Bearing electric corrosion-resistant dual-motor power assembly and electric vehicle

Abstract

The present application provides a bearing electric corrosion-resistant dual-motor power assembly and an electric vehicle. The power assembly comprises two drive motors arranged adjacent to each other. A housing of the power assembly comprises a middle partition plate, and each of two opposite end surfaces of the middle partition plate comprises a bearing groove and an oil guide structure. Each bearing groove is configured to fix a motor shaft of one drive motor by means of a motor bearing. Two ends of each oil guide structure are respectively configured to be fixedly connected to the groove bottom of one bearing groove and configured to extend into a shaft hole of one motor shaft in the axial direction of the power assembly and convey a cooling liquid or lubricating oil into said shaft hole. A gap exists between the outer peripheral surface of each oil guide structure and the inner peripheral surface of the shaft hole of one motor shaft and is configured to accommodate an annular conductive structure. Each conductive structure is configured to electrically connect one motor shaft and one oil guide structure. In the power assembly provided by the present application, the structure in which the middle partition plate supplies oil to the shaft holes of the motor shafts on two sides is used to conduct shaft currents to the housing for grounding so as to protect motor bearings.

Description

Dual-motor powertrains and electric vehicles that prevent bearing electrolytic corrosion

[0001] This application claims priority to Chinese Patent Application No. 202411466400.1, filed on October 18, 2024, with the invention entitled "Dual-motor powertrain and electric vehicle for preventing bearing electro-corrosion", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of electric vehicle technology, specifically to a dual-motor powertrain for preventing bearing electro-corrosion and an electric vehicle. Background Technology

[0003] In a dual-motor powertrain, during operation, the shaft voltage of the drive motor can break down the oil film in the motor bearing, causing bearing electro-corrosion. This leads to localized melting and unevenness at the bearing contact surfaces. Bearing electro-corrosion not only degrades bearing performance and causes premature bearing failure on the motor shaft, but also reduces the overall lifespan of the powertrain. Summary of the Invention

[0004] This application provides a dual-motor powertrain to prevent bearing electro-corrosion and an electric vehicle. The powertrain utilizes a structure in which the middle partition of the powertrain supplies oil to the shaft hole of the motor shaft, thereby conducting the shaft current of the motor shaft to the housing ground to protect the motor bearing.

[0005] In a first aspect, this application provides a dual-motor powertrain for preventing bearing electro-corrosion. The powertrain includes two drive motors arranged adjacent to each other along the axial direction of the powertrain. The housing of the powertrain includes a partition plate with two opposite end faces along the axial direction of the powertrain. Each end face includes a bearing groove and an oil guide structure. Each bearing groove is used to fix the motor shaft of one drive motor via a motor bearing. One end of each oil guide structure is used to fix and connect to the bottom of the bearing groove, and the other end of each oil guide structure is used to extend along the axial direction of the powertrain and deliver coolant or lubricating oil to the shaft hole of the motor shaft. A gap exists between the outer peripheral surface of each oil guide structure and the inner peripheral surface of the shaft hole of the motor shaft. The gap is used to accommodate an annular conductive structure, and each conductive structure is used to electrically connect the motor shaft and the oil guide structure.

[0006] The dual-motor powertrain for preventing bearing electro-corrosion provided in this application forms two bearing slots through a partition plate, with the openings of the two bearing slots facing away from each other along the axial direction of the powertrain. The slot wall of each bearing slot is used to fix a motor bearing and to drive the motor shaft of a drive motor via the motor bearing. The bottom of each bearing slot is used to fix an oil guide structure, with the extension directions of the two oil guide structures facing away from each other along the axial direction of the powertrain. Each oil guide structure extends into the shaft hole of the motor shaft and delivers lubricating oil or coolant toward the shaft hole.

[0007] The powertrain provided in this application also utilizes the gap between an oil-guiding structure and the shaft hole of the motor shaft to fix a conductive structure. This conductive structure facilitates the electrical connection between the outer circumferential surface of the oil-guiding structure and the inner circumferential surface of the shaft hole, allowing the current at the motor shaft end to be conducted to the intermediate partition for grounding, thus preventing the current at the motor shaft end from flowing through the motor bearings and causing bearing failure. The powertrain provided in this application rationally utilizes the internal space of the shaft holes of the two motor shafts to achieve electrical connections between the two motor shafts and the housing, effectively protecting the motor bearings and extending the service life of the powertrain.

[0008] In one implementation, the partition includes an internal oil passage for supplying coolant or lubricating oil to the oil guiding structures at both ends.

[0009] In this implementation, a drive motor is arranged on each side of the axial partition of the powertrain. Internal oil passages within the partition extend radially along the powertrain, thereby reducing the axial dimension of the powertrain. The partition is connected to two oil guiding structures via these internal oil passages, simplifying its internal structure.

[0010] In one implementation, each gap comprises two gaps with different radial dimensions. Along the direction in which each oil guide structure extends into the shaft hole, one gap and the other gap are arranged sequentially. The radial dimension of one gap is greater than the radial dimension of the other gap, and the radial dimension of the other gap is less than the radial dimension of the conductive structure.

[0011] In this implementation, in the opening region near each shaft hole, the radial dimension of a gap between each oil guiding structure and the shaft hole is relatively large, providing sufficient installation space for the two conductive structures. In the internal region deep within the shaft hole, the radial dimension of another gap between each oil guiding structure and the shaft hole is smaller, to reduce the amount of coolant or lubricating oil leaking towards the opening of the shaft hole after it is fed into the shaft hole, thereby delivering more coolant or lubricating oil towards the drive motor and reducer.

[0012] In one implementation, each oil guide structure includes an axial protrusion, one end of which is used to fix the bottom of the bearing groove, and the other end of which is used to extend into the shaft hole of the motor shaft along the axial direction of the powertrain. The end face of the other end of each axial protrusion includes a through hole for conveying coolant or lubricating oil to the shaft hole of the motor shaft.

[0013] In this implementation, each oil guide structure extends axially along the powertrain axis toward the shaft bore of the motor shaft via an axial protrusion. The other end of each axial protrusion extending into the shaft bore is used to deliver coolant or lubricating oil toward the shaft bore through a through-hole. Each through-hole is used to communicate with the internal oil passage of the partition plate.

[0014] In one implementation, the axes of the two axially protruding through holes coincide.

[0015] In this implementation, the internal oil passages of the partition plate extend radially along the powertrain, and the two through holes are symmetrically positioned on the partition plate. The amount of coolant or lubricating oil flowing from the internal oil passages into the two through holes is relatively uniform, ensuring that the cooling or lubrication effects of the two drive motors on both sides of the partition plate are similar.

[0016] In one implementation, each axial protrusion includes a first protrusion and a second protrusion, arranged sequentially along the direction in which each oil guide structure extends into the shaft hole. The outer diameter of the first protrusion is larger than the outer diameter of the second protrusion, and the first protrusion is used to mount the conductive structure.

[0017] In this implementation, the outer diameter of the first section of each axial protrusion is larger to stably support the conductive structure, while the outer diameter of the second section of the protrusion is smaller to facilitate insertion into the shaft hole. This helps to reduce the inner diameter of the protrusion into the shaft hole, thereby improving the structural stability of the motor shaft.

[0018] In one implementation, the outer peripheral surface of each first protrusion along the axial direction of the powertrain includes one or more limiting structures. The radial dimension of each limiting structure in each first protrusion along the radial direction of the powertrain differs from the outer diameter of the rest of each first protrusion.

[0019] In this implementation, one or more limiting structures are used to increase the contact area between the first protrusion and the conductive structure, thereby enhancing the conductivity between the axial protrusion and the conductive structure.

