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

Abstract

The invention provides a power assembly capable of preventing electric corrosion of a bearing and an electric vehicle. A shell of the power assembly is used for containing a driving motor, and the driving motor comprises a motor shaft and a motor stator. The motor shaft is used for driving wheels through the reducer. The shell comprises an axial shell arranged on one side of the motor stator in the axial direction of the motor shaft, and the end face, facing the motor stator, of the axial shell comprises a bearing groove and an axial protrusion. The bearing groove is used for containing a motor bearing to be in transmission connection with a motor shaft. One end of the axial protrusion is used for being fixedly connected with the groove bottom of the bearing groove, and the other end of the axial protrusion is used for extending into a shaft hole of the motor shaft in the axial direction of the motor shaft. The end face of the other end of the axial protrusion comprises a through hole used for communicating the internal flow channel of the axial shell with the shaft hole of the motor shaft. And a gap between the axial bulge and the shaft hole is used for accommodating the conductive structure. According to the power assembly, the structure that the shell supplies oil to the shaft hole of the motor shaft is used for conducting the shaft current of the motor shaft to the shell to be grounded so as to protect the motor bearing.

Description

Technical Field

[0001] The present application relates to the technical field of electric vehicles, and in particular to a power assembly and an electric vehicle that are capable of preventing electrical corrosion of bearings. Background Art

[0002] When the drive motor in the powertrain of an electric vehicle 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 powertrain and an electric vehicle that prevent electrical corrosion of bearings, utilizing a structure in which the housing of the powertrain supplies oil toward the shaft hole of the 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 powertrain that prevents electrical corrosion of bearings. The housing of the powertrain is used to accommodate a drive motor. The drive motor includes a motor shaft and a motor stator, and the motor shaft is used to drive the wheels through a reducer. The housing includes an axial housing, and the axial housing is arranged on one side of the motor stator along the axial direction of the motor shaft. The end surface of the axial housing facing the motor stator includes a bearing groove and an axial protrusion, and the bearing groove is used to accommodate a motor bearing, and the motor bearing is used to transmit and connect the motor shaft. One end of the axial protrusion is used to fix and connect the bottom of the bearing groove, and the other end of the axial protrusion is used to extend into the shaft hole of the motor shaft along the axial direction of the motor shaft. The end surface of the other end of the axial protrusion includes a through hole, and the through hole is used to connect the internal flow channel of the axial housing and the shaft hole of the motor shaft. The gap between the outer peripheral surface of the axial protrusion and the inner peripheral surface of the shaft hole is used to accommodate a conductive structure, and the conductive structure is used to conduct the electrical connection between the outer peripheral surface of the axial protrusion and the inner peripheral surface of the shaft hole.

[0005] The powertrain for preventing electric corrosion of bearings provided by the present application forms a bearing groove through the axial part structure of the housing, and the groove wall of the bearing groove is used to fix the motor bearing, and the motor shaft of the drive motor is connected through the motor bearing transmission. The groove bottom of the bearing groove is used to fix the axial protrusion, and the axial protrusion is used to extend into the shaft hole of the motor shaft and convey lubricating oil or coolant toward the shaft hole. The powertrain provided by the present application also conducts the electrical connection between the outer peripheral surface of the axial protrusion and the inner peripheral surface of the shaft hole through a conductive structure to conduct the shaft end current of the motor shaft to the housing to achieve grounding, so as to avoid the shaft end current of the motor shaft flowing through the motor bearing and causing the motor bearing to fail. The powertrain provided by the present application reasonably utilizes the internal space of the shaft hole of the motor shaft to realize the electrical connection between the motor shaft and the housing. The motor bearing is effectively protected and the service life of the powertrain is extended.

[0006] In one implementation, the axial hole along the motor shaft includes two sections, one of which is used to accommodate the conductive structure, and the other end of the axial protrusion is used to pass through the conductive structure and extend into the other section of the motor shaft. In the radial direction of the motor shaft, the gap between the outer circumference of the axial protrusion and the inner circumference of one section is greater than the gap between the outer circumference of the axial protrusion and the inner circumference of the other section.

[0007] In this implementation, the shaft hole of the motor shaft is divided into two sections with different inner diameters, and along the axial direction of the motor shaft, two gaps with different radial dimensions are formed between the outer peripheral surface of the axial protrusion and the inner peripheral surface of one section. The radial dimension of one gap is larger than the radial dimension of the other gap. One gap is used to accommodate the conductive structure, and the axial protrusion conveys lubricating oil or coolant toward the shaft hole in the other gap. Under the premise of ensuring that there is enough space for the conductive structure to be installed, the coolant or lubricating oil can reliably enter the shaft hole of the motor shaft.

[0008] In one implementation, the axial conductive structure along the motor shaft includes two opposite end faces, 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.

[0009] In this implementation, the conductive structure is closer to the bottom of the bearing groove along the axial direction of the motor shaft 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.

[0010] In one implementation, along the axial direction of the motor shaft, the outer peripheral surface of the axial protrusion includes a fitting section, and the conductive structure is used to electrically connect the outer peripheral surface of the fitting section and the inner peripheral surface of the shaft hole. In the radial direction of the motor shaft, the outer diameter of the fitting section is smaller than the outer diameter of the rest of the axial protrusion.

[0011] In this implementation, the fitting section is used to form a limiting groove on the outer peripheral surface of the axial protrusion. The limiting groove is used to limit the displacement of the conductive structure relative to the axial protrusion along the axial direction of the motor shaft to ensure that the conductive structure is reliably in contact with the outer peripheral surface of the axial protrusion and achieve electrical connection.

[0012] In one implementation, along the axial direction of the motor shaft, the length of the fitting section is greater than or equal to the length of the conductive structure.

[0013] In this implementation, the inner circumference of the conductive structure can be completely in contact with the contact section. The limiting groove completely accommodates the conductive structure to limit the axial displacement of the conductive structure along the motor shaft.

[0014] In one implementation, the two shaft holes of the motor shaft are used to form a step surface, and the step surface along the axial direction of the motor shaft faces the conductive structure, 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.

[0015] In this implementation, the smaller the distance between the axial step surface and the conductive structure along the motor shaft is, the longer the length of the axial protrusion extending into the other section of the shaft hole is. Because the radial dimension of the gap between the other section of the shaft hole and the axial protrusion is smaller, the distance for the coolant or lubricating oil to flow back from the other section of the shaft hole to the first section is longer, which can reduce the contact between the conductive structure and the coolant or lubricating oil.

[0016] In one implementation, the inner circumference of a section of the axial hole of the motor shaft includes another fitting section, and the conductive structure is used to conduct electrical connection between the inner circumference of the other fitting section and the outer circumference of the axial protrusion. In the radial direction of the motor shaft, the inner diameter of the other fitting section is greater than the inner diameter of the rest of the section of the axial hole.

