Double-motor power assembly capable of preventing bearing electrocorrosion and electric vehicle

Abstract

The invention provides a dual-motor power assembly capable of preventing electric corrosion of bearings and an electric vehicle. The power assembly comprises two driving motors which are arranged adjacently. A shell of the power assembly comprises a middle partition plate, and each of two opposite end faces of the middle partition plate comprises a bearing groove and an oil guide structure. And each bearing groove is used for fixing a motor shaft of a driving motor through a motor bearing. The two ends of each oil guide structure are used for being fixedly connected with the groove bottom of one bearing groove and extending into a shaft hole of one motor shaft in the axial direction of the power assembly to convey cooling liquid or lubricating oil correspondingly. And a gap is formed 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 used for accommodating one annular conductive structure. And each conductive structure is used for electrically connecting one motor shaft and one oil guide structure. According to the power assembly, the shaft current is conducted to the shell to be grounded through the structure that the middle partition plate supplies oil to the shaft holes of the motor shafts on the two sides so that the motor bearings can be protected.

Description

Technical Field

[0001] The present application relates to the technical field of electric vehicles, and in particular to a dual-motor powertrain and an electric vehicle that are resistant to electrical corrosion of bearings. Background Art

[0002] When the drive motor in the dual-motor powertrain is running, the shaft voltage of the motor shaft will break through the oil film of the motor bearing and cause electrical corrosion of the bearing, which will cause local melting and unevenness of the contact surface of the motor bearing. Electrical corrosion of the bearing not only reduces the performance of the bearing, but also causes premature failure of the motor shaft bearing, thereby reducing the overall life of the powertrain. Summary of the invention

[0003] The present application provides a dual-motor powertrain and an electric vehicle that prevent electrical corrosion of bearings, utilizing a structure in which a center partition of the powertrain supplies oil toward an axial hole of a motor shaft, so as to conduct the shaft current of the motor shaft to the housing for grounding to protect the motor bearings.

[0004] In a first aspect, the present application provides a dual-motor powertrain that prevents electrical corrosion of bearings. The powertrain includes two drive motors, which are arranged adjacent to each other along the axial direction of the powertrain. The housing of the powertrain includes a middle partition, which includes two end faces opposite to each other along the axial direction of the powertrain, and each end face includes a bearing groove and an oil guide structure. Each bearing groove is used to fix a motor shaft of a drive motor through a motor bearing, one end of each oil guide structure is used to fix the bottom of the bearing groove, and the other end of each oil guide structure is used to extend into the axial direction of the powertrain and transport coolant or lubricating oil to the shaft hole of the motor shaft. There is a gap between the outer circumference of each oil guide structure and the inner circumference of the shaft hole of the motor shaft, and the gap is used to accommodate an annular conductive structure, and each conductive structure is used to electrically connect the motor shaft and an oil guide structure.

[0005] The dual-motor powertrain for preventing electrical corrosion of bearings provided in the present application forms two bearing grooves through a middle partition, and the openings of the two bearing grooves are opposite to each other along the axial direction of the powertrain. The groove wall of each bearing groove is used to fix the motor bearing, and is connected to a motor shaft of a drive motor through the motor bearing transmission. The groove bottom of each bearing groove is used to fix an oil guide structure, and the extension directions of the two oil guide structures are opposite to each other along the axial direction of the powertrain. Each oil guide structure is used to extend into the shaft hole of the motor shaft and transport lubricating oil or coolant toward the shaft hole.

[0006] The powertrain provided in the present application also uses the gap between an oil-conducting structure and the shaft hole of the motor shaft to fix a conductive structure. A conductive structure is used to conduct the electrical connection between the outer circumference of an oil-conducting structure and the inner circumference of the shaft hole, so as to conduct the shaft end current of the motor shaft to the middle partition to achieve grounding, and prevent the shaft end current of the motor shaft from flowing through the motor bearing and causing the motor bearing to fail. The powertrain provided in the present application reasonably utilizes the internal space of the shaft holes of the two motor shafts to respectively realize the electrical connection between the two motor shafts and the housing. It effectively protects the motor bearings and extends the service life of the powertrain.

[0007] In one implementation, the middle partition includes an internal oil passage, and the internal oil passage is used to transport coolant or lubricating oil to the oil guide structures on the two end surfaces.

[0008] In this implementation, a driving motor is arranged on both sides of the middle partition along the axial direction of the powertrain. The internal oil channel in the middle partition is used to extend in the radial direction of the powertrain to reduce the axial dimension of the powertrain. The middle partition is connected to two oil guide structures through the internal oil channel to simplify the internal structure of the middle partition.

[0009] In one implementation, each gap includes two gaps of different radial sizes, and one gap is arranged in sequence with the other gap along the direction in which each oil guiding structure extends into the shaft hole. The radial size of one gap is larger than the radial size of the other gap, and the radial size of the other gap is smaller than the radial size of the conductive structure.

[0010] In this implementation, in the opening area close to each shaft hole, the radial dimension of a gap between each oil guide structure and the shaft hole is large, providing sufficient installation space for the two conductive structures. In the inner area deep into the shaft hole, the radial dimension of another gap between each oil guide structure and the shaft hole is small, so as to reduce the amount of coolant or lubricant oil leaking toward the opening of the shaft hole after being fed into the shaft hole, thereby delivering more coolant or lubricant oil toward the drive motor and reducer.

[0011] In one implementation, each oil guide structure includes an axial protrusion, one end of each axial protrusion is used to fix the bottom of the bearing groove, the other end of each axial protrusion is used to extend into the axial hole of the motor shaft along the axial direction of the power assembly, and the end face of the other end of each axial protrusion includes a through hole, which is used to transport coolant or lubricating oil to the axial hole of the motor shaft.

[0012] In this implementation, each oil guide structure is used to extend through the axial protrusion along the axial direction of the power assembly toward the shaft hole of the motor shaft, and the other end of each axial protrusion extending into the shaft hole is used to transport coolant or lubricating oil toward the shaft hole through the through hole. Each through hole is used to communicate with the internal oil channel of the middle partition.

[0013] In one implementation, the axes of the two axially protruding through holes coincide with each other.

[0014] In this implementation, the internal oil passage of the middle partition extends in the radial direction of the powertrain, and the positions of the two through holes on the middle partition are symmetrical to each other. The amount of coolant or lubricating oil flowing from the internal oil passage into the two through holes is relatively uniform, which can ensure that the cooling effect or lubrication effect of the two drive motors on both sides of the middle partition is similar.

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

[0016] In this implementation, the outer diameter of the first section of each axial protrusion is larger to stably support the conductive structure, and the outer diameter of the second section is smaller to facilitate insertion into the shaft hole, which helps to reduce the inner diameter size deep into the shaft hole and thus improve the structural stability of the motor shaft.

[0017] In one implementation, the outer peripheral surface of each first-stage protrusion along the axial direction of the powertrain includes one or more limiting structures, wherein along the radial direction of the powertrain, the radial dimension of each limiting structure in each first-stage protrusion is different from the outer diameter of the rest of each first-stage protrusion.

