Stator winding end submersion cooled drive motor, powertrain and electric vehicle

Abstract

The embodiment of the present application provides a kind of stator winding end submersion cooling driving motor, power assembly and electric vehicle.The driving motor includes stator core, stator winding and cooling cover.The stator core is used to fix stator winding.One winding end of stator winding exposes to the end of stator core along the axial direction of driving motor, and the inner diameter of one winding end of stator winding along the radial direction of driving motor is greater than the inner diameter of stator core.The cooling cover is used to contain cooling liquid and one winding end.The cooling cover includes first annular wall, and the outer diameter of first annular wall along the radial direction of driving motor is less than or equal to the inner diameter of one winding end of stator winding.The first annular wall is used to enclose the end of stator core along the axial direction of driving motor to form containing structure.The cooling liquid contained in containing structure is used to submersion cooling one winding end of stator winding.The embodiment of the present application can well dissipate heat for stator winding.

Description

[0001] This application is a divisional application. The original application has the application number 202311872048.7 and the original application date is December 29, 2023. The entire contents of the original application are incorporated herein by reference. Technical Field

[0002] This application relates to the field of vehicles, and more particularly to a drive motor, powertrain, and electric vehicle with stator winding end immersion cooling. Background Technology

[0003] Electric vehicle drive motors require high current to drive the stator windings, resulting in high operating temperatures, particularly in the stator windings. Overheating of the stator windings increases their internal resistance and weakens the magnetic properties of the stator silicon steel sheets, making the stator windings a significant heat dissipation bottleneck in the motor. Current technologies typically employ oil or water cooling for drive motors; however, conventional oil or water cooling methods cannot adequately dissipate heat from the ends of the stator windings, thus affecting the performance of the drive motor and the electric vehicle. Summary of the Invention

[0004] This application provides a drive motor, powertrain, and electric vehicle with stator winding end immersion cooling, which can effectively dissipate heat from the drive motor, especially the stator winding end, resulting in better motor performance.

[0005] In a first aspect, embodiments of this application provide a drive motor with stator winding end immersion cooling, including a stator core, a stator winding, and a cooling shroud. The stator core is used to fix the stator winding. Along the axial direction of the drive motor, one winding end of the stator winding is exposed at one end of the stator core. Along the radial direction of the drive motor, the inner diameter of one winding end of the stator winding is larger than the inner diameter of the stator core. The cooling shroud is used to contain coolant and one winding end. The cooling shroud includes a first annular wall. Along the radial direction of the drive motor, the outer diameter of the first annular wall is smaller than or equal to the inner diameter of one winding end of the stator winding. The first annular wall along the axial direction of the drive motor toward one end of the stator core is used to enclose that end of the stator core to form a receiving structure. The receiving structure is used to contain coolant and immerse and cool one winding end of the stator winding.

[0006] In this embodiment, by designing a cooling shroud that includes a first annular wall enclosing one end of the stator core, a containment structure is formed to accommodate the winding end and the coolant, thereby achieving immersion cooling of the winding end. Therefore, this embodiment allows the heat from the stator winding to be rapidly absorbed and carried away by the coolant, greatly improving the heat dissipation effect of the stator winding, enhancing the temperature uniformity and heat dissipation performance of the drive motor, which is beneficial for increasing the rated power output of the drive motor and extending its peak power duration.

[0007] In one implementation of the first aspect, the cooling shroud includes a second annular wall. The inner diameter of the second annular wall along the radial direction of the drive motor is larger than the outer diameter of the first annular wall and the outer diameter of one winding end. In this implementation, the cooling shroud further includes a second annular wall that can surround the outer periphery of the first annular wall. The second annular wall can be connected to the stator core, thus making the receiving structure an annular groove, achieving good containment of the winding end and coolant, which is beneficial to improving the immersion liquid cooling effect of the winding end.

[0008] In one implementation of the first aspect, the drive motor includes a stator housing for fixing a stator core. The length of the stator housing along the axial direction of the drive motor is greater than that of the stator core, and the outer diameter of the stator core along the radial direction of the drive motor is less than or equal to the inner diameter of the stator housing. The drive motor also includes an end cover for fixedly connecting to the stator housing. Along the axial direction of the drive motor, one end face of the end cover is aligned opposite to one end face of the stator core. For a drive motor with a stator housing and an end cover, a cooling shroud can be used to contain the coolant and the winding ends, achieving immersion liquid cooling of the winding ends.

[0009] In one implementation of the first aspect, the inner circumferential surface of the stator housing is used to fix the first annular wall. The first annular wall can be an independent component that can be fixedly connected to the inner circumferential surface of the stator housing. This implementation is simple and reliable in structure, facilitates the assembly of the cooling shroud, and ensures the performance of the cooling shroud.

[0010] In one implementation of the first aspect, the inner circumferential surface of the stator housing is used to fix the second annular wall or serves as the second annular wall. The second annular wall can be a separate component; or the second annular wall itself is part of the inner circumferential surface of the stator housing, or the second annular wall is integrated with the stator housing. This implementation is simple and reliable in structure, facilitates the assembly of the cooling shroud, and ensures the performance of the cooling shroud.

[0011] In one implementation of the first aspect, one end face of the end cap is used to: fix the other end of the first annular wall away from the stator core along the axial direction of the drive motor; or, fix the other end of the second annular wall away from the stator core along the axial direction of the drive motor; or, fix both the other end of the first annular wall and the other end of the second annular wall away from the stator core along the axial direction of the drive motor. The first annular wall can be an independent component, the second annular wall can be an independent component, and at least one of the first and second annular walls can be fixedly connected to the end face of the end cap. This implementation is simple in structure, reliable, and facilitates the assembly of the cooling cover, ensuring the performance of the cooling cover.

[0012] In one implementation of the first aspect, the cooling shroud includes an axial bottom wall, and along the axial direction of the drive motor, the end face of the axial bottom wall, a winding end, and one end of the stator core are arranged sequentially. In this implementation, by including the axial bottom wall in the cooling shroud, the axial bottom wall may or may not be connected to the first annular wall, and the axial bottom wall may or may not be connected to the second annular wall. The resulting containment structure can effectively contain the winding end and the coolant, which is beneficial to improving the immersion liquid cooling effect of the winding end.

[0013] In one implementation of the first aspect, one end face of the end cap serves as the axial bottom wall of the cooling shroud. The axial bottom wall itself is part of the end cap, or in other words, the axial bottom wall is integrated with the end cap. This implementation is simple and reliable in structure, facilitates the assembly of the cooling shroud, and ensures the performance of the cooling shroud.

[0014] In one implementation of the first aspect, the outer peripheral surface of the axial bottom wall is used to fixably connect to the second annular wall, and the end face of the axial bottom wall facing the stator core is used to fixably connect to the first annular wall of the cooling shroud. The second annular wall can be a separate component or integrated with other housings (e.g., the stator housing). The first annular wall can be a separate component or integrated with other housings. The second annular wall can be fixedly connected to the outer peripheral surface of the axial bottom wall, and the first annular wall can be fixedly connected to the end face of the axial bottom wall. The resulting housing structure can effectively contain the winding ends and coolant, which is beneficial for improving the immersion liquid cooling effect of the winding ends. This implementation allows for a simple and reliable design to realize the structural design of the cooling shroud and ensure its performance.

[0015] In one implementation of the first aspect, the end face of the axial bottom wall facing the stator core is used to fix and connect the second annular wall of the cooling shroud. The second annular wall can be a separate component or integrated with other housings (e.g., the stator housing). This implementation allows for a simple and reliable design to realize the structural design of the cooling shroud and ensure its performance.

[0016] In one implementation of the first aspect, the drive motor includes multiple stator cooling channels, each stator cooling channel including multiple coolant outlets. The multiple coolant outlets are spaced apart on the end face of one end of the stator core along the circumferential direction of the drive motor. The distance between each coolant outlet and the axis of the drive motor along the radial direction is greater than the outer diameter of one winding end. The outer diameter of the second annular wall along the radial direction of the drive motor is greater than the distance between at least some of the coolant outlets and the axis of the drive motor. For a drive motor with stator cooling channels, the second annular wall is positioned further away from the motor axis, while the coolant outlets are positioned closer to the motor axis, facilitating the introduction of coolant into the housing structure of the cooling shroud using the stator cooling channels. In one implementation of the first aspect, the second annular wall includes an opening for connecting the housing flow channel of the drive motor; wherein the opening faces the axis of the drive motor, and the end faces of the opening, a winding end, and one end of the stator core are arranged sequentially along the axial direction of the drive motor. By providing an opening in the second annular wall, the receiving structure and the housing flow channel can be connected, allowing the coolant cooling the winding end to flow through the housing flow channel to other components to be cooled, so that the heat dissipation of the stator winding is no longer the end point of heat dissipation for the entire powertrain, and coolant recycling and reuse can be achieved. In addition, more coolant can be allowed to flow through the stator winding simultaneously without increasing the flow rate of the drive pump, thereby enhancing the heat dissipation of the stator winding.

[0017] In one implementation of the first aspect, the axial bottom wall includes an opening for connecting to the housing flow channel of the drive motor. The opening faces one end face of the stator core and is arranged sequentially along the axial opening of the drive motor and the end of one winding. The distance between the radial opening of the drive motor and the axis of the drive motor is greater than the distance between the first annular wall and the axis. By providing an opening on the axial bottom wall, the receiving structure and the housing flow channel can be connected, allowing the coolant at the end of the cooling winding to flow through the housing flow channel to other components requiring cooling. This ensures that the heat dissipation of the stator winding is no longer the end point of heat dissipation for the entire powertrain, enabling coolant recovery and reuse. Furthermore, without increasing the flow rate of the drive pump, more coolant can flow through the stator winding simultaneously, enhancing the heat dissipation of the stator winding.

