Power assembly capable of preventing electric corrosion of bearing and electric vehicle

Abstract

The utility model provides a power assembly capable of preventing electric corrosion of a bearing and an electric vehicle. The power assembly comprises a shell, a speed reducer, a motor and a conductive structure. The shell comprises an axial shell, the axial shell is arranged on one side of the motor shaft in the axial direction of the motor shaft, the end face, facing the motor shaft, of the axial shell comprises an axial protrusion, and one end of the axial protrusion extends into one shaft hole of the motor shaft in the axial direction of the motor shaft. The end face of one end of one axial protrusion comprises a through hole, and one through hole is used for communicating an internal flow channel of one axial shell and one shaft hole. At least one of one through hole and one shaft hole is used for accommodating a conductive structure, and the conductive structure is used for conducting electric connection between the axial protrusion and the motor shaft. According to the power assembly, electric connection between the motor shaft and the shell is achieved by reasonably utilizing the internal space of the shaft hole of the motor shaft. The motor bearing is effectively protected, and the service life of the power assembly is prolonged.

Description

Technical Field

[0001] This application relates to the field of new energy vehicle technology, and in particular to a powertrain and electric vehicle that prevents bearing electro-corrosion. Background Technology

[0002] In the powertrain of electric vehicles, 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

[0003] This application provides a powertrain for preventing bearing electro-corrosion and an electric vehicle. This application utilizes the internal structure of the axial housing of the powertrain with an axial protrusion towards the motor shaft and the spatial structure inside the shaft hole of the motor shaft to arrange a conductive structure, so as to conduct the shaft current of the motor shaft to the housing ground to protect the motor bearing.

[0004] In a first aspect, this application provides a powertrain for preventing bearing electro-corrosion. The powertrain includes a housing, a reducer, a motor, and a conductive structure. The housing houses the motor, which includes a motor shaft for driving the wheels of an electric vehicle via the reducer. The housing includes an axial housing arranged along the axial direction of the motor shaft on one side of the motor shaft. The end face of the axial housing facing the motor shaft includes an axial protrusion, one end of which extends axially into a shaft hole of the motor shaft. The end face of the axial protrusion includes a through hole for connecting an internal flow channel of the axial housing and a shaft hole. At least one of the through hole and the shaft hole houses the conductive structure for conducting an electrical connection between the axial protrusion and the motor shaft.

[0005] The powertrain provided in this implementation includes an axial housing with an axial protrusion. The axial protrusion has a through hole communicating with the internal flow channel of the axial housing. The axial protrusion extends into the shaft hole of the motor shaft, allowing cooling oil in the internal flow channel to flow into the shaft hole of the motor shaft through the through hole, thereby cooling and lubricating the motor. On the other hand, at least one of the through hole of the axial protrusion and the shaft hole of the motor shaft is used to accommodate a conductive structure. The conductive structure is used to conduct an electrical connection between one of the axial protrusions and the motor shaft, thereby conducting the shaft end current of the motor shaft to the housing for grounding, preventing the shaft end current from flowing through the motor bearing and causing motor bearing failure. The powertrain provided in this application, by providing a conductive structure in the through hole of the axial protrusion or the shaft hole of the motor shaft, fully utilizes the internal space of the motor shaft and the housing, improves the integration and compactness of the powertrain, effectively protects the motor bearing, and extends the service life of the powertrain.

[0006] In one implementation of the first aspect, the conductive structure is further used to connect an axially protruding through-hole and a shaft hole of the motor shaft. The conductive structure provided in this implementation can, on the one hand, conduct the current at the end of the motor shaft to the housing; on the other hand, it can also connect the axially protruding through-hole and the shaft hole of the motor shaft, allowing cooling oil in the internal flow channel to flow smoothly into the shaft hole. Compared to a scheme where one end of the powertrain housing is oil-conducted while the other end has a conductive structure to prevent bearing electro-corrosion, the conductive structure of this application can conduct both electricity and oil, thus achieving both functions at only one end of the motor shaft's shaft hole. This improves component integration, reduces the Y-axis dimension of the powertrain, and also balances the safety of the powertrain against bearing electro-corrosion and cooling and lubrication efficiency.

[0007] In one implementation of the first aspect, along the axial direction of the motor shaft, the shaft hole includes two shaft holes, one of which has an inner diameter larger than the other. The axially protruding end extends into the shaft hole with the larger inner diameter. The shaft hole with the larger inner diameter is used to accommodate the conductive structure.

[0008] In this implementation, the motor shaft bore is divided into two sections with different inner diameters. The section with the larger inner diameter is used to accommodate the conductive structure, thus providing sufficient space for its arrangement and ensuring that cooling oil flows smoothly from the internal channels into the bore. Furthermore, because the conductive structure is located in the section with the larger inner diameter, it is difficult for it to move into the section with the smaller inner diameter, thereby improving the stability of the conductive structure.

[0009] In one implementation of the first aspect, two shaft holes are used to form a first stepped surface, and the conductive structure abuts against the first stepped surface.

[0010] In this implementation, the transition between the larger and smaller inner diameter shaft holes is not smooth but rather forms a first stepped surface. Firstly, the first stepped surface acts as a limiting surface for the axial protrusion. This means that when the axial protrusion extends into the shaft hole of the motor shaft, it can only extend up to the first stepped surface, thus preventing excessive extension of the axial protrusion into the shaft hole and the resulting large force between the axial housing and the motor shaft. Secondly, the first stepped surface also acts as a limiting surface for the conductive structure. The conductive structure abuts against the first stepped surface, thus fixing the conductive structure within the larger inner diameter shaft hole and preventing it from moving into the other shaft hole.

[0011] In one implementation of the first aspect, along the axial direction of the motor shaft, the axially protruding through hole includes two interconnected through holes, wherein the inner diameter of one through hole is larger than that of the other shaft hole, and the through hole with the larger inner diameter is used to accommodate a conductive structure.

[0012] In this implementation, the axially protruding through-hole is divided into two sections with different inner diameters. The section with the larger inner diameter is used to accommodate the conductive structure. Because the conductive structure is arranged in the section with the larger inner diameter, it is difficult for the conductive structure to move into the section with the smaller inner diameter, thereby improving the stability of the conductive structure.

[0013] In one implementation of the first aspect, through holes at both ends are used to form a second stepped surface, and one end of the conductive structure abuts against the second stepped surface.

[0014] In this implementation, the second step surface forms a limiting surface for the conductive structure. The conductive structure abuts against the first step surface, thereby fixing the conductive structure in the shaft hole with the larger inner diameter and preventing it from moving to the other shaft hole.