[0020] In one implementation, 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 circumferential surface of the shaft hole.

[0021] In this implementation, one or more limiting structures are used to form a positioning groove in the first protrusion. The bottom of the positioning groove is used to fix the conductive structure to limit the axial displacement of the conductive structure along the powertrain. The bottom of the positioning groove is used to fit against the inner circumferential surface of the conductive structure to enhance conductivity.

[0022] In one implementation, each shaft hole includes a first shaft hole, a second shaft hole, and a third shaft hole, arranged sequentially along the direction in which each oil guide structure extends into the shaft hole. The inner diameter of the first shaft hole is larger than that of the second shaft hole, and the inner diameter of the second shaft hole is larger than that 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.

[0023] In this implementation, the inner diameter of the first shaft hole is larger to accommodate and fix the conductive structure. The inner diameter of the third shaft hole is smaller to receive coolant or lubricating oil supplied by the axial protrusion and to reduce leakage of coolant or lubricating oil toward the conductive structure. The second shaft hole is used to connect the first and third shaft holes, and the end face of the second shaft hole facing the first shaft hole also serves to limit the axial displacement of the conductive structure.

[0024] In one implementation, a stepped surface is formed between the second and third shaft holes, with the stepped surface facing the conductive structure along the axial direction of the powertrain. The distance between the stepped surface and the conductive structure is less than the distance between the bottom of the bearing groove and the conductive structure.

[0025] In this implementation, the smaller the distance between the axial stepped surface of the powertrain and the conductive structure, the longer the axial protrusion extends into the third shaft hole. Because the radial dimension of the gap between the third shaft hole and the axial protrusion is small, the coolant or lubricating oil travels a longer distance from the third shaft hole back to the first shaft hole, which can reduce the contact between the conductive structure and the coolant or lubricating oil.

[0026] In one implementation, the inner circumferential surface of each first shaft bore includes one or more annular grooves. The inner diameter of the one or more annular grooves in each first shaft bore is larger than the inner diameter of the remaining portion of each first shaft bore along the radial direction of the powertrain.

[0027] In this implementation, one or more annular grooves are used to increase the contact area between the first shaft hole and the conductive structure, thereby enhancing the conductivity between the first shaft hole and the conductive structure.

[0028] In one implementation, each annular groove is used to accommodate a portion of the outer ring of the conductive structure.

[0029] In this implementation, the bottom of the annular groove is used to fix the conductive structure to limit its axial displacement along the powertrain. The bottom of the annular groove is also used to fit against the outer peripheral surface of the conductive structure to enhance conductivity.

[0030] In one implementation, the outer peripheral surface of the motor shaft along the axial direction of the powertrain includes a first peripheral surface and a second peripheral surface connected together. Along the radial direction of the powertrain, the outer diameter of the first peripheral surface is smaller than the outer diameter of the second peripheral surface and greater than or equal to the inner diameter of the motor bearing.

[0031] In this implementation, the first outer circumferential surface of the motor shaft is used to embed into the inner hole of the motor bearing. The motor shaft forms another stepped surface through the first and second outer circumferential surfaces. This second stepped surface faces the bottom of the bearing groove along the axial direction of the powertrain. This second stepped surface abuts against the side of the motor bearing to limit the axial displacement of the motor bearing relative to the motor shaft.

[0032] In one implementation, along the axial direction of the powertrain, the length of the first segment of the outer peripheral surface is greater than the sum of the lengths of the first segment of the shaft hole and the second segment of the shaft hole.

[0033] In this implementation, another stepped surface along the axial direction of the powertrain coincides with the third shaft hole. That is, the other stepped surface is aligned with the third shaft hole along the axial direction of the powertrain. This additional stepped surface provides greater structural stability within the motor shaft, better limiting the axial displacement of the motor bearings relative to the motor shaft.

[0034] In one implementation, each conductive structure along the axial direction of the powertrain includes two opposing end faces, one of which is positioned between the other end face and the bottom of the bearing groove, and the distance between one end of the axial protrusion and one end face is less than the distance between the other end of the axial protrusion and the other end face.

[0035] In this implementation, the conductive structure is closer to the bottom of the bearing groove along the axial direction of the powertrain and farther from the axial protrusion of the oil nozzle that delivers lubricating oil or coolant. This reduces the contact between the conductive structure and the coolant or lubricating oil, preventing the conductive structure from failing prematurely due to excessive immersion in the coolant or lubricating oil.

[0036] In one implementation, each conductive structure includes a conductive bearing and one or more conductive rubber rings.

[0037] In this implementation, the conductive bearing and the conductive rubber ring have different stiffnesses. The conductive bearing has higher stiffness, which improves the overall structural stability of the conductive structure. The conductive rubber ring has lower stiffness and is used to offset the wear of the conductive structure through elastic deformation, thereby ensuring reliable electrical connection.

[0038] In one implementation, the inner ring of the conductive bearing is used to fix it to the outer peripheral surface of the oil guiding structure, and the outer ring of the conductive bearing is used to fix one or more conductive rubber rings.

[0039] In this implementation, the oil guiding structure is a fixed structure on the middle partition, which facilitates the assembly of the conductive bearing.

[0040] In one implementation, the size of the conductive rubber ring along the axial direction of the powertrain is smaller than the size of the inner or outer ring of the conductive bearing.

[0041] In this implementation, the width of the conductive rubber ring along the axial direction of the powertrain is smaller, which facilitates the use of multiple conductive rubber rings to cooperate with the conductive bearing to enhance the conductivity.

[0042] In one implementation, each conductive structure includes two conductive rubber rings. The two conductive rubber rings are spaced apart along the axial direction of the conductive structure, and the sum of the distance between the two conductive rubber rings and the width of the two conductive rubber rings is less than or equal to the length of the conductive bearing.

[0043] In this implementation, two conductive rubber rings spaced apart along the axial direction of the powertrain can distribute the impact force of the radial movement of the motor shaft more evenly onto the conductive bearing, thereby improving the internal stress conditions of the conductive structure and extending its service life.

[0044] In one implementation, the elastic modulus of one conductive rubber ring in each oil guiding structure is less than the elastic modulus of the other conductive rubber ring.

[0045] In this implementation, by differentiating the elastic moduli of the materials of the two conductive rubber rings, the elastic forces of the two conductive rubber rings along the radial direction of the powertrain can be differentiated. After long-term operation of the powertrain provided in this application, the wear amounts of the two conductive rubber rings will differ, and the conductive rubber ring with smaller wear can compensate for the wear amount of the other conductive rubber ring through elastic deformation.

[0046] In one implementation, along the direction in which each oil guide structure extends into the shaft hole, one conductive rubber ring and another conductive rubber ring are arranged alternately.

[0047] In this implementation, the other conductive rubber ring, with a smaller axial elastic modulus along the powertrain, is closer to the other end of the shaft hole. Radial movement of the motor shaft causes greater compression of the other conductive rubber ring, thus creating a sealing effect on one conductive rubber ring and reducing its contact with coolant or lubricating oil, thereby protecting it.

[0048] In one implementation, the conductive structure includes an axial sleeve. The conductive structure is fixed to the outer peripheral surface of an axially protruding portion via the axial sleeve, and the outer peripheral surface of the conductive structure is used to coat a wear-resistant conductive coating.

[0049] In this implementation, an axial sleeve extends along the axial direction of the powertrain to increase the contact area between the conductive structure and the axial protrusion, thereby fixing the conductive structure to the outer peripheral surface of the axial protrusion. During the operation of the drive motor, the motor shaft rotates within the housing, and the inner peripheral surface of the motor shaft's bore continuously rubs against the outer peripheral surface of the conductive structure. The wear-resistant conductive coating applied to the outer peripheral surface of the conductive structure reduces wear on the outer peripheral surface and establishes an electrical connection between the outer peripheral surface of the conductive structure and the inner peripheral surface of the motor shaft's bore.