[0018] Secondly, embodiments of this application provide a powertrain including a reducer and a drive motor, wherein the input shaft of the reducer is used to fixably connect to the motor shaft of the drive motor.

[0019] In this embodiment, by designing a cooling shroud for the drive motor, including a first annular wall that surrounds one end of the stator core, a receiving structure can be constructed. This receiving structure can house the winding ends and the coolant, immersing the winding ends in the coolant to achieve immersion liquid cooling. Therefore, this embodiment allows the heat from the stator windings to be quickly absorbed and carried away by the coolant, greatly improving the heat dissipation effect of the stator windings and enhancing the temperature uniformity of the drive motor cooling, which is beneficial to improving the performance of the drive motor and powertrain.

[0020] Thirdly, embodiments of this application provide an electric vehicle, including a frame and a powertrain, with the frame used to fix the powertrain. In this embodiment, by designing a cooling shroud for the drive motor, the cooling shroud includes a first annular wall enclosing one end of the stator core, creating a receiving structure that can house the winding ends and coolant. The winding ends are immersed in the coolant, achieving immersion liquid cooling of the winding ends. Therefore, embodiments of this application allow the heat from the stator windings to be quickly absorbed and carried away by the coolant, greatly improving the heat dissipation effect of the stator windings and enhancing the temperature uniformity of the drive motor cooling, which is beneficial for improving the performance of the drive motor, powertrain, and the entire vehicle. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of the electric vehicle according to an embodiment of this application; Figure 2 This is a schematic diagram of the frame structure of the powertrain according to an embodiment of this application; Figure 3 This is a three-dimensional structural diagram of a stator core according to an embodiment of this application; Figure 4 yes Figure 3 A schematic diagram of the axial structure of the stator core in the image; Figure 5 This is a three-dimensional structural diagram of the cooling shroud in Embodiment 1 of this application from one perspective; Figure 6 This is a three-dimensional structural diagram of the cooling shroud in Embodiment 1 of this application from another perspective; Figure 7 This is a cross-sectional schematic diagram of the assembly structure of the cover, stator core, stator winding, etc. in Embodiment 1 of this application; Figure 8 yes Figure 7 A magnified schematic diagram of a partial structure at point A in the middle; Figure 9 yes Figure 7 Another enlarged schematic diagram of the structure at point A; Figure 10 This is a cross-sectional schematic diagram of the assembly structure of the cover, stator core, stator winding, etc. in Embodiment 2 of this application; Figure 11 This is a three-dimensional structural diagram of the cooling shroud in Embodiment 3 of this application from one perspective; Figure 12 This is a three-dimensional structural diagram of the cooling shroud in Embodiment 3 of this application from another perspective; Figure 13 This is a cross-sectional schematic diagram of the assembly structure of the cover, stator core, stator winding, etc. in Embodiment 3 of this application; Figure 14This is a three-dimensional structural diagram of the cooling shroud in Embodiment 4 of this application from one perspective; Figure 15 This is a three-dimensional structural diagram of the cooling shroud in Embodiment 4 of this application from another perspective; Figure 16 This is a cross-sectional schematic diagram of the assembly structure of the cover, stator core, stator winding, etc. in Embodiment 4 of this application; Figure 17 This is a schematic diagram of the topology of the powertrain assembly flow channel in Embodiment 5 of this application; Figure 18 Based on Figure 17 A cross-sectional view of the flow channel of the assembly topology shown. Figure 19 This is a schematic diagram of the topology of the powertrain assembly flow channel in Embodiment Six of this application; Figure 20 Based on Figure 19 A cross-sectional view of the flow channel of the assembly topology shown. Figure 21 This is a schematic diagram of the topology of the powertrain assembly flow channel in Embodiment 7 of this application; Figure 22 Based on Figure 21 A cross-sectional view of the flow channel of the assembly topology shown. Figure 23 This is a schematic diagram of the topology of the powertrain assembly flow channel in Embodiment 8 of this application; Figure 24 Based on Figure 23 A cross-sectional view of the flow channel of the assembly topology shown. Figure 25 This is a schematic diagram of the topology of the powertrain assembly flow channel in Embodiment 9 of this application; Figure 26 Based on Figure 25 The diagram shows a cross-sectional view of the assembly flow channel of the topology. Detailed Implementation

[0022] For ease of understanding, the relevant technical terms involved in the embodiments of this application will be explained and described below.

[0023] In the description of the embodiments in this application, unless otherwise stated, "multiple" means two or more.

[0024] The terms "first," "second," etc., are used for descriptive purposes only and should not be construed as implying or suggesting relative importance or implicitly indicating the number of technical features indicated. Features specified as "first" or "second" may explicitly or implicitly include one or more of that feature.

[0025] The directional terms mentioned in the embodiments of this application, such as "upper," "lower," "front," "rear," "left," "right," "inner," "outer," "side," "top," and "bottom," are only for reference to the directions in the accompanying drawings. These directional terms are used to better and more clearly explain and understand the embodiments of this application, and are not intended to explicitly or implicitly suggest that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation, etc., and therefore should not be construed as limiting the embodiments of this application.

[0026] This application provides an electric vehicle, including but not limited to electric sedans, electric SUVs (Sport Utility Vehicles), electric buses, and electric motorcycles. This electric vehicle can be a pure electric vehicle, a hybrid vehicle, or a fuel cell vehicle.

[0027] Figure 1 An electric vehicle 1 is illustrated, which may include a frame 2, a thermal management system 3, and a powertrain 4. The thermal management system 3 and the powertrain 4 can be mounted on the frame 2.

[0028] The powertrain 4 is a system consisting of a series of components used to generate power and transmit that power to the road surface, driving the wheels to rotate. Schematic, the electric vehicle 1 may also include a power battery, which provides electrical energy to the powertrain 4, converting the electrical energy into mechanical energy to drive the wheels. The thermal management system 3 is used for overall vehicle thermal management, which may include processes such as heat dissipation (e.g., heat dissipation of the power battery and powertrain), heating (e.g., heating of the power battery and drive motor), air conditioning, temperature control (e.g., monitoring and regulating the operating temperature of the power battery and drive motor), and heat distribution (e.g., ensuring stable and balanced temperatures of the power battery and drive motor). A heat exchanger in the powertrain 4 can be connected to the thermal management system 3, allowing the powertrain 4 to exchange heat with the thermal management system 3.

[0029] Figure 2 The diagram illustrates the framework structure of powertrain 4, which is understandable. Figure 2 The positions and connections of the various components shown are merely illustrative and do not constitute a limitation on the actual structure.

[0030] like Figure 2 As shown, the powertrain 4 may include a drive motor 6, a motor controller 7, a reducer 8, a drive pump 9, a filter 10, a heat exchanger 5, etc. In this embodiment, the drive motor 6 may be a radial motor.

[0031] In one embodiment, the powertrain 4 can be an integrated powertrain, where the drive motor 6, motor controller 7, and reducer 8 can be assembled within the same assembly housing. The drive motor housing of the powertrain 4 houses the drive motor 6. The controller housing of the powertrain 4 houses the motor controller 7. The reducer housing of the powertrain 4 houses the reducer 8. For ease of reference, the housing portion housing the drive motor 6 can be called the motor housing, the housing portion housing the motor controller 7 can be called the motor controller housing, and the housing portion housing the reducer 8 can be called the reducer housing.

[0032] In one embodiment, the powertrain 4 can also be a split powertrain. One or more of the drive motor 6, motor controller 7, and reducer 8 have separate housings.

[0033] like Figure 2 As shown, the motor controller 7 is used to control the drive motor 6. The motor controller 7 receives DC power from the power battery and outputs AC power to the drive motor 6. The motor shaft of the drive motor 6 is connected to the input shaft of the reducer 8, and the drive motor 6 transmits its power to the wheels through the reducer 8.

[0034] like Figure 2 As shown, the drive pump 9 is installed in the pump housing of the powertrain 4. The drive pump is used to drive the coolant to circulate between the internal flow channels of the powertrain 4 housing, the coolant flow channels of the drive motor 6, and the coolant flow channels of the reducer 8. In one embodiment, the coolant can be cooling oil.

[0035] like Figure 2 As shown, the heat exchanger 5 is mounted on the housing of the powertrain 4 and is connected to at least one of the internal flow channels of the powertrain 4 housing, the coolant flow channel of the drive motor 6, or the coolant flow channel of the reducer 8. The heat exchanger 5 is used to dissipate heat from the high-temperature coolant flowing out of at least one of the internal flow channels of the powertrain 4 housing, the coolant flow channel of the drive motor 6, or the coolant flow channel of the reducer 8.

[0036] Combination Figure 2 and Figure 1 As shown, the coolant absorbs heat and heats up after flowing through at least one of the internal flow channels of the powertrain 4 housing, the coolant flow channel of the drive motor 6, or the coolant flow channel of the reducer 8. The heated coolant can then exchange heat with the thermal management system 3 through the heat exchanger 5 to cool down. Thus, the coolant can circulate within the powertrain 4 and provide circulating cooling for the powertrain 4. This circulating cooling process will be further explained below.

[0037] like Figure 2As shown, filter 10 is installed in the housing of powertrain 4. Filter 10 is used to filter foreign matter and impurities from at least one of the internal flow channels of the powertrain 4 housing, the coolant flow channels of the drive motor 6, or the coolant flow channels of the reducer 8. In one embodiment, filter 10 is located upstream of drive pump 9. In another embodiment, filter 10 is located downstream of drive pump 9. In one example, filter 10 is located between drive pump 9 and heat exchanger 5.