[0017] In this implementation, another fitting section is used to form a positioning groove on the inner circumference of the shaft hole. The positioning groove is used to limit the displacement of the conductive structure relative to the shaft hole along the axial direction of the motor shaft to ensure that the conductive structure is reliably in contact with the inner circumference of the shaft hole and achieve electrical connection.

[0018] In one implementation, along the axial direction of the motor shaft, the length of another fitting section is greater than or equal to the length of the conductive structure.

[0019] In this implementation, the outer peripheral surface of the conductive structure can be completely in contact with another contact section. The positioning groove completely accommodates the conductive structure to limit the axial displacement of the conductive structure along the motor shaft.

[0020] In one implementation, the outer peripheral surface of the motor shaft along the axial direction of the motor shaft includes a first section and a second section connected to each other, wherein along the radial direction of the motor shaft, the outer diameter of the first section is smaller than the outer diameter of the second section and greater than or equal to the inner diameter of the motor bearing.

[0021] In this implementation, the first section of the outer circumferential surface of the motor shaft is used to be embedded in the inner hole of the motor bearing. The outer circumferential surface of the motor shaft forms another step surface through the first section and the second section. The other step surface faces the groove bottom of the bearing groove along the axial direction of the motor shaft. 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.

[0022] In one implementation, along the axial direction of the motor shaft, the length of the first section is greater than the length of a section of the shaft hole.

[0023] In this implementation, the other step surface coincides with the other section of the shaft hole along the axial direction of the motor shaft. That is, the other step surface is located on the other section of the shaft hole along the axial direction of the motor shaft. 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.

[0024] In one implementation, the conductive structure is annular, wherein along the radial direction of the motor shaft, the outer diameter of the conductive structure is greater than or equal to the inner diameter of the shaft hole of the motor shaft, and the inner diameter of the conductive structure is less than or equal to the outer diameter of the axial protrusion.

[0025] In this implementation, the outer circumference of the conductive structure forms an interference fit with the inner circumference of the shaft hole of the motor shaft, or the outer circumference of the conductive structure fits with the inner circumference of the shaft hole of the motor shaft through elastic deformation, so as to ensure that the conductive structure and the shaft hole are in reliable contact and form an electrical connection. The inner circumference of the conductive structure forms an interference fit with the outer circumference of the axial protrusion, or the inner circumference of the conductive structure fits with the outer circumference of the axial protrusion through elastic deformation, so as to ensure that the conductive structure and the axial protrusion are in reliable contact and form an electrical connection.

[0026] 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.

[0027] In this implementation, the axial sleeve is used to extend along the axial direction of the motor shaft to increase the contact area between the conductive structure and the axial protrusion, thereby fixing the conductive structure to the outer peripheral surface of the axial protrusion. During the operation of the drive motor, the motor shaft rotates in the housing, and the inner peripheral surface of the shaft hole of the motor shaft continuously rotates and rubs the outer peripheral surface of the conductive structure. The wear-resistant conductive coating coated on the outer peripheral surface of the conductive structure is used to reduce the wear of the outer peripheral surface of the conductive structure and conduct the electrical connection between the outer peripheral surface of the conductive structure and the inner peripheral surface of the shaft hole of the motor shaft.

[0028] 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.

[0029] In this implementation, the axial sleeve is used to extend along the axial direction of the motor shaft 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.

[0030] In one implementation, along the axial direction of the motor shaft, the axial sleeve extends in a direction away from the groove bottom of the bearing groove.

[0031] In this implementation, along the axial direction of the motor shaft, the axial sleeve is relatively close to the other section of the shaft hole of the motor shaft. The conductive structure is electrically connected to the inner peripheral surface of the shaft hole and the outer peripheral surface 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 other section of the shaft hole relative to the part used for conducting and realizing electrical connection, reducing the contact between the conductive structure and the coolant or lubricating oil to extend the service life of the conductive structure.

[0032] In one implementation, the conductive structure includes a radial protrusion. The conductive structure electrically connects the outer peripheral surface of the axial protrusion and the inner peripheral surface 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 motor shaft.

[0033] In one implementation, the conductive structure includes an inner ring and an outer ring, wherein the inner ring and the outer ring are sequentially sleeved on the outer peripheral surface of the axial protrusion along the radial direction of the motor shaft, and the outer diameter of the inner ring is larger than the inner diameter of the outer ring.

[0034] In this implementation, the conductive structure is composed of an inner ring and an outer ring that are nested with each other. The outer circumference of the inner ring and the inner circumference of the outer ring form an interference fit or abut each other through elastic deformation to ensure reliable electrical connection between the inner ring and the outer ring.

[0035] In this implementation, one of the inner ring and the outer ring is a conductive bearing, and the other is a conductive rubber ring.

[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 inner ring or outer ring formed by the conductive bearing can improve the overall structural stability of the conductive structure. The conductive rubber ring has a lower stiffness, and the outer ring or inner ring formed by 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. By setting the structure or material of the inner ring and the outer ring differently, the conductive structure can take into account both structural reliability and wear resistance.

[0037] In one implementation, the length of the conductive rubber ring along the axial direction of the motor shaft is less than the length of the conductive bearing. The inner ring is the conductive bearing, and the gap between the portion of the outer circumference of the conductive bearing that exceeds the conductive rubber ring and one section of the shaft hole is less than the gap between the other section of the shaft hole and the other end of the axial protrusion.

[0038] In one implementation, the outer ring is a conductive bearing, and the gap between the portion of the inner circumference of the conductive bearing that extends beyond the conductive rubber ring and the axial protrusion is smaller than the gap between the other section of the shaft hole and the other end of the axial protrusion.

[0039] In the above two implementation methods, because the conductive bearing has a high stiffness, the radial movement of the motor shaft drives the conductive bearing to extend beyond the conductive rubber ring, which can be used to abut against the outer circumference of the axial protrusion or the inner circumference of the shaft hole, thereby preventing the axial protrusion from contacting another section of the shaft hole and preventing the axial protrusion from deforming due to collision and affecting the delivery of coolant or lubricating oil toward the shaft hole.

[0040] In one implementation, there are two conductive rubber rings, wherein the two conductive rubber rings are arranged at intervals along the axial direction of the motor shaft, and the sum of the interval between the two conductive rubber rings and the length of the two conductive rubber rings is less than or equal to the length of the conductive bearing.

[0041] In this implementation, two conductive rubber rings spaced axially along the motor shaft can distribute the impact force of the radial movement of the motor shaft more evenly to the conductive bearing, thereby improving the internal stress conditions of the conductive structure to extend the service life of the conductive structure.

[0042] In one implementation, the inner ring is a conductive bearing, and the gap between the inner circumference of the shaft hole between the two conductive rubber rings along the axial direction of the motor shaft and the outer circumference of the conductive bearing is smaller than the gap between the other section of the shaft hole and the other end of the axial protrusion.