[0018] In this implementation, one or more limiting structures are used to increase the contact area between the first section protrusion and the conductive structure, thereby enhancing the conductive effect between the axial protrusion and the conductive structure.

[0019] In one implementation, one or more limiting structures in each first-section 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 circumference of the shaft hole.

[0020] In this implementation, one or more limiting structures are used to form a positioning groove in the first section of the 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 with the inner circumference of the conductive structure to enhance the conductive effect.

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

[0022] In this implementation, the inner diameter of the first section shaft hole is larger, and is used to accommodate and fix the conductive structure. The inner diameter of the third section shaft hole is smaller, and is used to receive the coolant or lubricating oil delivered by the axial protrusion and reduce the leakage of the coolant or lubricating oil toward the conductive structure. The second section shaft hole is used to connect the first section shaft hole and the third section shaft hole, and the end surface of the second section shaft hole facing the first section shaft hole is also used to limit the axial displacement of the conductive structure.

[0023] In one implementation, a step surface is formed between the second section shaft hole and the third section shaft hole, and the step surface faces the conductive structure along the axial direction of the powertrain, and the distance between the step surface and the conductive structure is smaller than the distance between the bottom of the bearing groove and the conductive structure.

[0024] In this implementation, the smaller the distance between the axial step surface and the conductive structure along the powertrain, the longer the length of the axial protrusion extending into the third-section shaft hole. Because the radial dimension of the gap between the third-section shaft hole and the axial protrusion is small, the distance for the coolant or lubricant to flow back from the third-section shaft hole to the first-section shaft hole is longer, which can reduce the contact between the conductive structure and the coolant or lubricant.

[0025] In one implementation, the inner circumference of each first section shaft hole 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 first section shaft hole is larger than the inner diameter of the rest of each first section shaft hole.

[0026] In this implementation, one or more annular grooves are used to increase the contact area between the first section shaft hole and the conductive structure, thereby enhancing the conductive effect between the first section shaft hole and the conductive structure.

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

[0028] In this implementation, the groove bottom of the annular groove is used to fix the conductive structure to limit the axial displacement of the conductive structure along the power assembly. The groove bottom of the annular groove is used to fit with the outer peripheral surface of the conductive structure to enhance the conductive effect.

[0029] In one implementation, the outer peripheral surface of the motor shaft along the axial direction of the power assembly includes a first section of the outer peripheral surface and a second section of the outer peripheral surface connected to each other, wherein along the radial direction of the power assembly, the outer diameter of the first section of the outer peripheral surface is smaller than the outer diameter of the second section of the outer peripheral surface and greater than or equal to the inner diameter of the motor bearing.

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

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

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

[0033] In one implementation, each conductive structure includes two opposite end faces along the axial direction of the powertrain, one of which is arranged 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 smaller than the distance between the other end of the axial protrusion and the other end face.

[0034] 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 that delivers lubricating oil or coolant. This can reduce the contact between the conductive structure and the coolant or lubricating oil, and prevent the conductive structure from failing prematurely due to excessive immersion in the coolant or lubricating oil.

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

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

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

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

[0039] 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 ring or the outer ring of the conductive bearing.

[0040] In this implementation, the width of the conductive rubber ring along the axial direction of the powertrain is smaller, so that the conductive effect can be enhanced by cooperating with the conductive bearing through multiple conductive rubber rings.

[0041] In one implementation, each conductive structure includes two conductive rubber rings, wherein the two conductive rubber rings are arranged at intervals along the axial direction of the conductive structure, and the sum of the interval 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.

[0042] In this implementation, two conductive rubber rings spaced apart along the axial direction of the powertrain can more evenly distribute the impact force of the radial movement of the motor shaft to the conductive bearing, thereby improving the internal stress conditions of the conductive structure to extend the service life of the conductive structure.

[0043] In one implementation, the elastic modulus of one conductive rubber ring in each oil-conducting structure is smaller than the elastic modulus of another conductive rubber ring.

[0044] In this implementation, by setting the elastic modulus of the materials of the two conductive rubber rings differently, the elastic forces of the two conductive rubber rings along the radial direction of the powertrain can be different. After the powertrain provided by the present application works for a long time, the wear amount of the two conductive rubber rings is different, and the conductive rubber ring with less wear amount can compensate the wear amount of the other conductive rubber ring through elastic deformation.

[0045] In one implementation, along the direction in which each oil guide structure extends into the shaft hole, a conductive rubber ring and another conductive rubber ring are sequentially arranged at intervals.

[0046] In this implementation, the other conductive rubber ring with a smaller axial elastic modulus along the powertrain is closer to the other section of the shaft hole. The radial movement of the motor shaft causes a greater compression of the other conductive rubber ring, thereby forming a certain sealing effect on the one conductive rubber ring, reducing the contact of the one conductive rubber ring with the coolant or lubricating oil, so as to protect the one conductive rubber ring.

[0047] In one implementation, the conductive structure includes an axial sleeve, wherein the conductive structure is fixed to the outer peripheral surface of the axial protrusion through the axial sleeve, and the outer peripheral surface of the conductive structure is used for coating a wear-resistant conductive coating.

[0048] In this implementation, the axial sleeve is used to extend 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 circumference of the axial protrusion. During the operation of the drive motor, the motor shaft rotates in the housing, and the inner circumference of the shaft hole of the motor shaft continuously rotates and rubs the outer circumference of the conductive structure. The wear-resistant conductive coating coated on the outer circumference of the conductive structure is used to reduce the wear of the outer circumference of the conductive structure and to conduct electrical connection between the outer circumference of the conductive structure and the inner circumference of the shaft hole of the motor shaft.

[0049] In one implementation, the conductive structure is fixed to the inner circumference of the shaft hole through an axial sleeve, and the inner circumference of the conductive structure is used for coating a wear-resistant conductive coating.

[0050] In this implementation, the axial sleeve is used to extend 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 circumference of the shaft hole of the motor shaft. During the operation of the drive motor, the conductive structure is used to rotate with the motor shaft in the housing, and the inner circumference of the conductive structure continuously rotates and rubs against the outer circumference of the axial protrusion. The wear-resistant conductive coating coated on the inner circumference of the conductive structure is used to reduce the wear of the inner circumference of the conductive structure and to conduct electrical connection between the inner circumference of the conductive structure and the outer circumference of the axial protrusion.

[0051] In one implementation, along the axial direction of the power assembly, the axial sleeve extends in a direction away from the groove bottom of the bearing groove.

[0052] In this implementation, along the axial direction of the powertrain, the axial sleeve is relatively close to the third section of the shaft hole of the motor shaft. The conductive structure is electrically connected to the inner circumference of the first section of the shaft hole and the outer circumference of the axial protrusion on the side of the groove bottom close to the bearing groove. The conductive structure is relatively far away from the third section of the shaft hole relative to the part used for conduction and electrical connection, reducing the contact between the conductive structure and the coolant or lubricating oil to extend the service life of the conductive structure.