[0050] In one implementation, the conductive structure is fixed to the inner circumferential surface of the shaft hole by an axial sleeve, and the inner circumferential surface of the conductive structure is used to coat a wear-resistant conductive coating.

[0051] In this implementation, an axial sleeve extends along the axial direction of the powertrain to increase the contact area between the conductive structure and the shaft hole of the motor shaft, thereby fixing the conductive structure to the inner circumferential surface of the shaft hole of the motor shaft. During the operation of the drive motor, the conductive structure rotates with the motor shaft within the housing, and the inner circumferential surface of the conductive structure continuously rotates and rubs against the axially protruding outer circumferential surface. The wear-resistant conductive coating applied to the inner circumferential surface of the conductive structure reduces wear on the inner circumferential surface and conducts electrical connection between the inner circumferential surface of the conductive structure and the axially protruding outer circumferential surface.

[0052] In one implementation, along the axial direction of the powertrain, the axial sleeve extends toward the bottom of the bearing groove away from the groove.

[0053] In this implementation, along the axial direction of the powertrain, the axial sleeve is positioned relative to the third shaft hole, which is close to the motor shaft. The conductive structure electrically connects the inner circumferential surface of the first shaft hole and the outer circumferential surface of the axial protrusion on the side near the bottom of the bearing groove. The conductive structure is positioned away from the third shaft hole relative to the portion used for conduction and electrical connection, reducing contact between the conductive structure and coolant or lubricating oil to extend its service life.

[0054] In one implementation, the conductive structure includes a radial protrusion. The conductive structure provides electrical connection between the outer peripheral surface of the axial protrusion and the inner peripheral surface of the shaft hole via the radial protrusion. The radial protrusion is used to fix the axial sleeve to one end near the bottom of the bearing groove along the axial direction of the powertrain.

[0055] Secondly, this application provides an electric vehicle. The electric vehicle includes wheels and a powertrain provided by any implementation of the first aspect described above, the powertrain being used to drive the wheels of the electric vehicle.

[0056] The electric vehicle described in this application uses the aforementioned powertrain, resulting in a more compact structure and a longer service life. Attached Figure Description

[0057] Figure 1 is a schematic diagram of the external appearance of an electric vehicle provided in an embodiment of this application;

[0058] Figure 2 is a schematic diagram of a transmission system for an electric vehicle provided in an embodiment of this application;

[0059] Figure 3 is a cross-sectional schematic diagram of a powertrain provided in an embodiment of this application;

[0060] Figure 4 is a cross-sectional schematic diagram of a powertrain provided in an embodiment of this application;

[0061] Figure 5 is a partially enlarged schematic diagram of a powertrain provided in an embodiment of this application;

[0062] Figure 6 is another partially enlarged schematic diagram of the powertrain provided in the embodiment of this application;

[0063] Figure 7 is another exploded view of the powertrain provided in the embodiment of this application;

[0064] Figure 8 is another exploded view of the powertrain provided in the embodiment of this application;

[0065] Figure 9 is another cross-sectional schematic diagram of the powertrain provided in the embodiment of this application;

[0066] Figure 10 is another cross-sectional schematic diagram of the powertrain provided in the embodiment of this application;

[0067] Figure 11 is another exploded view of the powertrain provided in the embodiment of this application;

[0068] Figure 12 is another cross-sectional schematic diagram of the powertrain provided in the embodiment of this application;

[0069] Figure 13 is another cross-sectional schematic diagram of the powertrain provided in the embodiment of this application;

[0070] Figure 14 is another exploded view of the powertrain provided in the embodiment of this application;

[0071] Figure 15 is another cross-sectional schematic diagram of the powertrain provided in the embodiment of this application;

[0072] Figure 16 is another cross-sectional schematic diagram of the powertrain provided in the embodiment of this application;

[0073] Figure 17 is another cross-sectional schematic diagram of the powertrain provided in the embodiment of this application;

[0074] Figure 18 is another schematic diagram of the powertrain provided in the embodiment of this application;

[0075] Figure 19 is another cross-sectional schematic diagram of the powertrain provided in the embodiment of this application. Detailed Implementation

[0076] The technical solutions of the embodiments of this application will be described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0077] This application provides a dual-motor powertrain for preventing bearing electro-corrosion. The powertrain includes two drive motors arranged adjacent to each other along the axial direction of the powertrain. The powertrain housing includes a partition plate with two opposite end faces along the axial direction of the powertrain. Each end face includes a bearing groove and an oil guide structure. Each bearing groove is used to fix the motor shaft of one drive motor via a motor bearing. One end of each oil guide structure is used to fix and connect to the bottom of a bearing groove, and the other end of each oil guide structure is used to extend along the axial direction of the powertrain and deliver coolant or lubricating oil to the shaft hole of one motor shaft. A gap exists between the outer peripheral surface of each oil guide structure and the inner peripheral surface of the shaft hole of the motor shaft. The gap is used to accommodate an annular conductive structure, and each conductive structure is used to electrically connect one motor shaft and the oil guide structure.

[0078] This application provides an electric vehicle. The electric vehicle includes wheels and a powertrain provided in this application, the powertrain being used to drive the wheels of the electric vehicle. The electric vehicle provided in this application uses the powertrain provided in this application, resulting in a more compact structure and a longer service life.

[0079] Figure 1 is a schematic diagram of the external appearance of an electric vehicle 200 provided in an embodiment of this application. As shown in Figure 1, the electric vehicle 200 includes a battery 101, wheels 102, and a powertrain 100. The battery 101 supplies power to the powertrain 100. The powertrain 100 drives the wheels 102 to rotate, providing power to the electric vehicle 200.

[0080] Figure 2 is a schematic diagram of a transmission system for an electric vehicle 200 provided in an embodiment of this application. Figure 3 is a cross-sectional schematic diagram of a powertrain 100 provided in an embodiment of this application.

[0081] The dual-motor powertrain 100 for preventing bearing electro-corrosion provided in this application includes two drive motors 20, which are arranged adjacent to each other along the axial direction of the powertrain 100. The housing 10 of the powertrain 100 includes a partition 12.

[0082] In one embodiment, the housing 10 includes a first axial housing, a circumferential housing, and a second axial housing arranged sequentially along the axial direction of the powertrain 100. The circumferential housing includes a central partition 12 and two inner cavities, which are located on either side of the central partition 12 along the circumferential direction of the powertrain 100 and extend through the circumferential housing in a direction away from the central partition 12. The first and second axial housings are respectively fixed to the sides of the circumferential housing along the axial direction of the powertrain 100 to respectively enclose two receiving cavities. The two receiving cavities are used to respectively accommodate two drive motors 20.

[0083] In one embodiment, each drive motor 20 includes a motor shaft 211, a motor rotor 21, and a motor stator 22. Please refer to FIG4 for a schematic cross-sectional view of a drive motor 20 provided in an embodiment of this application.

[0084] In the drive motor 20 shown in Figure 4, the stator 22 of the drive motor 20 is fixedly connected to the housing 10 of the powertrain 100. The stator 22 is coaxially sleeved on the periphery of the motor rotor 21. The motor shaft 211 passes through the motor rotor 21 and is connected to the motor rotor 21 for transmission. The stator 22 is also used for electrical connection with the drive circuit. After the motor stator 22 is energized, it will generate an alternating magnetic field based on the alternating current of the drive circuit to drive the motor rotor 21 to rotate and drive the motor shaft 211 to rotate coaxially, so that the drive motor 20 transmits driving force to the wheel 102 through the motor shaft 211.

