penetrates the motor rotor 21 and is in driving connection with the motor rotor 21, the motor stator 22 is also electrically connected with the driving circuit, and the motor stator 22 generates an alternating magnetic field based on the alternating current of the driving circuit after being electrified, so as to drive the motor rotor 21 to rotate and coaxially rotate the motor shaft 211, so that the driving motor 20 transmits driving force to the wheel 102 through the motor shaft 211.

[0084] In an embodiment, as Figure 2 shown, the electric vehicle 200 comprises two reducers 103, and the two driving motors 20 of the power assembly 100 of the application are respectively in driving connection with the two wheels 102 through the two reducers 103, and the axis of the wheel 102 is parallel to the axial direction of the power assembly 100. In an embodiment, the power assembly 100 is fixed to the frame of the electric vehicle 200 through the housing 10, each reducer 103 is in driving connection between one driving motor 20 and the axle of one wheel 102, the driving force output by each driving motor 20 through the motor shaft 211 is transmitted to one wheel 102 through one reducer 103 to drive the wheel 102 to rotate, thereby driving the electric vehicle 200 to travel.

[0085] In an embodiment, each reducer 103 comprises a gear set comprising a plurality of pairs of meshing gears. Please refer to Figure 2As shown, the gear sets of the two reducers 103 are respectively located in the two accommodating cavities formed by the housing 10, and the gear sets of the two reducers 103 are respectively located on the two sides of the motor stator 22 opposite to each other along the axial direction of the power assembly 100. One end of each motor shaft 211 is engaged with one transmission gear of the gear set to drive the reducer 103 to rotate the wheel 102.

[0086] In an embodiment, the power assembly 100 further comprises two motor bearings 30 in each accommodating cavity of the power assembly 100. The two motor bearings 30 are arranged on the two sides of the motor stator 22 along the axial direction of the power assembly 100. The inner rings of the two motor bearings 30 are respectively connected in transmission with the two ends of the motor shaft 211, and the outer rings of the two motor bearings 30 are fixedly connected with the housing 10, so that the motor shaft 211 is rotatably connected to the housing 10 through the motor bearings 30, that is, the housing 10 supports the motor shaft 211 through the two motor bearings 30.

[0087] In an embodiment, one end of each motor shaft 211 is also used for fixedly connecting one end of one transmission shaft of one reducer 103, and the other end of one transmission shaft of one reducer 103 is used for embedding in the inner ring of the motor bearing 30 and is fixed to the housing 10 through the outer ring of the motor bearing 30. Similarly, the motor shaft 211 is rotatably connected to the housing 10 through the motor bearings 30, that is, the housing 10 supports the motor shaft 211 and one transmission shaft of one reducer 103 through the two motor bearings 30.

[0088] In an embodiment, the partition plate 12 of the power assembly 100 comprises two end faces opposite to each other along the axial direction of the power assembly 100. Each end face comprises a bearing groove 123 and an oil guide structure 120. Each bearing groove 123 is used for fixing one motor shaft 211 of one driving motor 20 through the motor bearing 30.

[0089] Please refer to Figure 5 The power assembly 100 provided by the embodiment of the present application is schematically shown in a partial enlarged view.

[0090] Please refer to Figure 4 and Figure 5 The two end faces of the partition plate 12 opposite to each other along the axial direction of the power assembly 100 respectively form two bearing grooves 123, and the two bearing grooves 123 are respectively used for fixing the outer rings of the two motor bearings 30. The inner ring of each motor bearing 30 is used for being connected in transmission with one end of the motor shaft 211, and the inner ring and the outer ring of the motor bearing 30 are rotatably connected, so that the two motor bearings 30 respectively support the two motor shafts 211.

[0091] In one embodiment, one end of each oil guide structure 120 of the power assembly 100 is fixedly connected to the bottom of the bearing groove 123, and the other end of each oil guide structure 120 extends into the shaft hole 212 of the motor shaft 211 along the axial direction of the power assembly 100 to deliver the cooling liquid or lubricating oil.

[0092] As shown in Figure 4 two oil guide structures 120 are arranged on the two sides of the partition plate 12 along the axial direction of the power assembly 100, and the two ends of the two oil guide structures 120 facing each other are fixedly connected to the bottoms of the two bearing grooves 123, and the two ends of the two oil guide structures 120 away from each other extend into the shaft holes 212 of the two motor shafts 211. Each oil guide structure 120 is provided with a through hole 122, and the two through holes 122 are used to deliver the cooling liquid or lubricating oil to the two shaft holes 212. The cooling liquid flows into the shaft hole 212 through the through hole 122 and absorbs heat to reduce the temperature of the driving motor 20; the lubricating oil can flow to the other end of the shaft hole 212 through the shaft hole 212, i.e. the lubricating oil flows towards the speed reducer 103, and after the lubricating oil flows to the speed reducer 103, it provides lubrication for the gear set inside the speed reducer 103 to reduce the wear of the gear set during meshing and improve the service life of the speed reducer 103.

[0093] Because the end of the motor shaft 211 away from the partition plate 12 is used for driving connection with the speed reducer 103, the power assembly 100 cannot supply oil to the speed reducer 103 and the driving motor 20 from the end of the motor shaft 211 close to the speed reducer 103 to achieve lubrication and cooling. The power assembly 100 supplies oil to the motor shafts 211 on both sides of the partition plate 12 to meet the working requirements of the driving motors 20 on both sides and the speed reducers 103 on both sides, saves the internal space of the power assembly 100, and is conducive to miniaturization of the power assembly 100.

[0094] It should be noted that in one embodiment, the above-mentioned cooling liquid and lubricating oil can be the same kind of liquid, which is used to cool the driving motor 20 during passing through the shaft hole 212, and is used to lubricate the gear set of the speed reducer 103 after flowing to the speed reducer 103.

[0095] In one embodiment, there is a gap 50 between the outer circumferential surface of each oil guide structure 120 and the inner circumferential surface of the shaft hole 212 of one motor shaft 211, and the gap 50 is used to accommodate an annular conductive structure 40, and each conductive structure 40 is used to electrically connect one motor shaft 211 and one oil guide structure 120.