[0015] In one implementation of the first aspect, the conductive structure includes a first structural member housed in a shaft hole and a second structural member housed in a through hole. The first structural member is electrically connected to a shaft hole of the motor shaft, the second structural member is electrically connected to an axially protruding through hole, and the first and second structural members are electrically connected.

[0016] In this implementation, the conductive structure adopts a split design. The first structural component is disposed in the shaft hole of the motor shaft, while the second structural component is disposed in the axially protruding through hole. The first and second structural components are electrically connected to the shaft hole and the through hole, respectively, and are also electrically connected to each other. This allows the shaft current at the motor shaft end to be sequentially introduced into the housing through the first and second structural components. The split design of the conductive structure improves its flexibility and maintainability. Specifically, during installation, the first and second structural components can be installed into the shaft hole and the through hole respectively, facilitating installation. Furthermore, during the operation of the powertrain, if either the first or second structural component is damaged and cannot continue to function, only the damaged component needs to be replaced, without the need to replace the entire conductive structure, thus improving its maintainability.

[0017] In one implementation of the first aspect, the conductive structure includes a conductive contact piece housed in a shaft hole, the conductive contact piece being used to contact the inner circumferential surface of the shaft hole. In another implementation of the first aspect, the conductive contact piece is disk-shaped, the outer circumferential surface of the conductive contact piece is in contact with the inner circumferential surface of the shaft hole, and an oil guide hole is provided on the surface of the conductive contact piece.

[0018] In this implementation, the conductive structure includes a disc-shaped conductive contact piece housed in a shaft hole, with its outer circumferential surface in contact with the inner circumferential surface of the shaft hole. During powertrain operation, the motor shaft rotates at high speed. By setting the conductive contact piece to a disc shape and ensuring its outer circumferential surface contacts the inner circumferential surface of the shaft hole, contact is maintained between the inner circumferential surface of the shaft hole and the outer circumferential surface of the conductive contact piece during high-speed motor rotation, thus preventing wobbling of the conductive structure caused by the high-speed rotation of the motor shaft. The conductive contact piece has oil guide holes on its surface, which guide cooling oil from the internal oil passages of the axial housing into the shaft hole of the motor shaft, thus giving the conductive contact piece both conductive and oil-guiding functions. In one implementation, the conductive contact piece directly contacts the axial protrusion to guide the current from the motor shaft into the housing. In another implementation, the conductive contact piece does not directly contact the axial protrusion; another structural component of the conductive structure contacts the axial protrusion, and the conductive contact piece is electrically connected to this other structural component. The current from the motor shaft is guided to the housing sequentially through the conductive contact piece and the other structural component.

[0019] In one implementation of the first aspect, along the axial direction of the motor shaft, the conductive structure includes a conductive spring housed in a through-hole of an axial protrusion, the conductive spring being used for contact with the inner circumferential surface of the through-hole, the conductive spring including a spring through-hole.

[0020] In this implementation, the conductive structure includes a conductive spring housed in a through hole of the axially protruding part. The conductive spring contacts the inner circumferential surface of the through hole, thereby achieving an electrical connection between the conductive spring and the housing. The conductive spring can directly contact the shaft hole of the motor shaft, allowing the current from the motor shaft to be guided to the housing through the conductive spring. Alternatively, the conductive spring may not directly contact the shaft hole of the motor shaft; another component of the conductive structure contacts the shaft hole of the motor shaft, and the conductive spring is electrically connected to this other component. The current from the motor shaft then flows sequentially through this other component and the conductive spring, guiding it to the housing.

[0021] In this implementation, a conductive spring is used in the conductive structure. During the high-speed rotation of the motor shaft, the conductive spring wears down. After wear, the compressed amount of the conductive spring is automatically released, so the length of the spring itself does not decrease. In other words, the conductive spring maintains good contact with the motor shaft or axial protrusion even after wear, thereby improving the service life and durability of the conductive structure. On the other hand, the spring is hollow, meaning that the conductive spring includes a spring through hole. The spring through hole can easily guide cooling oil from the internal oil passage into the shaft hole of the motor shaft, thus enabling the conductive structure to have an oil guiding function without any additional processing, reducing the cost of the conductive structure.

[0022] In one implementation of the first aspect, the conductive structure includes a conductive contact piece housed in a shaft hole of a motor shaft and a conductive spring housed in a through hole of an axial protrusion. The conductive contact piece is disc-shaped, with its outer peripheral surface contacting the inner peripheral surface of the shaft hole, and the outer peripheral surface of the conductive spring contacting the inner peripheral surface of the through hole. The conductive contact piece and the conductive spring are electrically connected. In this implementation, the conductive structure is a split conductive structure formed by the mutual cooperation between the conductive contact piece and the conductive spring, thus combining the advantages of both conductive contact pieces and conductive springs.

[0023] In one implementation of the first aspect, the conductive contact includes a central protrusion disposed at the center of the conductive contact and facing the conductive spring, the central protrusion being used to abut one end of the conductive spring.

[0024] The central protrusion of the conductive contact piece serves two purposes. First, it compresses the conductive spring, allowing it to release pressure and maintain close contact even after wear. This improves the lifespan and reliability of the conductive structure. Second, the high-speed rotation of the motor shaft results in a significantly lower linear velocity at the protrusion compared to the outer edge of the conductive contact piece. This greatly reduces wear during contact between the conductive spring and the contact piece, further extending the lifespan of the conductive structure.

[0025] In one implementation of the first aspect, the housing includes a circumferential housing and two axial housings, which together form a receiving cavity. The motor and the reducer are housed within the receiving cavity along the axial direction of the motor shaft. The two axial housings include a reducer end cover and a motor end cover. The reducer end cover is disposed along the axial direction of the motor shaft on the side of the circumferential housing near the reducer, and the motor end cover is disposed along the axial direction of the motor shaft on the side of the circumferential housing near the motor. In this implementation, the axial housing and the two axial housings together form the receiving cavity of the powertrain. The motor and the reducer are housed within the receiving cavity along the axial direction of the motor shaft, with the reducer end cover facing the reducer side and the motor end cover facing the motor side. The aforementioned axial housing can be either the reducer end cover or the motor end cover; that is, the conductive structure and internal oil passages can be located on either the motor side or the reducer side.

[0026] In one implementation of the first aspect, the internal flow channels of the axial housing are used to deliver cooling oil from the heat exchanger to a through hole and a shaft hole.