[0043] In one implementation, the outer ring is a conductive bearing, and the gap between the outer peripheral surface of the axial protrusion located between the two conductive rubber rings along the axial direction of the motor shaft and the inner peripheral surface of the conductive bearing is smaller than the gap between the other section of the shaft hole and the other end of the axial protrusion.

[0044] In the above two implementation methods, because the conductive bearing has a high stiffness, the radial movement of the motor shaft drives the conductive bearing located between the two conductive rubber rings to be used to abut against the outer circumference of the axial protrusion or the inner circumference of the shaft hole, thereby preventing the axial protrusion from contacting the other section of the shaft hole and preventing the axial protrusion from deforming due to collision and affecting the delivery of coolant or lubricating oil toward the shaft hole.

[0045] In one implementation, the elastic modulus of one of the two conductive rubber rings is greater than the elastic modulus of the other conductive rubber ring.

[0046] 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 motor shaft can be different. After the powertrain provided in this 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 can compensate the wear amount of the other conductive rubber ring through elastic deformation.

[0047] In one implementation, the conductive rubber ring is arranged between another conductive rubber ring and the bottom of the bearing groove along the axial direction of the motor shaft.

[0048] In this implementation, the other conductive rubber ring with a smaller axial elastic modulus along the motor shaft 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 conductive rubber ring, reducing the contact between the conductive rubber ring and the coolant or lubricating oil, so as to protect the conductive rubber ring.

[0049] In a second aspect, the present application provides an electric vehicle, the electric vehicle comprising wheels and a powertrain provided by any implementation of the first aspect, the powertrain being used to drive the wheels of the electric vehicle. The electric vehicle provided by the embodiment of the present application adopts the powertrain, and the electric vehicle has a more compact structure and a longer service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 A schematic diagram of the appearance of an electric vehicle provided in an embodiment of the present application;

[0051] Figure 2 A transmission schematic diagram of an electric vehicle provided in an embodiment of the present application;

[0052] Figure 3 A cross-sectional schematic diagram of a drive motor provided in an embodiment of the present application;

[0053] Figure 4 A cross-sectional schematic diagram of a powertrain provided in an embodiment of the present application;

[0054] Figure 5 A partially enlarged schematic diagram of a powertrain provided in an embodiment of the present application;

[0055] Figure 6 Another partially enlarged schematic diagram of the powertrain provided in the embodiment of the present application;

[0056] Figure 7 Another exploded schematic diagram of the powertrain provided in an embodiment of the present application;

[0057] Figure 8 Another cross-sectional schematic diagram of the powertrain provided in the embodiment of the present application;

[0058] Fig. 9 Another exploded schematic diagram of the powertrain provided in an embodiment of the present application;

[0059] Fig.10 Another cross-sectional schematic diagram of the powertrain provided in the embodiment of the present application;

[0060] Fig.11 Another exploded schematic diagram of the powertrain provided in an embodiment of the present application;

[0061] Fig.12Another cross-sectional schematic diagram of a powertrain provided in an embodiment of the present application;

[0062] Fig.13 Another cross-sectional schematic diagram of a powertrain provided in an embodiment of the present application;

[0063] Fig.14 Another cross-sectional schematic diagram of a powertrain provided in an embodiment of the present application;

[0064] Fig.15 Another cross-sectional schematic diagram of a powertrain provided in an embodiment of the present application;

[0065] Fig.16 Another cross-sectional schematic diagram of a powertrain provided in an embodiment of the present application;

[0066] Fig.17 Another cross-sectional schematic diagram of a powertrain provided in an embodiment of the present application;

[0067] Fig.18 Another schematic diagram of a powertrain provided in an embodiment of the present application;

[0068] Fig.19 Another cross-sectional schematic diagram of the powertrain provided in an embodiment of the present application. DETAILED DESCRIPTION

[0069] 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.

[0070] The present application provides a powertrain for preventing electrical corrosion of bearings. The housing of the powertrain is used to accommodate a drive motor. The drive motor includes a motor shaft and a motor stator, and the motor shaft is used to drive the wheel through a reducer. The housing includes an axial housing, and the axial housing is arranged on one side of the motor stator along the axial direction of the motor shaft. The end surface of the axial housing facing the motor stator includes a bearing groove and an axial protrusion, and the bearing groove is used to accommodate the motor bearing, and the motor bearing is used to drive and connect the motor shaft. One end of the axial protrusion is used to fix the bottom of the bearing groove, and the other end of the axial protrusion is used to extend into the shaft hole of the motor shaft along the axial direction of the motor shaft. The end surface of the other end of the axial protrusion includes a through hole, and the through hole is used to connect the internal flow channel of the axial housing and the shaft hole of the motor shaft. The gap between the outer peripheral surface of the axial protrusion and the inner peripheral surface of the shaft hole is used to accommodate a conductive structure, and the conductive structure is used to conduct the electrical connection between the outer peripheral surface of the axial protrusion and the inner peripheral surface of the shaft hole. The powertrain provided by the present application reasonably utilizes the internal space of the shaft hole of the motor shaft to realize the electrical connection between the motor shaft and the housing. It effectively protects the motor bearings and extends the service life of the powertrain.

[0071] The present application provides an electric vehicle, the electric vehicle comprising wheels and a powertrain provided in an embodiment of the present application, the powertrain being used to drive the wheels of the electric vehicle. The electric vehicle provided in an embodiment of the present application adopts the powertrain provided in an embodiment of the present application, and the electric vehicle has a more compact structure and a longer service life.

[0072] 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.

[0073] See also Figure 2 A transmission schematic diagram of an electric vehicle 200 provided in an embodiment of the present application is shown, and Figure 3 A cross-sectional schematic diagram of a driving motor 20 provided in an embodiment of the present application is shown.

[0074] The power assembly 100 for preventing electrical corrosion of bearings provided in the present application includes a housing 10 and a drive motor 20 , wherein the drive motor 20 includes a motor shaft 211 , a motor rotor 21 and a motor stator 22 , wherein the housing 10 is used to accommodate the drive motor 20 .

[0075] In one embodiment, if Figure 3As 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. 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 drive motor 20 transmits driving force to the wheel 102 through the motor shaft 211.

[0076] In one embodiment, the power assembly 100 includes a reducer 103. The motor shaft 211 of the power assembly 100 of the present application drives the wheel 102 through a reducer 103, and the axis of the wheel 102 is parallel to the axis of the motor shaft 211 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 the reducer 103 is transmission-connected between the motor shaft 211 of the drive motor 20 and the wheel axle of the wheel 102. The driving force output by the drive motor 20 through the motor shaft 211 is transmitted to the wheel 102 through the reducer 103 to drive the wheel 102 to rotate, thereby driving the electric vehicle 200 to travel.

[0077] In one embodiment, the reducer 103 includes a gear set, which includes a plurality of pairs of gears meshing with each other. The gear set is located in the accommodating cavity formed by the housing 10, and the gear set is located on one side of the motor stator 22 along the axial direction of the motor shaft 211. 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.