[0096] As shown in Figure 5As shown, the conductive structure 40 is annular, the conductive structure 40 is sleeved on the outer side of the oil guide structure 120, the inner circumferential surface of the conductive structure 40 is at least partially attached to the outer circumferential surface of the oil guide structure 120, and the outer circumferential surface of the conductive structure 40 is at least partially attached to the inner circumferential surface of the shaft hole 212, so as to realize the electrical connection between the oil guide structure 120 and the shaft hole 212.

[0097] In the working process of the driving motor 20, the shaft end current of the motor shaft 211 will be generated under the influence of the magnetic field generated by the motor stator 22. The shaft end current will form a local high temperature and corrosion when flowing through the motor bearing 30, thereby shortening the service life of the motor bearing 30. In addition, the shaft end current will also have an electrochemical reaction with the lubricating medium inside the motor bearing 30, thereby reducing the lubricating effect of the lubricating medium and accelerating the wear of the motor bearing 30.

[0098] The power assembly 100 of the present application realizes the electrical connection between the outer circumferential surface of each oil guide structure 120 and the inner circumferential surface of each shaft hole 212 through two conductive structures 40, so as to realize the grounding of the shaft end current of the two motor shafts 211 to the middle partition plate 12, thereby avoiding the flow of the shaft end current of the motor shaft 211 through the motor bearing 30 to cause the failure of the motor bearing 30.

[0099] Compared with the conductive structure of the motor bearing in the prior art, in the power assembly 100 of the present application, the two oil guide structures 120 of the middle partition plate 12 along the axial direction of the power assembly 100 are respectively located at the two ends of the two motor shafts 211 facing each other, the two oil guide structures 120 extend into the shaft holes 212 of the two motor shafts 211, and the conductive structure 40 is located inside the shaft hole 212, thereby fully utilizing the internal space of the motor shaft 211, reducing the axial dimension of the power assembly 100, and making the internal structure of the power assembly 100 more compact.

[0100] In addition, the two oil guide structures 120 along the axial direction of the power assembly 100 are respectively located at the ends of the two motor shafts 211 away from the wheels 102, that is, the oil guide structures 120 are away from the transmission connection position of the driving motor 20 and the wheels 102, thereby improving the reliability of the oil guide structure 120 in conveying the cooling liquid or lubricating oil. The conductive structure 40 is located between the oil guide structure 120 and the shaft hole 212, and does not affect the conveying of the cooling liquid or lubricating oil between the oil guide structure 120 and the shaft hole 212, thereby ensuring the cooling and lubrication requirements of the internal components of the power assembly 100.

[0101] Correspondingly, the electric vehicle provided by the embodiment of the present application also has a more compact structure and a longer service life due to the adoption of the above-mentioned power assembly 100.

[0102] In one embodiment, the middle partition plate 12 comprises an internal oil channel 124 for conveying the cooling liquid or lubricating oil to the two oil guide structures 120 on the end surfaces. As shown in FIG. 2, the internal oil channel 124 is formed in the middle partition plate 12, and the two oil guide structures 120 on the end surfaces of the middle partition plate 12 are connected to the internal oil channel 124. Figure 5As shown, the internal oil passage 124 extends along the radial direction of the power assembly 100. The internal oil passage 124 is communicated with the shaft holes 212 of the two motor shafts 211 through the two oil guide structures 120 respectively. The end of the internal oil passage 124 away from the oil guide structures 120 is communicated with the external oil supply line or the oil pump, so that the cooling liquid or lubricating oil flows into the shaft holes 212 of the two motor shafts 211 through the internal oil passage 124 and the two oil guide structures 120 respectively.

[0103] In Figure 5 As shown, the power assembly 100 has two driving motors 20 arranged on the two sides of the middle plate 12 along the axial direction of the power assembly 100 respectively. The internal oil passage 124 in the middle plate 12 extends along the radial direction of the power assembly 100, so as to reduce the axial dimension of the power assembly 100. The middle plate 12 is communicated with the two oil guide structures 120 through the internal oil passage 124, so as to simplify the internal structure of the power assembly 100.

[0104] In an embodiment, each oil guide structure 120 comprises an axial protrusion 121, one end of each axial protrusion 121 is fixedly connected with the bottom of the bearing groove 123, the other end of each axial protrusion 121 extends into the shaft hole 212 of a motor shaft 211 along the axial direction of the power assembly 100, and the end face of the other end of each axial protrusion 121 comprises a through hole 122 for delivering the cooling liquid or lubricating oil to the shaft hole 212 of the motor shaft 211.

[0105] In Figure 5 As shown, each oil guide structure 120 extends into the shaft hole 212 of a motor shaft 211 through an axial protrusion 121 along the axial direction of the power assembly 100, and the other end of each axial protrusion 121 extending into the shaft hole 212 is used for delivering the cooling liquid or lubricating oil to the shaft hole 212 through the through hole 122. Each through hole 122 is communicated with the internal oil passage 124 of the middle plate 12. The through hole 122 of each axial protrusion 121 is communicated between the internal oil passage 124 and one shaft hole 212, so that the cooling liquid or lubricating oil flows into the shaft hole 212 of one motor shaft 211 through the internal oil passage 124 and one through hole 122.

[0106] In an embodiment, the axes of the through holes 122 of the two axial protrusions 121 coincide. Figure 5 As shown, the two through holes 122 are symmetrically arranged on the middle plate 12. The amount of the cooling liquid or lubricating oil flowing into the two through holes 122 from the internal oil passage 124 is relatively uniform, so as to ensure that the cooling effect or lubricating effect of the two driving motors 20 on the two sides of the middle plate 12 is similar.

[0107] In one embodiment, each gap 50 comprises two sections of gaps with different radial sizes, one section of gap is arranged in sequence with another section of gap along the direction of each oil guide structure 120 extending into the shaft hole 212, the radial size of one section of gap is larger than that of another section of gap, and the radial size of another section of gap is smaller than the radial size of the conductive structure 40.

[0108] Referring to Figure 6 Fig. 4 shows another partial enlarged view of the power assembly 100 according to an embodiment of the present application.

