Driving motor with bearing active lubrication function, power assembly and electric vehicle

Abstract

This application provides a drive motor, powertrain, and electric vehicle with active bearing lubrication function. The drive motor housing includes a motor end cover and a motor housing. The motor end cover encloses the motor housing to form a receiving cavity. The side of the motor end cover facing the stator includes a bearing groove and an oil guide protrusion. The bearing groove is used to fix the motor bearing of the drive motor. The groove opening faces the rotor of the drive motor, and the groove peripheral wall of the bearing groove protrudes towards the motor housing. The inner surface of the groove peripheral wall of the bearing groove includes a first opening. The oil guide protrusion protrudes towards the rotor of the drive motor. The interior of the oil guide protrusion includes a first internal flow channel, which receives oil output from the oil pump and transports oil through the first opening into the bearing groove to actively lubricate the motor bearing. This application uses the first internal flow channel located inside the oil guide protrusion of the motor end cover to lubricate the motor bearing, which can improve the lubrication efficiency of the motor bearing.

Description

Technical Field

[0001] This application relates to the field of electric vehicle technology, and in particular to a drive motor, powertrain, and electric vehicle with active bearing lubrication function. Background Technology

[0002] In the new energy vehicle industry, the powertrain is the main power source for vehicles. Among them, the drive motor, as an important component of the powertrain, can convert the electrical energy delivered by the power battery into mechanical energy, and drive the wheels to rotate through the reducer to meet the needs of the vehicle during driving.

[0003] With the continuous development of the new energy industry, the requirements for the power density of drive motors are becoming increasingly stringent. High power density drive motors increase the load and friction on the bearings. However, current drive motor bearings suffer from insufficient lubrication, which can lead to severe bearing wear, shorten the drive motor's lifespan, and negatively impact the normal operation of the powertrain. Summary of the Invention

[0004] This application provides a drive motor, powertrain, and electric vehicle with active bearing lubrication function, which can enhance the lubrication effect on motor bearings.

[0005] In a first aspect, embodiments of this application provide a drive motor with active bearing lubrication function. The drive motor housing includes a motor end cover and a motor housing. The motor end cover encloses the motor housing to form a receiving cavity, which is used to fix the stator of the drive motor and accommodate the rotor of the drive motor. The side of the motor end cover facing the stator includes a bearing groove and an oil guide protrusion.

[0006] One bearing slot is used to fix the motor bearing of the drive motor. The opening of the bearing slot faces the rotor of the drive motor along the axial direction of the drive motor, and the peripheral wall of the bearing slot protrudes towards a motor housing along the axial direction of the drive motor. The inner surface of the peripheral wall of the bearing slot includes a first opening.

[0007] An oil guide protrusion protrudes along the axial direction of the drive motor toward the rotor of the drive motor. The interior of the oil guide protrusion includes a first internal flow channel, one end of which is used to receive oil output from an oil pump, and the other end of which is used to deliver oil through a first opening into a bearing groove to actively lubricate the motor bearing.

[0008] In this embodiment, the outer ring of the motor bearing is fixed to the bearing groove of the motor end cover, and the inner ring of the motor bearing is fixed to the motor shaft. The outer ring and inner ring of the motor bearing are rotatably connected, so that the motor shaft and the inner ring of the motor bearing can rotate relative to the motor end cover and the outer ring of the motor bearing.

[0009] Because motor shafts typically rotate at high speeds, driving motor bearings to rotate at high speeds, it is crucial to ensure adequate lubrication of the bearings to extend their service life and improve the safety performance of the drive motor and powertrain. However, current lubrication methods for motor bearings typically employ passive lubrication, which involves collecting oil ejected from rotating components such as the motor rotor or leaking from certain structures, and then channeling the collected oil into the bearing grooves. This passive lubrication method is limited by the rotational speed of the rotating components and the temperature of the oil: excessively low rotational speeds result in insufficient power for oil movement, and excessively low oil temperatures lead to high oil viscosity, both negatively impacting oil collection and hindering lubrication efficiency.

[0010] In this embodiment of the application, in order to avoid the defects caused by passive lubrication of the motor bearing, this embodiment of the application uses an oil pump to actively deliver oil to the bearing groove. Driven by the oil pump, the flow of oil is not easily affected by the rotation speed of the rotating parts and the oil temperature, so that the motor bearing in the bearing groove can be stably lubricated.

[0011] Active lubrication involves the delivery of oil. Some existing technologies use oil guides to deliver oil to the bearing grooves; these guides are separate from the motor end cover or motor housing. The assembly process between the oil guide and the motor end cover or housing is complex and costly, which is detrimental to improving the overall structural stability of the drive motor. Furthermore, the oil guides must be designed to avoid interference with other components within the housing, otherwise, it will adversely affect the normal operation of the drive motor.

[0012] Furthermore, some existing technologies utilize oil passages in the motor end cover for active lubrication of the motor bearings, with these passages directly exposed to the housing cavity. While integrating the oil passages into the motor end cover avoids the problems associated with using oil guides, the fact that these passages are not closed structures means that the oil may leak due to the influence of rotating components such as the motor shaft and rotor, making it difficult to ensure that the majority of the oil flows into the bearing groove.

[0013] In this embodiment, to reduce the risks associated with oil delivery during active lubrication, the first internal flow channel for delivering oil to the bearing groove is located inside the motor end cover. This effectively prevents oil leakage and improves oil utilization. This embodiment also reduces interference from rotating components such as the rotor on oil delivery, ensuring a stable delivery of oil to the bearing groove via the first internal flow channel.

[0014] In this embodiment, the bearing groove is distributed on one side of the motor end cover facing the motor housing. The bearing groove protrudes towards the motor housing along the axial direction of the drive motor, so that the bearing groove can utilize the space of the receiving cavity to reduce the overall axial length of the drive motor, making the arrangement of the drive motor more compact and conducive to the miniaturization design of the powertrain.

[0015] In the case where the bearing groove protrudes towards the motor housing, the first internal flow channel in this embodiment is distributed inside the oil guide protrusion of the motor end cover. Similar to the bearing groove, the oil guide protrusion also protrudes towards the motor housing, which can shorten the axial distance between the first internal flow channel located inside the oil guide protrusion and the bearing groove. This facilitates the fit between the first internal flow channel and the groove wall of the bearing groove, allowing the oil to flow through the first opening in the groove wall of the bearing groove to the motor bearing, thus reducing oil loss along the transmission path. The oil guide protrusion is an integrally formed structure with the motor end cover, resulting in strong structural stability. Compared to using an oil guide component separate from the motor end cover, this embodiment simplifies the assembly process and reduces processing costs.

[0016] In this embodiment, the first opening is distributed on the inner surface of the bearing groove's peripheral wall. The other end of the oil guide protrusion delivers oil to the bearing groove through the first opening, effectively connecting the first internal flow channel with the inner surface of the bearing groove's peripheral wall. This helps reduce oil loss at the first opening. Furthermore, the first opening's location on the bearing groove's peripheral wall allows the oil to flow along the drive motor's axial direction towards the bottom and opening of the bearing groove, respectively. This extends the contact time between the oil and the motor bearing, enhancing the oil's wetting effect on the motor bearing.

[0017] In one embodiment, the inner surface of the peripheral wall of a bearing groove further includes a second opening, and the outer surface of the peripheral wall of a bearing groove includes a third opening, with the second opening and the third opening communicating with each other. An oil guiding protrusion is used to guide oil through the third opening and the second opening into a bearing groove for passive lubrication of the motor bearing.

[0018] In this configuration, a second opening and a third opening are arranged on the same side of a first opening along the circumference of the drive motor.