[0078] The power assembly 100 also includes two motor bearings 30, which are arranged on both sides of the motor stator 22 along the axial direction of the motor shaft 211. 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.

[0079] In one embodiment, one end of the motor shaft 211 is used to be fixedly connected to one end of a transmission shaft of the reducer 103, and the other end of the transmission shaft of the reducer 103 is used to be embedded in the inner ring of a motor bearing 30, and is fixed to the housing 10 through the outer ring of the motor bearing 30. Similarly, the motor shaft 211 is rotatably connected to the housing 10 through the motor 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.

[0080] In one embodiment, the housing 10 includes an axial housing, a circumferential housing, and another axial housing arranged in sequence along the axial direction of the motor shaft 211. The circumferential housing includes an inner cavity, and the inner cavity penetrates the circumferential housing along the axial direction of the motor shaft 211. The two axial housings are respectively fixed to the two sides of the circumferential housing along the axial direction of the motor shaft 211 to enclose the inner cavity of the circumferential housing to form a receiving cavity, and the receiving cavity is used to receive the drive motor 20.

[0081] See also Figure 4 A cross-sectional schematic diagram of a powertrain 100 provided in an embodiment of the present application is shown. One of the two axial shells of the shell 10 of the powertrain 100 of the present application includes an internal flow channel 124. For ease of description, the first axial shell 12 is defined in the subsequent embodiments as including an internal flow channel 124. In some embodiments, the first axial shell 12 can be located on the side of the motor stator 22 of the drive motor 20 away from the gear set of the reducer 103. That is, the internal flow channel 124 is located on the side of the drive motor 20 away from the reducer 103. In one embodiment, the first axial shell 12 is arranged on one side of the motor stator 22 along the axial direction of the motor shaft 211. The end face of the first axial shell 12 facing the motor stator 22 includes a bearing groove 123 and an axial protrusion 121, and the bearing groove 123 is used to accommodate the motor bearing 30, and the motor bearing 30 is used to drive and connect the motor shaft 211.

[0082] like Figure 4 As shown, the first axial shell 12 of the shell 10 is located on the side of the motor shaft 211 away from the reducer 103, and the first axial shell 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 transmission-connected to one end of the motor shaft 211, and the inner ring of the motor bearing 30 is rotationally connected to the outer ring to support the motor shaft 211.

[0083] The axial protrusion 121 of the power assembly 100 of the present application is partially located in the bearing groove 123. One end of the axial protrusion 121 is used to be fixedly connected to the bottom of a bearing groove 123, 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 surface of the other end of the axial protrusion 121 includes a through hole 122, and the through hole 122 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.

[0084] like Figure 4 As shown, the first axial housing 12 is provided with an internal flow channel 124 , which extends in the radial direction of the motor shaft 211 and communicates with the through hole 122 , and is used for conveying coolant or lubricating oil.

[0085] In one embodiment, the internal flow channel 124 of the first axial housing 12 extends along the axial direction of the motor shaft 211 and penetrates the first axial housing 12. It can also be understood that the through hole 122 extends in a direction away from the motor shaft 211 and penetrates the housing 10, and the through hole 122 is connected to an external oil pipeline or an oil pump through the internal flow channel 124, so that the lubricating oil or coolant flows through the internal flow channel 124 and the through hole 122 in sequence to the shaft hole 212 of the motor shaft 211.

[0086] It can be understood that the coolant flows through the through hole 122 to the shaft hole 212 and absorbs heat to reduce the temperature of the drive motor 20; the lubricating oil can flow through the shaft hole 212 to the other end of the shaft hole 212, that is, the lubricating oil flows toward the reducer 103. After the lubricating oil flows to the reducer 103, it provides lubrication for the gear set inside the reducer to reduce the wear of the gear set during the meshing process and increase the service life of the reducer 103.

[0087] 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.

[0088] In one embodiment, the gap between the outer circumference of the axial protrusion 121 of the power assembly 100 of the present application and the inner circumference of the shaft hole 212 is used to accommodate the conductive structure 40, and the conductive structure 40 is used to conduct the electrical connection between the outer circumference of the axial protrusion 121 and the inner circumference of the shaft hole 212.

[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] like Figure 5 As shown, the conductive structure 40 is annular and is sleeved on the outside of the axial protrusion 121. The inner circumference of the conductive structure 40 is at least partially in contact with the outer circumference of the axial protrusion 121, and the outer circumference of the conductive structure 40 is at least partially in contact with the inner circumference of the axial hole 212 to achieve electrical connection between the axial protrusion 121 and the axial hole 212.

[0091] 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.

[0092] The power assembly 100 of the present application conducts the electrical connection between the outer circumference of the axial protrusion 121 and the inner circumference of the axial hole 212 through the conductive structure 40, so as to conduct the axial end current of the motor shaft 211 to the housing 10 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.

[0093] Compared with the conductive structure of the motor bearing in the prior art, the axial protrusion 121 in the power assembly 100 of the present application extends into the shaft hole 212, and the conductive structure 40 is located inside the shaft hole 212, making full use of the internal space of the motor shaft 211, so that the axial dimension of the power assembly 100 along the motor shaft 211 is smaller and the internal structure is more compact. Compared with the prior art, the conductive structure 40 of the power assembly 100 of the present application is located between the axial protrusion 121 and the shaft hole 212, which will not affect the coolant or lubricating oil in the through hole 122 from flowing to the shaft hole 212, ensuring the cooling and lubrication requirements of the internal components of the power assembly 100 of the present application.

[0094] Accordingly, the electric vehicle provided in the embodiment of the present application adopts the above-mentioned power assembly 100, so that the structure of the electric vehicle is more compact and the service life is longer.

[0095] In one embodiment, the axial shaft hole 212 along the motor shaft 211 includes two sections, one of which is used to accommodate the conductive structure 40, and the other end of the axial protrusion 121 is used to pass through the conductive structure 40 and extend into the other section of the motor shaft 211. In the radial direction of the motor shaft 211, the gap between the outer circumference of the axial protrusion 121 and the inner circumference of one section is greater than the gap between the outer circumference of the axial protrusion 121 and the inner circumference of the other section.

[0096] See also Figure 6 Another partially enlarged schematic diagram of the powertrain 100 provided in an embodiment of the present application is shown.

[0097] like Figure 6 As shown, the shaft hole 212 is divided into a first shaft hole section 2121 and a second shaft hole section 2122 along the axial direction of the motor shaft 211. The first shaft hole section 2121 is used to accommodate the conductive structure 40, and the second shaft hole section 2122 is used to accommodate part of the axial protrusion 121. The radial dimension of the first shaft hole section 2121 is greater than the radial dimension of the second shaft hole section 2122.