[0027] Secondly, this application provides an electric vehicle, which 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. The electric vehicle provided in the embodiments of this application employs the aforementioned powertrain, resulting in a more compact structure and a longer service life. Attached Figure Description

[0028] Figure 1 A schematic diagram of an electric vehicle provided for this application;

[0029] Figure 2 A schematic diagram of a powertrain provided for this application;

[0030] Figure 3 A schematic diagram of a powertrain provided for this application;

[0031] Figure 4 A schematic diagram of a powertrain provided for this application;

[0032] Figure 5 A schematic diagram of a powertrain provided for this application;

[0033] Figure 6 A schematic diagram of an axial housing provided for this application;

[0034] Figure 7 A schematic diagram of an axial protrusion provided for this application;

[0035] Figure 8 A schematic diagram of a motor shaft provided in this application;

[0036] Figure 9 A schematic diagram of a powertrain provided for this application;

[0037] Figure 10 A schematic diagram of a conductive structure provided in this application;

[0038] Figure 11 A schematic diagram of a conductive structure provided in this application;

[0039] Figure 12 A schematic diagram of a conductive contact sheet provided in this application;

[0040] Figure 13 A schematic diagram of a conductive spring provided in this application;

[0041] Figure 14 This is a schematic diagram of a conductive structure provided in this application. Detailed Implementation

[0042] The following sections will discuss the fabrication and use of various embodiments in detail. However, it should be understood that many applicable inventive concepts provided in this application can be implemented in a variety of specific environments. The specific embodiments discussed are merely illustrative of specific ways of implementing and using this application and technology, and do not limit the scope of this application.

[0043] This application provides a powertrain for preventing bearing electro-corrosion. The powertrain includes a housing, a reducer, a motor, and a conductive structure. The housing houses the motor, which includes a motor shaft for driving the wheels of an electric vehicle via the reducer. The housing includes an axial housing arranged along the axial direction of the motor shaft on one side. The end face of the axial housing facing the motor shaft includes an axial protrusion, one end of which extends axially into a shaft hole of the motor shaft. The end face of the axial protrusion includes a through hole for connecting an internal flow channel of the axial housing and the shaft hole. At least one of the through hole and the shaft hole houses the conductive structure, which conducts an electrical connection between the through hole and the motor shaft. The powertrain provided by this application efficiently utilizes the internal space of the motor shaft's shaft hole to achieve an electrical connection between the motor shaft and the housing, effectively protecting the motor bearings and extending the service life of the powertrain.

[0044] This application provides an electric vehicle, which includes wheels and a powertrain provided in the embodiments of this application. The powertrain is used to drive the wheels of the electric vehicle. The electric vehicle provided in the embodiments of this application uses the powertrain provided in the embodiments of this application, resulting in a more compact structure and a longer service life.

[0045] Figure 1 This is a schematic diagram of the external appearance of an electric vehicle 200 provided in an embodiment of this application. Figure 1 As shown, 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, thus providing power to the electric vehicle 200.

[0046] The powertrain 100 provided in this application embodiment can be a centralized powertrain or a distributed powertrain. In one embodiment, the powertrain 100 is a centralized powertrain, including a motor 20 and a reducer 103. The motor 20 drives two coaxial wheels of the electric vehicle 200 through the reducer 103, for example, the powertrain 100 drives the two front wheels or the two rear wheels of the electric vehicle 200. In another embodiment, the powertrain 100 is a distributed powertrain, including two motors 20 and two reducers 103. The two motors 20 are respectively used to drive two coaxial wheels of the electric vehicle 200, for example, one of the two motors 20 drives the left front wheel and the other drives the right front wheel, or one of the two motors 20 drives the left rear wheel and the other drives the right rear wheel. The following describes the cases of the powertrain 100 being a centralized powertrain and a distributed powertrain in conjunction with specific embodiments.

[0047] Figure 2This is a schematic diagram of a centralized powertrain 100. Figure 2 The powertrain 100 includes a housing 10, a motor 20, and a reducer 103. The motor 20 includes a motor shaft 211, a motor rotor 21, and a motor stator 22. The housing 10 houses the motor 20 and the reducer 103. The powertrain 100 drives two coaxial wheels. (Continue to see...) Figure 2 In one embodiment, the powertrain 100 housing 10 includes a circumferential housing 13 and two axial housings, which together form a receiving cavity to accommodate the motor 20 and the reducer 103. Specifically, the two axial housings are a reducer end cover 11 and a motor end cover 15, respectively. The reducer end cover 11, the circumferential housing 13, and the motor end cover 15 are arranged sequentially along the axial direction of the motor shaft 211. The reducer end cover 11 is fixed to the side of the axial housing 13 near the reducer 103, and the motor end cover 15 is fixed to the side of the axial housing 13 near the motor 20. Along the axial direction of the motor shaft 211, the reducer end cover 11 and the motor end cover 15 are respectively fixed to both sides of the circumferential housing 13 to enclose the inner cavity of the circumferential housing 13 to form a receiving cavity, in which the motor 20 and the reducer 103 are accommodated along the axial direction of the motor shaft 211.

[0048] In one embodiment, the motor stator 22 of the motor 20 is fixedly connected to the housing 10 of the powertrain 100. The motor stator 22 is coaxially sleeved around 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 motor stator 22 is also electrically connected to the drive circuit. When 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 motor 20 transmits driving force to the wheel 102 through the motor shaft 211.

[0049] In one embodiment, see further. Figure 2The powertrain 100 includes a reducer 103. The motor shaft 211 of the powertrain 100 drives the wheel 102 via the reducer 103. The axis of the wheel 102 is parallel to the axis of the motor shaft 211 of the powertrain 100. In one embodiment, the powertrain 100 is fixed to the frame of the electric vehicle 200 via a housing 10. The reducer 103 is drively connected between the motor shaft 211 of the motor 20 and the axle of the wheel 102. The driving force output by the motor 20 through the motor shaft 211 is transmitted to the wheel 102 via the reducer 103 to rotate the wheel 102, thereby driving the electric vehicle 200. The reducer 103 includes a gear set, which includes multiple pairs of meshing gears. The gear set is located in the receiving cavity formed by the housing 10. Along the axial direction of the motor shaft 211, the gear set is located on one side of the motor stator 22. The end of the motor shaft 211 facing the reducer 103 meshes with a transmission gear of the gear set to drive the reducer 103 to drive the wheel 102.

[0050] In one embodiment, see further. Figure 2 The powertrain 100 also includes two motor bearings 30, which are arranged along the axial direction of the motor shaft 211 on both sides of the motor stator 22. The inner rings of the two motor bearings 30 are respectively connected to the two ends of the motor shaft 211, 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. In one embodiment, one end of the motor shaft 211 is used to fixally connect to one end of a drive shaft of the reducer 103, and the other end of the drive shaft of the reducer 103 is used to embed the inner ring of a motor bearing 30 and is fixed to the housing 10 through the outer ring of a 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 a drive shaft of the reducer 103 through the two motor bearings 30.