[0038] Understandable, Figure 2 The powertrain 4 shown is merely one embodiment of the powertrain 4 provided in this application. The powertrain 4 may include more or fewer components as needed. In another embodiment, the powertrain 4 may not include the filter 10.

[0039] In the drive motor 6 and powertrain 4 provided in this application embodiment, by improving the heat dissipation design of the stator winding of the drive motor 6, not only can sufficient heat dissipation of the stator winding be achieved, but the coolant of the stator winding can also be used to cool other heat-generating components of the powertrain 4, realizing the recycling and reuse of the coolant. Furthermore, in the drive motor 6 and powertrain 4 provided in this application embodiment, the heat generated by the stator winding can also be effectively collected and transported to the thermal management system, reducing heat loss, thereby improving the coefficient of performance (COP, the ratio of generated heat output to consumed electrical energy), achieving energy saving and cost reduction. A detailed explanation follows.

[0040] In this embodiment, the axial, circumferential, and radial directions are defined with the motor shaft of the drive motor 6 as a reference. Specifically, the axial direction of the drive motor 6 is parallel to the length direction of the motor shaft, the circumferential direction of the drive motor 6 is the circumferential direction surrounding the motor shaft, and the radial direction of the drive motor 6 is parallel to the diameter direction of the motor shaft.

[0041] In this embodiment of the application, the drive motor 6 includes a stator core and a stator winding. The stator core is used to fix the stator winding. Along the axial direction of the drive motor 6, one end of the stator winding is exposed at one end of the stator core. Along the radial direction of the drive motor 6, the inner diameter of one end of the stator winding is larger than the inner diameter of the stator core.

[0042] Figure 3 and Figure 4 This illustrates a schematic structure of the stator core 61 in the drive motor 6. For example... Figure 3 and Figure 4As shown, the stator core 61 has end faces 61c and 61e at its two ends along the axial direction. Several slots 61a are formed on the inner circumferential side of the stator core 61. These slots 61a can be evenly distributed circumferentially, and each slot 61a can penetrate the two opposite end faces 61c and 61e of the stator core 61. Each slot 61a can form an opening on the inner circumferential surface of the stator core 61. A conductor can be wound into each slot 61a to form a stator winding. The axial length of the stator winding can be greater than the axial length of the stator core 61. The opposite ends of the stator winding along the axial direction can be exposed on the end faces of the stator core 61 at both ends along the axial direction. These two ends can be referred to as the first winding end and the second winding end (to be further explained below). Both the first winding end and the second winding end are winding ends. The inner circumferential surface of the winding end in the slot 61a can be recessed by a certain distance relative to the opening of the slot 61a, so that the inner diameter of the winding end is larger than the inner diameter of the stator core 61.

[0043] In some implementations, each groove 61a can also be used for circulating coolant (as will be described below).

[0044] In this embodiment, the drive motor 6 includes multiple stator cooling channels, and the stator cooling channels include multiple coolant outlets. The multiple coolant outlets are distributed at intervals on the end face of one end of the stator core 61 along the circumference of the drive motor 6. The distance between each coolant outlet and the axis of the drive motor 6 along the radial direction of the drive motor 6 is greater than the outer diameter of the winding end.

[0045] For example Figure 3 and Figure 4 As shown, a plurality of axial channels 61b can be formed within the stator core 61. These axial channels 61b can be evenly distributed circumferentially. Each axial channel 61b can extend axially and penetrate end face 61c and end face 61e, forming coolant outlets on end face 61c and end face 61e respectively. The multiple coolant outlets on each end face 61c and end face 61e can be distributed circumferentially around the drive motor 6. Compared to the slot 61a, the axial channels 61b can be closer to the outer periphery of the stator core 61, therefore the distance between each coolant outlet and the axis of the drive motor 6 is greater than the outer diameter of the winding end.

[0046] Schematic, a circumferential channel 61d can also be formed on the outer circumferential surface of the stator core 61. The circumferential channel 61d can be a groove that surrounds the entire circumference. The circumferential channel 61d is connected to each axial channel 61b.

[0047] In another embodiment, the circumferential channel 61d may also be composed of a plurality of radial holes arranged sequentially at intervals along the circumference, with the axis of each radial hole along the radial direction, and each radial hole may be connected to an axial channel 61b.

[0048] In this embodiment, the axial channel 61b and the circumferential channel 61d are both stator cooling channels.

[0049] like Figure 3 and Figure 4 As shown, a sealing layer 62 may be provided on the inner circumferential surface of the stator core 61.

[0050] In one embodiment, the sealing layer 62 can cover all areas of the inner circumferential surface of the stator core 61, and the sealing layer 62 can be a single cylindrical component. The sealing layer 62 seals the openings of each slot 61a on the inner circumferential surface of the stator core 61, so that the wires in each slot 61a are accommodated within the space enclosed by the slot wall of the slot 61a and the sealing layer 62. Schematically, the sealing layer 62 can be integrally formed with the stator core 61, for example, by using an injection molding process to manufacture the sealing layer 62 on the inner circumferential surface of the stator core 61. Alternatively, the sealing layer 62 can be manufactured separately and assembled to the stator core 61.

[0051] Unlike the above, in another embodiment, there may be multiple sealing layers 62, each of which may be an arc-shaped plate. These sealing layers 62 may be evenly distributed along the inner circumferential surface of the stator core 61, and one sealing layer 62 may cover the opening of one slot 61a.

[0052] The following description takes a single component, where the sealing layer 62 is cylindrical, as an example.

[0053] In this embodiment, cooling covers can be connected to both opposite ends of the stator core 61 along its axial direction to achieve immersion liquid cooling of the stator winding. The cooling covers are used to contain coolant and a winding end. The cooling covers include a first annular wall. The outer diameter of the first annular wall along the radial direction of the drive motor 6 is less than or equal to the inner diameter of a winding end of the stator winding. One end of the first annular wall along the axial direction of the drive motor 6 and facing the stator core 61 is used to enclose this end of the stator core to form a receiving structure. The coolant contained in the receiving structure is used to immerse and cool the winding end.

[0054] In this embodiment, one cooling shroud is used to contain coolant and one winding end, and another cooling shroud is used to contain coolant and another winding end.

[0055] In this embodiment, the first annular wall of the cooling shroud surrounds the entire circumference, and its radial dimension can be defined as the dimension along the radial direction of the drive motor 6. The first annular wall has a certain thickness, thus its inner and outer diameters can be defined. The outer diameter of the first annular wall is the radial dimension of the outer circumferential surface of the first annular wall away from the axis of the drive motor 6. The outer diameter of the first annular wall is less than or equal to the inner diameter of the winding end, meaning that the inner circumferential surface of the winding end, the outer circumferential surface of the first annular wall, and the axis of the drive motor 6 can be arranged sequentially along the radial direction of the drive motor 6. There is a certain gap between the inner circumferential surface of the winding end and the outer circumferential surface of the first annular wall, or there is essentially no gap between them.

[0056] In this embodiment, the first annular wall can be used to enclose one end of the stator core 61. The first annular wall can be used to surround one end of the stator core 61. The cooling cover can form a receiving structure that accommodates a winding end and coolant, thereby realizing immersion cooling of the winding end.

[0057] The following examples illustrate several design schemes for cooling covers.

[0058] Figure 5 and Figure 6 This illustrates the schematic structure of the cooling shroud 63 in Embodiment 1 of this application. For example... Figure 5 and Figure 6 As shown, the cooling shroud 63 can be roughly annular in shape.

[0059] The cooling shroud 63 may include a first annular wall 63c, an axial bottom wall 63b, and a second annular wall 63a, which are connected in sequence. The axial bottom wall 63b may be approximately annular, forming a first through hole 63d. Both the second annular wall 63a and the first annular wall 63c may protrude from the axial bottom wall 63b and connect the outer and inner edges of the axial bottom wall 63b, respectively. The second annular wall 63a may be located on the outer periphery of the first annular wall 63c, and the first annular wall 63c may surround the outer periphery of the first through hole 63d. The second annular wall 63a, the axial bottom wall 63b, and the first annular wall 63c may form an annular groove.

[0060] refer to Figure 7 As shown, along the axial direction of the drive motor, the axial bottom wall 63b of the cooling cover 63, the end of a winding 65a, and the end face 61c of one end of the stator core 61 are arranged in sequence. In this embodiment, any one of the three components of the cooling cover 63—the axial bottom wall 63b, the first annular wall 63c, and the second annular wall 63a—can be independent of the motor housing or integrated with it. The types of the axial bottom wall 63b, the first annular wall 63c, and the second annular wall 63a can be freely combined according to product requirements.

[0061] In Embodiment 1, a cooling cover 64 can also be designed. The structure of the cooling cover 64 can be identical to that of the cooling cover 63, and the two can be arranged in a mirror image. This will be described below.

[0062] Figure 7 The diagram illustrates the assembled cross-sectional structure of the stator core 61, stator winding 65, sealing layer 62, cooling shroud 63, and cooling shroud 64 in Embodiment 1. Figure 7 As shown, the stator winding 65 includes winding end 65a and winding end 65b, both of which protrude from one end face of the stator core 61. Cooling shrouds 63 and 64 can be located at opposite ends of the stator winding 65 along the axial direction. The axial bottom wall 63b and the second bottom wall 64b are arranged facing away from each other, while the second annular wall 63a and the second annular wall 64a are arranged facing each other. The second bottom wall 64b can form a second through hole.

[0063] like Figure 7 As shown, the inner diameter r1 of the second annular wall 63a along the radial direction of the drive motor 6 is greater than the outer diameter r3 of the first annular wall 63c and the outer diameter r2 of a winding end 65a.