[0019] In this embodiment, the oil-guiding protrusion, in addition to actively lubricating the motor bearing through the first internal flow channel, also serves as a passive lubricator, supplementing the effect of active lubrication. Specifically, the oil-guiding protrusion protrudes towards the motor housing along the axial direction of the drive motor, shortening the axial distance between the oil-guiding protrusion and the stator and rotor of the drive motor. This makes it easier for the oil transmitted from the stator or rotor to the motor end cover to be collected by the outer surface of the oil-guiding protrusion. The outer surface of the oil-guiding protrusion is used to transport the collected oil to the bearing groove, achieving structural reuse of the oil-guiding protrusion. This embodiment combines active and passive lubrication, which helps to increase the amount of oil used to lubricate the motor bearing and enhances the lubrication effect on the motor bearing.

[0020] In this embodiment, the bearing groove's peripheral wall includes a second opening and a third opening, which are respectively distributed on the inner and outer surfaces of the bearing groove's peripheral wall. An oil-guiding protrusion is arranged adjacent to the second and third openings, which are located on the same side of the first opening along the circumference of the drive motor. This facilitates the sequential flow of oil collected by the oil-guiding protrusion to the third and second openings, and also avoids negative impacts on the layout of the oil-guiding protrusion and the first opening.

[0021] In one embodiment, the distance between a first opening and the bottom of a bearing groove is greater than or equal to the distance between a second opening and the bottom of a bearing groove.

[0022] In this embodiment, the first opening is further away from the bottom of the bearing groove than the second opening. This means the axial distance between the first opening and the opening of the bearing groove is less than or equal to the axial distance between the second opening and the opening of the bearing groove. This facilitates the engagement of the first opening with the first internal flow channel of the oil guide protrusion, thus shortening the active lubrication path. The second opening is used for passive lubrication. Passive lubrication relies on the oil guide protrusion and the outer surface of the bearing groove's peripheral wall to collect and guide the oil. The second opening is relatively close to the bottom of the bearing groove, further shortening the passive lubrication path. By adjusting the distances between the first and second openings and the bottom of the bearing groove, this embodiment reduces oil loss along the transmission path in both active and passive lubrication.

[0023] In one embodiment, the diameter of a second opening is larger than the diameter of a first opening and smaller than the diameter of a third opening, and the diameter of a first opening is smaller than the length of an oil guide protrusion along the circumference of the drive motor.

[0024] In this embodiment, passive lubrication is affected by the rotational speed of the drive motor, resulting in an unstable oil source. The diameters of both the second and third openings are larger than the diameter of the first opening, which helps increase the amount of oil used for passive lubrication. The third opening is located on the outer surface of the bearing groove's peripheral wall. Since the diameter of the third opening is larger than that of the second opening, it reduces the difficulty of oil flowing from the guide protrusion into the third opening, thus reducing the flow resistance of the oil in passive lubrication.

[0025] In this embodiment, the diameter of the first opening is smaller than the circumferential length of the oil guide protrusion. The first opening can be used to throttle the active lubricating oil, which is beneficial to controlling the flow rate and velocity of the oil flowing into the bearing groove through the first opening.

[0026] In one embodiment, a third opening faces the opposite direction to a second opening, and the angle between the orientation of the third opening and the radial direction of the drive motor is greater than 0 degrees and less than 30 degrees.

[0027] In this embodiment, the third and second openings are used to cooperate with the oil guide protrusions to achieve passive lubrication. Passive lubrication requires the oil to be collected and guided by the oil guide protrusions and the outer surface of the bearing groove's peripheral wall. The angle between the orientation of the third opening and the radial direction of the drive motor is within the range of 0 to 30 degrees, allowing the oil collected by the oil guide protrusions to flow more quickly into the third and second openings. Controlling the angle between the orientation of the third opening and the radial direction of the drive motor within a small range also helps to reduce the machining difficulty of the third and second openings.

[0028] In one embodiment, the height of an oil guide protrusion along the axial direction of the drive motor is less than the height of the peripheral wall of a bearing groove.

[0029] In this embodiment, the length of the transmission path of the first internal flow channel affects the efficiency of oil lubrication. If the axial height of the oil guide protrusion is greater than or equal to the axial height of the bearing groove's peripheral wall, and the inner diameter of the first internal flow channel remains unchanged, the distance between at least one end of the first internal flow channel and the bottom of the bearing groove will be greater than or equal to the axial height of the bearing groove's peripheral wall. This will lengthen the transmission path of the first internal flow channel and increase the energy loss of the oil. Furthermore, since the first opening is distributed on the bearing groove's peripheral wall, an axial height of the oil guide protrusion greater than or equal to the axial height of the bearing groove's peripheral wall will also make it difficult for the first internal flow channel to directly connect with the first opening.

[0030] In this embodiment, the axial height of the oil guide protrusion is less than the axial height of the bearing groove's peripheral wall, which helps to shorten the oil transmission path in the first internal flow channel and reduces the difficulty of connecting the first internal flow channel and the first opening. This embodiment also reduces the space occupied by the oil guide protrusion in the receiving cavity, which is beneficial for optimizing the layout of the drive motor.

[0031] In one embodiment, an oil guide protrusion extends in a direction parallel to the radial direction of the drive motor.

[0032] In this embodiment, the extension direction of the first internal flow channel is parallel to the extension direction of the oil guide protrusion. The extension direction of the oil guide protrusion is parallel to the radial direction of the drive motor, which means the flow direction of the oil from one end of the first internal flow channel to the other is perpendicular to the protrusion direction of the bearing groove's peripheral wall. This helps to shorten the flow path of the oil in the first internal flow channel and improve lubrication efficiency. Assuming that the projection positions of the two ends of the first internal flow channel along the axial direction of the drive motor remain unchanged, only by adjusting the extension direction of the first internal flow channel can the transmission path of the first internal flow channel be minimized when the extension direction of the first internal flow channel is perpendicular to the axial direction of the drive motor. Furthermore, this embodiment also helps to reduce the machining difficulty of the oil guide protrusion and the first internal flow channel.

[0033] In one embodiment, a motor end cover further includes an annular mounting surface for securing a housing mounting surface of a motor housing. The annular mounting surface faces the motor housing along the axial direction of the drive motor and surrounds the peripheral wall of a bearing groove. The housing mounting surface of the motor housing includes an oil outlet for discharging oil received from an oil pump through a second internal flow channel of the motor housing. The annular mounting surface includes a connecting hole for connecting the oil outlet and a first internal flow channel.

[0034] In this embodiment, the motor housing includes a second internal flow channel, which sequentially delivers oil from the oil pump to the oil outlet of the motor housing, the connecting hole of the motor end cover, and the first internal flow channel. The second internal flow channel is located inside the motor housing, which helps to reduce oil leakage.

[0035] In this embodiment, the annular mounting surface of the motor end cover and the housing mounting surface of the motor housing are fixed along the axial direction of the drive motor. A connecting hole and an oil outlet are respectively distributed on the annular mounting surface and the housing mounting surface, and the connecting hole and the oil outlet are opposite each other along the axial direction of the drive motor. An oil guide protrusion protrudes towards the motor housing along the axial direction of the drive motor, which can shorten the axial distance between the first internal flow channel and the connecting hole and the oil outlet, reducing the energy loss of oil transported from the motor housing to the motor end cover.

[0036] In one embodiment, an annular mounting surface further includes a plurality of fixing holes, each fixing hole for receiving a fixing member, and each fixing member for being embedded in the housing mounting surface of a motor housing after passing through a fixing hole.

[0037] In this configuration, along the circumference of the drive motor, a connecting hole is arranged between two fixed holes, and the distance between a connecting hole and an adjacent fixed hole is less than the distance between any two fixed holes.

[0038] In this embodiment, the fastener passes through the fixing hole of the motor end cover and is embedded in the motor housing to fix the motor end cover to the motor housing. Both the fixing hole and the connecting hole are distributed on the annular mounting surface of the motor end cover, with the connecting hole arranged between two fixing holes. If the distance between the connecting hole and an adjacent fixing hole is greater than the distance between any two fixing holes, it indicates that the distance between the two fixing holes adjacent to the connecting hole is too large, which may impair the connection strength between the motor end cover and the motor housing at the two fixing holes. This embodiment adjusts the distance between the connecting hole and the fixing holes on both sides to be smaller than the distance between any two fixing holes, thus avoiding the negative impact of the connecting hole on the arrangement of the fixing holes.