[0085] In one embodiment, as shown in FIG2, the electric vehicle 200 includes two reducers 103. The two drive motors 20 of the powertrain 100 are respectively connected to two wheels 102 through the two reducers 103. The axis of the wheel 102 is parallel to the axis of the powertrain 100. In one embodiment, the powertrain 100 is fixed to the frame of the electric vehicle 200 by a housing 10. Each reducer 103 is connected to the axle of one drive motor 20 and one wheel 102. The driving force output by each drive motor 20 through the motor shaft 211 is transmitted to one wheel 102 through a reducer 103 to drive the wheel 102 to rotate, thereby driving the electric vehicle 200 to move.

[0086] In one embodiment, each reducer 103 includes a gear set comprising multiple pairs of meshing gears. Referring to Figure 2, the gear sets of the two reducers 103 are respectively located in two receiving cavities formed by the housing 10. Along the axial direction of the powertrain 100, the gear sets of the two reducers 103 are located on opposite sides of the two motor stators 22. The end of each motor shaft 211 facing the reducer 103 meshes with a transmission gear of the gear set to drive the reducer 103 to rotate the wheel 102.

[0087] In one embodiment, each cavity of the powertrain 100 further includes two motor bearings 30. The two motor bearings 30 are arranged on both sides of the motor stator 22 along the axial direction of the powertrain 100. The inner rings of the two motor bearings 30 are respectively connected to the two ends of the motor shaft 211 for transmission, and the outer rings of the two motor bearings 30 are fixedly connected to 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.

[0088] In one embodiment, one end of each motor shaft 211 is also used to fixally connect to one end of a drive shaft of a reducer 103, and the other end of a drive shaft of a reducer 103 is used to embed into the inner ring of a motor bearing 30 and is fixed to the housing 10 by the outer ring of the motor bearing 30. This also allows the motor shaft 211 to be rotatably connected to the housing 10 via the motor bearing 30, meaning the housing 10 supports the motor shaft 211 and one drive shaft of the reducer 103 via two motor bearings 30.

[0089] In one embodiment, the partition plate 12 of the powertrain 100 of this application includes two end faces opposite to each other along the axial direction of the powertrain 100. Each end face includes a bearing groove 123 and an oil guide structure 120, wherein each bearing groove 123 is used to fix the motor shaft 211 of a drive motor 20 by means of a motor bearing 30.

[0090] Please refer to Figure 5, which shows a partially enlarged schematic diagram of the powertrain 100 provided in an embodiment of this application.

[0091] Referring to Figures 4 and 5, two bearing grooves 123 are formed on the two opposite end faces of the axial partition 12 of the powertrain 100. The two bearing grooves 123 are used to fix the outer rings of the two motor bearings 30 respectively. The inner ring of each motor bearing 30 is used for transmission connection with one end of the motor shaft 211. The inner and outer rings of the motor bearings 30 are rotatably connected so that the two motor bearings 30 support the two motor shafts 211 respectively.

[0092] In one embodiment, one end of each oil guide structure 120 of the powertrain 100 is used to fix the bottom of the bearing groove 123, and the other end of each oil guide structure 120 is used to extend along the axial direction of the powertrain 100 and deliver coolant or lubricating oil to the shaft hole 212 of the motor shaft 211.

[0093] As shown in Figure 4, two oil guiding structures 120 are arranged on both sides of the partition plate 12 along the axial direction of the powertrain 100. The two opposing ends of the two oil guiding structures 120 are fixed to the bottom of the two bearing grooves 123, and the two back ends of the two oil guiding structures 120 extend into the shaft holes 212 of the two motor shafts 211. Each oil guiding structure 120 is provided with a through hole 122, which is used to deliver coolant or lubricating oil to the two shaft holes 212. The coolant flows through the through hole 122 into the shaft hole 212 and absorbs heat to reduce the temperature of the drive motor 20; the lubricating oil can flow through the shaft hole 212 to the other end of the shaft hole 212, that is, the lubricating oil flows towards the reducer 103. After the lubricating oil flows to the reducer 103, it provides lubrication for the gear set inside the reducer 103, so as to reduce the wear generated by the gear set during meshing and improve the service life of the reducer 103.

[0094] Because the end of the motor shaft 211 furthest from the partition 12 is used for transmission connection to the reducer 103, it is inconvenient for the powertrain 100 to supply oil from the end of the motor shaft 211 closest to the reducer 103 towards the reducer 103 and the drive motor 20 for lubrication and cooling. The powertrain 100 of this application utilizes the partition 12 to supply oil to the motor shafts 211 on both sides, meeting the working requirements of the drive motors 20 on both sides and the reducers 103 on both sides, saving internal space in the powertrain 100, and facilitating miniaturization of the powertrain 100.

[0095] It should be noted that, in one embodiment, the coolant and lubricating oil mentioned above can be the same type of liquid, which is used to cool the drive motor 20 during the process of passing through the shaft hole 212, and is used to lubricate the gear set of the reducer 103 after flowing to the reducer 103.

[0096] In one embodiment, a gap 50 exists between the outer peripheral surface of each oil guide structure 120 and the inner peripheral surface of the shaft hole 212 of a motor shaft 211. The gap 50 is used to accommodate an annular conductive structure 40, and each conductive structure 40 is used to electrically connect a motor shaft 211 and an oil guide structure 120.

[0097] As shown in Figure 5, the conductive structure 40 is annular and is sleeved on the outside of the oil guiding structure 120. The inner circumferential surface of the conductive structure 40 is at least partially in contact with the outer circumferential surface of the oil guiding structure 120, and the outer circumferential surface of the conductive structure 40 is at least partially in contact with the inner circumferential surface of the shaft hole 212, so as to realize the electrical connection between the oil guiding structure 120 and the shaft hole 212.

[0098] During the operation of the drive motor 20, the motor shaft 211 will generate shaft end current under the influence of the magnetic field generated by the motor stator 22. When the shaft end current flows through the motor bearing 30, it will cause local high temperature and corrosion, resulting in a shortened service life of the motor bearing 30. In addition, the shaft end current will also undergo an electrochemical reaction with the lubricating medium inside the motor bearing 30, reducing the lubrication effect of the lubricating medium and accelerating the wear of the motor bearing 30.

[0099] The powertrain 100 of this application uses two conductive structures 40 to conduct electrical connections between the outer peripheral surface of an oil guiding structure 120 and the inner peripheral surface of a shaft hole 212, so as to conduct the shaft end current of the two motor shafts 211 to the middle partition 12 to achieve grounding, thereby preventing the shaft end current of the motor shafts 211 from flowing through the motor bearings 30 and causing the motor bearings 30 to fail.

[0100] Compared to the conductive structure of motor bearings in the prior art, in the powertrain 100 of this application, the two oil guiding structures 120 along the axial partition 12 of the powertrain 100 are located at opposite ends of the two motor shafts 211. The two oil guiding structures 120 extend into the shaft holes 212 of the two motor shafts 211, and the conductive structure 40 is located inside the shaft holes 212. This makes full use of the internal space of the motor shafts 211, reduces the axial dimension of the powertrain 100, and makes the internal structure of the powertrain 100 more compact.

[0101] Furthermore, along the axial direction of the powertrain 100, two oil guiding structures 120 are respectively located at the ends of the two motor shafts 211 away from the wheel 102, that is, away from the transmission connection position between the drive motor 20 and the wheel 102, which improves the reliability of the oil guiding structure 120 in delivering coolant or lubricating oil. The conductive structure 40 is located between the oil guiding structure 120 and the shaft hole 212, and will not affect the delivery of coolant or lubricating oil between the oil guiding structure 120 and the shaft hole 212, thus ensuring the cooling and lubrication requirements of the internal components of the powertrain 100 of this application.