[0064] refer to Figure 7 As shown, the outer diameter of the second annular wall along the radial direction of the drive motor 6 is greater than at least a portion of the distance between the coolant outlet and the axis of the drive motor 6. For example, the outer diameter r4 of the second annular wall 64a is greater than the distance d1 between at least a portion of the coolant outlet of the axial channel 61b and the axis of the drive motor 6. Figure 7 As shown, the second annular wall 63a of the cooling shroud 63 can be connected to the end face 61a of the stator core 61. Schematably, the second annular wall 63a can be connected to the end face 61a via a sealing structure made of a material with good sealing performance, such as a sealing ring. Alternatively, the second annular wall 63a can be directly connected to the end face 61a without a connecting medium. The second annular wall 63a is farther from the stator winding 65, while the axial channel 61b is closer to the stator winding 65. The first annular wall 63c of the cooling shroud 63 can be connected to the sealing layer 62. Thus, the winding end 65a is encapsulated within a first end flow channel 6a formed by the cooling shroud 63, the stator core 61, and the sealing layer 62. All axial channels 61b can communicate with the first end flow channel 6a. The first end flow channel 6a can also be referred to as a receiving structure.

[0065] like Figure 7As shown schematically, the second annular wall 64a of the cooling shroud 64 can be connected to the end face 61c of the stator core 61. Schematically, the second annular wall 64a can be connected to the end face 61c via a sealing structure made of a material with good sealing performance, such as a sealing ring. Alternatively, the second annular wall 64a can be directly connected to the end face 61c without a connecting medium. The second annular wall 64a is farther from the stator winding 65, while the axial channel 61b is closer to the stator winding 65. The first annular wall 64c of the cooling shroud 64 can be connected to the sealing layer 62. Thus, the winding end 65b is encapsulated within a second end flow channel 6b formed by the cooling shroud 64, the stator core 61, and the sealing layer 62. The second end flow channel 6b can also be referred to as a receiving structure.

[0066] All axial channels 61b can be connected to the second end channel 6b. Therefore, the second end channel 6b can be connected to the first end channel 6a through the axial channels 61b.

[0067] Figure 8 yes Figure 7 A magnified schematic diagram of a partial structure at point A in the middle. Figure 8 This can represent one connection method between the first annular wall 63c of the cooling shroud 63 and the sealing layer 62. For example... Figure 8 The first annular wall 63c and the sealing layer 62 can be distributed axially, and the two can be connected by a sealing structure 66. The sealing structure 66 is made of a material with good sealing performance. Schematic, the sealing structure 66 can be a sealing ring.

[0068] and Figure 8 The difference shown is that in another embodiment, such as Figure 9 As shown, the first annular wall 63c and the sealing layer 62 can be distributed radially, and the two can be connected by the sealing structure 66. Figure 9 In the illustrated embodiment, the first annular wall 63c is connected to the inner circumferential surface of one end of the stator core 61 via the sealing layer 62. Correspondingly, the connection area between the first annular wall 63c and the sealing layer 62 is relatively large, resulting in better sealing of the first end flow channel 6a. In other embodiments, the first annular wall 63c and the sealing layer 62 can be directly connected without a connecting medium.

[0069] The connection between the first annular wall 64c of the cooling cover 64 and the sealing layer 62 can also be done in the manner described above, and will not be repeated here.

[0070] In this embodiment, both the first end channel 6a and the second end channel 6b can serve as coolant channels, and they can communicate with the drive pump 9, filter 10, heat exchanger 5, and other channels in the powertrain 4. Both the first end channel 6a and the second end channel 6b can receive and contain coolant, thus allowing both ends of the stator winding 65 to be immersed in the coolant within the first end channel 6a and the second end channel 6b, respectively, achieving immersion liquid cooling. The above description will be further explained below.

[0071] In this embodiment, the cooling cover 63, cooling cover 64, and motor housing can be independent of each other, and neither cooling cover 63 nor cooling cover 64 is directly connected to the motor housing. Illustratively, the drive motor 6 can be a lug-type motor, with stator lugs on the outer periphery of the stator core 61. Both cooling cover 63 and cooling cover 64 can have cover lugs formed on them, which are then assembled with stator lugs and fixed to the motor housing, thereby fixing the cooling cover 63, cooling cover 64, and stator core 61 to the same position on the motor housing. In one embodiment, the cooling cover 63, cooling cover 64, and motor housing are independent of each other, but both cooling cover 63 and cooling cover 64 are connected to the motor housing, as will be described below.

[0072] like Figure 10 As shown, the drive motor 6 includes a stator housing 6x, which is used to fix the stator core 61. Along the axial direction of the drive motor 6, the length of the stator housing 6x is greater than that of the stator core 61, and along the radial direction of the drive motor 6, the outer diameter of the stator core 61 is less than or equal to the inner diameter of the stator housing 6x. The drive motor 6 also includes an end cover, which is used to fixably connect to the stator housing 6x. Along the axial direction of the drive motor 6, one end face of the end cover is aligned opposite to one end face of the stator core 61. like Figure 10 As shown, the stator housing 6x surrounds the outer periphery of the stator core 61 and is used to fix the stator core 61. Along the axial direction of the drive motor 6, one end of the stator housing 6x (e.g., the left end), one end of the stator core 61 (e.g., the left end), the other end of the stator core 61 (e.g., the right end), and the other end of the stator housing 6x (e.g., the right end) can be arranged sequentially. The end caps may include a first end cap 67 and a second end cap 68. The outer peripheral surface of the end cap is used to fixably connect to the inner peripheral surface of the stator housing 6x, or the end face of the end cap is used to fixably connect to the end face of the stator housing 6x.

[0073] Figure 10 The diagram illustrates the assembled cross-sectional structure of the stator housing 6x, the first end cover 67, the stator core 61, the stator winding 65, the sealing layer 62, the cooling cover 63, the cooling cover 64, and the second end cover 68 in Embodiment 2.

[0074] Both the first end cover 67 and the second end cover 68 are motor housings. The first end cover 67 can be located on the side of the cooling cover 63 facing away from the cooling cover 64, and can be assembled with the cooling cover 63, for example, via a threaded connector. The first end cover 67 can press against the cooling cover 63, forming a sealed connection between the cooling cover 63, the stator core 61, and the sealing layer 62. The second end cover 68 can be located on the side of the cooling cover 64 facing away from the cooling cover 63, and can be assembled with the cooling cover 64, for example, via a threaded connector. The second end cover 68 can press against the cooling cover 64, forming a sealed connection between the cooling cover 64, the stator core 61, and the sealing layer 62.

[0075] In one embodiment, the inner circumferential surface of the stator housing is used to fix the first annular wall. The first annular wall can be a separate component that can be fixedly connected to the inner circumferential surface of the stator housing. This embodiment does not limit the connection structure between the first annular wall and the inner circumferential surface of the stator housing. For example, the inner circumferential surface of the stator housing can extend radially to form a connecting wall, which connects with the first annular wall to form a receiving structure. This embodiment can achieve the assembly of the cooling cover with a simple and reliable structure, ensuring the performance of the cooling cover.

[0076] In one embodiment, the inner circumferential surface of the stator housing is used to fix the second annular wall or serves as the second annular wall. The second annular wall can be a separate component that can be fixedly connected to the inner circumferential surface of the stator housing. Alternatively, the stator housing can be integrated with the second annular wall, utilizing at least a portion of the stator housing as the second annular wall. This allows for a simple and reliable structural fabrication of the cooling shroud, enabling it to contain the coolant and the winding ends.

[0077] refer to Figure 10 As shown, in one embodiment, one end face of the end cap of the drive motor 6 is used to fix the other end of the first annular wall away from the stator core 61 along the axial direction of the drive motor 6; or to fix the other end of the second annular wall away from the stator core 61 along the axial direction of the drive motor 6; or, to fix the other end of the first annular wall away from the stator core 61 along the axial direction of the drive motor 6 and to fix the other end of the second annular wall away from the stator core 61 along the axial direction of the drive motor 6.

[0078] In this embodiment, the first annular wall and the second annular wall of the cooling shroud can be independent components, and at least one of them can be fixedly connected to one end face of the end cap. The axial bottom wall of the cooling shroud can be an independent component or can be integrated with the end cap. Taking the end cap 67 as an example: one end face of the end cap 67 (e.g., the right end face) can be used to fix one end of the first annular wall away from the stator core 61, or one end face of the end cap 67 (e.g., the right end face) can be used to fix one end of the second annular wall away from the stator core 61, or one end face of the end cap 67 (e.g., the right end face) can be used to fix both one end of the first annular wall away from the stator core 61 and one end of the second annular wall away from the stator core 61.

[0079] In one embodiment of this application, the cooling cover 63, the cooling cover 64 and the motor housing can be integrated into one unit, as will be described below.

[0080] Figure 11 and Figure 12 The structure of the cooling shroud 63 in Embodiment 3 is illustrated. For example... Figure 11 and Figure 12 As shown, the cooling cover 63 can be approximately annular. The cooling cover 63 may include an axial bottom wall 63b, a second annular wall 63a, and a first annular wall 63c. The axial bottom wall 63b can be approximately annular, and a first through hole 63d can be formed thereon for mounting the motor shaft. Both the second annular wall 63a and the first annular wall 63c can protrude from the axial bottom wall 63b. The second annular wall 63a can be located on the outer periphery of the first annular wall 63c, and there can be a certain distance between the edge of the second annular wall 63a and the edge of the axial bottom wall 63b.

[0081] like Figure 13 As shown, the axial bottom wall 63b can be integrated with the end cover of the drive motor 6, and one end face of the end cover serves as the axial bottom wall 63b of the cooling shroud 63.