[0039] In this embodiment, the distance between the connecting hole and the adjacent fixing hole is relatively small, which also helps to distinguish the connecting hole from multiple fixing holes, avoid mixing the connecting hole and the fixing hole, ensure that the oil flows normally into the connecting hole, and ensure that the motor end cover and the motor housing can be properly fixed.

[0040] In one embodiment, a connecting hole includes two first openings distributed along the axial direction of the drive motor, one of the first openings being used to connect to an oil outlet, and the other of the two first openings being used to connect to a first internal flow channel.

[0041] In this case, the diameter of one first opening in a connecting hole is larger than the diameter of each fixed hole, and the diameter of the other first opening in a connecting hole is smaller than the diameter of one first opening in a connecting hole and the diameter of an oil outlet hole.

[0042] In this embodiment, one first opening and the other first opening of the connecting hole are axially opposite to each other along the drive motor. The inner diameter of one first opening is larger than the inner diameter of the other first opening, which helps to prevent debris from clogging the connecting hole. The larger diameter of one first opening compared to the other first opening ensures that even if some debris enters one first opening, the oil can still flow sequentially through it to the other first opening and the first internal flow channel, reducing interference between the annular mounting surface and the housing mounting surface on the oil flow.

[0043] In this embodiment, the diameter of the other first opening of the connecting hole is smaller than the diameter of one first opening and one oil outlet, allowing the other first opening of the connecting hole to act as a throttling device, preventing excessive oil from flowing into the bearing groove through the first internal flow channel, thus reducing oil churning losses in the motor bearing. This embodiment also facilitates the rational distribution of oil in the drive motor through the other first opening of the connecting hole, and further allows for the use of oil to lubricate or cool other components of the drive motor, improving oil utilization.

[0044] In one embodiment, the projection of the second internal flow channel along the axial direction of the drive motor is located within the projection of one first opening of the connecting hole, and the projection of the second internal flow channel along the axial direction of the drive motor does not overlap with the projection of the other first opening of the connecting hole.

[0045] In this embodiment, one first opening of the connecting hole is opposite to the second internal flow channel along the axial direction of the drive motor, which helps to reduce the flow resistance of oil flowing from the motor housing into the motor end cover. The other first opening of the connecting hole is offset from the second internal flow channel along the axial direction of the drive motor, allowing oil flowing into one of the first openings of the connecting hole to change its flow direction and move away from the edge of the first opening. In this case, even if some debris moves from the edge of one first opening into the connecting hole, it can be ensured that the oil in the connecting hole flows smoothly into the first internal flow channel.

[0046] In one embodiment, the length of a connecting hole along the axial direction of the drive motor is less than the height of the peripheral wall of a bearing groove.

[0047] In this embodiment, the connecting hole is used to connect an oil outlet hole of the motor housing with the first internal flow channel. The axial length of the connecting hole is less than the axial height of the groove wall of the bearing groove. It cooperates with the oil guide protrusion protruding towards the motor housing, which can further shorten the axial distance between the motor housing and the first internal flow channel and reduce the loss of oil transmission between the motor housing and the first internal flow channel.

[0048] In one embodiment, an inner peripheral wall of a motor housing includes another oil outlet. This other oil outlet is used to discharge oil received from an oil pump by a second internal flow channel of the motor housing to the stator cooling flow channel of the drive motor. The second openings of a plurality of oil drain holes in the stator cooling flow channel face a motor end cover. The diameter of one oil outlet is smaller than the diameter of the other oil outlet but larger than the diameter of each individual oil drain hole.

[0049] In this embodiment, one oil outlet of the motor housing connects the second internal flow channel to the first internal flow channel of the motor end cover, and the other oil outlet of the motor housing connects the second internal flow channel to the stator cooling flow channel. After receiving the oil from the oil pump, the second internal flow channel transmits a portion of the oil to the bearing groove of the motor end cover for active lubrication of the motor bearings, and transmits the other portion of the oil to the stator cooling flow channel for cooling the stator of the drive motor, which helps to improve the utilization rate of the oil.

[0050] In this embodiment, the oil in the stator cooling channel cools the stator and then flows out of the stator cooling channel through the oil drain hole. The oil drain hole includes a second opening facing the motor end cover, so that the oil guide protrusion of the motor end cover can collect part of the oil flowing out through the second opening.

[0051] In this embodiment, the diameter of one oil outlet is smaller than that of the other oil outlet, so that more oil flows to the stator cooling channel and less oil flows to the first internal channel. The reasonable distribution of oil is achieved by the cooperation of one oil outlet and the other oil outlet, which can enhance the cooling effect on the stator while reducing the oil churning loss of the motor bearing.

[0052] In one embodiment, a motor end cover further includes a fourth opening and a sealing element, the sealing element being used to enclose the fourth opening.

[0053] One of the fourth openings is used to connect to one of the first openings. The orientation of the fourth opening is opposite to that of the first opening along the radial direction of the drive motor. The projection of the fourth opening along the radial direction of the drive motor overlaps the projection of the first opening. The diameter of the fourth opening is larger than that of the first opening.

[0054] In this embodiment, the fourth opening is oriented radially away from the bearing groove's peripheral wall, and the fourth opening communicates with the first opening via a first internal flow channel. The fourth opening facilitates the machining of the first internal flow channel from the outside of the motor end cover inwards. A sealing member is accommodated in the fourth opening to seal it, preventing oil in the first internal flow channel from leaking out through the fourth opening.

[0055] In this embodiment, the radial projection of the fourth opening covers the radial projection of the first opening, which facilitates the first internal flow channel and the first opening to communicate radially along the drive motor, and helps to shorten the flow path of the oil in the first internal flow channel. The diameter of the fourth opening is larger than that of the first opening, which helps to reduce the processing of the fourth opening.

[0056] Secondly, embodiments of this application provide a powertrain, which includes a motor controller, a reducer, an oil pump, and a drive motor as described in any embodiment of the first aspect. The motor controller controls the drive motor, and the drive motor is used to drive the reducer. The oil pump outputs oil to actively cool the drive motor and actively lubricate the motor bearings of the drive motor.

[0057] In the embodiments of this application, the drive motor described in any embodiment of the first aspect is applied to the powertrain. The drive motor can utilize the oil provided by the oil pump to improve the lubrication effect on the motor bearings and the cooling effect on the drive motor, reducing the risk of severe local wear or local overheating of the drive motor, which is beneficial to extending the service life of the drive motor and improving the working efficiency and safety performance of the powertrain.

[0058] Thirdly, embodiments of this application provide an electric vehicle, which includes a power battery and a powertrain as described in the second aspect, the powertrain being used to receive power from the power battery and to drive the wheels of the electric vehicle.

[0059] In this embodiment of the application, the powertrain described in the second aspect is applied to an electric vehicle. Since the lubrication effect of the powertrain is improved, it helps to ensure the smooth and safe driving of the electric vehicle. Attached Figure Description

[0060] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the embodiments of this application will be described below.

[0061] Figure 1 This is a schematic diagram of the electric vehicle provided in an embodiment of this application;

[0062] Figure 2 This is a schematic diagram of the powertrain provided in an embodiment of this application;

[0063] Figure 3 This is a schematic diagram of the drive motor provided in an embodiment of this application;

[0064] Figure 4 This is a schematic diagram of the motor end cover provided in an embodiment of this application;

[0065] Figure 5 This is a partial exploded view of the powertrain provided in the embodiments of this application;

[0066] Figure 6 This is a cross-sectional view of the motor end cover provided in an embodiment of this application;

[0067] Figure 7 yes Figure 6 A partial enlarged view of part N in the motor end cover shown;

[0068] Figure 8 yes Figure 4 A partial enlarged view of part M in the motor end cover shown;

[0069] Figure 9 This is a schematic diagram of the stator provided in an embodiment of this application. Detailed Implementation

[0070] The technical solutions of the embodiments of this application will be described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0071] For ease of understanding, the relevant technical terms involved in the embodiments of this application will be explained and described below.