[0102] Accordingly, the electric vehicle provided in this application embodiment also has a more compact structure and a longer service life because it adopts the above-mentioned powertrain 100.

[0103] In one embodiment, the partition 12 includes an internal oil passage 124 for supplying coolant or lubricating oil to the oil guiding structures 120 at both ends. As shown in FIG5, the internal oil passage 124 extends radially along the powertrain 100. The internal oil passage 124 is connected to the shaft holes 212 of the two motor shafts 211 via the two oil guiding structures 120, respectively. The end of the internal oil passage 124 away from the oil guiding structures 120 is connected to an external oil supply line or an oil pump, so that coolant or lubricating oil flows sequentially through the internal oil passage 124 and the two oil guiding structures 120 to the shaft holes 212 of the two motor shafts 211, respectively.

[0104] In the powertrain 100 shown in Figure 5, a drive motor 20 is arranged on each side of the axial partition 12 of the powertrain 100. An internal oil passage 124 within the partition 12 extends radially along the powertrain 100, thereby reducing the axial dimension of the powertrain 100. The partition 12 connects to two oil guiding structures 120 via the internal oil passage 124, thus simplifying the internal structure of the powertrain 100.

[0105] In one embodiment, each oil guide structure 120 includes an axial protrusion 121. One end of each axial protrusion 121 is used to fix the bottom of the bearing groove 123. The other end of each axial protrusion 121 is used to extend into the shaft hole 212 of a motor shaft 211 along the axial direction of the powertrain 100. The end face of the other end of each axial protrusion 121 includes a through hole 122 for conveying coolant or lubricating oil to the shaft hole 212 of the motor shaft 211.

[0106] In the powertrain 100 shown in Figure 5, each oil guide structure 120 extends axially along the powertrain 100 toward a shaft bore 212 of a motor shaft 211 via an axial protrusion 121. The other end of each axial protrusion 121 extending into the shaft bore 212 is used to deliver coolant or lubricating oil toward the shaft bore 212 via a through hole 122. Each through hole 122 communicates with the internal oil passage 124 of the partition plate 12. The through hole 122 of each axial protrusion 121 communicates between the internal oil passage 124 and a shaft bore 212, so that coolant or lubricating oil flows sequentially through the internal oil passage 124 and a through hole 122 into the shaft bore 212 of the motor shaft 211.

[0107] In one embodiment, the axes of the through holes 122 of the two axial protrusions 121 coincide. In the powertrain 100 shown in FIG. 5, the positions of the two through holes 122 on the partition plate 12 are symmetrical. The amount of coolant or lubricating oil flowing into the two through holes 122 from the internal oil passage 124 is relatively uniform, which can ensure that the cooling or lubrication effect of the two drive motors 20 on both sides of the partition plate 12 is similar.

[0108] In one embodiment, each gap 50 includes two gaps with different radial dimensions. One gap and the other gap are arranged sequentially along the direction in which each oil guide structure 120 extends into the shaft hole 212. The radial dimension of one gap is greater than the radial dimension of the other gap, and the radial dimension of the other gap is less than the radial dimension of the conductive structure 40.

[0109] Please refer to Figure 6 for another partially enlarged schematic diagram of the powertrain 100 provided in an embodiment of this application.

[0110] As shown in Figure 6, the gap 50 along the direction in which each oil guiding structure 120 extends into the shaft hole 212 includes a first gap 51 and a second gap 52 arranged sequentially. The radial dimension of the first gap 51 is larger than that of the second gap 52, and the radial dimension of the second gap 52 is smaller than that of the conductive structure 40. In the opening region near the shaft hole 212, the radial dimension of the first gap 51 between the oil guiding structure 120 and the shaft hole 212 is larger, providing sufficient installation space for the conductive structure 40. In the internal region deep within the shaft hole 212, the radial dimension of the second gap 52 between the oil guiding structure 120 and the shaft hole 212 is smaller, to reduce the amount of coolant or lubricating oil leaking towards the opening of the shaft hole 212 after it is fed into the shaft hole 212, thereby delivering more coolant or lubricating oil towards the drive motor 20 and the reducer.

[0111] In one embodiment, each axial protrusion 121 includes a first protrusion 1211 and a second protrusion 1212. The first protrusion 1211 and the second protrusion 1212 are arranged sequentially along the direction in which each oil guide structure 120 extends into the shaft hole 212. The outer diameter of the first protrusion 1211 is larger than the outer diameter of the second protrusion 1212. The first protrusion 1211 is used to sleeve the conductive structure 40.

[0112] Please refer to Figure 7 for another exploded view of the powertrain 100 provided in an embodiment of this application.

[0113] As shown in Figure 7, the conductive structure 40 is sleeved on the outside of the first section of the axial protrusion 1211. The outer diameter of the first section of each axial protrusion 1211 is larger to stably support a conductive structure 40. The outer diameter of the second section of the protrusion is smaller, which facilitates its insertion into the shaft hole 212 and helps to reduce the inner diameter of the shaft hole 212, thereby improving the structural stability of the motor shaft 211.

[0114] In one embodiment, the outer peripheral surface of each first protrusion 1211 along the axial direction of the powertrain 100 includes one or more limiting structures 1213. The radial dimension of each limiting structure 1213 in each first protrusion 1211 is different from the outer diameter of the rest of each first protrusion 1211 along the radial direction of the powertrain 100.

[0115] In the powertrain 100 shown in Figure 7, the limiting structure 1213 is a groove, and the radial dimension of the bottom of the groove along the radial direction of the powertrain 100 is smaller than the outer diameter of the remaining part of the first protrusion 1211. The groove is used to accommodate part of the conductive structure 40 to increase the contact area between the first protrusion 1211 and the conductive structure 40, thereby enhancing the conductivity between the axial protrusion 121 and the conductive structure 40.

[0116] In one embodiment, the limiting structure 1213 consists of a plurality of protrusions spaced apart along the axial direction of the powertrain 100, and the radial dimension of the protrusions along the radial direction of the powertrain 100 is larger than the outer diameter of the remaining portion of the first protrusion 1211. The conductive structure 40 is located between two adjacent protrusions, which can also increase the contact area between the first protrusion 1211 and the conductive structure 40, thereby enhancing the conductivity between the axial protrusion 121 and the conductive structure 40.

[0117] In one embodiment, one or more limiting structures in each first 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 shown in FIG7, the limiting structure 1213 is a groove, the bottom of which is used to fix the conductive structure 40 to limit the axial displacement of the conductive structure 40 along the powertrain 100. The bottom of the groove is used to fit against the inner circumferential surface of the conductive structure 40 to enhance the conductivity.

[0118] In one embodiment, the limiting structure 1213 consists of a plurality of protrusions spaced apart along the axial direction of the powertrain 100. These protrusions form a plurality of positioning grooves with the outer peripheral surface of the first protrusion 1211. The protrusions are respectively used to embed the conductive structure 40, meaning the conductive structure 40 contacts the bottom of the positioning grooves. This better restricts the axial displacement of the conductive structure 40 along the powertrain 100 and enhances the conductivity between the conductive structure 40 and the oil-guiding structure 120.

[0119] In one embodiment, each shaft hole 212 includes a first shaft hole 2121, a second shaft hole 2122, and a third shaft hole 2123, arranged sequentially along the direction in which each oil guide structure 120 extends into the shaft hole 212. The inner diameter of the first shaft hole 2121 is larger than the inner diameter of the second shaft hole 2122, and the inner diameter of the second shaft hole 2122 is larger than the inner diameter of the third shaft hole 2123. The length of the first shaft hole 2121 is greater than the length of the second shaft hole 2122, and the length of the first shaft hole 2121 is less than the length of the third shaft hole 2123.