[0051] Figure 3 This is a schematic diagram of a distributed powertrain 100. Figure 3 The powertrain 100 includes a housing 10, two motors 20, and two reducers 103. The housing 10 is used to house the two motors 20 and the two reducers 103. Figure 3 The two motors 20 of the powertrain 100 drive the two coaxial wheels of the electric vehicle 200. (Continue to refer to...) Figure 3The housing 10 includes a circumferential housing 13 and three axial housings. The circumferential housing 13 and the three axial housings enclose two receiving cavities. One of the two receiving cavities is used to accommodate a motor 20 and a reducer 103, and the other of the two receiving cavities is used to accommodate another motor 20 and another reducer 103. Specifically, the three axial housings include two reducer end covers 11 and a partition plate 14. One of the two reducer end covers 11, the partition plate 14, and the circumferential housing 13 enclose one receiving cavity, and the other of the two reducer end covers 11, the partition plate 14, and the circumferential housing 13 enclose another receiving cavity. The two receiving cavities are located on both sides of the partition plate 12.

[0052] For example Figure 3 Regarding the distributed powertrain 100 shown, the housing 10 forms two accommodating cavities, each enclosed by a central partition 14, a circumferential housing 13, and a reducer end cover 11. Each accommodating cavity is used to accommodate a motor 20 and a reducer 103. The specific structure and connection relationship of the motor 20 and the reducer 103 in each accommodating cavity are as follows: Figure 2 The centralized powertrain 100 shown is the same, so it will not be described again here.

[0053] For ease of description, a first axial housing 12 is defined in subsequent embodiments. In one embodiment, the first axial housing 12 is Figure 2 One of the two axial housings of the centralized powertrain, namely the first axial housing 12, is either the reducer end cover 11 or the motor end cover 15. In one embodiment, the first axial housing 12 is Figure 3 One of the three axial housings of the distributed powertrain, namely the first axial housing 12, is one of the two reducer end caps 11 or the middle partition 14 of the distributed powertrain.

[0054] Figure 4 This is a schematic cross-sectional view of a centralized powertrain 100 provided in an embodiment of this application. Figure 4 As shown, the first axial housing 12 of the centralized powertrain 100 includes an internal flow channel 124. The first axial housing 12 is one of the reducer end cover 11 or the motor end cover 15. Figure 4 Taking the first axial housing 12 as an example, which is the motor end cover 15.

[0055] Figure 5 This is a cross-sectional schematic diagram of a distributed powertrain 100 provided in an embodiment of this application. Figure 5As shown, the first axial housing 12 of the distributed powertrain 100 includes an internal flow channel 124. The first axial housing 12 is one of the reducer end cover 11, the motor end cover 15, or the partition 14 of the distributed powertrain 100. Figure 5 Taking the first axial housing 12 as an example where the middle partition 14 is the central partition.

[0056] See Figure 4 or Figure 5 In one embodiment, the end face of the first axial housing 12 facing the motor stator 22 includes a bearing groove 123 for accommodating a motor bearing 30, which is used for drive connection to the motor shaft 211. Figure 4 As shown, the first axial housing 12 of the housing 10 is located on the side of the motor shaft 211 away from the reducer 103. The first axial housing 12 is provided with a bearing groove 123 on the side facing the motor shaft 211. The bearing groove 123 is used to fix the outer ring of the motor bearing 30. The inner ring of the motor bearing 30 is connected to one end of the motor shaft 211. The inner ring and the outer ring of the motor bearing 30 are rotatably connected to support the motor shaft 211.

[0057] Continue reading Figure 4 or Figure 5 In one embodiment, the end face of the first axial housing 12 facing the motor stator 22 further includes an axial protrusion 121. One end of the axial protrusion 121 is fixed to the first axial housing 12, and the other end of the axial protrusion 121 is used to extend into the shaft hole 212 of the motor shaft 211 along the axial direction of the motor shaft 211. The end face of the other end of the axial protrusion 121 includes a through hole 122, which is used to connect the internal flow channel 124 of the first axial housing 12 and the shaft hole 212 of the motor shaft 211.

[0058] In one embodiment, the axial protrusion 121 is a hollow protrusion integrally formed with the first axial housing 12, and the axial protrusion 121 is used to connect the internal flow channel 124 and the shaft hole 212. When the first axial housing 12 is a motor end cover 15, the axial protrusion 121 protrudes from the surface of the first axial housing 12 toward the stator of the motor and extends into the shaft hole 212 along the axial direction of the motor shaft 211. When the first axial housing 12 is a reducer end cover, the axial protrusion 121 protrudes from the surface of the first axial housing 12 toward the reducer 103 and extends into the shaft hole 212 along the axial direction of the motor shaft 211.

[0059] In one embodiment, see Figure 6 and Figure 7The first axial housing 12 is a reducer end cover 11. The axial protrusion 121 is a separate oil guiding structure 121, which is located in the fixing hole 125 of the first axial housing 12. One end of the motor shaft 211 is fixed to the fixing hole 125. The oil guiding structure includes a protrusion 121-3 that extends into the fixing hole 125. The through hole 122 of the oil guiding structure includes an axial through hole 122-1 along the axial direction of the motor shaft 211 and a radial through hole 122-2 along the radial direction of the motor shaft 211. The radial through hole 122-2 connects to the internal flow channel 124, and the axial through hole 122-1 connects to the shaft hole 212 of the motor shaft 211. The cooling oil in the internal flow channel 124 flows into the shaft hole 212 through the radial through hole 122-2 and the axial through hole 122-1 in sequence. In one embodiment, the first axial housing 12 further includes a sealing member 131 for fixing the oil guiding structure 121 in the fixing hole 125.

[0060] In one embodiment, the internal flow channel 124 of the first axial housing 12 extends axially along the motor shaft 211 and penetrates the first axial housing 12. Alternatively, the through hole 122 extends axially along the motor shaft 211 and penetrates the housing 10. The through hole 122 communicates with an external oil supply line or an oil pump through the internal flow channel 124, allowing cooling oil from the oil supply line or oil pump to flow sequentially through the internal flow channel 124 and the through hole 122 into the shaft hole 212 of the motor shaft 211. It is understood that the cooling oil flows through the through hole 122 into the shaft hole 212 and absorbs heat to reduce the temperature of the motor 20. The cooling oil can also flow through the shaft hole 212 to the other end of the shaft hole 212, i.e., towards the reducer 103. After flowing to the reducer 103, the cooling oil provides lubrication to the gear set inside the reducer, reducing wear on the gear set during meshing and improving the service life of the reducer 103. In one embodiment, the powertrain 100 further includes a heat exchanger 500 for oil-water heat exchange, which is used to supply cooling oil to the powertrain 100. Specifically, the cooling oil flowing out of the cooling oil outlet of the heat exchanger flows into the internal flow channel 124 of the axial housing, and then flows into the shaft hole of the motor shaft 211 through the through hole 122 in the axial protrusion 121 to cool and dissipate heat from the motor system.