[0098] exist Figure 6In the power assembly 100 shown, the first shaft hole section 2121 is located on the side of the second shaft hole section 2122 facing the bottom of the bearing groove 123 along the axial direction of the motor shaft 211. The first shaft hole section 2121 is used to accommodate the conductive structure 40, and the second shaft hole section 2122 is used to accommodate part of the axial protrusion 121. Along the radial direction of the motor shaft 211, the gap between the inner circumference of the first shaft hole section 2121 and the outer circumference of the axial protrusion 121 is larger than the gap between the inner circumference of the second shaft hole section 2122 and the outer circumference of the axial protrusion 121.

[0099] By dividing the shaft hole 212 of the motor shaft 211 into a first shaft hole section 2121 and a second shaft hole section 2122 with different inner diameters, two gaps of different radial sizes are formed between the outer circumference of the axial protrusion 121 and the inner circumference of the shaft hole 212 along the axial direction of the motor shaft 211. The radial size of the gap of the first shaft hole section 2121 is larger than the radial size of the second shaft hole section 2122. The gap of the first shaft hole section 2121 is used to accommodate the conductive structure 40, and the axial protrusion 121 conveys coolant or lubricating oil toward the shaft hole 212 in the gap of the second shaft hole section 2122. Under the premise of ensuring that there is enough space for the conductive structure 40 to be installed, it is ensured that the coolant or lubricating oil can reliably enter the shaft hole 212 of the motor shaft 211.

[0100] In one embodiment, the two sections of the shaft hole 212 of the motor shaft 211 are used to form a step surface, and the axial step surface of the motor shaft 211 faces the conductive structure 40, 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.

[0101] like Figure 6 As shown, the first shaft hole section 2121 and the second shaft hole section 2122 of the motor shaft 211 are used to form a first step surface 213. The first step surface 213 faces the conductive structure 40 along the axial direction of the motor shaft 211, and the distance between the first step surface 213 and the conductive structure 40 is smaller than the distance between the groove bottom of the bearing groove 123 and the conductive structure 40.

[0102] It can be understood that the smaller the distance between the first step surface 213 and the conductive structure 40 along the axial direction of the motor shaft 211, the longer the length of the axial protrusion 121 extending into the second shaft hole section 2122 of the shaft hole 212. Because the radial dimension of the gap between the second shaft hole section 2122 of the shaft hole 212 and the axial protrusion 121 is smaller, the distance for the coolant or lubricating oil to flow back from the second shaft hole section 2122 to the first shaft hole section 2121 is longer, which can reduce the contact between the conductive structure 40 and the coolant or lubricating oil.

[0103] In one embodiment, the inner circumference of a section of the axial hole 212 along the motor shaft 211 includes a fitting section, and the conductive structure 40 is used to electrically connect the inner circumference of the fitting section and the outer circumference of the axial protrusion 121. In the radial direction of the motor shaft 211, the inner diameter of the fitting section is greater than the inner diameter of the rest of the section of the axial hole 212.

[0104] See also Figure 7 and Figure 8 ,in Figure 7 Another exploded schematic diagram of the powertrain 100 provided in an embodiment of the present application. Figure 8 Another cross-sectional schematic diagram of the powertrain 100 provided in an embodiment of the present application.

[0105] like Figure 7 As shown, the inner circumference of the first shaft hole section 2121 along the axial shaft hole 212 of the motor shaft 211 includes a first fitting section 2124, and the conductive structure 40 is used to electrically connect the inner circumference of the first fitting section 2124 and the outer circumference of the axial protrusion 121. Figure 8 , along the radial direction of the motor shaft 211, the inner diameter of the first fitting section 2124 is larger than the inner diameter of the rest of the first shaft hole section 2121. The first fitting section 2124 is used to form a limiting groove on the inner circumference of the shaft hole 212. The limiting groove is used to limit the displacement of the conductive structure 40 relative to the shaft hole 212 along the axial direction of the motor shaft 211, so as to ensure that the conductive structure 40 is reliably in contact with the inner circumference of the shaft hole 212 and realize electrical connection.

[0106] In one embodiment, along the axial direction of the motor shaft 211, the length of the first fitting section 2124 is greater than or equal to the length of the conductive structure 40. The outer peripheral surface of the conductive structure 40 can be completely fitted with the first fitting section 2124. The limiting groove completely accommodates the conductive structure 40 to limit the axial displacement of the conductive structure 40 along the motor shaft 211.

[0107] In one embodiment, the outer peripheral surface of the motor shaft 211 along the axial direction of the motor shaft 211 includes a first section 2111 and a second section 2112 connected to each other. In the radial direction of the motor shaft 211, the outer diameter of the first section 2111 is smaller than the outer diameter of the second section 2112 and is greater than or equal to the inner diameter of the motor bearing 30.

[0108] like Figure 8 As shown, the first section 2111 along the axial direction of the motor shaft 211 is located on the side of the second section 2112 facing the bottom of the bearing groove 123, and the outer peripheral surface of the motor shaft 211 forms a second step surface 214 through the first section 2111 and the second section 2112. The second step surface 214 along the axial direction of the motor shaft 211 faces the bottom of the bearing groove 123. The second step surface 214 is used to abut the side surface of the motor bearing 30 to limit the axial displacement of the motor bearing 30 relative to the motor shaft 211.

[0109] In one embodiment, along the axial direction of the motor shaft 211, the length of the first section 2111 is greater than the length of a section of the shaft hole 212. Figure 6 and Figure 7 As shown, the length of the first section 2111 along the axial direction of the motor shaft 211 is greater than the length of the first shaft hole section 2121. The second step surface 214 along the axial direction of the motor shaft 211 coincides with the second shaft hole section 2122 of the shaft hole 212. That is, the second step surface 214 is located on the second shaft hole section 2122 of the shaft hole 212 along the axial direction of the motor shaft 211, so that the size of the first section 2111 along the radial direction of the motor shaft 211 is larger, 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.

[0110] In one embodiment, along the axial direction of the motor shaft 211, the outer circumference of the axial protrusion 121 includes another fitting segment, and the conductive structure 40 is used to conduct electrical connection between the outer circumference of the other fitting segment and the inner circumference of the shaft hole 212. In the radial direction of the motor shaft 211, the outer diameter of the other fitting segment is smaller than the outer diameter of the rest of the axial protrusion 121.

[0111] See also Fig. 9 Another exploded schematic diagram of the powertrain 100 provided in an embodiment of the present application is shown.

[0112] like Figure 6 and Fig. 9 As shown, along the axial direction of the motor shaft 211, the outer peripheral surface of the axial protrusion 121 includes a second fitting section 1211, and the second fitting section 1211 is used to form a positioning groove 1212 on the outer peripheral surface of the axial protrusion 121, and the positioning groove 1212 is used to limit the displacement of the conductive structure 40 relative to the axial protrusion 121 along the axial direction of the motor shaft 211, so as to ensure that the conductive structure 40 is in reliable contact with the outer peripheral surface of the axial protrusion 121 and realize electrical connection.