[0072] Parallelism: The parallelism defined in the embodiments of this application is not limited to absolute parallelism. This definition of parallelism can be understood as basic parallelism, allowing for situations where the parallelism is not absolute due to factors such as assembly tolerance, design tolerance, and structural flatness.

[0073] Perpendicularity: The perpendicularity defined in this application is not limited to an absolutely perpendicular intersection. Cases where the intersection is not absolutely perpendicular due to factors such as assembly tolerances, design tolerances, and structural flatness are allowed. Small angular errors are permissible, for example, within the range of 80 to 100 degrees, which can be understood as a perpendicular relationship.

[0074] The lubrication effect of bearings in current drive motors needs improvement. This application provides a drive motor with active bearing lubrication. The drive motor housing includes a motor end cover and a motor housing. The motor end cover encloses the motor housing to form a receiving cavity, which is used to fix the stator of the drive motor and accommodate the rotor. The side of the motor end cover facing the stator includes a bearing groove and an oil guide protrusion.

[0075] One bearing groove is used to fix the outer ring of the motor bearing of the drive motor, and the inner ring of the motor bearing is fixed to the motor shaft of the drive motor. The groove opening of one bearing groove faces the rotor of the drive motor along the axial direction of the drive motor. The peripheral wall of one bearing groove protrudes towards a motor housing along the axial direction of the drive motor. The inner surface of the peripheral wall of one bearing groove includes a first opening for introducing oil into the interior of the bearing groove.

[0076] An oil guide protrusion protrudes along the axial direction of the drive motor toward the rotor of the drive motor. The interior of the oil guide protrusion includes a first internal flow channel, one end of which is used to receive oil output from an oil pump, and the other end of which is used to deliver oil through a first opening into a bearing groove to actively lubricate the motor bearing.

[0077] This application embodiment utilizes a first internal flow channel located inside the motor end cover for lubricating the motor bearings, thereby improving the lubrication efficiency of the motor bearings. The drive motor provided in this application embodiment can be applied to a powertrain, and a powertrain including the drive motor of this application can be applied to an electric vehicle.

[0078] Please see Figure 1 , Figure 1 This is a schematic diagram of an electric vehicle 1 provided in an embodiment of this application. In one embodiment, the electric vehicle 1 includes a powertrain 10 and a power battery 20. In another embodiment, the electric vehicle 1 further includes a frame 30, which is used to mount the powertrain 10 and the power battery 20. The frame 30 is the structural skeleton of the electric vehicle 1, capable of bearing the loads from the internal and external environments. In this embodiment, the electric vehicle 1 refers to a wheeled device driven or towed by a power unit. The power battery 20 is used to supply power to the powertrain 10; the power battery 20 can also be called a battery pack. The powertrain 10 is the power source of the electric vehicle 1, and the powertrain 10 is used to drive the wheels 40 of the electric vehicle 1.

[0079] Please see Figure 2 , Figure 2 This is a schematic diagram of a powertrain 10 provided in an embodiment of this application. In one embodiment, the powertrain 10 includes a drive motor 11, a motor controller 12, and a reducer 13. A power battery 20 supplies power to the drive motor 11 via the motor controller 12. The drive motor 11 converts the electrical energy transmitted from the power battery 20 into mechanical energy, and then transmits the mechanical energy to the reducer 13 to drive the wheels 40 to rotate.

[0080] In one embodiment, the powertrain 10 further includes an oil pump 14 for delivering oil to at least one of the drive motor 11, the motor controller 12, or the reducer 13.

[0081] In one embodiment, the motor controller 12 is used to convert the direct current transmitted by the power battery 20 into alternating current.

[0082] In one embodiment, the drive motor 11 includes a stator 400, a rotor 500, a motor shaft 600, and a motor bearing. When alternating current transmitted from the motor controller 12 is applied to the windings 410 of the stator 400, alternating magnetic flux is generated. This alternating magnetic flux interacts with the permanent magnet flux generated by the rotor 500, causing the rotor 500 to rotate relative to the stator 400. The rotor 500 is fixedly connected to the motor shaft 600, allowing the motor shaft 600 to rotate with the rotor 500. The stator 400 is rotatably connected to the motor shaft 600, enabling the motor shaft 600 to rotate relative to the stator 400, converting electrical energy into mechanical energy. The output end of the motor shaft 600 is used to transmit this mechanical energy. The inner ring of the motor bearing is fitted onto the motor shaft 600, and the motor bearing serves to support and position the motor shaft 600.

[0083] During the operation of the powertrain, the motor bearings of the drive motor operate at high speeds and bear heavy loads. Therefore, one of the key factors in improving the reliability of the motor bearings is the effectiveness of lubrication. Insufficient lubrication, leading to a lack of oil film formation in the motor bearings, will cause rapid wear and may even pose safety risks in severe cases.

[0084] This application embodiment improves the lubrication method for motor bearings, thereby enhancing the lubrication effect and ensuring the normal operation of the powertrain and electric vehicle.

[0085] The drive motor 11 provided in the embodiments of this application is described below.

[0086] Please refer to the following: Figures 3 to 5 , Figure 3 This is a schematic diagram of the drive motor 11 provided in an embodiment of this application. Figure 4 This is a schematic diagram of the motor end cover 100 provided in an embodiment of this application. Figure 5 This is a partial exploded view of the powertrain 10 provided in the embodiments of this application.

[0087] In one embodiment, such as Figure 3 As shown, the housing of the drive motor 11 includes a motor end cover 100 and a motor housing 200. The motor end cover 100 encloses the motor housing 200 to form a receiving cavity 300, which is used to fix the stator 400 of the drive motor 11 and to house the rotor 500 of the drive motor 11. Figures 3 to 5 As shown, a motor end cover 100 includes a bearing groove 110 and an oil guide protrusion 120 on the side facing the stator 400.

[0088] Among them, such as Figure 5 As shown, a bearing groove 110 is used to fix the motor bearing 700 of the drive motor 11. Figure 3As shown, the opening of a bearing groove 110 faces the rotor 500 of the drive motor 11 along the axial direction O of the drive motor 11, and the peripheral wall of the bearing groove 110 protrudes towards a motor housing 200 along the axial direction O of the drive motor 11. Figure 3 and Figure 4 As shown, the inner surface of the groove peripheral wall of a bearing groove 110 includes a first opening 111.

[0089] like Figure 3 As shown, an oil guide protrusion 120 protrudes along the axial direction O of the drive motor 11 toward the rotor 500 of the drive motor 11. The interior of the oil guide protrusion 120 includes a first internal flow channel 121. One end of the first internal flow channel 121 is used to receive oil output from an oil pump, and the other end of the first internal flow channel 121 is used to transport oil through a first opening 111 into a bearing groove 110 to actively lubricate the motor bearing 700.

[0090] In this embodiment, the outer ring of the motor bearing 700 is fixed to the bearing groove 110 of the motor end cover 100, and the inner ring of the motor bearing 700 is fixed to the motor shaft 600. The outer ring and the inner ring of the motor bearing 700 are rotatably connected, so that the motor shaft 600 and the inner ring of the motor bearing 700 can rotate relative to the motor end cover 100 and the outer ring of the motor bearing 700.

[0091] Since the motor shaft 600 typically rotates at high speeds, driving the motor bearing 700 to rotate at high speeds, it is essential to ensure adequate lubrication of the motor bearing 700 to extend its service life and improve the safety performance of the drive motor 11 and the powertrain. However, current lubrication methods for motor bearings typically employ passive lubrication, which involves collecting oil ejected from rotating components such as the rotor of the drive motor, or oil leaking from certain structures, and then guiding the collected oil into the bearing groove. This passive lubrication method is limited by the rotational speed of the rotating components and the temperature of the oil. Too low a rotational speed results in insufficient power for oil movement, and too low a temperature leads to higher oil viscosity, both negatively impacting oil collection and hindering lubrication efficiency.