[0061] In one embodiment, the internal flow channel 124 of the first axial housing 12 extends radially within the first axial housing 12 along the motor shaft 211. The radial arrangement of the internal flow channel 124 along the motor shaft 211 can be found in [reference needed]. Figure 9 The internal flow channel 124.

[0062] Figure 8This is a schematic diagram of a motor shaft 211 provided in one embodiment of this application. In one embodiment, the powertrain 100 further includes a reducer shaft, which is used to fixably connect to the gear set of the reducer. The motor shaft 211 is fixedly connected to the reducer shaft via a spline, and the motor shaft 211 drives the gear set of the reducer to rotate during rotation. In one embodiment, the motor shaft 211 is an integral shaft, that is, the motor shaft 211 directly extends into the reducer side and is fixedly connected to the gear set of the reducer, so that the motor shaft 211 can directly drive the gear set of the reducer to rotate during rotation.

[0063] like Figure 9 As shown, in one embodiment, at least one of the through hole 122 and shaft hole 212 of the powertrain 100 provided in this application embodiment is used to accommodate a conductive structure 40. The conductive structure 40 is used to conduct the electrical connection between the axial protrusion 121 and the motor shaft 211. The conductive structure 40 conducts the electrical connection between the axial protrusion 121 and the motor shaft 211 to conduct the shaft end current of the motor shaft 211 to the housing 10 to achieve grounding, thereby preventing the shaft end current of the motor shaft 211 from flowing through the bearing 30 and causing the bearing 30 to fail. The powertrain 100 provided in this application, by providing the conductive structure 40 in the through hole of the axial protrusion 121 or the shaft hole 212 of the motor shaft 211, makes full use of the internal space of the motor shaft 211 and the housing, without occupying additional space to arrange the conductive structure 40, thereby improving the integration and compactness of the powertrain 100 and effectively protecting the bearing 30, and extending the service life of the powertrain 100.

[0064] Continue reading Figure 9 In one embodiment, the conductive structure 40 is also used to connect the through hole 122 and the shaft hole 212. Specifically, in one embodiment, the conductive structure 40 includes an oil guide hole 43. Cooling oil in the internal flow channel 124 flows into the through hole 122, and cooling oil in the through hole 122 flows into the shaft hole 212 through the oil guide hole 43. The conductive structure 40 provided in this application embodiment can conduct the shaft end current of the motor shaft 211 to the housing 10 on the one hand, and on the other hand, the conductive structure 40 can also connect the through hole 122 of the axial protrusion 121 and the shaft hole 212 of the motor shaft 211, so that the cooling oil in the internal flow channel 124 can flow smoothly into the shaft hole 212. The conductive structure 40 of this application can conduct electricity and conduct oil, so that the two functions of oil conduction and electricity conduction are realized at only one end of the shaft hole 212 of the motor shaft 211, which improves the integration of components, reduces the Y-axis dimension of the powertrain 100, and also takes into account the safety of the powertrain 100 against bearing electro-corrosion and the cooling and lubrication efficiency.

[0065] Continue reading Figure 9In one embodiment, along the axial direction of the motor shaft 211, the shaft hole 212 includes two shaft hole sections, one of which has an inner diameter larger than the other. One end of the axial protrusion 121 extends into the shaft hole with the larger inner diameter. The shaft hole with the larger inner diameter is used to accommodate the conductive structure 40. (See also...) Figure 9 The shaft hole 212 of the motor shaft 211 includes a first shaft hole 212-1 and a second shaft hole 212-2 that are connected. The inner diameter of the first shaft hole 212-1 is larger than the inner diameter of the second shaft hole 212-2. The first shaft hole 212-1 is closer to the axial protrusion 121 than the second shaft hole 212-2. The first shaft hole 212 is used to accommodate the conductive structure 40. In this embodiment, the shaft hole 212 of the motor shaft 211 is divided into two sections with different inner diameters, which can improve the flow of cooling oil. Since the conductive structure 40 is accommodated in the first shaft hole 212-1, the flow area of ​​the first shaft hole 212 for the cooling oil to flow through will be reduced. If the inner diameters of the first shaft hole 212 and the second shaft hole 212 are the same, the flow area of ​​the cooling oil will be reduced when it flows through the first shaft hole 212, resulting in increased flow resistance and obstruction of the flow of cooling oil. In this embodiment, the inner diameter of the first shaft hole 212-1 is larger than the inner diameter of the second shaft hole 212-2. Although the conductive structure 40 being disposed in the first shaft hole 212 reduces the flow area in the first shaft hole 212, the cross-sectional area of ​​the first shaft hole 212 is larger than that of the second shaft hole 212. This ensures that the flow resistance of the cooling oil flowing from the second shaft hole 212 into the first shaft hole 212 is not significantly different, thus guaranteeing smooth flow in the shaft hole 212. On the other hand, since the conductive structure 40 is arranged in the section of the shaft hole 212 with the larger inner diameter, it is difficult for the conductive structure 40 to migrate to the other section of the shaft hole 212 with the smaller inner diameter, thereby improving the stability of the conductive structure 40.

[0066] Continue reading Figure 9 In one embodiment, two shaft holes are used to form a first stepped surface 212-3, and the conductive structure 40 abuts against the first stepped surface 212-3. In this embodiment, the first shaft hole 212-1 with a larger inner diameter and the second shaft hole 212-2 with a smaller inner diameter do not transition smoothly but form a first stepped surface 212-3. First, the first stepped surface 212-3 forms a limiting surface for the axial protrusion 121. That is, when the axial protrusion 121 extends into the shaft hole 212 of the motor shaft 211, it can only extend to the first stepped surface 212-3 at most, thereby avoiding the axial protrusion 121 from extending too far into the shaft hole 212, which would cause a large force between the first axial housing 12 and the motor shaft 211. Secondly, the first step surface 212-3 forms a limiting surface for the conductive structure 40. The conductive structure 40 abuts against the first step surface 212-3, thereby fixing the conductive structure 40 in the first shaft hole 212-1 with a larger inner diameter and preventing it from moving into the second shaft hole 212-2 with a smaller inner diameter.