[0109] As Figure 6 shown, the gap 50 along the direction of each oil guide structure 120 extending into the shaft hole 212 comprises a first section of gap 51 and a second section of gap 52 arranged in sequence. The radial size of the first section of gap 51 is larger than that of the second section of gap 52, and the radial size of the second section of gap 52 is smaller than the radial size of the conductive structure 40. In the opening region close to the shaft hole 212, the radial size of the first section of gap 51 between the oil guide structure 120 and the shaft hole 212 is larger, which provides sufficient installation space for the conductive structure 40. In the internal region deep into the shaft hole 212, the radial size of the second section of gap 52 between the oil guide structure 120 and the shaft hole 212 is smaller, so as to reduce the amount of oil leakage of the cooling liquid or lubricating oil sent into the shaft hole 212 towards the opening of the shaft hole 212, thereby transporting more cooling liquid or lubricating oil towards the driving motor 20 and the speed reducer.

[0110] In one embodiment, each axial protrusion 121 comprises a first section of protrusion 1211 and a second section of protrusion 1212 arranged in sequence along the direction of each oil guide structure 120 extending into the shaft hole 212, and the outer diameter of the first section of protrusion 1211 is larger than that of the second section of protrusion 1212, and the first section of protrusion 1211 is used for sleeving the conductive structure 40.

[0111] Referring to Figure 7 Fig. 5 shows another exploded view of the power assembly 100 according to an embodiment of the present application.

[0112] As Figure 7 shown, the conductive structure 40 is sleeved outside the first section of protrusion 1211 of the axial protrusion 121, and the outer diameter of the first section of protrusion 1211 of each axial protrusion 121 is larger to stably support one conductive structure 40. The outer diameter of the second section of protrusion is smaller to facilitate extending into the shaft hole 212, which is beneficial to reducing the internal diameter size deep into the internal region of the shaft hole 212, thereby improving the structural stability of the motor shaft 211.

[0113] In one embodiment, the outer circumferential surface of each first segment protrusion 1211 along the axial direction of the power assembly 100 comprises one or more limiting structures 1213. In one embodiment, the radial dimension of each limiting structure 1213 in each first segment protrusion 1211 is different from the outer diameter of the rest of each first segment protrusion 1211 along the radial direction of the power assembly 100.

[0114] In Figure 7 In the illustrated power assembly 100, the limiting structure 1213 is a groove, and the radial dimension of the groove bottom is smaller than the outer diameter of the rest of the first segment protrusion 1211 along the radial direction of the power assembly 100. The groove is used to accommodate the partial conductive structure 40 to increase the contact area between the first segment protrusion 1211 and the conductive structure 40 and to enhance the conductive effect between the axial protrusion 121 and the conductive structure 40.

[0115] In one embodiment, the limiting structure 1213 is a plurality of protrusions arranged along the axial direction of the power assembly 100, and the radial dimension of the protrusions is larger than the outer diameter of the rest of the first segment protrusion 1211 along the radial direction of the power assembly 100. The conductive structure 40 is located between two adjacent protrusions, which also increases the contact area between the first segment protrusion 1211 and the conductive structure 40 and enhances the conductive effect between the axial protrusion 121 and the conductive structure 40.

[0116] In one embodiment, the one or more limiting structures in each first segment protrusion are used to fix and electrically connect the inner ring of the conductive structure 40, and the outer ring of the conductive structure 40 is used to contact and electrically connect the inner circumferential surface of the shaft hole 212. As Figure 7 illustrated, the limiting structure 1213 is a groove, and the groove bottom is used to fix the conductive structure 40 to limit the axial displacement of the conductive structure 40 along the power assembly 100. The groove bottom is used to fit the inner circumferential surface of the conductive structure 40 to enhance the conductive effect.

[0117] In one embodiment, the limiting structure 1213 is a plurality of protrusions arranged along the axial direction of the power assembly 100, and the plurality of protrusions are used to form a plurality of positioning grooves with the outer circumferential surface of the first segment protrusion 1211. The plurality of protrusions are respectively used to embed the conductive structure 40, i.e., the conductive structure 40 is used to contact the groove bottoms of the plurality of positioning grooves, which can better limit the axial displacement of the conductive structure 40 along the power assembly 100 and enhance the conductive effect between the conductive structure 40 and the oil guide structure 120.

[0118] In one embodiment, each shaft hole 212 includes a first shaft hole section 2121, a second shaft hole section 2122 and a third shaft hole section 2123, which are arranged in sequence along the direction of the oil guide structure 120 into the shaft hole 212. The inner diameter of the first shaft hole section 2121 is larger than that of the second shaft hole section 2122, and the inner diameter of the second shaft hole section 2122 is larger than that of the third shaft hole section 2123. The length of the first shaft hole section 2121 is larger than that of the second shaft hole section 2122, and the length of the first shaft hole section 2121 is smaller than that of the third shaft hole section 2123.

[0119] Referring to Figure 8 and Figure 9 , wherein Figure 8 is another exploded view of the power assembly 100 provided by the embodiments of the present application; Figure 9 is another cross-sectional view of the power assembly 100 provided by the embodiments of the present application.

[0120] As shown in Figure 8 and Figure 9 , the first shaft hole section 2121 has a larger inner diameter for accommodating and fixing the conductive structure 40. The third shaft hole section 2123 has a smaller inner diameter for receiving the cooling liquid or lubricating oil delivered by the axial protrusion 121 and reducing the leakage of the cooling liquid or lubricating oil towards the conductive structure 40. The second shaft hole section 2122 is used to connect the first shaft hole section 2121 and the third shaft hole section 2123, and the end surface of the second shaft hole section 2122 towards the first shaft hole section 2121 is also used to limit the axial displacement of the conductive structure 40.

[0121] In one embodiment, a step surface is formed between the second shaft hole section 2122 and the third shaft hole section 2123, and the step surface is towards the conductive structure 40 along the axial direction of the power assembly 100. The distance between the step surface and the conductive structure 40 is smaller than the distance between the bottom of the bearing groove 123 and the conductive structure 40.