[0053] In one implementation, the conductive structure includes a radial protrusion. The conductive structure electrically connects the outer circumference of the axial protrusion and the inner circumference of the shaft hole through the radial protrusion. The radial protrusion is used to be fixed to one end of the axial sleeve near the bottom of the bearing groove along the axial direction of the powertrain.

[0054] In a second aspect, the present application provides an electric vehicle, which includes wheels and a powertrain provided by any implementation of the first aspect, wherein the powertrain is used to drive the wheels of the electric vehicle.

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

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

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

[0058] Figure 3 A cross-sectional schematic diagram of a drive motor provided in an embodiment of the present application;

[0059] Figure 4 A cross-sectional schematic diagram of a powertrain provided in an embodiment of the present application;

[0060] Figure 5 A partially enlarged schematic diagram of a powertrain provided in an embodiment of the present application;

[0061] Figure 6 Another partially enlarged schematic diagram of the powertrain provided in the embodiment of the present application;

[0062] Figure 7 Another exploded schematic diagram of the powertrain provided in an embodiment of the present application;

[0063] Figure 8 Another exploded schematic diagram of the powertrain provided in an embodiment of the present application;

[0064] Fig. 9 Another cross-sectional schematic diagram of the powertrain provided in the embodiment of the present application;

[0065] Fig.10 Another cross-sectional schematic diagram of the powertrain provided in the embodiment of the present application;

[0066] Fig.11 Another exploded schematic diagram of the powertrain provided in an embodiment of the present application;

[0067] Fig.12 Another cross-sectional schematic diagram of the powertrain provided in the embodiment of the present application;

[0068] Fig.13 Another cross-sectional schematic diagram of the powertrain provided in the embodiment of the present application;

[0069] Fig.14 Another exploded schematic diagram of the powertrain provided in an embodiment of the present application;

[0070] Fig.15 Another cross-sectional schematic diagram of the powertrain provided in the embodiment of the present application;

[0071] Fig.16 Another cross-sectional schematic diagram of the powertrain provided in the embodiment of the present application;

[0072] Fig.17 Another cross-sectional schematic diagram of the powertrain provided in the embodiment of the present application;

[0073] Fig.18 Another schematic diagram of a powertrain provided in an embodiment of the present application;

[0074] Fig.19 Another cross-sectional schematic diagram of the powertrain provided in an embodiment of the present application. DETAILED DESCRIPTION

[0075] The following will describe the technical solutions in the embodiments of the present application in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0076] The present application provides a dual-motor powertrain that prevents electrical corrosion of bearings. The powertrain includes two drive motors, which are arranged adjacent to each other along the axial direction of the powertrain. The housing of the powertrain includes a middle partition, and a middle partition includes two end faces opposite to each other along the axial direction of the powertrain, and each end face includes a bearing groove and an oil guide structure. Each bearing groove is used to fix the motor shaft of a drive motor through a motor bearing, one end of each oil guide structure is used to fix the bottom of a bearing groove, and the other end of each oil guide structure is used to extend into the axial direction of the powertrain and transport coolant or lubricating oil to the shaft hole of a motor shaft. There is a gap between the outer circumference of each oil guide structure and the inner circumference of the shaft hole of a motor shaft, and the gap is used to accommodate an annular conductive structure, and each conductive structure is used to electrically connect a motor shaft and an oil guide structure.

[0077] The present application provides an electric vehicle. The electric vehicle includes wheels and a powertrain provided in the present application, and the powertrain is used to drive the wheels of the electric vehicle. The electric vehicle provided in the embodiment of the present application adopts the powertrain provided in the embodiment of the present application, and the electric vehicle has a more compact structure and a longer service life.

[0078] Figure 1 FIG. 2 is a schematic diagram of an electric vehicle 200 provided in an embodiment of the present application. Figure 1 As shown, the electric vehicle 200 includes a battery 101, wheels 102, and a powertrain 100. The battery 101 is used to supply power to the powertrain 100. The powertrain 100 is used to drive the wheels 102 to rotate to provide power for the electric vehicle 200.

[0079] Figure 2 A transmission schematic diagram of the electric vehicle 200 provided in an embodiment of the present application. Figure 3 A cross-sectional schematic diagram of a powertrain 100 provided in an embodiment of the present application.

[0080] The dual-motor powertrain 100 for preventing electrical corrosion of bearings provided in the present 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 middle partition 12 .

[0081] In one embodiment, the housing 10 includes a first axial housing, a circumferential housing, and a second axial housing arranged in sequence along the axial direction of the power assembly 100. The circumferential housing includes a middle partition 12 and two inner cavities, the two inner cavities are arranged on both sides of the middle partition 12 along the circumference of the power assembly 100, and the two inner cavities penetrate the circumferential housing in a direction away from the middle partition 12. The first axial housing and the second axial housing are respectively used to be fixed on both sides of the circumferential housing along the axial direction of the power assembly 100 to enclose and form two accommodating cavities. The two accommodating cavities are used to accommodate two drive motors 20 respectively.

[0082] In one embodiment, each drive motor 20 includes a motor shaft 211, a motor rotor 21 and a motor stator 22. Figure 4 A cross-sectional schematic diagram of a driving motor 20 provided in an embodiment of the present application is shown.

[0083] exist Figure 4 In the drive motor 20 shown, the motor stator 22 of the drive motor 20 is used to be fixedly connected to the housing 10 of the powertrain 100, the motor 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 transmission-connected to the motor rotor 21, and the motor stator 22 is also used to be electrically connected to 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.

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

[0085] In one embodiment, each reducer 103 includes a gear set, and the gear set includes a plurality of pairs of gears meshing with each other. Figure 2As shown, the gear sets of the two reducers 103 are respectively located in the two accommodating cavities formed by the shell 10, and the gear sets of the two reducers 103 are respectively located on the opposite sides of the two motor stators 22 along the axial direction of the powertrain 100. One end of each motor shaft 211 facing the reducer 103 is meshed with a transmission gear of the gear set to drive the reducer 103 to drive the wheel 102 to rotate.

[0086] In one embodiment, each accommodating cavity of the power assembly 100 also includes two motor bearings 30, and the two motor bearings 30 are arranged on both sides of the motor stator 22 along the axial direction of the power assembly 100, and the inner rings of the two motor bearings 30 are respectively transmission-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.

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

[0088] In one embodiment, the middle partition 12 of the power assembly 100 of the present application includes two end faces opposite to each other along the axial direction of the power assembly 100, each end face includes a bearing groove 123 and an oil guide structure 120, wherein each bearing groove 123 is used to fix a motor shaft 211 of a drive motor 20 through a motor bearing 30.

[0089] See also Figure 5 A partially enlarged schematic diagram of a powertrain 100 provided in an embodiment of the present application is shown.