[0067] Continue reading Figure 9 In one embodiment, along the axial direction of the motor shaft 211, the through hole 122 of the axial protrusion 121 includes two interconnected through holes, wherein the inner diameter of one through hole is larger than that of the other shaft hole, and the through hole with the larger inner diameter is used to accommodate the conductive structure 40. See also... Figure 9 The through-hole 122 of the axial protrusion 121 includes a first through-hole 121-1 and a second through-hole 121-2 that are connected. The inner diameter of the first through-hole 121-1 is larger than the inner diameter of the second through-hole 121-2. The first through-hole 121-1 is closer to the shaft hole 212 of the motor shaft 211 than the second through-hole 121-2. The first through-hole 121-1 is used to accommodate the conductive structure 40. In this embodiment, the through-hole of the axial protrusion 121 is divided into two sections with different inner diameters, which can improve the flow of cooling oil. Since the conductive structure 40 is accommodated in the first through-hole 121-1, the flow area of ​​the first through-hole 121-1 for cooling oil to flow through will be reduced. If the inner diameters of the first through-hole 121-1 and the second through-hole 121-2 are the same, the flow area of ​​the cooling oil will be reduced when it flows through the first through-hole 121-1, resulting in increased flow resistance and obstruction of the flow of cooling oil. In this embodiment, the inner diameter of the first through hole 121-1 is larger than the inner diameter of the second through hole 121-2. Although the flow area in the first through hole 121-1 is reduced due to the placement of the conductive structure 40 in the first through hole 121-1, the cross-sectional area of ​​the first through hole 121-1 is larger than that of the second through hole 121-2. This ensures that the flow resistance of the cooling oil flowing from the second through hole 121-2 into the first through hole 121-1 will not differ significantly. On the other hand, since the conductive structure 40 is arranged in the section of the through hole with a larger inner diameter, it is difficult for the conductive structure 40 to move into the other section of the through hole with a smaller inner diameter, thereby improving the stability of the conductive structure 40.

[0068] In one embodiment, the first through hole 121-1 and the second through hole 121-2 are used to form a second stepped surface 121-3, with one end of the conductive structure 40 abutting against the second stepped surface 121-3. In this embodiment, the first through hole 121-1 and the second through hole 121-2 are not smoothly transitioned, but rather a second stepped surface 121-3 is formed at the junction of the first through hole 121-1 and the second through hole 121-2. On the one hand, this method facilitates processing; on the other hand, the second stepped surface 121-3 forms a limiting surface for the conductive structure 40. The abutment between the conductive structure 40 and the second stepped surface 121-3 fixes the conductive structure 40 in the through hole with the larger inner diameter, preventing it from moving into the other through hole.

[0069] In one embodiment, the outer diameter of the axial protrusion 121 is smaller than the inner diameter of the first shaft hole 212-1 and larger than the inner diameter of the second shaft hole 212-2. The smaller outer diameter of the axial protrusion 121 allows it to extend into the shaft hole 212 of the motor shaft 211. However, the difference between the outer diameter of the axial protrusion 121 and the inner diameter of the first shaft hole 212-1 is small, resulting in a smaller gap between the outer circumferential surface of the axial protrusion 121 and the inner circumferential surface of the first shaft hole 212-1, thus improving the sealing performance of the powertrain 100 and preventing cooling oil from flowing out of the housing after entering the shaft hole 212 of the motor shaft 211 through the through hole of the axial protrusion 121. For example, the difference between the outer diameter of the axial protrusion 121 and the inner diameter of the first shaft hole 212-1 is 1~3 mm.

[0070] In one embodiment, the inner diameter of the first through hole 212-1 is smaller than the inner diameter of the second shaft hole 212-2. This smaller inner diameter of the first through hole 212-1 allows the cooling oil in the first through hole 212-1 to flow more smoothly into the second shaft hole 212-2 when the end face of the axial protrusion 121 is close to the first stepped surface 212-3, thus preventing backflow of the cooling oil.

[0071] In one embodiment, the conductive structure 40 is integral, and the integral conductive structure 40 simultaneously contacts the motor shaft 211 and the axial protrusion 121 to guide the axial current of the motor shaft 211 to the housing. Specifically, in one embodiment, such as Figure 9 As shown, the integrated conductive structure 40 is accommodated in the through-hole 122 of the axial protrusion 121 and is electrically connected to the axial protrusion 121 and the motor shaft 211. In one embodiment, as... Figure 10 As shown, the integrated conductive structure 40 is housed in the shaft hole 212 of the motor shaft 211 and electrically connected to the axial protrusion 121 and the motor shaft 211. The integrated conductive structure 40 is compact and easy to install. It can be set in the through hole 122 or the shaft hole 212 and electrically connected to the motor shaft 211 and the first axial housing 12. At the same time, it can also guide the cooling oil in the internal flow channel 124 into the motor shaft 211.

[0072] In one embodiment, the conductive structure 40 is a split type, comprising a first structural member 41 accommodated in the shaft hole 212 and a second structural member 42 accommodated in the through hole 122. The first structural member 41 is electrically connected to the motor shaft 211, and the second structural member 42 is electrically connected to the first axial housing 12. The electrical connection between the first structural member 41 and the second structural member 42 allows the shaft current generated on the motor shaft 211 to be sequentially introduced into the first axial housing 12 through the first structural member 41 and the second structural member 42. Specifically, in one embodiment, the first structural member 41 is electrically connected to the inner circumferential surface of the shaft hole 212, and the second structural member 42 is electrically connected to the inner circumferential surface of the through hole 122. See also: [link to embodiment]. Figure 11 The first conductive structure 41 is a disk-shaped structure with a hole penetrating its surface. The second conductive structure 42 is a hollow columnar structure, with the hole on the surface of the first conductive structure 41 and the through hole of the second conductive structure 42 connected. Together, the hole on the surface of the first conductive structure 41 and the through hole of the second conductive structure 42 form an oil passage 43, used to guide the cooling oil in the internal flow channel 124 into the shaft hole 212. Both the first conductive structure 41 and the second conductive structure 42 are conductors, enabling the shaft current generated on the motor shaft 211 to be guided into the first axial housing 12. Since the housing 10 is grounded, the shaft current is thus guided to the ground.

[0073] In this embodiment, the conductive structure 40 adopts a split structure. The first structural member 41 of the conductive structure 40 is disposed in the shaft hole 212 of the motor shaft 211, while the second structural member 42 is disposed in the through hole 122 of the axial protrusion 121. The first structural member 41 and the second structural member 42 are electrically connected to the inner circumferential surface of the shaft hole 212 and the inner circumferential surface of the through hole 122, respectively. The first structural member 41 and the second structural member 42 are also electrically connected to each other, so that the shaft current at the end of the motor shaft 211 can be sequentially introduced into the first axial housing 12 through the first structural member 41 and the second structural member 42. By adopting a split structure for the conductive structure 40, the flexibility and maintainability of the conductive structure 40 can be improved. Specifically, during the installation process, the first structural member 41 and the second structural member 42 can be installed into the shaft hole 212 and the through hole 122, respectively, thus facilitating installation. Furthermore, during the operation of the powertrain 100, if one of the first structural component 41 and the second structural component 42 is damaged and cannot continue to work, only the damaged one needs to be replaced, and there is no need to replace the entire conductive structure 40, thereby improving the maintainability of the conductive structure 40.