[0092] In this embodiment, to avoid the drawbacks of passive lubrication of the motor bearing 700, an oil pump is used to actively deliver oil to the bearing groove 110. Driven by the oil pump, the oil flow is less affected by the rotational speed of the rotating parts and the oil temperature, ensuring stable lubrication of the motor bearing 700 within the bearing groove 110. In one embodiment, the oil can be any one of ethylene glycol-based cooling oil, synthetic oil, and mineral oil.

[0093] Active lubrication involves the delivery of oil. Some existing technologies use oil guides to deliver oil to the bearing grooves; these guides are separate from the motor end cover or motor housing. The assembly process between the oil guide and the motor end cover or housing is complex and costly, which is detrimental to improving the overall structural stability of the drive motor. Furthermore, the oil guides must be designed to avoid interference with other components within the housing, otherwise, it will adversely affect the normal operation of the drive motor.

[0094] Furthermore, some existing technologies utilize oil passages in the motor end cover for active lubrication of the motor bearings, with these passages directly exposed to the housing cavity. While integrating the oil passages into the motor end cover avoids the problems associated with using oil guides, the fact that these passages are not closed structures means that the oil may leak due to the influence of rotating components such as the motor shaft and rotor, making it difficult to ensure that the majority of the oil flows into the bearing groove.

[0095] In this embodiment of the application, in order to reduce the risks faced in conveying oil during active lubrication, the first internal flow channel 121 for conveying oil to the bearing groove 110 is located inside the motor end cover 100. This can effectively avoid the problem of oil leakage, improve the utilization rate of oil, and reduce the interference caused by rotating parts such as the rotor 500 to the oil conveying. This is conducive to ensuring that the first internal flow channel 121 stably conveys oil to the bearing groove 110.

[0096] In this embodiment, the bearing groove 110 is distributed on one side of the motor end cover 100 facing the motor housing 200. The bearing groove 110 protrudes along the axial direction O of the drive motor 11 towards the motor housing 200, so that the bearing groove 110 can utilize the space of the receiving cavity 300 to reduce the overall axial length of the drive motor 11, making the arrangement of the drive motor 11 more compact, which is conducive to realizing the miniaturization design of the powertrain.

[0097] With the bearing groove 110 protruding towards the motor housing 200, the first internal flow channel 121 of this embodiment is distributed inside the oil guide protrusion 120 of the motor end cover 100. Similar to the bearing groove 110, the oil guide protrusion 120 also protrudes towards the motor housing 200, which can shorten the axial distance between the first internal flow channel 121 located inside the oil guide protrusion 120 and the bearing groove 110, making it easier for the first internal flow channel 121 to fit with the groove peripheral wall of the bearing groove 110, so that the oil flows through the first opening 111 of the groove peripheral wall of the bearing groove 110 to the motor bearing 700, which helps to reduce the loss of oil in the transmission path. The oil guide protrusion 120 is an integrally formed structure with the motor end cover 100, with strong structural stability. Compared with using an oil guide component that is separate from the motor end cover 100, this embodiment of the application helps to simplify the assembly process and reduce processing costs.

[0098] In this embodiment, the first opening 111 is distributed on the inner surface of the peripheral wall of the bearing groove 110. The other end of the oil guiding protrusion 120 conveys oil to the bearing groove 110 through the first opening 111, which is equivalent to the first internal flow channel 121 being connected to the inner surface of the peripheral wall of the bearing groove 110, which helps to reduce oil loss at the first opening 111. In addition, the first opening 111 is distributed on the peripheral wall of the bearing groove 110, so that after the oil flows through the first opening 111, it can flow along the axial direction O of the drive motor 11 towards the bottom and opening of the bearing groove 110, which helps to prolong the contact time between the oil and the motor bearing 700 and enhance the wetting effect of the oil on the motor bearing 700.

[0099] It should be noted that, Figure 3 The diagram only schematically illustrates the connection between the various flow channels in the drive motor and the positional relationship between the bearing grooves and oil guide protrusions relative to the stator and rotor, and does not represent their specific structure, shape and size.

[0100] Please continue reading. Figure 3 and Figure 5 In one embodiment, the height of an oil guide protrusion 120 along the axial direction of the drive motor 11 is less than the height of the peripheral wall of a bearing groove 110.

[0101] In this embodiment, the length of the transmission path of the first internal flow channel 121 affects the efficiency of oil lubrication. If the axial height of the oil guide protrusion 120 is greater than or equal to the axial height of the peripheral wall of the bearing groove 110, and the inner diameter of the first internal flow channel 121 remains unchanged, the distance between at least one end of the first internal flow channel 121 and the bottom of the bearing groove 110 will be greater than or equal to the axial height of the peripheral wall of the bearing groove 110, which will lengthen the transmission path of the first internal flow channel 121 and increase the energy loss of the oil. Furthermore, since the first opening 111 is distributed on the peripheral wall of the bearing groove 110, if the axial height of the oil guide protrusion 120 is greater than or equal to the axial height of the peripheral wall of the bearing groove 110, it will also make it difficult for the first internal flow channel 121 to directly communicate with the first opening 111.

[0102] In this embodiment, the axial height of the oil guide protrusion 120 is less than the axial height of the groove peripheral wall of the bearing groove 110, which helps to shorten the transmission path of the oil in the first internal flow channel 121 and reduce the difficulty of connecting the first internal flow channel 121 and the first opening 111. This embodiment also reduces the space occupied by the oil guide protrusion 120 in the receiving cavity 300, which is beneficial to optimizing the layout of the drive motor 11.

[0103] Please continue reading. Figures 3 to 5 In one embodiment, an oil guide protrusion 120 extends in a direction parallel to the radial direction R of the drive motor 11.

[0104] In this embodiment, the extension direction of the first internal flow channel 121 is parallel to the extension direction of the oil guide protrusion 120. The extension direction of the oil guide protrusion 120 is parallel to the radial direction R of the drive motor 11, which means that the flow direction of the oil from one end of the first internal flow channel 121 to the other end is perpendicular to the protrusion direction of the groove peripheral wall of the bearing groove 110. This helps to shorten the flow path of the oil in the first internal flow channel 121 and improve lubrication efficiency. Assuming that the projection positions of the two ends of the first internal flow channel 121 along the axial direction O of the drive motor 11 remain unchanged, only by adjusting the extension direction of the first internal flow channel 121, the transmission path of the first internal flow channel 121 can be minimized only when the extension direction of the first internal flow channel 121 is perpendicular to the axial direction O of the drive motor 11. In addition, this embodiment also helps to reduce the processing difficulty of the oil guide protrusion 120 and the first internal flow channel 121.

[0105] Please continue reading. Figures 3 to 5 In one embodiment, a motor end cover 100 further includes an annular mounting surface 130 for fixedly connecting a housing mounting surface 210 of a motor housing 200. The annular mounting surface 130 faces the motor housing 200 along the axial direction O of the drive motor 11 and surrounds the peripheral wall of a bearing groove 110. The housing mounting surface 210 of the motor housing 200 includes an oil outlet 211 for discharging oil received from an oil pump through a second internal flow channel 220 of the motor housing 200. The annular mounting surface 130 includes a connecting hole 131 for connecting the oil outlet 211 and a first internal flow channel 121.

[0106] In this embodiment, the motor housing 200 includes a second internal flow channel 220, which sequentially delivers oil from the oil pump to the oil outlet 211 of the motor housing 200, the connecting hole 131 of the motor end cover 100, and the first internal flow channel 121. The second internal flow channel 220 is distributed inside the motor housing 200, which helps to reduce oil leakage.