[0113] In one embodiment, along the axial direction of the motor shaft 211, the length of another bonding section is greater than or equal to the length of the conductive structure 40. That is, the length of the second bonding section 1211 is greater than or equal to the length of the conductive structure 40. Figure 8 In the power assembly 100 shown, the inner circumference of the conductive structure 40 can be completely in contact with the second contact section 1211. The positioning groove 1212 completely accommodates the conductive structure 40 to limit the axial displacement of the conductive structure 40 along the motor shaft 211.

[0114] In one embodiment, the axial conductive structure 40 along the motor shaft 211 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.

[0115] See also Fig.10 Another cross-sectional schematic diagram of the powertrain 100 provided in an embodiment of the present application is shown.

[0116] like Fig.10 As shown, the axial conductive structure 40 along the motor shaft 211 includes a first end face 401 and a second end face 402 that are opposite to each other. Fig. 9 , one of the first end surface 401 and the second end surface 402 is arranged between the other and the bottom of the bearing groove 123. For ease of description, in the subsequent embodiments, it is defined that the first end surface 401 of the conductive structure 40 is 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.

[0117] Please combine Figure 5 and Fig.10 As shown, 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 the other end of the axial protrusion 121 and the second end face 402. The conductive structure 40 is closer to the bottom of the bearing groove 123 along the axial direction of the motor shaft 211, and farther from the oil nozzle for conveying coolant or lubricating oil from the axial protrusion 121. That is, the conductive structure 40 is closer to the bottom of the bearing groove 123 along the axial direction of the motor shaft 211. The contact between the conductive structure 40 and the coolant or lubricating oil can be reduced, and the conductive structure 40 can be prevented from premature failure due to excessive infiltration of the coolant or lubricating oil.

[0118] In one embodiment, the conductive structure 40 is annular, wherein along the radial direction of the motor shaft 211 , the outer diameter of the conductive structure 40 is greater than or equal to the inner diameter of the shaft hole 212 of the motor shaft 211 , and the inner diameter of the conductive structure 40 is less than or equal to the outer diameter of the axial protrusion 121 .

[0119] In one embodiment, please combine Figure 7 and Figure 8 As shown, the outer peripheral surface of the conductive structure 40 is in contact with the first bonding section 2124, so that an electrical connection is formed between the conductive structure 40 and the shaft hole 212. Fig. 9 and Fig.10As shown, the inner circumference of the conductive structure 40 and the second fitting section 1211 are in contact with each other, so that the conductive structure 40 is electrically connected to the axial protrusion 121. The conductive structure 40 is elastically deformed so that the outer circumference of the conductive structure 40 fits with the first fitting section 2124, and the inner circumference of the conductive structure 40 fits with the second fitting section 1211, thereby achieving electrical connection between the shaft hole 212 and the axial protrusion 121.

[0120] It can be understood that the outer circumference of the conductive structure 40 forms an interference fit with the inner circumference of the shaft hole 212 of the motor shaft 211, or the outer circumference of the conductive structure 40 is elastically deformed to fit with the inner circumference of the shaft hole 212 of the motor shaft 211, so as to ensure reliable contact and electrical connection between the conductive structure 40 and the shaft hole 212. The inner circumference of the conductive structure 40 forms an interference fit with the outer circumference of the axial protrusion 121, or the inner circumference of the conductive structure 40 is elastically deformed to fit with the outer circumference of the axial protrusion 121, so as to ensure reliable connection and electrical connection between the conductive structure 40 and the axial protrusion 121.

[0121] See also Fig.11 Another exploded schematic diagram of the powertrain 100 provided in an embodiment of the present application.

[0122] In one embodiment, the conductive structure 40 includes an inner ring and an outer ring, wherein the inner ring and the outer ring are sequentially sleeved on the outer circumference of the axial protrusion 121 along the radial direction of the motor shaft 211, and the outer diameter of the inner ring is greater than the inner diameter of the outer ring.

[0123] In one embodiment, if Fig.11 As shown, the conductive structure 40 is composed of an inner ring and an outer ring which are nested with each other, the outer ring is a conductive bearing 42, and the inner ring is a conductive rubber ring 41. The outer circumference of the inner ring is interference fit with the inner circumference of the outer ring to ensure reliable electrical connection between the inner ring and the outer ring.

[0124] In one embodiment, the outer circumference of the inner ring of the conductive structure 40 and the inner circumference of the outer ring abut against each other through elastic deformation, which can also ensure the reliability of the electrical connection between the inner ring and the outer ring.

[0125] In one embodiment, one of the inner ring and the outer ring is a conductive bearing 42 , and the other is a conductive rubber ring 41 .

[0126] like Fig.10 and Fig.11 As shown, the outer ring is a conductive bearing 42, and the inner ring is a conductive rubber ring 41. In one embodiment, the outer ring is a conductive rubber ring 41, and the inner ring is a conductive bearing 42.

[0127] It can be understood 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 inner ring or outer ring formed by 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 inner ring or outer ring formed by the conductive rubber ring 41 is used to offset the wear of the conductive structure 40 through elastic deformation to ensure reliable electrical connection. Further, by setting the structure or material of the inner ring and the outer ring differently, the conductive structure 40 can take into account both structural reliability and wear resistance.

[0128] In one embodiment, the length of the conductive rubber ring 41 along the axial direction of the motor shaft 211 is smaller than the length of the conductive bearing 42. The inner ring is the conductive bearing 42, and the gap between the portion of the outer circumference of the conductive bearing 42 that exceeds the conductive rubber ring 41 and one section of the shaft hole 212 is smaller than the gap between the other section of the shaft hole 212 and the other end of the axial protrusion 121.

[0129] See also Fig.12 Another cross-sectional schematic diagram of the powertrain 100 provided in an embodiment of the present application is shown.

[0130] like Fig.12 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 motor shaft 211 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 motor shaft 211 and the inner peripheral surface of the first shaft hole section 2121 of the shaft hole 212 is the second size L2. The gap size between the inner peripheral surface of the second shaft hole section 2122 of the radial shaft hole 212 of the motor shaft 211 and the outer peripheral surface of the axial protrusion 121 is the first size L1.

[0131] The second dimension L2 is smaller than the first dimension L1. The radial movement of the motor shaft 211 drives the exposed outer peripheral surface of the conductive bearing 42 to abut against the first shaft hole section 2121 of the shaft hole 212 to limit the radial displacement of the motor shaft 211 relative to the axial protrusion 121 and prevent the second shaft hole section 2122 from contacting the axial protrusion 121.

[0132] In one embodiment, the outer ring is a conductive bearing 42 , and the gap between the portion of the inner circumference of the conductive bearing 42 that extends beyond the conductive rubber ring 41 and the axial protrusion 121 is smaller than the gap between the other section of the shaft hole 212 and the other end of the axial protrusion 121 .

[0133] See also Fig.13 Another cross-sectional schematic diagram of the powertrain 100 provided in an embodiment of the present application is shown.

[0134] like Fig.13As 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 motor shaft 211 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 motor shaft 211 and the outer circumference of the axial protrusion 121 is the third size L3.