[0074] In one embodiment, the conductive structure 40 includes a conductive contact piece, the structure of which is described in [reference needed]. Figure 12 .like Figure 12As shown, the conductive contact piece is disc-shaped and includes an outer ring 44 and a web 45 fixedly connected. The thickness of the outer ring 44 is greater than the thickness of the web 45. Multiple evenly distributed oil guide holes 43 are provided circumferentially on the surface of the web of the conductive contact piece. The oil guide holes 43 are used to guide the cooling oil in the through hole 122 of the axial protrusion 121 into the shaft hole 212 of the motor shaft 211. In addition to guiding cooling oil into the shaft hole 212 of the motor shaft 211, the multiple evenly distributed oil guide holes 43 also reduce the weight of the conductive contact piece.

[0075] In one embodiment, the conductive contact piece is housed in the shaft hole 212 of the motor shaft 211, with its outer peripheral surface in contact with the inner peripheral surface of the shaft hole 212. During the operation of the powertrain 100, the motor shaft 211 rotates at high speed. By setting the conductive contact piece to a disc shape and ensuring that its outer peripheral surface is in contact with the inner peripheral surface of the shaft hole 212, the inner peripheral surface of the shaft hole 212 and the outer peripheral surface of the conductive contact piece remain in contact during the high-speed rotation of the motor, thus preventing the conductive structure 40 from shaking due to the high-speed rotation of the motor shaft 211. Similarly, in one embodiment, the conductive contact piece can also be housed in the through hole 122 of the axial protrusion 121. Furthermore, the thickness of the outer ring 44 being greater than the thickness of the web 45 allows the outer surface of the outer ring 44 to fully contact the through hole 122 or the inner peripheral surface of the shaft hole 212, thereby improving conductivity.

[0076] In one embodiment, the conductive contact patch itself constitutes an integral conductive structure 40. For example... Figure 10 As shown, the conductive contact piece is accommodated in the shaft hole 212 of the motor shaft 211 and contacts the axial protrusion 121, thereby guiding the shaft current generated by the motor shaft 211 into the housing 10. In another embodiment, the conductive contact piece is accommodated in the through hole 122 of the axial protrusion 121 and contacts the motor shaft 211, thereby electrically connecting the motor shaft 211 and the axial protrusion 121.

[0077] In one embodiment, the conductive structure 40 includes a conductive spring, the structure of which is as follows: Figure 13 As shown. In one embodiment, the conductive spring is hollow, meaning it includes a spring through-hole. This through-hole allows cooling oil to be easily guided from the internal oil passage 124 into the shaft hole 212 of the motor shaft 211. This eliminates the need for any additional processing of the conductive structure 40, thus providing oil guiding functionality and reducing its cost. In another embodiment, the spring pitch of the conductive spring is greater than the diameter or thickness of the spring base material. This allows cooling oil to flow into the through-hole 122 of the axial protrusion 121 and then into the shaft hole 212 of the motor shaft 211 through the gap between the spring pitches of the conductive spring.

[0078] In this embodiment, the conductive structure 40 uses a conductive spring. When the conductive spring is installed in the through hole 122 or the shaft hole 212, it is in a compressed state. During the high-speed rotation of the motor shaft 211, the conductive spring will wear due to contact with the motor shaft 211 or the axial protrusion 121. After the conductive spring is worn, the compressed amount will be automatically released so that the length of the spring itself will not decrease. In other words, the conductive spring will still maintain good contact with the motor shaft 211 or the axial protrusion 121 after wear, thereby improving the service life and reliability of the conductive structure 40.

[0079] In one embodiment, the conductive spring itself constitutes an integral conductive structure 40. For example... Figure 9 As shown, the conductive spring is housed in the through hole 122 of the axial protrusion 121 and contacts the motor shaft 211, thereby guiding the shaft current generated by the motor shaft 211 into the housing 10. In another embodiment, the conductive spring is housed in the shaft hole 212 of the motor shaft 211 and contacts the axial protrusion 121, thereby electrically connecting the motor shaft 211 and the axial protrusion 121.

[0080] In one embodiment, the conductive spring is part of the distributed conductive structure 40, that is, the conductive spring is one of the first structural member 41 or the second structural member 42. The conductive spring and the other structural member cooperate to guide the shaft current of the motor shaft 211 into the housing 10.

[0081] In one embodiment, such as Figure 14As shown, the conductive structure 40 is a split type, wherein the first structural component 41 is a conductive contact piece, and the second structural component is a conductive spring. The conductive contact piece is disposed in the shaft hole 212 of the motor shaft 211, and the outer peripheral surface of the conductive contact piece contacts the inner peripheral surface of the shaft hole 212. The conductive spring is disposed in the through hole 122 of the axial protrusion 121, and one end of the conductive spring contacts the conductive contact piece. The conductive structure 40 provided in this embodiment has both conductive and oil-guiding functions. The shaft current generated in the motor shaft 211 is conducted sequentially through the conductive contact piece and the conductive spring to the axial protrusion 121. The axial protrusion 121 is fixedly connected to the housing 10, and the housing 10 is grounded, thereby forming a current path for releasing the shaft current. On the other hand, the cooling oil in the cooling system of the powertrain 100 flows from the internal flow channel 124 into the through hole 122 of the axial protrusion 121, then flows through the through hole of the conductive spring into the oil guide hole of the conductive contact piece, and finally flows through the oil guide hole of the conductive contact piece into the shaft hole 212 of the motor shaft 211. The conductive structure 40 provided in this embodiment combines the advantages of both conductive contact pieces and conductive springs, achieving both oil guiding and electrical conduction. Furthermore, the conductive structure 40 provided in this embodiment is disposed in the space formed by the through hole 122 of the axial protrusion 121 and the shaft hole 212 of the motor shaft 211, eliminating the need for a separate space for the conductive structure 40, thus improving the space utilization and compactness of the powertrain 100.

[0082] like Figure 14 As shown, in one embodiment, the conductive spring is in a compressed state after being installed into the through hole 122 of the axial protrusion 121, thereby ensuring close contact between the conductive spring and the conductive contact piece and improving the conductivity of the conductive structure 40. On the other hand, during the high-speed rotation of the motor shaft 211, the conductive contact piece or the conductive spring will wear. After the conductive contact piece or the conductive spring wears down, the compression of the conductive spring is released, allowing the conductive spring and the conductive contact piece to still maintain close contact, thereby improving the life and reliability of the powertrain 100.