[0107] In this embodiment, the annular mounting surface 130 of the motor end cover 100 and the housing mounting surface 210 of the motor housing 200 are fixed along the axial direction O of the drive motor 11. A connecting hole 131 and an oil outlet hole 211 are respectively distributed on the annular mounting surface 130 and the housing mounting surface 210, and are opposite each other along the axial direction O of the drive motor 11. An oil guide protrusion 120 protrudes towards the motor housing 200 along the axial direction O of the drive motor 11, which can shorten the axial distance between the first internal flow channel 121 and the connecting hole 131 and the oil outlet hole 211, reducing the energy loss of oil transported from the motor housing 200 to the motor end cover 100.

[0108] Please continue reading. Figure 4 and Figure 5 In one embodiment, an annular mounting surface 130 further includes a plurality of fixing holes 132, each fixing hole 132 for receiving a fixing member, and each fixing member for passing through a fixing hole 132 and being embedded in the housing mounting surface 210 of a motor housing 200.

[0109] Along the circumferential direction C of the drive motor 11, a connecting hole 131 is arranged between two fixed holes 132, and the distance between the connecting hole 131 and the adjacent fixed hole 132 is less than the distance between any two fixed holes 132.

[0110] In this embodiment, the fastener passes through the fixing hole 132 of the motor end cover 100 and is embedded in the motor housing 200 to fix the motor end cover 100 to the motor housing 200. The fixing hole 132 and the connecting hole 131 are both distributed on the annular mounting surface 130 of the motor end cover 100, with the connecting hole 131 arranged between two fixing holes 132. For ease of description, the fixing hole 132 adjacent to the connecting hole 131 is referred to as fixing hole 132a. If the distance between the connecting hole 131 and one of the fixing holes 132a is greater than the distance between two fixing holes 132, it indicates that the distance between the two fixing holes 132a is too large, which may impair the connection strength between the motor end cover 100 and the motor housing 200 at the two fixing holes 132a. This embodiment adjusts the distance between the connecting hole 131 and the fixing hole 132a to be smaller than the distance between any two fixing holes 132, thus avoiding the negative impact of the connecting hole 131 on the arrangement of the fixing holes 132.

[0111] In this embodiment, the distance between the connecting hole 131 and the fixing hole 132a is relatively small, which is also beneficial to distinguish the connecting hole 131 from the multiple fixing holes 132, avoid the mixing of the connecting hole 131 and the fixing hole 132, ensure that the oil flows normally into the connecting hole 131, and ensure that the motor end cover 100 and the motor housing 200 can be properly fixed.

[0112] Please see Figure 6 and Figure 7 , Figure 6 This is a cross-sectional view of the motor end cover 100 provided in an embodiment of this application. Figure 7 yes Figure 6 A partial enlarged view of part N in the motor end cover 100 shown.

[0113] In one embodiment, a connecting hole 131 includes two first openings 1311 distributed along the axial direction O of the drive motor 11. One of the two first openings 1311 is used to connect to an oil outlet 211, and the other of the two first openings 1311 is used to connect to a first internal flow channel 121.

[0114] In one of the connecting holes 131, the diameter of one first opening 1311 is larger than the diameter of each fixed hole 132, and the diameter of the other first opening 1311 of the connecting hole 131 is smaller than the diameter of one first opening 1311 of the connecting hole 131 and the diameter of an oil outlet hole 211.

[0115] In this embodiment of the application, for ease of description, one first opening 1311 of the connecting hole 131 is referred to as first opening 1311a, the other first opening 1311 of the connecting hole 131 is referred to as first opening 1311b, and one oil outlet 211 of the motor housing 200 is referred to as oil outlet 211a. The first opening 1311a is used to connect to the oil outlet 211a, and the first opening 1311b is used to connect to the first internal flow channel 121.

[0116] In this embodiment, the first opening 1311a and the first opening 1311b are opposite each other along the axial direction O of the drive motor 11. The inner diameter of the first opening 1311a is larger than that of the first opening 1311b, which can prevent debris from clogging the connecting hole 131. In one embodiment, a bonding adhesive can be applied between the annular mounting surface 130 of the motor end cover 100 and the housing mounting surface 210 of the motor housing 200. The bonding adhesive can enhance the stability and sealing effect of the fixed connection between the motor end cover 100 and the motor housing 200. The aperture of the first opening 1311a is larger than that of the first opening 1311b, so that even if some bonding adhesive seeps into the first opening 1311a, the oil can still flow through the first opening 1311a to the first opening 1311b and the first internal flow channel 121 in sequence, reducing the interference of the annular mounting surface 130 and the housing mounting surface 210 on the oil flow.

[0117] In this embodiment, the diameter of the first opening 1311b is smaller than the diameter of the first opening 111 and the diameter of the oil outlet 211a. This allows the first opening 1311b to act as a throttling device, preventing excessive oil from flowing into the bearing groove 110 through the first internal flow channel 121, thus reducing oil churning losses in the motor bearing 700. This embodiment also facilitates the efficient distribution of oil in the drive motor 11 via the first opening 1311b, and further enhances the use of oil for lubrication or cooling of other components of the drive motor 11, improving oil utilization.

[0118] In one embodiment, the projection of the second internal flow channel along the axial direction of the drive motor is located within the projection of one first opening of the connecting hole, and the projection of the second internal flow channel along the axial direction of the drive motor does not overlap with the projection of the other first opening of the connecting hole.

[0119] In this embodiment, one first opening of the connecting hole is opposite to the second internal flow channel along the axial direction of the drive motor, which helps to reduce the flow resistance of oil flowing from the motor housing into the motor end cover. The other first opening of the connecting hole is offset from the second internal flow channel along the axial direction of the drive motor, so that after oil flows into one of the first openings of the connecting hole, it can change its flow direction and move away from the edge of the first opening. In this case, even if some sealing adhesive seeps into the connecting hole from the edge of one of the first openings, it can still ensure that the oil in the connecting hole flows smoothly into the first internal flow channel.

[0120] Please continue reading. Figure 3 and Figure 7 In one embodiment, the length of a connecting hole 131 along the axial direction of the drive motor 11 is less than the height of the peripheral wall of a bearing groove 110.

[0121] In this embodiment, the connecting hole 131 is used to connect the oil outlet hole 211a of the motor housing 200 with the first internal flow channel 121. The axial length of the connecting hole 131 is less than the axial height of the groove peripheral wall of the bearing groove 110. It cooperates with the oil guide protrusion 120 protruding towards the motor housing 200, which can further shorten the axial distance between the motor housing 200 and the first internal flow channel 121 and reduce the loss of oil in the transmission between the motor housing 200 and the first internal flow channel 121.

[0122] Please refer to the following: Figure 5 and Figure 8 , Figure 8 for Figure 4 The diagram shows a partial enlarged view of portion M in the motor end cover 100. In one embodiment, the inner surface of the peripheral wall of a bearing groove 110 further includes a second opening 112, and the outer surface of the peripheral wall of a bearing groove 110 includes a third opening 113. The second opening 112 and the third opening 113 are connected. An oil guide protrusion 120 is used to guide oil through the third opening 113 and the second opening 112 into the bearing groove 110 to passively lubricate the motor bearing 700.

[0123] In this configuration, a second opening 112 and a third opening 113 are arranged on the same side of a first opening 111 along the circumferential direction C of the drive motor 11.

[0124] In this embodiment, the oil guide protrusion 120, in addition to actively lubricating the motor bearing 700 through the first internal flow channel 121, also serves as a passive lubricant to supplement the effect of active lubrication. Specifically, the oil guide protrusion 120 protrudes towards the motor housing 200 along the axial direction O of the drive motor 11, which shortens the axial distance between the oil guide protrusion 120 and the stator 400 and rotor 500 of the drive motor 11. This makes it easier for the oil transmitted from the stator 400 or rotor 500 to the motor end cover 100 to be collected by the outer surface of the oil guide protrusion 120. The outer surface of the oil guide protrusion 120 is used to transport the collected oil to the bearing groove 110, achieving a combination of active and passive lubrication and enabling structural reuse of the oil guide protrusion 120. This embodiment combines active and passive lubrication, which helps to increase the amount of oil used to lubricate the motor bearing 700 and enhances the lubrication effect on the motor bearing 700.