[0120] Please refer to Figures 8 and 9, where Figure 8 is another exploded view of the powertrain 100 provided in the embodiment of this application; and Figure 9 is another cross-sectional view of the powertrain 100 provided in the embodiment of this application.

[0121] As shown in Figures 8 and 9, the first shaft hole section 2121 has a larger inner diameter to accommodate and fix a conductive structure 40. The third shaft hole section 2123 has a smaller inner diameter to receive coolant or lubricating oil supplied by the axial protrusion 121 and to reduce leakage of coolant or lubricating oil toward 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 face of the second shaft hole section 2122 toward the first shaft hole section 2121 also serves to limit the axial displacement of the conductive structure 40.

[0122] In one embodiment, a stepped surface is formed between the second shaft hole 2122 and the third shaft hole 2123. The stepped surface faces the conductive structure 40 along the axial direction of the powertrain 100, and the distance between the stepped surface and the conductive structure 40 is smaller than the distance between the bottom of the bearing groove 123 and the conductive structure 40.

[0123] Referring to Figures 6 and 9, a first stepped surface 213 is formed between the second shaft hole 2122 and the third shaft hole 2123. The smaller the distance between the first stepped surface 213 and the conductive structure 40, the longer the axial protrusion 121 extends into the third shaft hole 2123. Because the radial dimension of the gap between the third shaft hole 2123 and the axial protrusion 121 is small, that is, the radial dimension of the second gap 52 is small, the coolant or lubricating oil has to travel a longer distance through the second gap 52 back to the first shaft hole 2121, which can reduce the contact between the conductive structure 40 and the coolant or lubricating oil.

[0124] In one embodiment, the inner circumferential surface of each first shaft bore 2121 includes one or more annular grooves 215. The inner diameter of one or more annular grooves 215 in each first shaft bore 2121 is larger than the inner diameter of the remaining portion of each first shaft bore 2121 along the radial direction of the powertrain 100.

[0125] As shown in Figures 8 and 9, the annular groove 215 is used to accommodate part of the conductive structure 40, so as to increase the contact area between the first shaft hole 2121 and the conductive structure 40 and enhance the conductivity between the first shaft hole 2121 and the conductive structure 40.

[0126] In one embodiment, each annular groove 215 is used to receive a portion of the outer ring of the conductive structure 40. Referring to FIG8, the bottom of the annular groove 215 is used to fix the conductive structure 40 to limit the axial displacement of the conductive structure 40 along the powertrain 100. The bottom of the annular groove 215 is used to conform to the outer peripheral surface of the conductive structure 40 to enhance conductivity.

[0127] In one embodiment, the outer peripheral surface of the motor shaft 211 along the axial direction of the powertrain 100 includes a first peripheral surface 2111 and a second peripheral surface 2112 connected together. Along the radial direction of the powertrain 100, the outer diameter of the first peripheral surface 2111 is smaller than the outer diameter of the second peripheral surface 2112 and greater than or equal to the inner diameter of the motor bearing 30.

[0128] As shown in Figure 9, the first outer peripheral 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 through the first outer peripheral surface 2111 and the second outer peripheral surface 2112, namely the second stepped surface 214 shown in the figure. Along the axial direction of the powertrain 100, the second stepped surface 214 faces the bottom of the bearing groove 123. The second stepped surface 214 abuts against the side of the motor bearing 30 to limit the axial displacement of the motor bearing 30 relative to the motor shaft 211.

[0129] In one embodiment, along the axial direction of the powertrain 100, the length of the first segment of the outer peripheral surface 2111 is greater than the sum of the lengths of the first segment of the shaft hole 2121 and the second segment of the shaft hole 2122.

[0130] As shown in Figure 9, the second step surface 214 along the axial direction of the powertrain 100 coincides with the third shaft hole 2123. That is, the second step surface 214 is located on the third shaft hole 2123 along the axial direction of the powertrain 100. The first shaft hole 2121 and the second shaft hole 2122 along the radial direction of the powertrain 100 are larger, and the second step surface 214 has higher structural stability in the motor shaft 211, which can better limit the axial displacement of the motor bearing 30 relative to the motor shaft 211.

[0131] In one embodiment, the axial conductive structure 40 along the powertrain 100 includes two opposite end faces, one of which is positioned between the other end face and the bottom of the bearing groove 123, and the distance between one end of the axial protrusion 121 and one end face is smaller than the distance between the other end of the axial protrusion 121 and the other end face.

[0132] Please refer to Figure 10, which shows another cross-sectional view of the powertrain 100 provided in an embodiment of this application.

[0133] As shown in Figure 10, the axial conductive structure 40 along the powertrain 100 includes a first end face 401 and a second end face 402 facing away from each other. Referring to Figure 8, the first end face 401 faces the bottom of the bearing groove 123, that is, the first end face 401 is located between the second end face 402 and the bottom of the bearing groove 123. For ease of description, in subsequent embodiments, the first end face 401 of the conductive structure 40 is defined as being arranged between the second end face 402 and the bottom of the bearing groove 123. In one embodiment, the second end face 402 of the conductive structure 40 is arranged between the first end face 401 and the bottom of the bearing groove 123.

[0134] Referring to Figures 5 and 10, along the axial direction of the powertrain 100, the distance between the end of the axial protrusion 121 facing the bottom of the bearing groove 123 and the first end face 401 is less than the distance between the end of the axial protrusion 121 away from the bottom of the bearing groove 123 and the second end face 402. That is, the conductive structure 40 is closer to the bottom of the bearing groove 123 along the axial direction of the powertrain 100 and farther from the oil nozzle of the axial protrusion 121 that delivers lubricating oil or coolant. This can reduce the contact between the conductive structure 40 and the coolant or lubricating oil, and prevent the conductive structure 40 from failing prematurely due to excessive immersion in coolant or lubricating oil.

[0135] In one embodiment, each conductive structure 40 includes a conductive bearing 42 and one or more conductive rubber rings 41.

[0136] Figure 11 is another exploded view of the powertrain 100 provided in an embodiment of this application. Figure 12 is another cross-sectional view of the powertrain 100 provided in an embodiment of this application.

[0137] In one embodiment, as shown in Figures 11 and 12, the conductive structure 40 includes a conductive bearing 42 and a conductive rubber ring 41, with the conductive bearing 42 sleeved around the conductive rubber ring 41. Referring to Figure 5, the inner circumferential surface of the conductive rubber ring 41 at least partially contacts the outer circumferential surface of the axial protrusion 121, and the outer circumferential surface of the conductive bearing 42 at least partially contacts the inner circumferential surface of the first shaft hole 2121, thereby achieving an electrical connection between the oil guiding structure 120 and the motor shaft 211.

[0138] In one embodiment, the inner ring of the conductive bearing 42 is used to be fixedly sleeved on the outer peripheral surface of the oil guiding structure 120, and the outer ring of the conductive bearing 42 is used to fix one or more conductive rubber rings 41.

[0139] Please refer to Figure 13 for another cross-sectional view of the powertrain 100 provided in an embodiment of this application.

[0140] As shown in Figure 13, the inner circumferential surface of the conductive bearing 42 is at least partially in contact with the outer circumferential surface of the axial protrusion 121, and the outer circumferential surface of the conductive rubber ring 41 is at least partially in contact with the inner circumferential surface of the first shaft hole 2121, thus achieving electrical connection between the oil guiding structure 120 and the motor shaft 211. The oil guiding structure 120 is a fixed structure on the partition plate 12, and the conductive bearing 42 is sleeved on the outer circumferential surface of the oil guiding structure 120, facilitating the assembly of the conductive bearing 42.