[0122] Referring to Figure 6 and Figure 9 , a first step surface 213 is formed between the second shaft hole section 2122 and the third shaft hole section 2123. The smaller the distance between the first step surface 213 and the conductive structure 40, the longer the length of the axial protrusion 121 extending into the third shaft hole section 2123. Because the gap between the third shaft hole section 2123 and the axial protrusion 121 has a smaller radial dimension, i.e., the radial dimension of the second gap 52 is smaller, the cooling liquid or lubricating oil has a longer distance to flow back to the first shaft hole section 2121 through the second gap 52, which can reduce the contact between the conductive structure 40 and the cooling liquid or lubricating oil.

[0123] In an embodiment, the inner circumferential surface of each first segment shaft hole 2121 comprises one or more annular grooves 215. Wherein along the radial direction of the power assembly 100, the inner diameter of the one or more annular grooves 215 in each first segment shaft hole 2121 is greater than the inner diameter of the rest of each first segment shaft hole 2121.

[0124] As shown in Figure 8 and Figure 9 , the annular grooves 215 are used to accommodate part of the electrically conductive structure 40 to increase the contact area between the first segment shaft hole 2121 and the electrically conductive structure 40 and to enhance the electrically conductive effect between the first segment shaft hole 2121 and the electrically conductive structure 40.

[0125] In an embodiment, each annular groove 215 is used to accommodate part of the outer ring of the electrically conductive structure 40. Please refer to Figure 8 , the groove bottom of the annular groove 215 is used to fix the electrically conductive structure 40 to limit the axial displacement of the electrically conductive structure 40 along the power assembly 100. The groove bottom of the annular groove 215 is used to fit with the outer circumferential surface of the electrically conductive structure 40 to enhance the electrically conductive effect.

[0126] In an embodiment, the outer circumferential surface of the motor shaft 211 along the axial direction of the power assembly 100 comprises a first segment outer circumferential surface 2111 and a second segment outer circumferential surface 2112 connected in sequence. Wherein along the radial direction of the power assembly 100, the outer diameter of the first segment outer circumferential surface 2111 is smaller than the outer diameter of the second segment outer circumferential surface 2112 and greater than or equal to the inner diameter of the motor bearing 30.

[0127] As shown in Figure 9 , the first segment outer circumferential surface 2111 of the motor shaft 211 is used to be embedded in the inner hole of the motor bearing 30. The motor shaft 211 forms another stepped surface, i.e. the second stepped surface 214 shown in the figure, through the first segment outer circumferential surface 2111 and the second segment outer circumferential surface 2112. Along the axial direction of the power assembly 100, the second stepped surface 214 faces the groove bottom of the bearing groove 123. The second stepped surface 214 is used to abut against the side surface of the motor bearing 30 to limit the axial displacement of the motor bearing 30 relative to the motor shaft 211.

[0128] In an embodiment, along the axial direction of the power assembly 100, the length of the first segment outer circumferential surface 2111 is greater than the sum of the lengths of the first segment shaft hole 2121 and the second segment shaft hole 2122.

[0129] As shown in Figure 9As shown, the second step surface 214 along the axial direction of the power assembly 100 coincides with the third section shaft hole 2123. That is, the second step surface 214 is located on the third section shaft hole 2123 along the axial direction of the power assembly 100. The first section shaft hole 2121 and the second section shaft hole 2122 along the radial direction of the power assembly 100 are larger in size, and the second step surface 214 is more stable in structure in the motor shaft 211, which can better limit the axial displacement of the motor bearing 30 relative to the motor shaft 211.

[0130] In an embodiment, the conductive structure 40 along the axial direction of the power assembly 100 includes two opposite end surfaces, one of which is arranged between the other end surface and the groove bottom of the bearing groove 123, and one end of the axial protrusion 121 is spaced apart from one end surface by a distance smaller than the other end of the axial protrusion 121 and the other end surface.

[0131] Please refer to Figure 10 Another cross-sectional view of the power assembly 100 provided by the embodiments of the present application is shown.

[0132] As Figure 10 shown, the conductive structure 40 along the axial direction of the power assembly 100 includes a first end surface 401 and a second end surface 402 opposite to each other. Please refer to Figure 8 , the first end surface 401 faces the groove bottom of the bearing groove 123, that is, the first end surface 401 is located between the second end surface 402 and the groove bottom of the bearing groove 123. For ease of description, in subsequent embodiments, the first end surface 401 of the conductive structure 40 is defined as being arranged between the second end surface 402 and the groove bottom of the bearing groove 123. In an embodiment, the second end surface 402 of the conductive structure 40 is arranged between the first end surface 401 and the groove bottom of the bearing groove 123.

[0133] Please refer to Figure 5 and Figure 10 shown, along the axial direction of the power assembly 100, the distance between the end of the axial protrusion 121 facing the groove bottom of the bearing groove 123 and the first end surface 401 is smaller than the distance between the other end of the axial protrusion 121 away from the groove bottom of the bearing groove 123 and the second end surface 402, that is, the conductive structure 40 is closer to the groove bottom of the bearing groove 123 and farther from the oil nozzle of the axial protrusion 121 along the axial direction of the power assembly 100, which can reduce the contact between the conductive structure 40 and the cooling liquid or lubricating oil, and avoid the premature failure of the conductive structure 40 due to excessive immersion in the cooling liquid or lubricating oil.

[0134] In an embodiment, each conductive structure 40 includes one conductive bearing 42 and one or more conductive rubber rings 41.

[0135] Figure 11 Another exploded view of the power assembly 100 provided by the embodiments of the present application is shown. Figure 12Another cross-sectional view of the power assembly 100 provided by the embodiments of the present application is shown.

[0136] In an embodiment, as shown in Figure 11 and Figure 12 , the conductive structure 40 includes a conductive bearing 42 and a conductive rubber ring 41, and the conductive bearing 42 is sleeved on the outer periphery of the conductive rubber ring 41. Please refer to Figure 5 , the inner periphery of the conductive rubber ring 41 is at least partially attached to the outer periphery of the axial protrusion 121, and the outer periphery of the conductive bearing 42 is at least partially attached to the inner periphery of the first section shaft hole 2121, so as to realize the electrical connection between the oil guide structure 120 and the motor shaft 211.