[0135] The third dimension L3 is smaller than the first dimension L1. Accordingly, the radial movement of the motor shaft 211 drives the exposed inner circumference of the conductive bearing 42 to abut against the axial protrusion 121 to limit the radial displacement of the motor shaft 211 relative to the axial protrusion 121 and prevent the second shaft hole section 2122 from contacting the axial protrusion 121.

[0136] It can be understood that the conductive bearing 42 has a high rigidity, and the radial movement of the motor shaft 211 drives the portion of the conductive bearing 42 that extends 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 second shaft hole section 2122 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.

[0137] In one embodiment, there are two conductive rubber rings 41 , wherein the two conductive rubber rings 41 are arranged at intervals along the axial direction of the motor shaft 211 , and the sum of the interval between the two conductive rubber rings 41 and the length of the two conductive rubber rings 41 is less than or equal to the length of the conductive bearing 42 .

[0138] See also Fig.14 Another cross-sectional schematic diagram of the powertrain 100 provided in an embodiment of the present application is shown.

[0139] like Fig.14 As shown, the 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 motor shaft 211 to form an inner ring of the conductive structure 40. The two conductive rubber rings 41 spaced apart along the axial direction of the motor shaft 211 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.

[0140] In one embodiment, the elastic modulus of one of the two conductive rubber rings 41 is greater than the elastic modulus of the other conductive rubber ring 41. Fig.14As 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 elastic modulus of the materials of the two conductive rubber rings 41 differently, the elastic forces of the two conductive rubber rings 41 along the radial direction of the motor shaft 211 can be different. After the power assembly 100 of the present application has been working for a long time, the wear amount of the two conductive rubber rings 41 is different. The conductive rubber ring 41 with less wear can compensate the wear amount of the other conductive rubber ring 41 through elastic deformation.

[0141] In one embodiment, one conductive rubber ring 41 is arranged between another conductive rubber ring 41 and the bottom of the bearing groove 123 along the axial direction of the motor shaft 211 .

[0142] See also Fig.15 Another cross-sectional schematic diagram of the powertrain 100 provided in an embodiment of the present application is shown.

[0143] like Fig.15 As shown, along the axial direction of the motor shaft 211, the second conductive rubber ring 412 is located on the side of the first conductive rubber ring 411 away from the bottom of the bearing groove 123. That is, compared with the first conductive rubber ring 411, the second conductive rubber ring 412 is closer to the second shaft hole section 2122 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.

[0144] In one embodiment, the inner ring is a conductive bearing 42, and the gap between the outer circumference of the conductive bearing 42 located between the two conductive rubber rings 41 along the axial direction of the motor shaft 211 and the inner circumference of the shaft hole 212 is smaller than the gap between the other section of the shaft hole 212 and the other end of the axial protrusion 121.

[0145] like Fig.15 As shown, the inner ring of the conductive structure 40 is a conductive bearing 42, and the outer ring is a first conductive rubber ring 411 and a second conductive rubber ring 412 arranged at intervals. Along the axial direction of the motor shaft 211, the sum of the spacing between the first conductive rubber ring 411 and the second conductive rubber ring 412, the size of the first conductive rubber ring 411, and the size of the second conductive rubber ring 412 is smaller than the size 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 motor shaft 211 and the inner peripheral surface of the first shaft hole section 2121 of the shaft hole 212 is the fourth size L4.

[0146] The fourth dimension L4 is smaller than the first dimension L1. Accordingly, the radial movement of the motor shaft 211 drives the exposed outer peripheral surface of the conductive bearing 42 to abut against the first shaft hole section 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 second shaft hole section 2122 from contacting the axial protrusion 121.

[0147] In one embodiment, the outer ring is a conductive bearing 42, and the gap between the inner circumference of the conductive bearing 42 located between the two conductive rubber rings 41 along the axial direction of the motor shaft 211 and the outer circumference of the axial protrusion 121 is smaller than the gap between the other section of the shaft hole 212 and the other end of the axial protrusion 121.

[0148] See also Fig.16 Another cross-sectional schematic diagram of the powertrain 100 provided in an embodiment of the present application is shown.

[0149] like Fig.16 As shown, the inner ring of the conductive structure 40 is a first conductive rubber ring 411 and a second conductive rubber ring 412 arranged at intervals, and the outer ring is a conductive bearing 42. Along the axial direction of the motor shaft 211, the sum of the spacing between the first conductive rubber ring 411 and the second conductive rubber ring 412, the size of the first conductive rubber ring 411, and the size of the second conductive rubber ring 412 is smaller than the size 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 motor shaft 211 and the outer circumference of the axial protrusion 121 is the fifth size L5.

[0150] The fifth dimension L5 is smaller than the first dimension L1. Accordingly, the radial movement of the motor shaft 211 drives the exposed inner circumference of the conductive bearing 42 to abut against the axial protrusion 121 to limit the radial displacement of the motor shaft 211 relative to the axial protrusion 121 and prevent the second shaft hole section 2122 from contacting the axial protrusion 121.

[0151] It can be understood that the conductive bearing 42 has a high rigidity, and the radial movement of the motor shaft 211 drives the portion of the conductive bearing 42 located between the two conductive rubber rings 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 second shaft hole section 2122 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.

[0152] 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.

[0153] See also Fig.17 Another cross-sectional schematic diagram of the powertrain 100 provided in an embodiment of the present application is shown.

[0154] like Fig.17 As shown, the axial sleeve 43 is used to extend along the axial direction of the motor shaft 211 to increase the contact area between the conductive structure 40 and the axial protrusion 121, thereby fixing the conductive structure 40 to the outer circumference 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 circumference of the shaft hole 212 of the motor shaft 211 continuously rotates and rubs the outer circumference of the conductive structure 40. The wear-resistant conductive coating coated on the outer circumference of the conductive structure 40 is used to reduce the wear of the outer circumference of the conductive structure 40, and conduct the electrical connection between the outer circumference of the conductive structure 40 and the inner circumference of the shaft hole 212 of the motor shaft 211.

[0155] 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 to be coated with a wear-resistant conductive coating. Fig.17 The axial sleeve 43 is used to extend along the axial direction of the motor shaft 211 to increase the contact area between the conductive structure 40 and the shaft hole 212 of the motor shaft 211, so as to fix 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.

[0156] 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 one end of the axial sleeve 43 near the bottom of the bearing groove 123 along the axial direction of the motor shaft 211.

[0157] 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 the present application.

[0158] 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 shaft hole section 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 near 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.

[0159] 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 shaft hole 212 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 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.

[0160] 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 shaft hole section 2121. It can be understood that the curling edge is elastic, and when the conductive structure 40 is installed in the gap between the axial protrusion 121 and the shaft hole 212, the curling edge undergoes a certain elastic deformation toward the axial sleeve 43. The elasticity of the curling edge can compensate when the curling edge is worn, avoiding the formation of a gap between the curling edge and the inner peripheral surface of the first shaft hole section 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 edge.