[0141] Understandably, the conductive bearing 42 and the conductive rubber ring 41 have different stiffnesses. The conductive bearing 42 has higher stiffness, which improves the overall structural stability of the conductive structure 40. The conductive rubber ring 41 has lower stiffness and is used to offset the wear of the conductive structure 40 through elastic deformation, thereby ensuring reliable electrical connection.

[0142] In one embodiment, the size of the axial conductive rubber ring 41 along the powertrain 100 is smaller than the size of the inner or outer ring of the conductive bearing 42. Referring to Figures 12 and 13, the width of the axial conductive rubber ring 41 along the powertrain 100 is smaller, which facilitates the use of multiple conductive rubber rings 41 in conjunction with the conductive bearing 42 to enhance the conductivity of the conductive structure 40.

[0143] 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.

[0144] As shown in Figure 12, 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.

[0145] 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.

[0146] 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.

[0147] As shown in Figure 13, 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.

[0148] 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.

[0149] Understandably, the conductive bearing 42 has high rigidity. When the motor shaft 211 moves radially along the power assembly 100, the portion of the conductive bearing 42 that extends beyond the conductive rubber ring 41 abuts against the outer circumferential surface of the axial protrusion 121 or the inner circumferential surface of the shaft hole 212. This prevents the axial protrusion 121 from contacting the third section of the shaft hole 2123 of the shaft hole 212, and prevents the axial protrusion 121 from being deformed due to collision, thus affecting the delivery of coolant or lubricating oil toward the shaft hole 212.

[0150] In one embodiment, each conductive structure 40 includes two conductive rubber rings 41. The two conductive rubber rings 41 are spaced apart along the axial direction of the conductive structure 40, and the sum of the distance 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.

[0151] Please refer to Figure 14 for another exploded view of the powertrain 100 provided in an embodiment of this application.

[0152] As shown in Figure 14, 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 powertrain 100 to form the inner circumferential surface of the conductive structure 40. The first conductive rubber ring 411 and the second conductive rubber ring 412, which are spaced apart along the axial direction of the powertrain 100, can distribute the impact force of the radial movement of the motor shaft 211 more evenly to the conductive bearing 42, thereby improving the internal stress conditions of the conductive structure 40 and extending the service life of the conductive structure 40.

[0153] In one 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 shown in FIG14, 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 powertrain 100 can be differentiated. After long-term operation of the powertrain 100 provided in this application, the wear amounts of the first conductive rubber ring 411 and the second conductive rubber ring 412 are different, wherein 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.

[0154] In one embodiment, along the direction in which each oil guide structure 120 extends into the shaft hole 212, one conductive rubber ring 41 and another conductive rubber ring 41 are arranged alternately.

[0155] Please refer to Figure 15 for another cross-sectional view of the powertrain 100 provided in an embodiment of this application.

[0156] As shown in Figure 15, along the axial direction of the powertrain 100, the first conductive rubber ring 411 is located between the second conductive rubber ring 412 and the bottom of the bearing groove 123. That is, compared to the first conductive rubber ring 411, the second conductive rubber ring 412 is closer to the third section of the shaft hole 2123. The radial movement of the motor shaft 211 causes a greater compression of the second conductive rubber ring 412, thereby creating a certain sealing effect on the first conductive rubber ring 411, reducing the contact between the first conductive rubber ring 411 and the coolant or lubricating oil, and protecting the first conductive rubber ring 411.

[0157] In one embodiment, the conductive bearing 42 is sleeved on the outside of the two conductive rubber rings 41. The gap between the portion of the inner circumferential surface of the conductive bearing 42 extending beyond the two conductive rubber rings 41 along the axial direction of the power assembly 100 and the outer circumferential surface of the first section of the axial protrusion 1211 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.

[0158] As shown in Figure 15, the inner ring of the conductive structure 40 consists of two conductive rubber rings 41, and the outer ring is a conductive bearing 42. Along the axial direction of the powertrain 100, the sum of the distance 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 less than the width of the conductive bearing 42. That is, the inner circumferential surface of the conductive bearing 42 is exposed to the outside of the first conductive rubber ring 411 and the second conductive rubber ring 412. Along the radial direction of the powertrain 100, the gap between the exposed inner circumferential surface of the conductive bearing 42 and the outer circumferential surface of the first segment of the axial protrusion 121 is the fourth dimension L4.

[0159] The fourth dimension L4 is smaller than the first dimension L1. Correspondingly, 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 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.

[0160] In one embodiment, two conductive rubber rings 41 are fitted onto the outer side of the conductive bearing 42. The gap between the portion of the outer peripheral surface of the conductive bearing 42 extending beyond the two conductive rubber rings 41 along the axial direction of the power assembly 100 and the inner peripheral surface of the first section of the shaft hole 2121 of the shaft hole 212 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.

[0161] Please refer to Figure 16 for another cross-sectional view of the powertrain 100 provided in an embodiment of this application.

[0162] As shown in Figure 16, the outer ring of the conductive structure 40 consists of two conductive rubber rings 41, and the inner ring is a conductive bearing. Along the axial direction of the powertrain 100, the sum of the distance 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 less than the width of the conductive bearing 42. That is, the outer peripheral surface of the conductive bearing 42 is exposed to the outside of the first conductive rubber ring 411 and the second conductive rubber ring 412. Along the radial direction of the powertrain 100, the clearance 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 fifth dimension L5.

[0163] The fifth dimension L5 is smaller than the first dimension L1. Correspondingly, the motor shaft 211 moves radially along the powertrain 100, causing the exposed outer peripheral surface of the conductive bearing 42 to abut against 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.

[0164] In one embodiment, the conductive structure 40 includes an axial sleeve 43. The conductive structure 40 is fixed to the outer peripheral surface of the axial protrusion 121 by the axial sleeve 43, and the outer peripheral surface of the conductive structure 40 is used to coat a wear-resistant conductive coating.

[0165] Please refer to Figure 17 for another cross-sectional view of the powertrain 100 provided in an embodiment of this application.

[0166] As shown in Figure 17, the axial sleeve 43 extends axially along the powertrain 100 to increase the contact area between the conductive structure 40 and the axial protrusion 121, thereby fixing the conductive structure 40 to the outer peripheral surface of the axial protrusion 121. During the operation of the drive motor 20, the motor shaft 211 rotates within the housing 10, and the inner peripheral surface of the shaft hole 212 of the motor shaft 211 continuously rotates and rubs against the outer peripheral surface of the conductive structure 40. The wear-resistant conductive coating applied to the outer peripheral surface of the conductive structure 40 reduces wear on the outer peripheral surface of the conductive structure 40 and conducts electrical connection between the outer peripheral surface of the conductive structure 40 and the inner peripheral surface of the shaft hole 212 of the motor shaft 211.

[0167] In one embodiment, the conductive structure 40 is fixed to the inner circumferential surface of the shaft hole 212 by an axial sleeve 43, and the inner circumferential surface of the conductive structure 40 is used to coat a wear-resistant conductive coating.

[0168] Referring to Figure 17, the 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 establishes the electrical connection between the inner circumferential surface of the conductive structure 40 and the outer circumferential surface of the axial protrusion 121.

[0169] 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.

[0170] Figure 18 is another schematic diagram of the powertrain 100 provided in an embodiment of this application. Figure 19 is another cross-sectional schematic diagram of the powertrain 100 provided in an embodiment of this application.

[0171] As shown in Figures 18 and 19, 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.

[0172] 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.