[0137] In an embodiment, the inner ring of the conductive bearing 42 is used to fix the outer periphery of the oil guide structure 120, and the outer ring of the conductive bearing 42 is used to fix one or more conductive rubber rings 41.

[0138] Please refer to Figure 13 Another cross-sectional view of the power assembly 100 provided by the embodiments of the present application is shown.

[0139] As shown in Figure 13 , the inner periphery of the conductive bearing 42 is at least partially attached to the outer periphery of the axial protrusion 121, and the outer periphery of the conductive rubber ring 41 is at least partially attached to the inner periphery of the first section shaft hole 2121, so as to realize the electrical connection between the oil guide structure 120 and the motor shaft 211. The oil guide structure 120 is a fixed structure on the partition plate 12, and the conductive bearing 42 is sleeved on the outer periphery of the oil guide structure 120, which facilitates the assembly of the conductive bearing 42.

[0140] It can be understood that the stiffness of the conductive bearing 42 and the conductive rubber ring 41 is different. The stiffness of the conductive bearing 42 is higher, and the conductive bearing 42 can improve the overall structural stability of the conductive structure 40. The stiffness of the conductive rubber ring 41 is lower, and the conductive rubber ring 41 is used to offset the wear of the conductive structure 40 through elastic deformation, so as to ensure the reliability of the electrical connection.

[0141] In an embodiment, the size of the conductive rubber ring 41 along the axial direction of the power assembly 100 is smaller than the size of the inner ring or the outer ring of the conductive bearing 42. Please refer to Figure 12 and Figure 13 , the width of the conductive rubber ring 41 along the axial direction of the power assembly 100 is smaller, which facilitates the cooperation of the plurality of conductive rubber rings 41 and the conductive bearing 42 to enhance the conductive effect of the conductive structure 40.

[0142] In one embodiment, the conductive bearing 42 is sleeved on the outside of the conductive rubber ring 41. The gap between the portion of the inner circumferential surface of the conductive bearing 42 that extends beyond the conductive rubber ring 41 and the outer circumferential surface of the first segment of the axial protrusion 121 is smaller than the gap between the inner circumferential surface of the shaft hole 212 and the outer circumferential surface of the axial protrusion 121.

[0143] like Figure 12 As shown, the inner ring of the conductive structure 40 is a conductive rubber ring 41, and the outer ring is a conductive bearing 42. Along the axial direction of the powertrain 100, the size of the conductive bearing 42 is larger than the size of the conductive rubber ring 41. That is, the inner circumferential surface of the conductive bearing 42 is exposed to the outside of the conductive rubber ring 41. The gap between the exposed inner circumferential surface of the conductive bearing 42 and the outer circumferential surface of the first section of the axial protrusion 1211 along the radial direction of the powertrain 100 is the second dimension L2. The gap between the inner circumferential surface of the third section of the shaft hole 2123 of the radial shaft hole 212 of the powertrain 100 and the outer circumferential surface of the first section of the axial protrusion 1211 is the first dimension L1.

[0144] The second dimension L2 is smaller than the first dimension L1. The motor shaft 211 moves radially along the powertrain 100, causing the exposed inner circumferential surface of the conductive bearing 42 to abut against the outer circumferential surface of the first section of the axial protrusion 1211, thereby limiting the radial displacement of the motor shaft 211 relative to the axial protrusion 121 and preventing the third section of the shaft hole 2123 from contacting the axial protrusion 121.

[0145] In one embodiment, a conductive rubber ring 41 is fitted onto the outside of the conductive bearing 42. The gap between the portion of the outer peripheral surface of the conductive bearing 42 that extends beyond the conductive rubber ring 41 and the inner peripheral surface of the first shaft hole 2121 is smaller than the gap between the inner peripheral surface of the shaft hole 212 and the outer peripheral surface of the axial protrusion 121.

[0146] like Figure 13 As shown, the outer ring of the conductive structure 40 is a conductive rubber ring 41, and the inner ring is a conductive bearing 42. Along the axial direction of the powertrain 100, the size of the conductive bearing 42 is larger than the size of the conductive rubber ring 41. That is, the outer peripheral surface of the conductive bearing 42 is exposed to the outside of the conductive rubber ring 41. Along the radial direction of the powertrain 100, the gap between the exposed outer peripheral surface of the conductive bearing 42 and the inner peripheral surface of the first section of the shaft hole 2121 is the third dimension L3.

[0147] The third dimension L3 is smaller than the first dimension L1. Correspondingly, the motor shaft 211 moves radially along the powertrain 100, causing the exposed outer circumferential surface of the conductive bearing 42 to abut against the inner circumferential surface of the first section of the shaft hole 2121 of the shaft hole 212, thereby limiting the radial displacement of the motor shaft 211 relative to the axial protrusion 121 and preventing the third section of the shaft hole 2123 from contacting the axial protrusion 121.

[0148] It can be understood that the rigidity of the conductive bearing 42 is high, and the radial movement of the motor shaft 211 drives the part of the conductive bearing 42 beyond the conductive rubber ring 41 to abut against the outer circumferential surface of the axial protrusion 121 or the inner circumferential surface of the shaft hole 212, avoiding the contact between the axial protrusion 121 and the third section shaft hole 2123 of the shaft hole 212, and preventing the axial protrusion 121 from being deformed due to collision to affect the delivery of the cooling liquid or lubricating oil towards the shaft hole 212.

[0149] In an embodiment, each conductive structure 40 includes two conductive rubber rings 41. The two conductive rubber rings 41 are arranged at intervals along the axial direction of the conductive structure 40, and the sum of the interval between the two conductive rubber rings 41 and the width of the two conductive rubber rings 41 is less than or equal to the length of the conductive bearing 42.

[0150] Please refer to Figure 14 Another exploded schematic view of the power assembly 100 provided by the embodiments of the present application is shown.