[0090] Please combine Figure 4 and Figure 5 Two bearing grooves 123 are respectively formed on the two end surfaces opposite to each other in the axial direction of the power assembly 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 ring and the outer ring of the motor bearing 30 are rotatably connected so that the two motor bearings 30 support the two motor shafts 211 respectively.

[0091] In one embodiment, one end of each oil guiding structure 120 of the power assembly 100 of the present application is used to be fixedly connected to the bottom of the bearing groove 123, and the other end of each oil guiding structure 120 is used to extend into the axial direction of the power assembly 100 and transport coolant or lubricating oil to the shaft hole 212 of the motor shaft 211.

[0092] like Figure 4 As shown, along the axial direction of the power assembly 100, two oil guide structures 120 are arranged on both sides of the middle partition 12, and the two ends of the two oil guide structures 120 facing each other are respectively fixed to the bottom of the two bearing grooves 123, and the two ends of the two oil guide structures 120 facing each other extend into the shaft holes 212 of the two motor shafts 211. Each oil guide structure 120 is provided with a through hole 122, and the two through holes 122 are used to transport coolant or lubricating oil to the two shaft holes 212. The coolant flows into the shaft hole 212 through the through hole 122 and absorbs heat to reduce the temperature of the drive motor 20; the lubricating oil can flow to the other end of the shaft hole 212 through the shaft hole 212, that is, the lubricating oil flows toward 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 of the gear set during the meshing process and improve the service life of the reducer 103.

[0093] Because the end of the motor shaft 211 away from the middle partition 12 is used for transmission connection to the reducer 103, it is not convenient for the power assembly 100 to supply oil from the end of the motor shaft 211 close to the reducer 103 toward the reducer 103 and the drive motor 20 to achieve lubrication and cooling. The power assembly 100 of the present application uses the middle partition 12 to supply oil toward the motor shaft 211 on both sides to meet the working requirements of the drive motors 20 on both sides and the reducers 103 on both sides, saving the internal space of the power assembly 100, which is conducive to miniaturization of the power assembly 100.

[0094] It should be pointed out that, in one embodiment, the above-mentioned coolant and lubricating oil can be the same type of liquid, which is used to cool the drive motor 20 in 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.

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

[0096] like Figure 5As shown, the conductive structure 40 is annular and is sleeved on the outside of the oil-conducting structure 120. The inner circumference of the conductive structure 40 is at least partially in contact with the outer circumference of the oil-conducting structure 120, and the outer circumference of the conductive structure 40 is at least partially in contact with the inner circumference of the shaft hole 212, so as to achieve electrical connection between the oil-conducting structure 120 and the shaft hole 212.

[0097] 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 form local high temperature and corrosion, resulting in a shortened service life of the motor bearing 30. In addition, the shaft end current will also electrochemically react with the lubricating medium inside the motor bearing 30, reducing the lubricating effect of the lubricating medium and accelerating the wear of the motor bearing 30.

[0098] The power assembly 100 of the present application respectively conducts electrical connection between the outer circumference of an oil-conducting structure 120 and the inner circumference of an axial hole 212 through two conductive structures 40, so as to conduct the axial end current of the two motor shafts 211 to the middle partition 12 for grounding, thereby preventing the axial end current of the motor shaft 211 from flowing through the motor bearing 30 and causing failure of the motor bearing 30.

[0099] Compared with the conductive structure of the motor bearing in the prior art, in the power assembly 100 of the present application, the two oil guiding structures 120 along the axial middle partition 12 of the power assembly 100 are respectively located at the two opposite ends of the two motor shafts 211, and the two oil guiding structures 120 extend into the axial holes 212 of the two motor shafts 211. The conductive structure 40 is located inside the axial hole 212, which makes full use of the internal space of the motor shaft 211, reduces the axial dimension of the power assembly 100, and makes the internal structure of the power assembly 100 more compact.

[0100] In addition, along the axial direction of the power assembly 100, the two oil guide structures 120 are respectively located at the ends of the two motor shafts 211 away from the wheel 102, that is, the oil guide structure 120 is away from the transmission connection position between the drive motor 20 and the wheel 102, which improves the reliability of the oil guide structure 120 in conveying coolant or lubricating oil. The conductive structure 40 is located between the oil guide structure 120 and the shaft hole 212, and will not affect the conveyance of coolant or lubricating oil between the oil guide structure 120 and the shaft hole 212, ensuring the cooling and lubrication requirements of the internal components of the power assembly 100 of the present application.

[0101] Accordingly, the electric vehicle provided in the embodiment of the present application also adopts the above-mentioned power assembly 100, so that the electric vehicle has a more compact structure and a longer service life.

[0102] In one embodiment, the middle partition plate 12 includes an internal oil passage 124, and the internal oil passage 124 is used to transport coolant or lubricating oil to the oil guide structures 120 at the two end surfaces. Figure 5As shown, the internal oil passage 124 extends in the radial direction of the power assembly 100. The internal oil passage 124 is respectively connected to the shaft holes 212 of the two motor shafts 211 through the two oil guide structures 120. The end of the internal oil passage 124 away from the oil guide structure 120 is connected to the external oil pipeline or the oil pump, so that the coolant or lubricating oil passes through the internal oil passage 124 and the two oil guide structures 120 in sequence and flows to the shaft holes 212 of the two motor shafts 211.

[0103] exist Figure 5 In the power assembly 100 shown, a driving motor 20 is arranged on both sides of the middle partition 12 along the axial direction of the power assembly 100. The internal oil passage 124 in the middle partition 12 is used to extend along the radial direction of the power assembly 100 to reduce the axial dimension of the power assembly 100. The middle partition 12 is connected to the two oil guide structures 120 through the internal oil passage 124, thereby simplifying the internal structure of the power assembly 100.

[0104] In one embodiment, each oil guiding structure 120 includes an axial protrusion 121, one end of each axial protrusion 121 is used to be fixedly connected to the bottom of the bearing groove 123, and the other end of each axial protrusion 121 is used to extend into the axial hole 212 of a motor shaft 211 along the axial direction of the power assembly 100, and the end face of the other end of each axial protrusion 121 includes a through hole 122, and the through hole 122 is used to transport coolant or lubricating oil to the axial hole 212 of the motor shaft 211.

[0105] exist Figure 5 In the power assembly 100 shown, each oil guide structure 120 is used to extend through an axial protrusion 121 along the axial direction of the power assembly 100 toward the shaft hole 212 of a motor shaft 211, and the other end of each axial protrusion 121 extending into the shaft hole 212 is used to convey coolant or lubricating oil toward the shaft hole 212 through a through hole 122. Each through hole 122 is used to communicate with the internal oil passage 124 of the middle partition 12. The through hole 122 of each axial protrusion 121 is connected between the internal oil passage 124 and the shaft hole 212, so that the coolant or lubricating oil flows into the shaft hole 212 of the motor shaft 211 through the internal oil passage 124 and a through hole 122 in sequence.