[0125] In this embodiment, the peripheral wall of the bearing groove 110 includes a second opening 112 and a third opening 113, which are respectively distributed on the inner and outer surfaces of the peripheral wall of the bearing groove 110. The oil guiding protrusion 120 is arranged adjacent to the second opening 112 and the third opening 113. The second opening 112 and the third opening 113 are arranged on the same side of the first opening 111 along the circumferential direction C of the drive motor 11, facilitating the sequential flow of oil collected by the oil guiding protrusion 120 to the third opening 113 and the second opening 112. This also avoids negative impacts of the second opening 112 and the third opening 113 on the layout of the oil guiding protrusion 120 and the first opening 111. In one embodiment, the second opening 112 and the third opening 113 are arranged on the same side of the first opening 111 in a clockwise or counterclockwise direction.

[0126] In one embodiment, the inner surface of the bearing groove 110's peripheral wall further includes another second opening 112, and the outer surface of the bearing groove 110's peripheral wall includes another third opening 113. The second opening 112 communicates with the third opening 113. One second opening 112 and another second opening 112 are respectively distributed on both sides of the first opening 111 along the circumferential direction C of the drive motor 11, and one third opening 113 and another third opening 113 are respectively distributed on both sides of the first opening 111 along the circumferential direction C of the drive motor 11. In this embodiment, the second opening 112 and the third opening 113 are distributed on both sides of the first opening 111, which facilitates the oil guiding protrusion 120 to cooperate with the second opening 112 and the third opening 113 in both forward and reverse rotation of the drive motor 11, reducing the impact of the forward and reverse rotation of the drive motor 11 on the passive oil collection.

[0127] Please continue reading. Figure 7 and Figure 8In one embodiment, the distance between a first opening 111 and the bottom of a bearing groove 110 is greater than or equal to the distance between a second opening 112 and the bottom of a bearing groove 110.

[0128] In this embodiment, the first opening 111 is further away from the bottom of the bearing groove 110 than the second opening 112. This means the axial distance between the first opening 111 and the opening of the bearing groove 110 is less than or equal to the axial distance between the second opening 112 and the opening of the bearing groove 110. This facilitates the engagement of the first opening 111 with the first internal flow channel 121 of the oil guide protrusion 120, thus shortening the active lubrication path. The second opening 112 is used for passive lubrication. Passive lubrication relies on the oil guide protrusion 120 and the outer surface of the groove peripheral wall of the bearing groove 110 to collect and guide the oil. The second opening 112 is relatively close to the bottom of the bearing groove 110, further shortening the passive lubrication path. By adjusting the distances between the first and second openings 111 and the bottom of the bearing groove 110, this embodiment can reduce oil loss along the transmission path in both active and passive lubrication.

[0129] Please continue reading. Figure 5 , Figure 7 and Figure 8 In one embodiment, the diameter of a second opening 112 is larger than the diameter of a first opening 111, the diameter of a second opening 112 is smaller than the diameter of a third opening 113, and the diameter of a first opening 111 is smaller than the length of an oil guide protrusion 120 along the circumferential direction C of the drive motor 11.

[0130] In this embodiment, passive lubrication is affected by the rotational speed of the drive motor 11, resulting in an unstable oil source. The diameters of both the second opening 112 and the third opening 113 are larger than the diameter of the first opening 111, which helps increase the amount of oil used for passive lubrication. The third opening 113 is located on the outer surface of the peripheral wall of the bearing groove 110. Since the diameter of the third opening 113 is larger than that of the second opening 112, it reduces the difficulty of oil flowing from the oil guide protrusion 120 into the third opening 113, thus reducing the flow resistance of the oil in passive lubrication.

[0131] In this embodiment, the diameter of the first opening 111 is smaller than the circumferential length of the oil guide protrusion 120. The first opening 111 can be used to throttle the active lubricating oil, which is beneficial to control the flow rate and velocity of the oil flowing into the bearing groove 110 through the first opening 111.

[0132] In one embodiment, a third opening 113 is oriented opposite to a second opening 112. The angle between the orientation of the third opening 113 and the radial direction R of the drive motor 11 is greater than 0 degrees, and the angle between the orientation of the third opening 113 and the radial direction R of the drive motor 11 is less than 30 degrees.

[0133] In this embodiment, the third opening 113 and the second opening 112 are used to cooperate with the oil guide protrusion 120 to achieve passive lubrication. Passive lubrication requires the oil to be collected and guided by the outer surfaces of the oil guide protrusion 120 and the groove peripheral wall of the bearing groove 110. The angle between the orientation of the third opening 113 and the radial direction R of the drive motor 11 is within the range of 0 degrees to 30 degrees, so that the oil collected by the oil guide protrusion 120 can flow into the third opening 113 and the second opening 112 more quickly. Controlling the angle between the orientation of the third opening 113 and the radial direction R of the drive motor 11 to a small range also helps to reduce the processing difficulty of the third opening 113 and the second opening 112.

[0134] In one embodiment, the angle between the orientation of the third opening 113 and the radial direction R of the drive motor 11 is also the angle between the orientation of the second opening 112 and the orientation of the first opening 111. The orientation of the second opening 112 intersects with the orientation of the first opening 111, so that the oil can provide three-dimensional lubrication to the motor bearing 700 from different angles through the second opening 112 and the first opening 111. This helps to expand the movement range of the oil in the bearing groove 110 and avoid the problem of insufficient local lubrication of the motor bearing 700.

[0135] Please refer to the following: Figure 3 and Figure 9 , Figure 9 This is a schematic diagram of a stator 400 provided in an embodiment of this application. In one embodiment, the inner side of the peripheral wall of a motor housing 200 includes another oil outlet 211. The other oil outlet 211 is used to output oil received from an oil pump by a second internal flow channel 220 of the motor housing 200 to the stator cooling flow channel of the drive motor 11. The second openings 810 of the plurality of oil drain holes 800 of the stator cooling flow channel face a motor end cover 100. The diameter of one oil outlet 211 is smaller than the diameter of another oil outlet 211, and the diameter of one oil outlet 211 is larger than the diameter of each oil drain hole 800.

[0136] In this embodiment, for ease of description, the other oil outlet 211 of the motor housing 200 is referred to as oil outlet 211b. Oil outlet 211a of the motor housing 200 connects the second internal flow channel 220 with the first internal flow channel 121 of the motor end cover 100, and oil outlet 211b connects the second internal flow channel 220 with the stator cooling flow channel. After receiving oil from the oil pump, the second internal flow channel 220 transmits a portion of the oil to the bearing groove 110 of the motor end cover 100 for active lubrication of the motor bearing 700, and transmits the other portion of the oil to the stator cooling flow channel for cooling the stator 400 of the drive motor 11, which helps to improve the utilization rate of the oil. In one embodiment, the stator cooling flow channel is distributed on the outer peripheral surface of the stator 400, and the extension of the stator cooling flow channel is parallel to the axial direction O of the drive motor 11. In one embodiment, the oil in the stator cooling channel can also be used to cool the rotor 500 and winding 410 of the drive motor 11.

[0137] In this embodiment, the oil in the stator cooling channel cools the stator 400 and then flows out of the stator cooling channel through the oil drain hole 800. The oil drain hole 800 includes a second opening 810 facing the motor end cover 100, so that the oil guide protrusion 120 of the motor end cover 100 can collect a portion of the oil flowing out through the second opening 810. In one embodiment, the oil guide protrusion 120 of the motor end cover 100 can also collect a portion of the oil splashed due to the swinging of the rotor 500.