[0151] As Figure 14 shown, each conductive structure 40 includes a first conductive rubber ring 411 and a second conductive rubber ring 412. The first conductive rubber ring 411 and the second conductive rubber ring 412 are arranged at intervals along the axial direction of the power assembly 100, and are used to form the inner circumferential surface of the conductive structure 40. The first conductive rubber ring 411 and the second conductive rubber ring 412 arranged at intervals along the axial direction of the power assembly 100 can more evenly distribute the impact force of the radial movement of the motor shaft 211 to the conductive bearing 42, thereby improving the internal stress condition of the conductive structure 40 to prolong the service life of the conductive structure 40.

[0152] In an embodiment, the elastic modulus of one conductive rubber ring 41 in each conductive structure 40 is less than that of the other conductive rubber ring 41. As Figure 14 shown, the conductive rubber ring 41 includes a first conductive rubber ring 411 and a second conductive rubber ring 412. The elastic modulus of the first conductive rubber ring 411 is greater than that of the second conductive rubber ring 412. By distinguishing the first conductive rubber ring 411 and the second conductive rubber ring 412, the elastic force of the two conductive rubber rings 41 along the radial direction of the power assembly 100 can be distinguished. After the power assembly 100 provided by the present application works for a long time, the wear amount of the first conductive rubber ring 411 and the second conductive rubber ring 412 is different, and the conductive rubber ring 41 with smaller wear amount can compensate for the wear amount of the other conductive rubber ring 41 through elastic deformation.

[0153] In an embodiment, along the direction in which each oil guide structure 120 extends into the shaft hole 212, one conductive rubber ring 41 and the other conductive rubber ring 41 are arranged at intervals in sequence.

[0154] Please refer toFigure 15 Another cross-sectional view of the power assembly 100 according to an embodiment of the present application is shown.

[0155] As shown in FIG. 4, the first conductive rubber ring 411 is located between the second conductive rubber ring 412 and the bottom of the bearing groove 123 along the axial direction of the power assembly 100. That is, the second conductive rubber ring 412 is closer to the third section of the shaft hole 2123 of the shaft hole 212 than the first conductive rubber ring 411. When the motor shaft 211 moves radially, the compression of the second conductive rubber ring 412 is greater, thereby forming a certain sealing effect on the first conductive rubber ring 411, reducing the contact of the first conductive rubber ring 411 with the cooling liquid or lubricating oil, and protecting the first conductive rubber ring 411. Figure 15 In an embodiment, the conductive bearing 42 is sleeved outside the two conductive rubber rings 41. The gap between the inner circumferential surface of the conductive bearing 42 and the outer circumferential surface of the first section of the protrusion 1211 of the axial protrusion 121 is smaller than the gap between the inner circumferential surface of the shaft hole 212 and the outer circumferential surface of the axial protrusion 121 along the axial direction of the power assembly 100.

[0156] As shown in FIG. 4, the inner ring of the conductive structure 40 is the two conductive rubber rings 41, and the outer ring is the conductive bearing 42. The sum of the gap between the first conductive rubber ring 411 and the second conductive rubber ring 412, the width of the first conductive rubber ring 411, and the width of the second conductive rubber ring 412 is smaller than the width of the conductive bearing 42 along the axial direction of the power assembly 100. That is, the inner circumferential surface of the conductive bearing 42 is partially exposed to the outside of the first conductive rubber ring 411 and the second conductive rubber ring 412. The gap between the exposed inner circumferential surface of the conductive bearing 42 and the outer circumferential surface of the first section of the protrusion 1211 of the axial protrusion 121 is of a fourth size L4 along the radial direction of the power assembly 100.

[0157] Figure 15 The fourth size L4 is smaller than the first size L1. Accordingly, when the motor shaft 211 moves radially along the power assembly 100, the exposed inner circumferential surface of the conductive bearing 42 abuts against the first section of the protrusion 1211 of the axial protrusion 121, thereby limiting the radial displacement of the motor shaft 211 relative to the axial protrusion 121 and avoiding the contact between the third section of the shaft hole 2123 and the axial protrusion 121.

[0158] In an embodiment, the two conductive rubber rings 41 are sleeved outside the conductive bearing 42. The gap between the outer circumferential surface of the conductive bearing 42 and the inner circumferential surface of the first section of the shaft hole 2121 of the shaft hole 212 is smaller than the gap between the inner circumferential surface of the shaft hole 212 and the outer circumferential surface of the axial protrusion 121 along the axial direction of the power assembly 100.

[0159] In an embodiment, the two conductive rubber rings 41 are sleeved outside the conductive bearing 42. The gap between the outer circumferential surface of the conductive bearing 42 and the inner circumferential surface of the first section of the shaft hole 2121 of the shaft hole 212 is smaller than the gap between the inner circumferential surface of the shaft hole 212 and the outer circumferential surface of the axial protrusion 121 along the axial direction of the power assembly 100.

[0160] Please refer to Figure 16 ​Another cross-sectional view of the power assembly 100 according to an embodiment of the present application is shown.

[0161] As shown in Figure 16 , the outer ring of the conductive structure 40 is two conductive rubber rings 41, and the inner ring is a conductive bearing. The distance between the first conductive rubber ring 411 and the second conductive rubber ring 412 along the axial direction of the power assembly 100, the width of the first conductive rubber ring 411, and the width of the second conductive rubber ring 412 are all less than the width of the conductive bearing 42. That is, the outer circumferential surface of the conductive bearing 42 is partially exposed to the outside of the first conductive rubber ring 411 and the second conductive rubber ring 412. The gap size between the exposed outer circumferential surface of the conductive bearing 42 and the inner circumferential surface of the first section shaft hole 2121 of the shaft hole 212 along the radial direction of the power assembly 100 is the fifth size L5.

[0162] Wherein the fifth size L5 is less than the first size L1. Correspondingly, the radial displacement of the motor shaft 211 along the radial direction of the power assembly 100 drives the exposed outer circumferential surface of the conductive bearing 42 to abut the first section shaft hole 2121 of the shaft hole 212, so as to limit the radial displacement of the motor shaft 211 relative to the axial protrusion 121, and avoid the third section shaft hole 2123 from contacting the axial protrusion 121.