[0106] In one embodiment, the axes of the through holes 122 of the two axial protrusions 121 coincide with each other. Figure 5 In the power assembly 100 shown, the positions of the two through holes 122 on the middle partition 12 are symmetrical to each other. The amount of coolant or lubricating oil flowing from the internal oil passage 124 into the two through holes 122 is relatively uniform, which can ensure that the cooling effect or lubrication effect of the two drive motors 20 on both sides of the middle partition 12 is similar.

[0107] In one embodiment, each gap 50 includes two gaps of different radial sizes, and one gap of the two gaps is arranged in sequence with the other gap along the direction in which each oil guiding structure 120 extends into the axial hole 212, the radial size of one gap is larger than the radial size of the other gap, and the radial size of the other gap is smaller than the radial size of the conductive structure 40.

[0108] See also Figure 6 Another partially enlarged schematic diagram of the powertrain 100 provided in an embodiment of the present application is shown.

[0109] like Figure 6 As shown, the gap 50 along the direction in which each oil guide structure 120 extends into the shaft hole 212 includes a first section gap 51 and a second section gap 52 arranged in sequence. The radial dimension of the first section gap 51 is greater than the radial dimension of the second section gap 52, and the radial dimension of the second section gap 52 is smaller than the radial dimension of the conductive structure 40. In the opening area close to the shaft hole 212, the radial dimension of the first section gap 51 between the oil guide structure 120 and the shaft hole 212 is larger, providing sufficient installation space for the conductive structure 40. In the inner area deep into the shaft hole 212, the radial dimension of the second section gap 52 between the oil guide structure 120 and the shaft hole 212 is smaller, so as to reduce the amount of oil leaking toward the opening of the shaft hole 212 after the coolant or lubricating oil is fed into the shaft hole 212, thereby delivering more coolant or lubricating oil toward the direction of the drive motor 20 and the reducer.

[0110] In one embodiment, each axial protrusion 121 includes a first section protrusion 1211 and a second section protrusion 1212. The first section protrusion 1211 and the second section protrusion 1212 are arranged in sequence along the direction in which each oil guiding structure 120 extends into the axial hole 212. The outer diameter of the first section protrusion 1211 is greater than the outer diameter of the second section protrusion 1212. The first section protrusion 1211 is used to sleeve the conductive structure 40.

[0111] See also Figure 7 Another exploded schematic diagram of the powertrain 100 provided in an embodiment of the present application is shown.

[0112] like Figure 7 As shown, the conductive structure 40 is sleeved on the outer side of the first section protrusion 1211 of the axial protrusion 121, and the first section protrusion 1211 of each axial protrusion 121 has a larger outer diameter to stably support a conductive structure 40. The second section protrusion has a smaller outer diameter to facilitate insertion into the shaft hole 212, which is beneficial to reduce the inner diameter of the shaft hole 212, thereby improving the structural stability of the motor shaft 211.

[0113] In one embodiment, the outer peripheral surface of each first-section protrusion 1211 along the axial direction of the power assembly 100 includes one or more limiting structures 1213. In the radial direction of the power assembly 100, the radial size of each limiting structure 1213 in each first-section protrusion 1211 is different from the outer diameter of the remaining part of each first-section protrusion 1211.

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

[0115] In one embodiment, the limiting structure 1213 is a plurality of protrusions arranged at intervals along the axial direction of the power assembly 100, and the radial dimension of the radial protrusion along the power assembly 100 is larger than the outer diameter of the remaining portion of the first section protrusion 1211. The conductive structure 40 is located between two adjacent protrusions, which can also increase the contact area between the first section protrusion 1211 and the conductive structure 40, and enhance the conductive effect of the axial protrusion 121 and the conductive structure 40.

[0116] In one embodiment, one or more limiting structures in each first-stage 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 circumference of the shaft hole 212. Figure 7 As shown, the limiting structure 1213 is a groove, and the bottom of the groove is used to fix the conductive structure 40 to limit the axial displacement of the conductive structure 40 along the power assembly 100. The bottom of the groove is used to fit with the inner circumference of the conductive structure 40 to enhance the conductive effect.

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

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

[0119] See also Figure 8 and Fig. 9 ,in Figure 8 Another exploded schematic diagram of the powertrain 100 provided in an embodiment of the present application; Fig. 9 Another cross-sectional schematic diagram of the powertrain 100 provided in an embodiment of the present application.

[0120] like Figure 8 and Fig. 9 As shown, the first section shaft hole section 2121 has a larger inner diameter and is used to accommodate and fix a conductive structure 40. The third section shaft hole 2123 has a smaller inner diameter and is used to receive the coolant or lubricating oil delivered by the axial protrusion 121 and reduce the leakage of the coolant or lubricating oil toward the conductive structure 40. The second section shaft hole 2122 is used to connect the first section shaft hole 2121 and the third section shaft hole 2123, and the end surface of the second section shaft hole 2122 facing the first section shaft hole 2121 is also used to limit the axial displacement of the conductive structure 40.

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

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

[0123] In one embodiment, the inner circumference of each first section shaft hole 2121 includes one or more annular grooves 215. In the radial direction of the power assembly 100, the inner diameter of the one or more annular grooves 215 in each first section shaft hole 2121 is greater than the inner diameter of the rest of each first section shaft hole 2121.

[0124] like Figure 8 and Fig. 9 As shown, the annular groove 215 is used to accommodate part of the conductive structure 40 to increase the contact area between the first section shaft hole 2121 and the conductive structure 40 and enhance the conductive effect between the first section shaft hole 2121 and the conductive structure 40 .

[0125] In one embodiment, each annular groove 215 is used to accommodate a portion of the outer ring of the conductive structure 40. Figure 8 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 power assembly 100. The bottom of the annular groove 215 is used to fit with the outer peripheral surface of the conductive structure 40 to enhance the conductive effect.

[0126] In one embodiment, the outer peripheral surface of the motor shaft 211 along the axial direction of the power assembly 100 includes a first section of the outer peripheral surface 2111 and a second section of the outer peripheral surface 2112. In the radial direction of the power assembly 100, the outer diameter of the first section of the outer peripheral surface 2111 is smaller than the outer diameter of the second section of the outer peripheral surface 2112, and is greater than or equal to the inner diameter of the motor bearing 30.

[0127] like Fig. 9 As shown, the first section outer circumferential surface 2111 of the motor shaft 211 is used to be embedded in the inner hole of the motor bearing 30. The motor shaft 211 forms another step surface through the first section outer circumferential surface 2111 and the second section outer circumferential surface 2112, namely the second step surface 214 shown in the figure. The second step surface 214 faces the bottom of the bearing groove 123 along the axial direction of the power assembly 100. The second step surface 214 is used to abut the side of the motor bearing 30 to limit the axial displacement of the motor bearing 30 relative to the motor shaft 211.