[0173] In one embodiment, the radial protrusion 44 includes multiple rolled edges, which are fixed around and spaced apart from the end of the radial protrusion 44 away from the axial sleeve 43. When the axial sleeve 43 is fixed to the outer peripheral surface of the axial protrusion 121, the multiple rolled edges abut against the inner peripheral surface of the first shaft hole 2121. It is understood that the rolled edges are elastic, and when the conductive structure 40 is installed in the gap between the axial protrusion 121 and the shaft hole 212, the rolled edges undergo a certain elastic deformation towards the axial sleeve 43. The elasticity of the rolled edges can compensate for wear, preventing gaps between the rolled edges and the inner peripheral surface of the first shaft hole 2121, thus ensuring reliable electrical connection. Furthermore, the side of the multiple rolled edges facing the inner peripheral surface of the shaft hole 212 can also be coated with a wear-resistant conductive coating to reduce wear on the rolled edges.

[0174] 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 toward and contacts the outer circumferential surface of the axial protrusion 121 to achieve 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 side of the radial protrusion 44 facing the outer circumferential surface of the axial protrusion 121 is coated with a wear-resistant conductive coating to reduce wear on the radial protrusion 44.

[0175] Correspondingly, the radial protrusion 44 may also include multiple rolled edges, i.e., the axial sleeve 43 is fixed to the inner circumferential surface of the shaft hole 212, and the multiple rolled edges abut against the outer circumferential surface of the axial protrusion 121. Similarly, the elasticity of the rolled edges can also compensate for wear and prevent gaps from forming between the rolled edges and the outer circumferential surface of the axial protrusion 121, so as to ensure reliable electrical connection. Furthermore, the side of the multiple rolled edges facing the outer circumferential surface of the axial protrusion 121 may also be coated with a wear-resistant conductive coating to reduce wear on the rolled edges.

[0176] In one embodiment, the axial sleeve 43 is engaged and fixed with the radial protrusion 44 to form a conductive structure 40. In another embodiment, the axial sleeve 43 and the radial protrusion 44 are integrally stamped to improve the structural strength of the conductive structure 40 and reduce the assembly steps of the powertrain 100.

[0177] In one embodiment, along the axial direction of the powertrain 100, the axial sleeve 43 extends toward the bottom of the groove away from the bearing groove 123.

[0178] As shown in Figures 18 and 19, along the axial direction of the powertrain 100, the axial sleeve 43 is positioned relative to the third section of the shaft hole 2123, which is close to the shaft hole 212 of the motor shaft 211. A radial protrusion 44, on the side near the bottom of the bearing groove 123, electrically connects the inner circumferential surface of the shaft hole 212 to the outer circumferential surface of the axial protrusion 121. The radial protrusion 44 is positioned relative to the third section of the shaft hole 2123, which is further away from the shaft hole 212, reducing contact between the radial protrusion 44 and the coolant or lubricating oil to extend the service life of the conductive structure 40.

[0179] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the scope of protection of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A dual motor powertrain protected against bearing galvanic corrosion, characterized in that, The powertrain includes two drive motors arranged adjacent to each other along the axial direction of the powertrain. The housing of the powertrain includes a central partition, which includes two opposite end faces along the axial direction of the powertrain. Each end face includes a bearing groove and an oil guide structure, wherein: Each of the bearing slots is used to fix the motor shaft of the drive motor by a motor bearing, one end of each oil guide structure is used to fix and connect to the bottom of the bearing slot, and the other end of each oil guide structure is used to extend along the axial direction of the powertrain and deliver coolant or lubricating oil to the shaft hole of the motor shaft. There is a gap between the outer peripheral surface of each of the oil guiding structures and the inner peripheral surface of the shaft hole of the motor shaft, the gap being used to accommodate an annular conductive structure, each of the conductive structures being used to electrically connect one of the motor shafts and one of the oil guiding structures.

2. The powertrain of claim 1, wherein, The partition includes an internal oil passage for supplying coolant or lubricating oil to the oil guiding structures at the two end faces.

3. The powertrain of claim 1 or 2, wherein, The gap comprises two gaps with different radial dimensions. Along the direction in which each of the oil guiding structures extends into one of the shaft holes, one gap and the other gap are arranged sequentially. The radial dimension of the first gap is greater than the radial dimension of the second gap, and the radial dimension of the second gap is smaller than the radial dimension of the conductive structure.

4. The powertrain of any one of claims 1-3, wherein, Each of the oil guiding structures includes an axial protrusion, one end of which is fixedly connected to the bottom of a bearing groove, and the other end of which is extended into a shaft hole of a motor shaft along the axial direction of the powertrain. The end face of the other end of each axial protrusion includes a through hole for supplying coolant or lubricating oil to the shaft hole of the motor shaft.

5. The powertrain of claim 4, wherein, Each of the axial protrusions includes a first protrusion and a second protrusion, which are arranged sequentially along the direction in which each of the oil guiding structures extends into a shaft hole. The outer diameter of the first protrusion is larger than the outer diameter of the second protrusion, and the first protrusion is used to fit a conductive structure.

6. The powertrain of claim 5, wherein, Along the axial direction of the powertrain, the outer peripheral surface of each of the first protrusions includes one or more limiting structures, wherein: Along the radial direction of the powertrain, the radial dimension of each of the limiting structures in each of the first protrusions is different from the outer diameter of the rest of 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 to fix and electrically connect the inner ring of one of the conductive structures, and the outer ring of one of the conductive structures is used to contact and electrically connect the inner circumferential surface of one of the shaft holes.

8. The powertrain of any one of claims 1-7, wherein, Each of the aforementioned shaft holes includes a first shaft hole, a second shaft hole, and a third shaft hole, which are arranged sequentially along the direction in which each of the oil guiding structures extends into one of the aforementioned shaft holes, wherein: The inner diameter of the first segment shaft hole is larger than the inner diameter of the second segment shaft hole, and the inner diameter of the second segment shaft hole is larger than the inner diameter of the third segment shaft hole. The length of the first segment shaft hole is greater than the length of the second segment shaft hole, and the length of the first segment shaft hole is less than the length of the third segment shaft hole.

9. The powertrain of claim 8, wherein, The inner circumferential surface of each of the first segment shaft holes includes one or more annular grooves, wherein: Along the radial direction of the powertrain, the inner diameter of the one or more annular grooves in each of the first shaft segments is greater than the inner diameter of the remaining portion in each of the first shaft segments.

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

11. The powertrain of any one of claims 1-10, wherein, Each of the conductive structures includes a conductive bearing and one or more conductive rubber rings. The inner ring of the conductive bearing is used to fix the outer circumferential surface of the oil guiding structure, and the outer ring of the conductive bearing is used to fix the one or more conductive rubber rings, wherein: Along the axial direction of the conductive structure, the size of one conductive rubber ring is smaller than the size of the inner or outer ring of the conductive bearing.

12. The powertrain of claim 11, wherein, Each of the conductive structures comprises two of the conductive rubbers, wherein: Along the axial direction of the powertrain, the two conductive rubber rings are arranged at intervals, and the sum of the distance between the two conductive rubber rings and the width of the two conductive rubber rings is less than or equal to the length of the conductive bearing.

13. The powertrain of claim 12, wherein, In each of the oil guiding structures, the elastic modulus of one of the conductive rubber rings is less than that of the other conductive rubber ring.

14. The powertrain of claim 13, wherein, The conductive rubber rings are arranged alternately in a direction that extends into one of the shaft holes along each of the oil guiding structures.

15. An electric vehicle characterized by comprising: The electric vehicle includes wheels and a powertrain as described in any one of claims 1-14, wherein the axis of the wheels is parallel to the axis of a motor shaft in the powertrain.

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