[0082] Figure 13 The diagram illustrates the assembled cross-sectional structure of the stator core 61, stator winding 65, sealing layer 62, cooling cover 63, and cooling cover 64 in Embodiment 3, wherein the structure of cooling cover 64 can be the same as that of cooling cover 63.

[0083] like Figure 13As shown, cooling cover 63 can serve as the first end cover, and cooling cover 64 can serve as the second end cover. The connection method of cooling cover 63, cooling cover 64, stator core 61, and sealing layer 62 can be as described above and will not be repeated here. Embodiment 3, by combining the cover body and the end cover of the drive motor into one, enables a compact structure, simplifies the assembly process, and improves assembly accuracy. In other embodiments, at least a portion of cooling cover 63 can also be a peripheral shell of the motor housing (a shell that surrounds the motor circumferentially, and the end cover can be assembled with the peripheral shell axially), and at least a portion of cooling cover 64 can also be a peripheral shell of the motor housing. This peripheral shell can also be referred to as the stator housing.

[0084] In Embodiment 4 of this application, unlike Embodiment 3 above, a portion of the cooling cover 63 and a portion of the cooling cover 64 can be integrated with the motor housing, while another portion of the cooling cover 63 and another portion of the cooling cover 64 can be independent of the motor housing. This will be explained below.

[0085] Figure 14 and Figure 15 The structure of the cooling shroud 63 in Embodiment 4 is illustrated. For example... Figure 14 and Figure 15 As shown, the cooling shroud 63 may include an axial bottom wall 63b and a first annular wall 63c. The axial bottom wall 63b may be approximately annular, forming a first through hole 63d through which the motor shaft passes. The first annular wall 63c may protrude from the axial bottom wall 63b, and there may be a certain distance between the edge of the first annular wall 63c and the edge of the axial bottom wall 63b. The first annular wall 63c surrounds the outer periphery of the first through hole 63d. (Comparison) Figure 14 and Figure 11 As can be seen, compared with Embodiment 3, the cooling shroud 63 of Embodiment 4 may not have a first annular wall.

[0086] Figure 16 The diagram illustrates the assembled cross-sectional structure of the stator core 61, stator winding 65, sealing layer 62, cooling cover 63, cooling cover 64, peripheral shell 671, first end cover 672 and second end cover 673 in Embodiment 4, wherein the structures of cooling cover 64 and cooling cover 63 can be identical.

[0087] like Figure 16As shown, a peripheral shell 671 surrounds the outer periphery of the stator core 61, and the peripheral shell 671 can be connected to the outer peripheral surface of the stator core 61. The axial bottom wall 63b of the cooling shroud 63 can be connected to the peripheral shell 671, and the peripheral shell 671, the axial bottom wall 63b, the sealing layer 62, and the stator core 61 can form a first end flow channel 6a. Therefore, a portion of the peripheral shell 671 can serve as the first annular wall of the cooling shroud 63. The second bottom wall 64b of the cooling shroud 64 can be connected to the peripheral shell 671, and the peripheral shell 671, the second bottom wall 64b, the sealing layer 62, and the stator core 61 can form a second end flow channel 6b. Therefore, a portion of the peripheral shell 671 can serve as the second annular wall of the cooling shroud 64.

[0088] like Figure 16 As shown, the peripheral shell 671 may have an inlet 671b near the bottom, which can communicate with the second end flow channel 6b, allowing coolant to enter the second end flow channel 6b. The peripheral shell 671 may have an outlet 671a near the top, which can communicate with the first end flow channel 6a, allowing coolant to flow out from the first end flow channel 6a.

[0089] refer to Figure 7 As shown, in one embodiment, the outer peripheral surface of the axial bottom wall 63b of the cooling shroud 63 is used to fixably connect the second annular wall 63a, and the end face of the axial bottom wall 63b facing the stator core 61 is used to fixably connect the first annular wall 63c of the cooling shroud 63. The axial bottom wall 63b can be a separate component or integrated with the motor housing. The second annular wall 63a can be a separate component or integrated with the motor housing. The first annular wall 63c can be a separate component or integrated with the motor housing.

[0090] refer to Figure 13 and Figure 7 As shown, in one embodiment, the axial bottom wall 63b of the cooling shroud 63, facing the end face of the stator core 61, is used to fixably connect the second annular wall 63a of the cooling shroud 63. The axial bottom wall 63b can be a separate component or integrated with the motor housing. The second annular wall 63a can be a separate component or integrated with the motor housing, for example, integrated with the stator housing.

[0091] Based on the descriptions of the above embodiments, it can be understood that in the embodiments of this application, any one of the axial bottom wall, the first annular wall, and the second annular wall of the cooling cover can be integrated with the motor housing, or all can be independent of the motor housing. Furthermore, the types of the bottom wall, the first annular wall, and the second annular wall can be freely combined according to product needs. For example: For example, in another embodiment, the first annular wall and the axial bottom wall can both be integrated with the motor housing, while the second annular wall is independent of the motor housing and can be assembled with the axial bottom wall. The first annular wall can be part of the peripheral shell, and the axial bottom wall can be part of the first end cap.

[0092] Alternatively, in another embodiment, both the first annular wall and the second annular wall can be integrated with the motor housing, while the axial bottom wall is independent of the motor housing and is assembled with both the first and second annular walls. The first annular wall may be part of the peripheral shell, and the second annular wall may be part of the first end cap; or, both the first and second annular walls may be part of the first end cap.

[0093] Alternatively, in another embodiment, the second annular wall is integrated with the motor housing, while the first annular wall and the axial bottom wall are independent of the motor housing, and the axial bottom wall is assembled with the second annular wall. The second annular wall may be part of the first end cap. The first annular wall and the axial bottom wall may be integrally connected or assembled together.

[0094] Alternatively, in another embodiment, the second annular wall and the axial bottom wall are both integrated with the motor housing, while the first annular wall is independent of the motor housing and is assembled with the axial bottom wall. Both the second annular wall and the axial bottom wall can be part of the first end cap.

[0095] Alternatively, in another embodiment, the axial bottom wall is integrated with the motor housing, and both the first annular wall and the second annular wall are independent of the motor housing. Both the first annular wall and the second annular wall are assembled with the axial bottom wall. The axial bottom wall may be part of the first end cap.

[0096] The above embodiments illustrate different types of cooling covers, and the types of cooling cover 63 and cooling cover 64 in each embodiment can be the same. In another embodiment, the types of cooling cover 63 and cooling cover 64 can be different, and the types of cooling cover 63 and cooling cover 64 can be arbitrarily combined as needed. For example, cooling cover 63 can be... Figure 7 The type shown, cooling shroud 64 can be adopted Figure 10 or Figure 13 The type shown; or, the cooling shroud 63 can be adopted. Figure 10 The type shown, cooling shroud 64 can be adopted Figure 7 or Figure 13 The type shown.

[0097] The above describes how the first end flow channel 6a and the second end flow channel 6b are constructed by designing cooling shrouds 63 and 64. The following will explain the position of the first end flow channel 6a and the second end flow channel 6b in the overall flow channel of the powertrain 4, and explain the immersion heat dissipation principle of the stator winding 65, as well as the heat dissipation principle of the entire powertrain 4.

[0098] In this embodiment of the application, the first end flow channel 6a and the second end flow channel 6b can both be located in the middle section of the powertrain 4 assembly flow channel and can only be located at the end. That is, after the coolant flows through the first end flow channel 6a and the second end flow channel 6b, it can continue to flow into other flow channels in the assembly flow channel, rather than only falling into the bottom shell of the powertrain 4.

[0099] Figure 17 This is a schematic diagram of the topology of the powertrain 4 assembly flow channel in Embodiment 5 of this application. Figure 17 This illustrates a key portion of the assembly's flow path, not the entire flow path. For example... Figure 17 As shown, the assembly flow channel may include flow channels within the drive pump, heat exchanger, stator core, housing (including cooling shroud and cooling shield), motor shaft, rotor, and reducer, as well as flow channels between the aforementioned components. The assembly flow channel is enclosed by a solid structure; for example, it may include pipes, flow channel grooves on the casing, etc. Figure 17 The arrowhead is represented by a solid line. Figure 17 The dashed lines with arrows indicate the flow of coolant between the base and the aforementioned components through methods such as spraying, leakage, and gear agitation. Spraying, for example, means coolant is ejected from a nozzle onto the base. Leaking, for example, can occur naturally at the joints of physical flow channels or at the mounting locations of internal sensors. Gear agitation involves a portion of the gears in the reducer being immersed in the coolant in the base, and the agitation of these gears transports coolant from the base to the interior of the reducer.

[0100] like Figure 17 As shown, the stator core has stator cooling channels, and the cooling shroud participates in forming the end flow channels (including the first end flow channel and the second end flow channel). The motor shaft, rotor, and reducer participate in forming other flow channels. These other flow channels may include the first channel and the second channel. The first channel is the flow channel in the drive motor other than the end flow channels and stator cooling channels, such as the motor shaft channel within the motor shaft, the motor bearing housing cavity, and the rotor channel within the rotor. The second channel is the flow channel within the reducer, such as the gear shaft flow channel in the reducer.

[0101] like Figure 17As shown, the drive pump draws high-temperature coolant from the bottom casing and pumps it into the heat exchanger, from which low-temperature coolant flows out. The low-temperature coolant can flow in parallel into the stator cooling channel, end channels, and other channels. Specifically, the low-temperature coolant can flow into the other channels along channel R1, into the stator cooling channel along channel R2, and into the end channels along channel R3; channels R1, R2, and R3 are connected in parallel. The coolant flowing out of the stator cooling channel can also flow into the end channels along channel R4. The coolant in the end channels can flow into the bottom casing via spraying or leakage (coolant can flow out from the first or second end channel and enter the bottom casing). The coolant in the end channels can also flow into the other channels along channel R5. The coolant in the other channels can also flow into the bottom casing via spraying or leakage. For the reducer in the other channels, the gears in the reducer can agitate the coolant from the bottom casing to the reducer's interior.