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

[0129] like Fig. 9As shown, the second step surface 214 coincides with the third section shaft hole 2123 along the axial direction of the power assembly 100. That is, the second step surface 214 is located on the third section shaft hole 2123 along the axial direction of the power assembly 100. The first section shaft hole 2121 and the second section shaft hole 2122 are larger in the radial direction of the power assembly 100, and the second step surface 214 has a 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.

[0130] In one embodiment, the axial conductive structure 40 along the powertrain 100 includes two opposite end faces, one of which is arranged 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.

[0131] See also Fig.10 Another cross-sectional schematic diagram of the powertrain 100 provided in an embodiment of the present application is shown.

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

[0133] Please combine Figure 5 and Fig.10 As shown, along the axial direction of the power assembly 100, the distance between one end of the axial protrusion 121 facing the bottom of the bearing groove 123 and the first end face 401 is smaller than the distance between one 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 power assembly 100 and farther from the oil nozzle for conveying lubricating oil or coolant from the axial protrusion 121, which can reduce the contact between the conductive structure 40 and the coolant or lubricating oil, and avoid premature failure of the conductive structure 40 due to excessive immersion in the coolant or lubricating oil.

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

[0135] Fig.11 Another exploded schematic diagram of the powertrain 100 provided in an embodiment of the present application. Fig.12Another cross-sectional schematic diagram of the powertrain 100 provided in an embodiment of the present application.

[0136] In one embodiment, if Fig.11 and Fig.12 As shown, the conductive structure 40 includes a conductive bearing 42 and a conductive rubber ring 41, and the conductive bearing 42 is sleeved on the outer periphery of the conductive rubber ring 41. Figure 5 The inner circumference of the conductive rubber ring 41 at least partially fits with the outer circumference of the axial protrusion 121, and the outer circumference of the conductive bearing 42 at least partially fits with the inner circumference of the first section shaft hole 2121 to achieve electrical connection between the oil guide structure 120 and the motor shaft 211.

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

[0138] See also Fig.13 Another cross-sectional schematic diagram of the powertrain 100 provided in an embodiment of the present application is shown.

[0139] like Fig.13 As shown, the inner circumference of the conductive bearing 42 is at least partially in contact with the outer circumference of the axial protrusion 121, and the outer circumference of the conductive rubber ring 41 is at least partially in contact with the inner circumference of the first section shaft hole 2121, which can also achieve electrical connection between the oil guide structure 120 and the motor shaft 211. The oil guide structure 120 is a fixed structure on the middle partition plate 12, and the conductive bearing 42 is sleeved on the outer circumference of the oil guide structure 120, which facilitates the assembly of the conductive bearing 42.

[0140] It is understandable that the stiffness of the conductive bearing 42 is different from that of the conductive rubber ring 41. The conductive bearing 42 has a higher stiffness, and the conductive bearing 42 can improve the overall structural stability of the conductive structure 40. The conductive rubber ring 41 has a lower stiffness, and the conductive rubber ring 41 is used to offset the wear of the conductive structure 40 through elastic deformation to ensure reliable electrical connection.

[0141] In one embodiment, the size of the conductive rubber ring 41 along the axial direction of the power assembly 100 is smaller than the size of the inner ring or outer ring of the conductive bearing 42. Fig.12 and Fig.13 The width of the conductive rubber ring 41 along the axial direction of the power assembly 100 is smaller, so that the conductive effect of the conductive structure 40 can be enhanced by cooperating with the conductive bearing 42 through the multiple conductive rubber rings 41 .

[0142] In one embodiment, the conductive bearing 42 is sleeved on the outer side of the conductive rubber ring 41. The gap between the portion of the inner circumference of the conductive bearing 42 that exceeds the conductive rubber ring 41 and the outer circumference of the first section protrusion 1211 of the axial protrusion 121 is smaller than the gap between the inner circumference of the shaft hole 212 and the outer circumference of the axial protrusion 121.

[0143] like Fig.12 As shown, the inner ring of the conductive structure 40 is a conductive rubber ring 41, and the outer ring is a conductive bearing 42. The size of the conductive bearing 42 along the axial direction of the power assembly 100 is larger than the size of the conductive rubber ring 41. That is, the inner circumference of the conductive bearing 42 is partially exposed to the outside of the conductive rubber ring 41. The gap size between the exposed inner circumference of the conductive bearing 42 along the radial direction of the power assembly 100 and the outer circumference of the first section protrusion 1211 of the axial protrusion 121 is the second size L2. The gap size between the inner circumference of the third section shaft hole 2123 of the radial shaft hole 212 of the power assembly 100 and the outer circumference of the first section protrusion 1211 of the axial protrusion 121 is the first size L1.

[0144] The second dimension L2 is smaller than the first dimension L1. The radial movement of the motor shaft 211 along the power assembly 100 drives the exposed inner circumference of the conductive bearing 42 to abut against the outer circumference of the first section protrusion 1211 of the axial protrusion 121, so as to limit the radial displacement of the motor shaft 211 relative to the axial protrusion 121 and prevent the third section shaft hole 2123 from contacting the axial protrusion 121.

[0145] In one embodiment, the conductive rubber ring 41 is sleeved on the outer side of the conductive bearing 42. The gap between the portion of the outer circumference of the conductive bearing 42 that exceeds the conductive rubber ring 41 and the inner circumference of the first section shaft hole 2121 is smaller than the gap between the inner circumference of the shaft hole 212 and the outer circumference of the axial protrusion 121.

[0146] like Fig.13 As shown, the outer ring of the conductive structure 40 is a conductive rubber ring 41, and the inner ring is a conductive bearing 42. The size of the conductive bearing 42 along the axial direction of the power assembly 100 is larger than the size of the conductive rubber ring 41. That is, the outer peripheral surface of the conductive bearing 42 is partially exposed to the outside of the conductive rubber ring 41. The gap size between the exposed outer peripheral surface of the conductive bearing 42 along the radial 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 the third size L3.

[0147] The third dimension L3 is smaller than the first dimension L1. Accordingly, the radial movement of the motor shaft 211 along the power assembly 100 drives the exposed outer peripheral surface of the conductive bearing 42 to abut against the inner peripheral surface of the first section of the shaft hole 2121 of the shaft hole 212, so as to limit the radial displacement of the motor shaft 211 relative to the axial protrusion 121 and prevent the third section of the shaft hole 2123 from contacting the axial protrusion 121.

[0148] It can be understood that the conductive bearing 42 has a high stiffness, and the radial movement of the motor shaft 211 along the power assembly 100 drives the conductive bearing 42 to extend beyond the conductive rubber ring 41 to abut against the outer circumference of the axial protrusion 121 or the inner circumference of the shaft hole 212, thereby preventing the axial protrusion 121 from contacting the third section shaft hole 2123 of the shaft hole 212, and preventing the axial protrusion 121 from being deformed due to collision and affecting the delivery of coolant or lubricating oil toward the shaft hole 212.

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

[0150] See also Fig.14 Another exploded schematic diagram of the powertrain 100 provided in an embodiment of the present application is shown.