[0163] In an embodiment, the conductive structure 40 includes an axial sleeve 43. Wherein the conductive structure 40 is fixed to the outer circumferential surface of the axial protrusion 121 through the axial sleeve 43, and the outer circumferential surface of the conductive structure 40 is coated with a wear-resistant conductive coating.

[0164] Please refer to Figure 17 Another cross-sectional view of the power assembly 100 according to an embodiment of the present application is shown.

[0165] As shown in Figure 17 , the axial sleeve 43 is used to extend along the axial direction of the power assembly 100 to increase the contact area between the conductive structure 40 and the axial protrusion 121, so as to fix the conductive structure 40 to the outer circumferential surface of the axial protrusion 121. During the operation of the driving motor 20, the shaft hole 212 inner circumferential surface of the motor shaft 211 continuously rotates and rubs the outer circumferential surface of the conductive structure 40. The wear-resistant conductive coating coated on the outer circumferential surface of the conductive structure 40 is used to reduce the wear of the outer circumferential surface of the conductive structure 40, and to conduct the electrical connection between the outer circumferential surface of the conductive structure 40 and the inner circumferential surface of the shaft hole 212 of the motor shaft 211.

[0166] In an embodiment, the conductive structure 40 is fixed to the inner circumferential surface of the shaft hole 212 through the axial sleeve 43, and the inner circumferential surface of the conductive structure 40 is coated with a wear-resistant conductive coating.

[0167] Please refer to Figure 17The axial sleeve 43 extends axially along the powertrain 100 to increase the contact area between the conductive structure 40 and the shaft hole 212 of the motor shaft 211, thereby fixing the conductive structure 40 to the inner circumferential surface of the shaft hole 212 of the motor shaft 211. During the operation of the drive motor 20, the conductive structure 40 rotates with the motor shaft 211 within the housing 10, and the inner circumferential surface of the conductive structure 40 continuously rotates and rubs against the outer circumferential surface of the axial protrusion 121. The wear-resistant conductive coating applied to the inner circumferential surface of the conductive structure 40 reduces wear on the inner circumferential surface of the conductive structure 40 and conducts the electrical connection between the inner circumferential surface of the conductive structure 40 and the outer circumferential surface of the axial protrusion 121.

[0168] In one embodiment, the conductive structure 40 includes a radial protrusion 44, which conducts an electrical connection between the outer peripheral surface of the axial protrusion 121 and the inner peripheral surface of the shaft hole 212. The radial protrusion 44 is used to fix the axial sleeve 43 near the bottom of the bearing groove 123 along the axial direction of the powertrain 100.

[0169] Figure 18 This is another schematic diagram of the powertrain 100 provided in an embodiment of this application. Figure 19 This is another cross-sectional schematic diagram of the powertrain 100 provided in an embodiment of this application.

[0170] like Figure 18 and Figure 19 As shown, the radial protrusion 44 is located on the side of the axial sleeve 43 away from the second section shaft hole 2122. The radial protrusion 44 conducts electrical connection between the inner circumferential surface of the shaft hole 212 and the outer circumferential surface of the axial protrusion 121 on the side near the bottom of the bearing groove 123, reducing the contact between the radial protrusion 44 and the coolant or lubricating oil to extend the service life of the conductive structure 40.

[0171] In one embodiment, the axial sleeve 43 is fixed to the outer peripheral surface of the axial protrusion 121, and the radial protrusion 44 extends toward the inner peripheral surface of the shaft hole 212 and contacts the inner peripheral surface of the first section of the shaft hole 2121 to achieve electrical connection between the axial protrusion 121 and the inner peripheral surface of the shaft hole 212. Further, in one embodiment, the side of the radial protrusion 44 facing the inner peripheral surface of the shaft hole 212 is coated with a wear-resistant conductive coating to reduce wear on the radial protrusion 44.

[0172] In one embodiment, the radial protrusion 44 comprises a plurality of beads which are circumferentially spaced apart and fixed to the radial protrusion 44 at a location distal to the axial sleeve 43. When the axial sleeve 43 is fixed to the outer circumferential surface of the axial protrusion 121, the plurality of beads abut the inner circumferential surface of the first section of the shaft hole 2121. It is appreciated that the beads are resilient and elastically deform towards the axial sleeve 43 when the electrically conductive structure 40 is installed in the gap between the axial protrusion 121 and the shaft hole 212. The resilience of the beads compensates for wear of the beads and prevents a gap from being formed between the beads and the inner circumferential surface of the first section of the shaft hole 2121, thereby ensuring a reliable electrical connection. Further, the plurality of beads can also be coated with a wear-resistant and electrically conductive coating on the side facing the inner circumferential surface of the shaft hole 212 to reduce wear of the beads.

[0173] In one embodiment, the axial sleeve 43 is fixed to the inner circumferential surface of the shaft hole 212, and the radial protrusion 44 extends towards and contacts the outer circumferential surface of the axial protrusion 121 to achieve an electrical connection between the outer circumferential surface of the axial protrusion 121 and the inner circumferential surface of the shaft hole 212. Further, in one embodiment, the radial protrusion 44 is coated with a wear-resistant and electrically conductive coating on the side facing the outer circumferential surface of the axial protrusion 121 to reduce wear of the radial protrusion 44.

[0174] Correspondingly, the radial protrusion 44 can also comprise a plurality of beads, i.e. the axial sleeve 43 is fixed to the inner circumferential surface of the shaft hole 212, and the plurality of beads abut the outer circumferential surface of the axial protrusion 121. Similarly, the resilience of the beads also compensates for wear and prevents a gap from being formed between the beads and the outer circumferential surface of the axial protrusion 121, thereby ensuring a reliable electrical connection. Further, the plurality of beads can also be coated with a wear-resistant and electrically conductive coating on the side facing the outer circumferential surface of the axial protrusion 121 to reduce wear of the beads.

[0175] In one embodiment, the axial sleeve 43 and the radial protrusion 44 are snap-fitted and fixed to form the electrically conductive structure 40. In one embodiment, the axial sleeve 43 and the radial protrusion 44 are integrally formed by stamping to improve the structural strength of the electrically conductive structure 40 and reduce the assembly steps of the power assembly 100.