[0102] pass Figure 17 The topology shown enables circulating liquid cooling of the powertrain.

[0103] Figure 18 For based on Figure 17 The diagram shows a cross-sectional view of the assembly flow channel of the topology. (See attached diagram.) Figure 18 As shown, the powertrain 4 can be an integrated powertrain, where the drive motor 6 and the reducer 8 can be assembled in the same assembly housing. Illustratively, both the cooling shroud 63 and cooling shroud 64 can be integrated with the motor housing of the drive motor 6. Since the motor housing of the drive motor 6 is also part of the assembly housing, it can be considered that both the cooling shroud 63 and cooling shroud 64 are integrated with the assembly housing. Figure 18 The diagram shows the bottom shell 41, peripheral shell 42, cooling cover 63 and cooling cover 64 in the assembly housing, but does not show the reducer housing of the reducer 8.

[0104] Understandable, Figure 18 The powertrain shown as 4 is merely illustrative and does not define the actual structure. For example, Figure 18 The cross-sectional shape of the drive motor 6 and the cross-sectional shape of the reducer 8 are shown on the same plane, but in reality, the cross-sectional shape of the drive motor 6 and the cross-sectional shape of the reducer 8 may not be coplanar.

[0105] like Figure 18As shown, the motor shaft 69 can be mounted on the assembly housing via a motor bearing 701 fixed to the assembly housing (e.g., cooling shrouds 63 and 64). The rotor 71 can surround and be fixed to the outer periphery of the motor shaft 69, with the sealing layer 62, stator winding 65, and stator core 61 surrounding the outer periphery of the rotor 71. The rotor 71, sealing layer 62, stator winding 65, and stator core 61 are located between cooling shrouds 63 and 64. One end of the motor shaft 69 (e.g., the right end) can extend out of the cooling shroud 64 and be fixedly connected to the input shaft 84 of the reducer 8.

[0106] like Figure 18 As shown schematically, the reducer 8 may include an input shaft 84, a gear 85, a gear shaft 88, a gear bearing 87, a gear 86, a gear shaft 81, a gear bearing 83, and a gear 82. Gear 85 may be fixed to the outer periphery of the input shaft 84. The gear shaft 88 may be mounted on the assembly housing via the gear bearing 87, and gear 86 may be fixed to the outer periphery of the gear shaft 88 and mesh with gear 85. The gear shaft 81 may be mounted on the assembly housing via the gear bearing 83, and gear 82 may be fixed to the outer periphery of the gear shaft 81 and mesh with gear 86. Gears 85, 86, and 82 are all located outside the cooling shrouds 63 and 64; for example, all three gears may be located on the side of the cooling shroud 64 facing away from the cooling shroud 63.

[0107] like Figure 18 As shown, the cooling shroud 63 may have a housing flow channel 63f, which can communicate with the motor shaft channel 69a inside the motor shaft 69. The motor shaft channel 69a can communicate with the rotor channel 71a inside the rotor 71. The coolant flowing out of the heat exchanger 5 can flow sequentially through the housing flow channel 63f, the motor shaft channel 69a, and the rotor channel 71a, thereby carrying away the heat from the motor shaft 69 and the rotor 71. The coolant flowing out of the rotor channel 71a can fall into the bottom shell 41. Figure 18 and Figure 17 As shown, the shell flow channel 63f can correspond to Figure 17 The flow channel R1 in the middle.

[0108] like Figure 18 As shown, a housing flow channel 42a can be provided inside the peripheral shell 42, and a housing flow channel 64g can be provided inside the cooling cover 64. The housing flow channel 42a, the housing flow channel 64g, and the gear shaft flow channel 88a inside the gear shaft 88 can be connected in sequence. Figure 18 and Figure 17 As shown, the shell flow channel 42a and shell flow channel 64g can also correspond to Figure 17 The flow channel R1 in the middle.

[0109] like Figure 18As shown, the cooling shroud 63 may also include a housing flow channel 63g. The housing flow channel 63g, housing flow channel 42a, circumferential channel 61d of the stator core 61, and axial channel 61b (both circumferential and axial channels 61b belong to the stator cooling channels) can be sequentially connected. The coolant flowing from the heat exchanger 5 can sequentially flow through the housing flow channel 63g, housing flow channel 42a, circumferential channel 61d, and axial channel 61b, entering the interior of the stator core 61, thereby carrying away heat from the stator core 61 and stator windings 65. Combined with... Figure 18 and Figure 17 As shown, the shell flow channel 63g and the shell flow channel 42a can correspond. Figure 17 The flow channel R2 in the middle.

[0110] like Figure 18 As shown, since both the first end flow channel 6a and the second end flow channel 6b are connected to the axial channel 61b, the coolant entering the axial channel 61b can flow to the left into the first end flow channel 6a and to the right into the second end flow channel 6b, respectively. That is, the axial channel 61b can divert the coolant to the first end flow channel 6a and the second end flow channel 6b. The first end flow channel 6a and the second end flow channel 6b can be filled with coolant, so that the stator winding 65 is immersed in the coolant, achieving immersion liquid cooling of the stator winding 65. Combined with... Figure 18 and Figure 17 As shown, the flow of coolant in the axial channel 61b, the first end flow channel 6a, and the second end flow channel 6b can correspond to Figure 17 The coolant flows along flow channel R4.

[0111] In this embodiment, the second annular wall includes an opening for communicating with the housing flow channel of the drive motor 6, and the opening faces the axis of the drive motor 6. An example will be provided below.

[0112] like Figure 18As shown, the first end flow channel 6a may have an opening 6c, which may be formed, for example, on the second annular wall 63a of the cooling shroud 63 and located radially near the bottom shell 41. Through the opening 6c, the shell flow channel 63g, the shell flow channel 42a, and the first end flow channel 6a can be connected in sequence. The second end flow channel 6b may have an opening 6d, which may be formed, for example, on the second annular wall 64a of the cooling shroud 64 and located radially near the bottom shell 41. Through the opening 6d, the shell flow channel 63g, the shell flow channel 42a, and the second end flow channel 6b can be connected in sequence. Therefore, the coolant flowing out of heat exchanger 5 can sequentially flow through shell flow channel 63g, shell flow channel 42a, and opening 6c, entering the first end flow channel 6a; the coolant flowing out of heat exchanger 5 can sequentially flow through shell flow channel 63g, shell flow channel 42a, and opening 6d, entering the second end flow channel 6b; the coolant can also flow between the first end flow channel 6a and the second end flow channel 6b through axial channel 61b. Therefore, the coolant can remove heat from the stator core 61 and stator winding 65. Figure 18 and Figure 17 As shown, the shell flow channel 63g and the shell flow channel 42a can correspond. Figure 17 The flow channel R3 in the middle.

[0113] For example Figure 18 As shown, the first end channel 6a may have an opening 6e, which may be formed, for example, on the second annular wall 63a of the cooling shroud 63 and located at one end radially away from the bottom shell 41. Figure 18 From a certain perspective, the opening 6e is positioned higher than the opening 6c. Coolant within the first end channel 6a can flow out from the opening 6e and fall into the bottom casing 41. The second end channel 6b may have an opening 6f, which, for example, can be formed on the second annular wall 64a of the cooling shroud 64 and located at the end radially away from the bottom casing 41. Figure 18 From the perspective of [the point of view], the position of opening 6f is higher than that of opening 6d.

[0114] In this embodiment, by adding covers (including cooling covers 63 and 64) at opposite ends of the stator winding 65, and covering the inner circumferential surface of the stator core 61 with a sealing layer 62, the covers are sealed to the stator core 61 and the sealing layer 62, and end channels (including a first end channel 6a and a second end channel 6b) are constructed. The stator winding 65 can be immersed in these end channels, and immersion liquid cooling is used to dissipate heat from the stator winding 65. This allows the heat from the stator winding 65 to be quickly absorbed and carried away by the coolant, thus greatly improving the heat dissipation effect of the stator winding 65 and enhancing the temperature uniformity of the drive motor 6. This is beneficial for increasing the rated power output of the drive motor 6 and extending its peak power duration. For example, in low-temperature, low-flow application scenarios (such as scenarios where electric drives actively generate heat), immersion liquid cooling can prevent the conductors of the stator winding 65 from overheating, ensuring that the drive motor 6 has excellent temperature uniformity characteristics.

[0115] In this embodiment, because the outlet (e.g., openings 6e and 6f) of the end flow channel is designed at a higher position, while the inlet (e.g., openings 6c and 6d) is designed at a lower position, the coolant in the end flow channel is less likely to overflow when the drive pump 9 stops and the liquid path is stationary and not circulating. Furthermore, due to the characteristics of the drive pump 9, the coolant in the end flow channel will not flow back when the liquid path is stationary and not circulating. This design ensures that the end flow channel is always full of coolant, guaranteeing that the stator winding 65 is always immersed in coolant.

[0116] In this embodiment, since the coolant in the end channel is less likely to leak into the air gap between the stator and the rotor 71, wear between the stator and the rotor 71 (e.g., oil rubbing) can be reduced or avoided, thereby reducing the energy consumption of the drive motor 6.