[0161] 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.

[0162] 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.

[0163] 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.

[0164] In one embodiment, along the axial direction of the motor shaft 211 , the axial sleeve 43 extends in a direction away from the groove bottom of the bearing groove 123 .

[0165] like Fig.18 and Fig.19 As shown, along the axial direction of the motor shaft 211, the axial sleeve 43 is relatively close to the second shaft hole section 2122 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 at the side of the groove bottom close to the bearing groove 123. The radial protrusion 44 is relatively far away from the second shaft hole section 2122 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.

[0166] 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 power assembly for preventing electrical corrosion of bearings, characterized in that: The housing of the power assembly is used to accommodate a drive motor, the drive motor includes a motor shaft and a motor stator, the motor shaft is used to drive the wheel through a reducer, the housing includes an axial housing, the axial housing is arranged on one side of the motor stator along the axial direction of the motor shaft, the end surface of the axial housing facing the motor stator includes a bearing groove and an axial protrusion, the bearing groove is used to accommodate a motor bearing, the motor bearing is used to drive and connect the motor shaft, one end of the axial protrusion is used to fix the bottom of the bearing groove, and the other end of the axial protrusion is used to extend into the shaft hole of the motor shaft along the axial direction of the motor shaft, wherein: The end surface of the other end of the one axial protrusion comprises a through hole, and the one through hole is used to connect the internal flow channel of the one axial housing and the shaft hole of the one motor shaft; The gap between the outer circumference of the one axial protrusion and the inner circumference of the axial hole is used to accommodate a conductive structure, and the conductive structure is used to conduct the electrical connection between the outer circumference of the one axial protrusion and the inner circumference of the axial hole.

2. The powertrain according to claim 1, characterized in that: The shaft hole includes two sections along the axial direction of the motor shaft, one section is used to accommodate the conductive structure, and the other end of the axial protrusion is used to pass through the conductive structure and extend into the other section of the motor shaft, wherein: Along the radial direction of the motor shaft, a gap between an outer circumferential surface of the one axial protrusion and an inner circumferential surface of the one segment is larger than a gap between an outer circumferential surface of the one axial protrusion and an inner circumferential surface of the other segment.

3. The powertrain according to claim 2, characterized in that: The conductive structure includes two end faces facing each other along the axial direction of the motor shaft, wherein one end face 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 the end face is smaller than the distance between the other end of the axial protrusion and the other end face.

4. The powertrain according to claim 2 or 3, characterized in that: The outer peripheral surface of the one axial protrusion along the axial direction of the one motor shaft includes a fitting section, and the one conductive structure is used to conduct electrical connection between the outer peripheral surface of the one fitting section and the inner peripheral surface of the shaft hole, wherein: Along the radial direction of the motor shaft, the outer diameter of the fitting section is smaller than the outer diameter of the remaining portion of the axial protrusion; Along the axial direction of the motor shaft, the length of the fitting section is greater than or equal to the length of the conductive structure.

5. The powertrain according to any one of claims 2 to 4, characterized in that: The two sections of the axial hole of the motor shaft are used to form a step surface, and the step surface faces the conductive structure along the axial direction of the motor shaft, 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.

6. The power assembly according to any one of claims 2 to 5, characterized in that: The inner circumference of a section of the shaft hole along the axial direction of the motor shaft includes another fitting section, and the conductive structure is used to electrically connect the inner circumference of the other fitting section and the outer circumference of the axial protrusion, wherein: Along the radial direction of the motor shaft, the inner diameter of the other fitting section is larger than the inner diameter of the remaining section of the shaft hole; Along the axial direction of the motor shaft, the length of the other fitting section is greater than or equal to the length of the conductive structure.

7. The power assembly according to any one of claims 2 to 6, characterized in that: The outer peripheral surface of the motor shaft along the axial direction of the motor shaft includes a first section and a second section connected to each other, wherein: Along the radial direction of the motor shaft, the outer diameter of the first section is smaller than the outer diameter of the second section and is greater than or equal to the inner diameter of the motor bearing; Along the axial direction of the motor shaft, the length of the first section is greater than the length of a section of the shaft hole.

8. The power assembly according to any one of claims 1 to 7, characterized in that: The one conductive structure is ring-shaped, wherein: Along the radial direction of the motor shaft, the outer diameter of the conductive structure is greater than or equal to the inner diameter of the shaft hole of the motor shaft, and the inner diameter of the conductive structure is less than or equal to the outer diameter of the axial protrusion.

9. The powertrain according to claim 8, characterized in that: The one conductive structure comprises an axial sleeve, wherein: The one conductive structure is fixed to the outer peripheral surface of the one axial protrusion through the one axial sleeve, and the outer peripheral surface of the one conductive structure is used for coating a wear-resistant conductive coating; or, The one conductive structure is fixed to the inner circumference of the axial hole through the one axial sleeve, and the inner circumference of the one conductive structure is used for coating a wear-resistant conductive coating.

10. The powertrain according to claim 9, characterized in that: Along the axial direction of the motor shaft, the axial sleeve extends in a direction away from a groove bottom of the bearing groove.

11. The powertrain according to claim 8, characterized in that: The conductive structure comprises an inner ring and an outer ring, wherein: The inner ring and the outer ring are sequentially sleeved on the outer peripheral surface of the axial protrusion along the radial direction of the motor shaft, and the outer diameter of the inner ring is greater than the inner diameter of the outer ring; One of the inner ring and the outer ring is a conductive bearing, and the other is a conductive rubber ring.

12. The powertrain according to claim 11, characterized in that: The length of the conductive rubber ring along the axial direction of the motor shaft is less than the length of the conductive bearing, wherein: The one inner ring is the conductive bearing, and the gap between the portion of the outer circumferential surface of the conductive bearing that exceeds the conductive rubber ring and one section of the shaft hole is smaller than the gap between the other section of the shaft hole and the other end of the one axial protrusion; or The one outer ring is the conductive bearing, and the gap between the portion of the inner circumference of the conductive bearing that exceeds the conductive rubber ring and the one axial protrusion is smaller than the gap between the other section of the shaft hole and the other end of the one axial protrusion.

13. The power assembly according to claim 11 or 12, characterized in that: The number of the conductive rubber rings is two, wherein: Along the axial direction of the motor shaft, the two conductive rubber rings are arranged at intervals, and the sum of the interval between the two conductive rubber rings and the length of the two conductive rubber rings is less than or equal to the length of the conductive bearing.

14. The powertrain according to claim 13, characterized in that: The elastic modulus of one of the two conductive rubber rings is greater than that of the other conductive rubber ring, and the one conductive rubber ring is arranged between the other conductive rubber ring and the bottom of the bearing groove along the axial direction of the motor shaft.

15. An electric vehicle, characterized in that: The electric vehicle comprises wheels and a powertrain as claimed in any one of claims 1 to 14, wherein the powertrain is used to drive the wheels of the electric vehicle.

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