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

[0152] In one embodiment, the elastic modulus of one conductive rubber ring 41 in each conductive structure 40 is smaller than the elastic modulus of another conductive rubber ring 41. Fig.14 As shown, the conductive rubber ring 41 includes a first conductive rubber ring 411 and a second conductive rubber ring 412. The elastic modulus of the first conductive rubber ring 411 is greater than the elastic modulus of the second conductive rubber ring 412. By setting the first conductive rubber ring 411 and the second conductive rubber ring 412 differently, the elastic forces of the two conductive rubber rings 41 along the radial direction of the power assembly 100 can be different. After the power assembly 100 provided in the present application has been working for a long time, the wear amount of the first conductive rubber ring 411 and the second conductive rubber ring 412 is different, and the conductive rubber ring 41 with a smaller wear amount can compensate the wear amount of the other conductive rubber ring 41 through elastic deformation.

[0153] 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 in sequence at intervals.

[0154] See also Fig.15 Another cross-sectional schematic diagram of the powertrain 100 provided in an embodiment of the present application is shown.

[0155] like Fig.15 As shown, the first conductive rubber ring 411 is located between the second conductive rubber ring 412 and the bottom of the bearing groove 123 along the axial direction of the power assembly 100. That is, compared with the first conductive rubber ring 411, the second conductive rubber ring 412 is closer to the third section of the shaft hole 2123 of the shaft hole 212. The radial movement of the motor shaft 211 makes the second conductive rubber ring 412 more compressed, thereby forming 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, so as to protect the first conductive rubber ring 411.

[0156] In one embodiment, the conductive bearing 42 is sleeved on the outer sides of the two conductive rubber rings 41. The gap between the portion of the inner circumference 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 circumference of the first section protrusion 1211 of the axial protrusion 121 is smaller than the gap between the inner circumference of the shaft hole 212 and the outer circumference of the axial protrusion 121.

[0157] like Fig.15 As shown, the inner ring of the conductive structure 40 is two conductive rubber rings 41, and the outer ring is a conductive bearing 42. The sum of the spacing between the first conductive rubber ring 411 and the second conductive rubber ring 412 along the axial direction of the power assembly 100, the width of the first conductive rubber ring 411, and the width of the second conductive rubber ring 412 is less than the width of the conductive bearing 42. That is, the inner circumference of the conductive bearing 42 is partially exposed to the outside of the first conductive rubber ring 411 and the second conductive rubber ring 412. The gap size between the inner circumference of the conductive bearing 42 exposed along the radial direction of the power assembly 100 and the outer circumference of the first section protrusion 1211 of the axial protrusion 121 is the fourth size L4.

[0158] The fourth dimension L4 is smaller than the first dimension L1. Accordingly, the radial movement of the motor shaft 211 along the power assembly 100 drives the exposed inner peripheral surface of the conductive bearing 42 to abut against the first section protrusion 1211 of the axial protrusion 121, so as to limit the radial displacement of the motor shaft 211 relative to the axial protrusion 121, and prevent the third section shaft hole 2123 from contacting the axial protrusion 121.

[0159] In one embodiment, two conductive rubber rings 41 are sleeved on the outer side of the conductive bearing 42. The gap between the portion of the outer circumference 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 circumference of the first section of the shaft hole 2121 of the shaft hole 212 is smaller than the gap between the inner circumference of the shaft hole 212 and the outer circumference of the axial protrusion 121.

[0160] See also Fig.16Another cross-sectional schematic diagram of the powertrain 100 provided in an embodiment of the present application is shown.

[0161] like Fig.16 As shown, the outer ring of the conductive structure 40 is two conductive rubber rings 41, and the inner ring is a conductive bearing. The sum of the spacing between the first conductive rubber ring 411 and the second conductive rubber ring 412 along the axial direction of the power assembly 100, the width of the first conductive rubber ring 411, and the width of the second conductive rubber ring 412 is less than the width of the conductive bearing 42. That is, the outer peripheral surface of the conductive bearing 42 is partially exposed to the outside of the first conductive rubber ring 411 and the second conductive rubber ring 412. The gap size between the exposed outer peripheral surface of the conductive bearing 42 along the radial 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 the fifth size L5.

[0162] The fifth dimension L5 is smaller than the first dimension L1. Accordingly, the radial movement of the motor shaft 211 along the power assembly 100 drives 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, so as to limit the radial displacement of the motor shaft 211 relative to the axial protrusion 121, and prevent the third section of the shaft hole 2123 from contacting the axial protrusion 121.

[0163] 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 through the axial sleeve 43, and the outer peripheral surface of the conductive structure 40 is used for coating a wear-resistant conductive coating.

[0164] See also Fig.17 Another cross-sectional schematic diagram of the powertrain 100 provided in an embodiment of the present application is shown.

[0165] like Fig.17 As shown, the axial sleeve 43 is used to extend along the axial direction of the power assembly 100 to increase the contact area between the conductive structure 40 and the axial protrusion 121, so as to fix the conductive structure 40 to the outer peripheral surface of the axial protrusion 121. During the operation of the drive motor 20, the motor shaft 211 rotates in the housing 10, and the inner peripheral surface of the shaft hole 212 of the motor shaft 211 continuously rotates and rubs the outer peripheral surface of the conductive structure 40. The wear-resistant conductive coating coated on the outer peripheral surface of the conductive structure 40 is used to reduce the wear of the outer peripheral surface of the conductive structure 40, and conduct the 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.

[0166] In one embodiment, the conductive structure 40 is fixed to the inner circumference of the shaft hole 212 through an axial sleeve 43 , and the inner circumference of the conductive structure 40 is used for coating a wear-resistant conductive coating.

[0167] Please combine Fig.17The axial sleeve 43 is used to extend along the axial direction of the power assembly 100 to increase the contact area between the conductive structure 40 and the shaft hole 212 of the motor shaft 211, thereby fixing the conductive structure 40 to the inner circumference of the shaft hole 212 of the motor shaft 211. During the operation of the drive motor 20, the conductive structure 40 is used to rotate with the motor shaft 211 in the housing 10, and the inner circumference of the conductive structure 40 continuously rotates and rubs against the outer circumference of the axial protrusion 121. The wear-resistant conductive coating coated on the inner circumference of the conductive structure 40 is used to reduce the wear of the inner circumference of the conductive structure 40 and to conduct the electrical connection between the inner circumference of the conductive structure 40 and the outer circumference of the axial protrusion 121.

[0168] In one embodiment, the conductive structure 40 includes a radial protrusion 44, and the conductive structure 40 electrically connects the outer circumference of the axial protrusion 121 and the inner circumference of the shaft hole 212 through the radial protrusion 44. The radial protrusion 44 is used to be fixed to the axial sleeve 43 along the axial direction of the power assembly 100, near the bottom end of the bearing groove 123.

[0169] Fig.18 Another schematic diagram of the powertrain 100 provided in an embodiment of the present application. Fig.19 Another cross-sectional schematic diagram of the powertrain 100 provided in an embodiment of the present application.