[0117] In this embodiment, a sealing layer 62 is designed to prevent coolant leakage at the stator core 61 when it flows between the first end channel 6a and the second end channel 6b. In other embodiments, the sealing layer 62 may be omitted, and both the second annular wall 63a and the first annular wall 63c of the cooling cover 63 are connected to the stator core 61, forming the first end channel 6a with the cooling cover 63 and the stator core 61. Similarly, both the second annular wall 64a and the first annular wall 64c of the cooling cover 64 are connected to the stator core 61, forming the second end channel 6b with the cooling cover 64 and the stator core 61.

[0118] like Figure 18As shown, the peripheral shell 42 may also be provided with a shell flow channel 42b, and the cooling cover 64 may also be provided with shell flow channels 64d, 64e, and 64f. The second end flow channel 6b, shell flow channel 42b, and shell flow channel 64e can be connected sequentially through the opening 6f of the second end flow channel 6b. Shell flow channels 64d and 64f can both be connected to shell flow channel 64e. Shell flow channel 64d can be connected to the receiving cavity of the motor bearing 702. Shell flow channel 64f can be connected to the gear shaft flow channel 81a inside the gear shaft 81. The coolant flowing out from the opening 6f of the second end flow channel 6b can flow through shell flow channels 42b and 64d into the receiving cavity of the motor bearing 702 to dissipate heat from the motor bearing 702. The coolant flowing out from the opening 6f of the second end channel 6b can also flow through the housing channels 42b, 64e, and 64f into the gear shaft channel 81a, dissipating heat from the gear shaft 81 and gear bearing 83. That is, the coolant flowing out from the opening 6f of the second end channel 6b will be diverted to the motor bearing 702 and the gear shaft channel 81a. The coolant can flow in from the opening located at the intersection of the housing channels 64f and 64e and fall into the bottom shell 41 (represented by three curves). Figure 18 and Figure 17 As shown, the flow of coolant in housing flow channels 42b, 64d and motor bearing 702, as well as the flow of coolant in housing flow channels 42b, 64e, 64f and gear shaft flow channel 81a, can all correspond to Figure 17 The coolant flows along flow channel R5.

[0119] like Figure 18 As shown, coolant can flow out from gear shaft channels 81a and 88a and fall into the bottom shell 41. The lower part of gear 86 can be immersed in coolant in the bottom shell 41. As gear 86 rotates, all parts of gear 86 in the circumferential direction can be coated with coolant, and gear 86 can also deliver coolant to gears 85 and 82, thereby dissipating heat from gears 86, 85, and 82.

[0120] In some conventional solutions, the cooling of the stator windings is the final stage of cooling for the entire powertrain. For example, in a solution that uses oil injection technology to cool the stator windings, after the cooling oil is sprayed onto the stator windings, it flows back to the oil pan, waiting for the oil pump to pump it back to the beginning of the oil circuit.

[0121] Unlike conventional solutions, as described above, in this embodiment, the coolant in the first end channel 6a and the second end channel 6b can also enter the other channels via channel R5, instead of only falling into the bottom shell 41. Therefore, the first end channel 6a and the second end channel 6b can serve as the middle section of the assembly channel, rather than being located only at the end. As part of the assembly channel, the first end channel 6a and the second end channel 6b deliver coolant to the various components constituting the other channels. This design ensures that the heat dissipation of the stator winding 65 is no longer the end point of the heat dissipation of the entire powertrain 4. After the coolant dissipates heat from the stator winding 64, it can continue to dissipate heat from the various components constituting the other channels. Therefore, this embodiment can achieve coolant recovery and reuse. This allows more coolant to flow through the stator winding 65 simultaneously without increasing the flow rate of the drive pump 9, thus enhancing the heat dissipation of the stator winding 65.

[0122] Additionally, refer to Figure 17 As shown, in this embodiment, the design of the first end flow channel 6a and the second end flow channel 6b enables the collection of heat from the stator winding 65, preventing direct heat loss to the atmosphere. This heat can be transferred to the electric vehicle's thermal management system via a heat exchanger. The thermal management system can then use the received heat for heating (e.g., heating the power battery and drive motor) and / or air conditioning (outputting warm air), effectively utilizing the heat from the stator winding 65 to improve COP and achieve energy saving and cost reduction.

[0123] For example, in scenarios where the drive motor operates in low-temperature environments, the heat from the stator windings 65 can be effectively utilized to shorten the oil preheating time, improve the low-temperature starting performance of the drive motor, reduce energy consumption, and increase COP.

[0124] For example, the heat from the stator winding 65 can be effectively utilized to heat the drive motor (using the heat from the drive motor to heat the air conditioner or power battery, etc.), using the drive motor to replace at least part of the electric heater, including but not limited to positive temperature coefficient (PTC) heaters. In some embodiments, the drive motor can be used to completely replace the electric heater, which can greatly reduce dependence on the electric heater, reduce costs, reduce energy consumption, and improve COP. In other embodiments, drive motor heating can be used as a supplement, replacing the high-voltage electric heater with a low-voltage electric heater, which can also have the effect of reducing costs, reducing energy consumption, and improving COP.

[0125] Figure 19 This is a schematic diagram of the topology of the flow channel of the powertrain 4 in Embodiment Six of this application. (Comparison) Figure 19 and Figure 20As shown, unlike Embodiment 5, the topology of Embodiment 6 may not have flow channel R3, that is, the coolant flowing out of the heat exchanger may not flow directly into the cover.

[0126] Figure 20 Based on Figure 19 The diagram shows a cross-sectional view of the assembly flow channel of the topology. (Compare with...) Figure 20 and Figure 18 As shown, unlike Embodiment 5, the end flow channel in Embodiment 6 may not have openings 6c and 6d.

[0127] The solution in Embodiment 5 can have the same or equivalent technical effects as that in Embodiment 4, and will not be described in detail here.

[0128] Unlike Embodiments 5 or 6 described above, in other embodiments, the axial channel 61b within the stator core 61 can be omitted, allowing the circumferential channel 61d on the stator core 61 to communicate with the slot 61a, and creating a gap between the conductor in the slot 61a and its inner wall for coolant flow. This allows coolant to enter the slot 61a to dissipate heat from the stator core 61; the slot 61a can connect the first end channel 6a and the second end channel 6b, thereby dissipating heat from both ends of the stator winding 65. Alternatively, in other embodiments, the axial channel 61b and the slot 61a can be used simultaneously to connect the first end channel 6a and the second end channel 6b.

[0129] Figure 21 This is a schematic diagram of the topology of the flow channel of the powertrain 4 in Embodiment 7 of this application. (Comparison) Figure 21 and Figure 19 As shown, in Embodiment Six, the coolant flowing out of the heat exchanger can sequentially pass through flow channel R2, stator core, and flow channel R4 to the cooling shroud. The coolant first flows into the stator core and then enters the two cooling shrouds respectively. However, in Embodiment Seven, the coolant flowing out of the heat exchanger sequentially passes through flow channel R6, one cooling shroud, flow channel R7, stator core, and flow channel R8 to another cooling shroud (for example, it can be located on the three-phase line side). The coolant sequentially enters one cooling shroud, stator core, and another cooling shroud.

[0130] Figure 22 Based on Figure 21 The diagram shows a cross-sectional view of the assembly flow channel of the topology. (Compare with...) Figure 22 and Figure 20As shown, unlike Embodiment Six, in Embodiment Seven, the stator core 61 may not have a circumferential channel 61d; the circumferential shell 42 may have a shell flow channel 42c, which can be connected to the first end flow channel 6a through an opening 6e; the cooling cover 63 may not have a shell flow channel 63f, but instead has a shell flow channel 63h, one end of which is connected to the shell flow channel 42c, and the other end of which is connected to the motor shaft channel 69a; the second annular wall 64a of the cooling cover 64 may not have an opening 6f.

[0131] like Figure 22 As shown, the drive pump 9, heat exchanger 5, and shell flow channel 42a (which can be called the first shell flow channel 42a) are connected in sequence. The coolant flowing out of the heat exchanger 5 can flow through the shell flow channel 42a and the opening 6d in sequence, and enter the second end flow channel 6b. The shell flow channel 42a and the opening 6d correspond to each other. Figure 21 The coolant in the housing flow channel 42a can also flow into the gear shaft flow channel 88a via the housing flow channel 64g, meaning the coolant in the first housing flow channel 42a can be diverted to the second end flow channel 6b. In other words, the coolant in the first housing flow channel 42a can be diverted to both the second end flow channel 6b and the gear shaft flow channel 88a.

[0132] like Figure 22 As shown, the coolant in the second end channel 6b can enter the axial channel 61b of the stator core 61, and then enter the first end channel 6a through the axial channel 61b. The axial channel 61b can correspond to... Figure 21 The flow channels R7 and R8 are located in the middle. The coolant in the first end flow channel 6a can enter the housing flow channels 42c, 42b, and 63h through the opening 6e, and enter the motor shaft channel 69a through the housing flow channel 63h. The housing flow channels 42b and 63h can correspond to each other. Figure 21 The flow channel R5 is located within the housing. Additionally, coolant can also enter housing flow channels 64d, 64e, and 64f from housing flow channel 42b, and these flow channels 64d, 64e, and 64f can also correspond to... Figure 21 The flow channel R5 is located in the middle. That is, the coolant flowing out from the opening 6e can be diverted to the motor shaft channel 69a, the rotor channel 71a, the motor bearing 702, and the gear shaft flow channel 81a. In this embodiment, the housing flow channels 42c, 42b, 63h, 64d, 64e, and 64f can all be referred to as the second housing flow channels.

[0133] The solution in Embodiment Seven can have the same or equivalent technical effects as that in Embodiment Six, and will not be described in detail here.