[0176] In one embodiment, the axial sleeve 43 extends in the axial direction of the power assembly 100 towards the bottom of the bearing groove 123.

[0177] As Figure 18 and Figure 19As shown, along the axial direction of the power assembly 100, the axial sleeve 43 is relatively close to the third section 2123 of the shaft hole 212 of the shaft hole 212 of the motor shaft 211. The radial protrusion 44 is electrically connected between the inner circumferential surface of the shaft hole 212 and the outer circumferential surface of the axial protrusion 121 on the side close to the bottom of the bearing groove 123. The radial protrusion 44 is relatively far away from the third section 2123 of the shaft hole 212, reducing the contact of the radial protrusion 44 with the cooling liquid or lubricating oil to prolong the service life of the conductive structure 40.

[0178] Obviously, various modifications and changes can be made to the present application by those skilled in the art without departing from the scope of the present application. Thus, it is intended that the present application cover the modifications and changes as long as they come within the scope of the claims of the present application and their equivalents.

Claims

1. A dual motor powertrain protected against bearing galvanic corrosion, characterized in that, The power assembly comprises two driving motors, the two driving motors are arranged adjacent along the axial direction of the power assembly, the housing of the power assembly comprises one middle partition plate, the one middle partition plate comprises two end faces opposite along the axial direction of the power assembly, each of the end faces comprises one bearing groove and one oil guide structure, wherein: Each of the bearing grooves is used for fixing an outer ring of one motor bearing, an inner ring of each of the motor bearings is used for fixing a motor shaft of one of the driving motors, one end of each of the oil guide structures is used for fixedly connecting a groove bottom of one of the bearing grooves, and the other end of each of the oil guide structures is used for extending into one of the motor shafts along the axial direction of the power assembly and conveying cooling liquid or lubricating oil to a shaft hole of one of the motor shafts. There is a gap between the outer circumferential surface of each of the oil guide structures and the inner circumferential surface of the shaft hole of one of the motor shafts, the gap is used for accommodating one annular conductive structure, and each of the conductive structures is used for electrically connecting one of the motor shafts and one of the oil guide structures. Each of the conductive structures comprises one conductive bearing and one or more conductive rubber rings, the inner ring of the one conductive bearing is used for being sleeved on the outer circumferential surface of the one oil guide structure, and the outer ring of the one conductive bearing is used for fixing the one or more conductive rubber rings, wherein along the axial direction of the conductive structure, the size of the one conductive rubber ring is smaller than the size of the inner ring or the outer ring of the one conductive bearing.

2. The powertrain of claim 1, wherein, The one middle partition plate comprises one internal oil channel, and the one internal oil channel is used for conveying cooling liquid or lubricating oil to the oil guide structures of the two end faces.

3. The powertrain of claim 1, wherein, The one gap comprises two gaps with different radial sizes, one of the two gaps is arranged in sequence with the other of the two gaps along the direction in which each of the oil guide structures extends into one of the shaft holes, the radial size of the one of the two gaps is greater than the radial size of the other of the two gaps, and the radial size of the other of the two gaps is smaller than the radial size of the conductive structure.

4. The powertrain of any one of claims 1-3, wherein, One end of each of the oil guide structures is used for fixedly connecting the groove bottom of one of the bearing grooves, and the other end of each of the oil guide structures is used for extending into one of the motor shafts along the axial direction of the power assembly and conveying cooling liquid or lubricating oil to the shaft hole of one of the motor shafts.

5. The powertrain of claim 4, wherein, Each of the axial protrusions comprises one first protrusion and one second protrusion, the one first protrusion and the one second protrusion are arranged in sequence along the direction in which each of the oil guide structures extends into one of the shaft holes, the outer diameter of the one first protrusion is greater than the outer diameter of the one second protrusion, and the one first protrusion is used for sleeving one of the conductive structures.

6. The powertrain of claim 5, wherein, The outer circumferential surface of each of the first protrusions along the axial direction of the power assembly comprises one or more limiting structures, wherein: Along the radial direction of the power assembly, the radial size of each of the limiting structures in each of the first protrusions is different from the outer diameter of the remaining part in each of the first protrusions.

7. The powertrain of claim 6, wherein, The one or more limiting structures in each of the first protrusions are used for fixedly connecting and electrically connecting the inner ring of one of the conductive structures, and the outer ring of the one of the conductive structures is used for contacting and electrically connecting the inner circumferential surface of one of the shaft holes.

8. The powertrain of claim 1, wherein, Each of the shaft holes comprises a first segment, a second segment and a third segment, which are arranged in sequence along a direction in which each of the oil guiding structures extends into one of the shaft holes, wherein: The inner diameter of the first segment is greater than that of the second segment, and the inner diameter of the second segment is greater than that of the third segment; The length of the first segment is greater than that of the second segment, and the length of the first segment is less than that of the third segment.

9. The powertrain of claim 8, wherein, The inner circumferential surface of each of the first segments comprises one or more annular grooves, wherein: Along a radial direction of the power assembly, the inner diameter of the one or more annular grooves in each of the first segments is greater than that of the rest of each of the first segments.

10. The powertrain of claim 9, wherein, Each of the annular grooves is configured to accommodate a portion of an outer ring of one of the electrically conductive structures.

11. The powertrain of claim 1, wherein, Each of the electrically conductive structures comprises two electrically conductive rubbers, wherein: Along an axial direction of the power assembly, the two electrically conductive rubbers are arranged in sequence with a spacing, and the spacing plus the width of the two electrically conductive rubbers is less than or equal to the length of the electrically conductive bearing.

12. The powertrain of claim 11, wherein, The elastic modulus of one of the electrically conductive rubbers in each of the oil guiding structures is less than that of the other electrically conductive rubber.

13. The powertrain of claim 12, wherein, Along a direction in which each of the oil guiding structures extends into one of the shaft holes, the one electrically conductive rubber and the other electrically conductive rubber are arranged in sequence with a spacing.

14. An electric vehicle characterized by comprising: The electric vehicle comprises wheels and a power assembly according to any one of claims 1-13, and the axis of the wheels is parallel to the axis of one of the motor shafts in the power assembly.

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