[0083] like Figure 14 As shown, in one embodiment, the conductive contact piece further includes a central protrusion 46 disposed at the center of the conductive contact piece, the central protrusion 46 facing the conductive spring and contacting one end of the conductive spring. The central protrusion 46 allows for compression of the conductive spring, ensuring that even after the conductive contact piece wears down, the conductive spring releases its compression while maintaining close contact, thus improving the lifespan and reliability of the conductive structure 40. Furthermore, the high-speed rotation of the motor shaft 211 results in a rotational linear velocity at the central protrusion 46 that is significantly lower than the linear velocity at the outer edge of the conductive contact piece, thereby greatly reducing wear during the contact process between the conductive spring and the conductive contact piece, further improving the lifespan of the conductive structure 40.

[0084] like Figure 14As shown, in one embodiment, the central protrusion 46 of the conductive contact sheet is a spherical protrusion. In one embodiment, the spherical protrusion 46 is formed by stamping on the body of the conductive contact sheet. In one embodiment, the spherical protrusion 46 is a metal ball embedded in the center of the conductive contact sheet.

[0085] In one embodiment, the diameter of the end of the conductive spring that contacts the conductive contact piece is smaller than the diameter of the end of the conductive spring that is farther from the conductive contact piece. This arrangement allows for better contact between the conductive spring and the conductive contact piece.

[0086] In one embodiment, the outer diameter of the conductive contact piece is smaller than the inner diameter of the first shaft hole 212 and larger than the outer diameter of the axial protrusion 121. The smaller outer diameter of the conductive contact piece allows for easy installation into the first shaft hole 212, but the outer peripheral surface of the conductive contact piece needs to maintain contact with the inner peripheral surface of the first shaft hole 212. Therefore, the difference between the outer diameter of the conductive contact piece and the inner diameter of the first shaft hole 212 should not be too large. For example, the difference between the outer diameter of the conductive contact piece and the inner diameter of the first shaft hole 212 is 0.1~1mm. During operation of the powertrain 100, the outer peripheral surface of the conductive contact piece and the inner peripheral surface of the first shaft hole 212 are in close contact, while the outer peripheral surface of the axial protrusion 121 and the inner peripheral surface of the first shaft hole 212 do not need to be in close contact. Therefore, the outer diameter of the conductive contact piece is larger than the outer diameter of the axial protrusion 121.

[0087] Finally, it should be noted that the above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A powertrain designed to prevent bearing electro-corrosion, characterized in that, The powertrain includes a housing, a reducer, a motor, and a conductive structure. The housing houses the motor, which includes a motor shaft for driving the wheels of an electric vehicle via the reducer. The housing includes an axial housing arranged along the axial direction of the motor shaft on one side. The end face of the axial housing facing the motor shaft includes an axial protrusion, one end of which extends axially into a shaft hole of the motor shaft. Wherein: The end face of one of the axially protruding ends includes a through hole, which is used to connect the internal flow channel of the axial housing and the shaft hole; At least one of the through hole and the shaft hole is used to accommodate the conductive structure, which is used to conduct electrical connection between the axial protrusion and the motor shaft.

2. The powertrain according to claim 1, characterized in that, The conductive structure is used to connect the through hole and the shaft hole.

3. The powertrain according to claim 1, characterized in that, Along the axial direction of the motor shaft, the shaft hole includes two shaft holes, one of which has an inner diameter larger than the other. One end of the axial protrusion extends into the first shaft hole, which is used to accommodate the conductive structure.

4. The powertrain according to claim 3, characterized in that, The two shaft holes are used to form a first stepped surface, and the conductive structure abuts against the first stepped surface.

5. The powertrain according to any one of claims 1-4, characterized in that, The through hole along the axial direction of the motor shaft includes two through holes, one of which has an inner diameter larger than the other through hole of the shaft, and the through hole is used to accommodate the conductive structure.

6. The powertrain according to claim 5, characterized in that, The two through holes are used to form a second stepped surface, and the conductive structure abuts against the second stepped surface.

7. The powertrain according to any one of claims 1-4, characterized in that, The conductive structure includes a first structural member accommodated in the one shaft hole and a second structural member accommodated in the one through hole; wherein: The first structural component is electrically connected to the shaft hole, and the second structural component is electrically connected to the through hole; The first structural component and the second structural component are electrically connected.

8. The powertrain according to any one of claims 1-4, characterized in that, The conductive structure includes a conductive contact piece housed in one of the shaft holes, the conductive contact piece being used to contact the inner circumferential surface of the shaft hole.

9. The powertrain according to claim 8, characterized in that, The conductive contact piece is disc-shaped, and its outer peripheral surface contacts the inner peripheral surface of the shaft hole or the inner peripheral surface of the through hole. The conductive contact piece is provided with oil guide holes on its surface.

10. The powertrain according to any one of claims 1-4, characterized in that, The conductive structure includes a conductive spring housed in one of the through holes, the conductive spring being used to contact the inner circumferential surface of the one of the through holes, and the conductive spring including a spring through hole.

11. The powertrain according to claim 7, characterized in that, The conductive structure includes a conductive contact piece housed in one shaft hole and a conductive spring housed in one through hole; in; The conductive contact piece is disc-shaped, and the outer peripheral surface of the conductive contact piece is in contact with the inner peripheral surface of the shaft hole. The outer peripheral surface of the conductive spring contacts the inner peripheral surface of one of the through holes. The conductive contact piece and the conductive spring are electrically connected.

12. The powertrain according to claim 11, characterized in that, The conductive contact piece includes a central protrusion, which is located at the center of the conductive contact piece and faces the conductive spring. The central protrusion is used to contact one end of the conductive spring.

13. The powertrain according to any one of claims 1-4, characterized in that, The housing includes a circumferential housing and two axial housings, which together form a receiving cavity. The motor and the reducer are housed in the receiving cavity along the axial direction of the motor shaft. The two axial housings include a reducer end cover and a motor end cover. The reducer end cover is disposed along the axial direction of the motor shaft on the side of the circumferential housing near the reducer, and the motor end cover is disposed along the axial direction of the motor shaft on the side of the circumferential housing near the motor.

14. The powertrain according to any one of claims 1-4, characterized in that, The internal flow channel of the axial housing is used to deliver cooling oil from the heat exchanger to the through hole and the shaft hole.

15. An electric vehicle, characterized in that, The electric vehicle includes wheels and a powertrain as described in any one of claims 1-14, the powertrain being used to drive the wheels of the electric vehicle.

Images