[0138] In this embodiment, the diameter of the oil outlet 211a is smaller than that of the oil outlet 211b, so that more of the oil flows to the stator cooling channel and less of the oil flows to the first internal channel 121. The oil is rationally distributed through the cooperation of the oil outlet 211a and the oil outlet 211b. This reduces the oil churning loss of the motor bearing 700 and enhances the cooling effect on the stator 400.

[0139] Please continue reading. Figure 3 , Figure 5 and Figure 7 In one embodiment, a motor end cap 100 further includes a fourth opening 140 and a sealing element 150, the sealing element 150 being used to enclose the fourth opening 140.

[0140] A fourth opening 140 is used to connect to a first opening 111. The orientation of the fourth opening 140 is opposite to that of the first opening 111 along the radial direction R of the drive motor 11. The projection of the fourth opening 140 along the radial direction R of the drive motor 11 overlaps the projection of the first opening 111. The diameter of the fourth opening 140 is larger than the diameter of the first opening 111.

[0141] In this embodiment, the fourth opening 140 is oriented radially R away from the peripheral wall of the bearing groove 110 along the drive motor 11, and the fourth opening 140 communicates with the first opening 111 through the first internal flow channel 121. The fourth opening 140 facilitates the machining of the first internal flow channel 121 from the outside of the motor end cover 100 inward. The sealing member 150 is accommodated in the fourth opening 140 to seal the fourth opening 140 and prevent oil in the first internal flow channel 121 from leaking out of the fourth opening 140.

[0142] In this embodiment, the radial projection of the fourth opening 140 covers the radial projection of the first opening 111, which facilitates the connection between the first internal flow channel 121 and the first opening 111 along the radial R of the drive motor 11. This helps to shorten the flow path of the oil in the first internal flow channel 121. The diameter of the fourth opening 140 is larger than that of the first opening 111, which helps to reduce the processing of the fourth opening 140.

[0143] In one embodiment, the fourth opening 140 and the first internal flow channel 121 are integrally die-cast, so that the fourth opening 140 and the first internal flow channel 121 do not need to be processed separately, which helps to reduce the number of processes and reduce the difficulty of processing and manufacturing.

[0144] In one embodiment, the fourth opening 140 and the first internal flow channel 121 can be formed by demolding during the die-casting process of the motor end cover 100.

[0145] The above provides a detailed description of the drive motor, powertrain, and electric vehicle with active bearing lubrication function provided in the embodiments of this application. Specific examples have been used to illustrate the principles and embodiments of this application. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core ideas of this application. Furthermore, those skilled in the art will recognize that, based on the ideas of this application, there will be changes in specific embodiments and application scope. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A drive motor with active bearing lubrication function, characterized in that, The drive motor housing includes a motor end cover and a motor housing. The motor end cover encloses the motor housing to form a receiving cavity. The receiving cavity is used to fix the stator of the drive motor and to accommodate the rotor of the drive motor. The side of the motor end cover facing the stator includes a bearing groove and an oil guide protrusion, wherein: The bearing groove is used to fix the motor bearing of the drive motor. The groove opening of the bearing groove faces the rotor of the drive motor along the axial direction of the drive motor. The groove peripheral wall of the bearing groove protrudes towards the motor housing along the axial direction of the drive motor. The inner surface of the groove peripheral wall of the bearing groove includes a first opening. The oil guide protrusion protrudes along the axial direction of the drive motor toward the rotor of the drive motor. The interior of the oil guide protrusion includes a first internal flow channel. One end of the first internal flow channel is used to receive oil output from an oil pump, and the other end of the first internal flow channel is used to transport oil through the first opening into the bearing groove to actively lubricate the motor bearing.

2. The drive motor according to claim 1, characterized in that, The inner surface of the bearing groove peripheral wall further includes a second opening, and the outer surface of the bearing groove peripheral wall includes a third opening. The second opening and the third opening are connected. The oil guiding protrusion is used to guide oil through the third opening and the second opening into the bearing groove to passively lubricate the motor bearing. Along the circumference of the drive motor, the second opening and the third opening are arranged on the same side of the first opening.

3. The drive motor according to claim 2, characterized in that, The distance between the first opening and the bottom of the bearing groove is greater than or equal to the distance between the second opening and the bottom of the bearing groove.

4. The drive motor according to claim 2 or 3, characterized in that, The diameter of the second opening is larger than the diameter of the first opening and smaller than the diameter of the third opening. The diameter of the first opening is smaller than the length of the oil guide protrusion along the circumference of the drive motor.

5. The drive motor according to any one of claims 2-4, characterized in that, The third opening is oriented opposite to the second opening, and the angle between the orientation of the third opening and the radial direction of the drive motor is greater than 0 degrees and less than 30 degrees.

6. The drive motor according to any one of claims 1-5, characterized in that, The height of the oil guide protrusion along the axial direction of the drive motor is less than the height of the peripheral wall of the bearing groove.

7. The drive motor according to any one of claims 1-6, characterized in that, The extension direction of one of the oil guide protrusions is parallel to the radial direction of the drive motor.

8. The drive motor according to any one of claims 1-7, characterized in that, The motor end cover also includes an annular mounting surface for fixing the housing mounting surface of the motor housing. The annular mounting surface faces the motor housing along the axial direction of the drive motor and surrounds the peripheral wall of the bearing groove. The housing mounting surface of the motor housing includes an oil outlet for outputting oil received from the oil pump by a second internal flow channel of the motor housing. The annular mounting surface includes a connecting hole for connecting the oil outlet and the first internal flow channel.

9. The drive motor according to claim 8, characterized in that, The annular mounting surface further includes multiple fixing holes, each fixing hole for accommodating a fixing member, and each fixing member for passing through one of the fixing holes and then embedding into the housing mounting surface of the motor housing, wherein: Along the circumference of the drive motor, the connecting hole is arranged between the two fixed holes, and the distance between the connecting hole and the adjacent fixed hole is less than the distance between any two fixed holes.

10. The drive motor according to claim 9, characterized in that, The connecting hole includes two first openings distributed along the axial direction of the drive motor, one of the two first openings being used to connect to the one oil outlet, and the other of the two first openings being used to connect to the one first internal flow channel, wherein: The diameter of the first opening in the connecting hole is larger than the diameter of each of the fixed holes, and the diameter of the other first opening in the connecting hole is smaller than the diameter of the first opening in the connecting hole and the diameter of the oil outlet hole.

11. The drive motor according to any one of claims 8-10, characterized in that, The length of the connecting hole along the axial direction of the drive motor is less than the height of the groove wall of the bearing groove.

12. The drive motor according to any one of claims 8-11, characterized in that, The inner side of the peripheral wall of the motor housing includes another oil outlet, which is used to output the oil received from the oil pump by the second internal flow channel of the motor housing to the stator cooling flow channel of the drive motor. The second openings of the plurality of oil drain holes of the stator cooling flow channel face the motor end cover. The diameter of the oil outlet is smaller than the diameter of the other oil outlet but larger than the diameter of each of the oil drain holes.

13. The drive motor according to any one of claims 1-12, characterized in that, The motor end cover also includes a fourth opening and a sealing element, wherein the sealing element is used to enclose the fourth opening, wherein: The fourth opening is used to connect to the first opening. The orientation of the fourth opening is opposite to that of the first opening along the radial direction of the drive motor. The projection of the fourth opening along the radial direction of the drive motor covers the projection of the first opening. The diameter of the fourth opening is larger than that of the first opening.

14. A powertrain, characterized in that, The powertrain includes a motor controller, a reducer, an oil pump, and a drive motor as described in any one of claims 1-13. The motor controller is used to control the drive motor, the drive motor is used to drive the reducer, and the oil pump is used to output oil to actively cool the drive motor and actively lubricate the motor bearings of the drive motor.

15. An electric vehicle, characterized in that, The electric vehicle includes a power battery and a powertrain as described in claim 14, the powertrain being used to receive power from the power battery and to drive the wheels of the electric vehicle.

Images