[0134] Figure 23This is a schematic diagram of the topology of the flow channel of the powertrain 4 in Embodiment 8 of this application. (Comparison) Figure 23 and Figure 21 As shown, unlike Embodiment 7, the topology of Embodiment 8 may not have flow channel R1, that is, the coolant flowing out of the heat exchanger may not directly enter the other flow channel.

[0135] Figure 24 Based on Figure 23 The diagram shows a cross-sectional view of the assembly flow channel of the topology. (Compare with...) Figure 24 and Figure 22 As shown, in Embodiment 7, the housing flow channel 64g connects the housing flow channel 42a and the gear shaft flow channel 88a. Unlike Embodiment 7, in Embodiment 8, the housing flow channel 64g may not be provided. The housing flow channel 42a (which may be called the first housing flow channel 42a) may only be connected to the second end flow channel 6b through the opening 6d. The housing flow channel 64f may extend downward (i.e., towards the bottom shell 41) and connect with the gear shaft flow channel 88a. The part where the housing flow channel 64f overlaps with the motor shaft 69 is blocked by the motor shaft 69.

[0136] The solution in Embodiment 8 can have the same or equivalent technical effects as that in Embodiment 7, and will not be described in detail here.

[0137] Figure 25 This is a schematic diagram of the topology of the flow channel of the powertrain 4 in Embodiment 8 of this application. (Comparison) Figure 25 and Figure 23 As shown, unlike Embodiment 8, the position of the heat exchanger in Embodiment 9 on the flow path of the coolant can be adjusted. The coolant flowing out from the drive pump can directly enter a cooling shroud along flow channel R6, the coolant flowing out from another cooling shroud can enter the heat exchanger along flow channel R9, and the coolant flowing out from the heat exchanger can enter the other flow channel along flow channel R10.

[0138] In this embodiment, the axial bottom wall includes an opening for connecting the housing flow channel of the drive motor 6. The opening faces the stator core 61, and the distance between the radial opening of the drive motor 6 and the axis of the drive motor 6 is greater than the distance between the first annular wall and the axis. An example will be given below.

[0139] Figure 26 Based on Figure 25 The diagram shows a cross-sectional view of the assembly flow channel of the topology. (Compare with...) Figure 26 and Figure 24As shown, unlike Embodiment 8, in Embodiment 9, a housing flow channel 63i can be formed inside the cooling cover 63. The housing flow channel 63i can connect the first end flow channel 6a and the heat exchanger 5. The housing flow channel 63i can overlap with the housing flow channel 63h but not connect with it. The axial bottom wall of the cooling cover 63 can be integrated with the end cover. The housing flow channel 63i can be formed on this axial bottom wall (or on the end cover). The opening of the housing flow channel 63i towards the first end flow channel 6a is an opening 63x on the axial bottom wall. The opening 63x faces the stator core 61 and connects to the housing flow channel 63i. Along the radial direction of the drive motor 6, the distance between the opening 63x and the axis of the drive motor 6 is greater than the distance between the first annular wall 63c and the axis.

[0140] like Figure 26 As shown, a shell flow channel 63j can also be formed inside the cooling shroud 63. The shell flow channel 63j can connect the heat exchanger 5 and the shell flow channel 42b, and can also connect with the shell flow channel 63h. The coolant in the first end flow channel 6a can enter the heat exchanger 5 through the shell flow channel 63i, which can correspond to... Figure 25 The coolant in heat exchanger 5 can enter the motor shaft channel 69a along the shell flow channels 63j and 63h. The coolant in heat exchanger 5 can also flow along the shell flow channels 63j and 42b, and enter the shell flow channels 64d and 64f from the shell flow channel 42b respectively. Shell flow channels 63j and 63h can correspond to... Figure 25 The flow channel R10, shell flow channel 63j, shell flow channel 42b, shell flow channel 64d, and shell flow channel 64f can also correspond. Figure 25 The flow channel R10 in the middle.

[0141] The solution in Embodiment Nine can have the same or equivalent technical effects as that in Embodiment Eight, and will not be described in detail here.

[0142] In the assembly flow channels of Embodiments 5, 7, and 8 described above, the amount of coolant passing through the casing can be increased sequentially while maintaining the same flow rate of the drive pump 9. Specifically, in Embodiment 7, since the second end flow channel 6b and the first end flow channel 6a are connected in series, the temperature of the stator winding 65 end 65b located in the second end flow channel 6b is different from the temperature of the stator winding 65 end 65a located in the first end flow channel 6a. In Embodiment 8, since the second end flow channel 6b, the stator cooling channel, the first end flow channel 6a, and the other flow channels are connected in series, the coolant flowing from the heat exchanger 5 is not split, resulting in a larger amount of coolant in the second end flow channel 6b and the first end flow channel 6a, thus providing better heat dissipation for the winding ends 65b and 65a. To achieve this "sequential series" design, the three-phase line interface can be well sealed.

[0143] Unlike embodiments seven, eight, or nine described above, in other embodiments, the axial channel 61b within the stator core 61 can be omitted, and a gap is formed between the conductor in the slot 61a and the inner wall of the slot 61a to allow coolant flow. This allows coolant to enter the slot 61a to dissipate heat from the stator core 61; the slot 61a can connect the first end channel 6a and the second end channel 6b, thereby dissipating heat from both ends of the stator winding 65. Alternatively, in other embodiments, the axial channel 61b and the slot 61a can be used simultaneously to connect the first end channel 6a and the second end channel 6b.

[0144] The above embodiment uses the integration of the cover and motor housing as an example; it is understood that this is merely one example. In other embodiments, at least a portion of the cover can be independent of the motor housing. Openings on the cover and corresponding housing flow channels can be designed to obtain an assembly flow channel that meets the product requirements.

[0145] In any of the above embodiments, the positions of any inlet and any outlet of each housing flow channel, as well as any inlet and any outlet of each end flow channel, can be designed according to product needs and are not limited to those shown in the figures.

[0146] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A drive motor with stator winding end immersion cooling, characterized in that, The drive motor includes: The stator housing and end caps are provided. The stator housing is used to fix the stator core. The length of the stator housing along the axial direction of the drive motor is greater than that of the stator core. The outer diameter of the stator core along the radial direction of the drive motor is less than or equal to the inner diameter of the stator housing. The end caps are used to fix the stator housing. One end face of the end cap is arranged opposite to the end face of one end of the stator core along the axial direction of the drive motor. The stator core and stator windings are provided. The stator core is used to fix the stator windings. Along the axial direction of the drive motor, one end of the stator winding protrudes from one end of the stator core. Along the radial direction of the drive motor, the inner diameter of the one end of the stator winding is larger than the inner diameter of the stator core. A cooling shroud is provided for containing coolant and one winding end. The cooling shroud includes a first annular wall and a second annular wall. The outer diameter of the first annular wall along the radial direction of the drive motor is less than or equal to the inner diameter of the one winding end of the stator winding. The inner diameter of the second annular wall along the radial direction of the drive motor is greater than the outer diameter of the first annular wall and the outer diameter of the one winding end. One end of the first annular wall along the axial direction of the drive motor towards the stator core is used to enclose the one end of the stator core to form a receiving structure. The coolant contained in the receiving structure is used to immerse and cool the one winding end.

2. The drive motor according to claim 1, characterized in that, The inner circumferential surface of the stator housing is used to fix the second annular wall or to serve as the second annular wall.

3. The drive motor according to claim 2, characterized in that, The one end face of the end cap is used for: The first annular wall is fixed at the other end opposite to the stator core along the axial direction of the drive motor; or, The second annular wall is fixed away from the other end of the stator core along the axial direction of the drive motor; or, The first annular wall is fixed at the other end opposite to the stator core along the axial direction of the drive motor, and the second annular wall is fixed at the other end opposite to the stator core along the axial direction of the drive motor.

4. The drive motor according to claim 1, characterized in that, The cooling shroud includes an axial bottom wall, and the axial bottom wall, the end face of one winding, and the end face of one end of the stator core are arranged sequentially along the axial direction of the drive motor.

5. The drive motor according to claim 4, characterized in that, One end face of the end cap serves as the axial bottom wall of the cooling shroud.

6. The drive motor according to claim 4, characterized in that, The outer peripheral surface of the axial bottom wall is used to fix the second annular wall, and the end face of the axial bottom wall facing the stator core is used to fix the first annular wall of the cooling shroud.

7. The drive motor according to claim 4, characterized in that, The end face of the axial bottom wall facing the stator core is used to fix the second annular wall of the cooling shroud.

8. The drive motor according to claim 1, characterized in that, The drive motor includes multiple stator cooling channels, and each stator cooling channel includes multiple coolant outlets, wherein: The plurality of coolant outlets are spaced apart on the end face of one end of the stator core along the circumference of the drive motor, and the distance between each coolant outlet and the axis of the drive motor along the radial direction of the drive motor is greater than the outer diameter of the end of the winding. The outer diameter of the second annular wall along the radial direction of the drive motor is greater than the distance between at least a portion of the coolant outlet and the axis of the drive motor.

9. The drive motor according to claim 1, characterized in that, The second annular wall includes an opening for communicating with the housing channel of the drive motor, the opening being oriented toward the axis of the drive motor.

10. The drive motor according to any one of claims 4-7, characterized in that, The axial bottom wall includes an opening for communicating with the housing flow channel of the drive motor. The opening faces the stator core, and the distance between the opening and the axis of the drive motor along the radial direction of the drive motor is greater than the distance between the first annular wall and the axis.

11. A powertrain, characterized in that, The powertrain includes a reducer and a drive motor as described in any one of claims 1-10, wherein the input shaft of the reducer is used to drive the motor shaft of the drive motor.

12. An electric vehicle, characterized in that, The electric vehicle includes a frame and the powertrain of claim 11, the frame being used to secure the powertrain.

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