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

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

[0172] In one embodiment, the radial protrusion 44 includes a plurality of curling edges, which are fixed around one end of the radial protrusion 44 away from the axial sleeve 43 and spaced from each other. When the axial sleeve 43 is fixed to the outer peripheral surface of the axial protrusion 121, the plurality of curling edges abut the inner peripheral surface of the first section shaft hole 2121. It can be understood that the curling 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 curling edges undergo a certain elastic deformation toward the axial sleeve 43. The elasticity of the curling edges can compensate when the curling edges are worn, avoiding the generation of a gap between the curling edges and the inner peripheral surface of the first section shaft hole 2121, so as to ensure the reliability of the electrical connection. Furthermore, the inner peripheral surface of the plurality of curling edges facing the shaft hole 212 can also be coated with a wear-resistant conductive coating to reduce the wear of the curling edges.

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

[0174] Correspondingly, the radial protrusion 44 may also include a plurality of curling edges, that is, the axial sleeve 43 is fixed to the inner circumference of the shaft hole 212, and the plurality of curling edges abut the outer circumference of the axial protrusion 121. Similarly, the elasticity of the curling edges may also compensate for wear and avoid a gap between the curling edges and the outer circumference of the axial protrusion 121 to ensure reliable electrical connection. Furthermore, the outer circumference of the plurality of curling edges facing the axial protrusion 121 may also be coated with a wear-resistant conductive coating to reduce wear of the curling edges.

[0175] In one embodiment, the axial sleeve 43 and the radial protrusion 44 are clamped and fixed to form the conductive structure 40. In one 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.

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

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

[0178] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the scope of protection of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A dual-motor powertrain for preventing electrical corrosion of bearings, characterized in that: The power assembly includes two drive motors, which are arranged adjacent to each other along the axial direction of the power assembly. The housing of the power assembly includes a middle partition, and the middle partition includes two end surfaces opposite to each other along the axial direction of the power assembly. Each end surface includes a bearing groove and an oil guide structure, wherein: Each of the bearing grooves is used to fix a motor shaft of the driving motor through a motor bearing, one end of each oil guide structure is used to be fixedly connected to a groove bottom of the bearing groove, and the other end of each oil guide structure is used to extend into the axial direction of the power assembly and transport coolant or lubricating oil to an axial hole of the motor shaft; There is a gap between the outer circumference of each oil-conducting structure and the inner circumference of the shaft hole of one of the motor shafts, and the gap is used to accommodate an annular conductive structure. Each of the conductive structures is used to electrically connect one of the motor shafts and one of the oil-conducting structures.

2. The powertrain according to claim 1, characterized in that: The middle partition includes an internal oil passage, and the internal oil passage is used to transport coolant or lubricating oil to the oil guide structures on the two end surfaces.

3. The powertrain according to claim 1 or 2, characterized in that: The one gap includes two gaps with different radial sizes. Along the direction in which each of the oil guiding structures extends into one of the axial holes, one gap and the other gap are arranged in sequence. The radial size of one gap is larger than the radial size of the other gap, and the radial size of the other gap is smaller than the radial size of the conductive structure.

4. The powertrain according to any one of claims 1 to 3, characterized in that: Each of the oil guide structures includes an axial protrusion, one end of each of the axial protrusions is used to be fixedly connected to the bottom of a bearing groove, the other end of each of the axial protrusions is used to extend into an axial hole of a motor shaft along the axial direction of the power assembly, and the end surface of the other end of each of the axial protrusions includes a through hole, and the through hole is used to transport coolant or lubricating oil to the axial hole of the motor shaft.

5. The powertrain according to claim 4, characterized in that: Each of the axial protrusions includes a first section protrusion and a second section protrusion. The first section protrusion and the second section protrusion are arranged in sequence along the direction in which each of the oil guiding structures extends into an axial hole. The outer diameter of the first section protrusion is greater than the outer diameter of the second section protrusion. The first section protrusion is used to sleeve one of the conductive structures.

6. The powertrain according to claim 5, characterized in that: The outer peripheral surface of each of the first-section protrusions along the axial direction of the power assembly includes one or more limiting structures, wherein: Along the radial direction of the power assembly, a radial dimension of each of the limiting structures in each of the first-section protrusions is different from an outer diameter of the remaining portion of each of the first-section protrusions.

7. The powertrain according to claim 6, characterized in that: The one or more limiting structures in each of the first-section protrusions are used to fix and electrically connect an inner ring of the conductive structure, and the outer ring of the conductive structure is used to contact and electrically connect an inner circumferential surface of the shaft hole.

8. The power assembly according to any one of claims 1 to 7, characterized in that: Each of the shaft holes comprises a first section shaft hole, a second section shaft hole and a third section shaft hole, and along the direction in which each of the oil guide structures extends into one of the shaft holes, the first section shaft hole, the second section shaft hole and the third section shaft hole are arranged in sequence, wherein: The inner diameter of the first-section shaft hole is greater than the inner diameter of the second-section shaft hole, and the inner diameter of the second-section shaft hole is greater than the inner diameter of the third-section shaft hole; The length of the first section shaft hole is greater than the length of the second section shaft hole, and the length of the first section shaft hole is less than the length of the third section shaft hole.

9. The powertrain according to claim 8, characterized in that: The inner circumference of each of the first-section shaft holes includes one or more annular grooves, wherein: Along the radial direction of the power assembly, the inner diameter of the one or more annular grooves in each of the first-section shaft holes is larger than the inner diameter of the remaining portion of each of the first-section shaft holes.

10. The powertrain according to claim 9, characterized in that: Each of the annular grooves is used to accommodate a portion of the outer ring of the conductive structure.

11. The power assembly according to any one of claims 1 to 10, characterized in that: Each of the conductive structures comprises a conductive bearing and one or more conductive rubber rings, the inner ring of the conductive bearing being used for fixedly sleeved on the outer peripheral surface of the oil-conducting structure, and the outer ring of the conductive bearing being used for fixing the one or more conductive rubber rings, wherein: Along the axial direction of the conductive structure, the size of the conductive rubber ring is smaller than the size of the inner ring or the outer ring of the conductive bearing.

12. The powertrain according to claim 11, characterized in that: Each of the conductive structures comprises two conductive rubbers, wherein: Along the axial direction of the power assembly, the two conductive rubber rings are arranged at intervals, and the sum of the interval 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 according to claim 12, characterized in that: The elastic modulus of one of the conductive rubber rings in each of the oil-conducting structures is smaller than the elastic modulus of another of the conductive rubber rings.

14. The powertrain according to claim 13, characterized in that: Along the direction in which each of the oil guide structures extends into one of the shaft holes, the one conductive rubber ring and the other conductive rubber ring are sequentially arranged at intervals.

15. An electric vehicle, characterized in that: The electric vehicle comprises a wheel and a power assembly as claimed in any one of claims 1 to 14, wherein an axis of the wheel is parallel to an axis of a motor shaft in the power assembly.

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