Driving electric motor having end of stator winding subjected to immersion cooling, power assembly, and electric vehicle

Abstract

Provided in the embodiments of the present application are a driving electric motor having one end of a stator winding subjected to immersion cooling, a power assembly, and an electric vehicle. The driving electric motor comprises: a stator core, a stator winding and a cooling cover. The stator core is used for fixing the stator winding. Along the axial direction of the driving electric motor, one winding end of the stator winding is exposed out of one end of the stator core. Along the radial direction of the driving electric motor, the inner diameter of one winding end of the stator winding is larger than the inner diameter of the stator core. The cooling cover is used for accommodating a cooling liquid and one winding end. The cooling cover comprises a first annular wall, wherein along the radial direction of the driving electric motor, the outer diameter of the first annular wall is less than or equal to the inner diameter of one winding end of the stator winding. The first annular wall faces one end of the stator core along the axial direction of the driving electric motor and is used for enclosing said end of the stator core to form an accommodating structure. The cooling liquid accommodated in the accommodating structure is used for immersion cooling of one winding end of the stator winding. The embodiments of the present application can perform good heat dissipation on the stator winding.

Description

Stator winding end immersion cooling for electric drives, powertrains, and electric vehicles

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on December 29, 2023, with application number 202311872048.7 and application name “Drive motor, powertrain and electric vehicle with immersion cooling of stator winding ends”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of vehicles, and in particular to a drive motor, a powertrain, and an electric vehicle with immersion cooling of stator winding ends. Background Art

[0003] The drive motor of an electric vehicle requires high current to drive the stator windings, resulting in high operating temperatures, particularly in the stator windings, which experience a rapid temperature rise. Overheating of the stator windings increases the internal resistance of the stator windings and weakens the magnetic properties of the stator silicon steel sheets, making the stator windings a significant heat dissipation bottleneck in the motor. Existing technologies typically use oil or water cooling to dissipate heat from the drive motors. However, conventional oil or water cooling methods cannot adequately dissipate heat from the ends of the stator windings, thus impacting the performance of the drive motor and the electric vehicle. Summary of the Invention

[0004] The embodiments of the present application provide a drive motor, a powertrain, and an electric vehicle with immersion cooling of the stator winding ends, which can effectively dissipate heat from the drive motor, especially the ends of the stator windings, so that the motor has better performance.

[0005] In a first aspect, an embodiment of the present application provides a drive motor with immersion cooling of a stator winding end, comprising a stator core, a stator winding and a cooling cover, wherein the stator core is used to fix the stator winding, and along the axial direction of the drive motor, one winding end of the stator winding is exposed at one end of the stator core, and 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 cover is used to accommodate coolant and one winding end, and the cooling cover comprises a first annular wall, and the outer diameter of the first annular wall along the radial direction of the drive motor is smaller than or equal to the inner diameter of one winding end of the stator winding; the first annular wall is used to enclose one end of the stator core along the axial direction of the drive motor toward the stator core to form a receiving structure, and the receiving structure is used to accommodate coolant and immerse and cool one winding end of the stator winding.

[0006] In the embodiment of the present application, the cooling hood is designed to include a first annular wall that encloses one end of the stator core, forming a structure that accommodates the winding ends and the coolant, thereby achieving immersion cooling of the winding ends. Therefore, the embodiment of the present application allows the heat of the stator winding to be quickly absorbed and removed by the coolant, greatly improving the heat dissipation effect of the stator winding and enhancing the temperature uniformity and heat dissipation performance of the drive motor cooling. This is conducive to increasing the rated power output of the drive motor and extending the duration of its peak power.

[0007] In one implementation of the first aspect, the cooling cover includes a second annular wall. 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 one winding end. In this implementation, the cooling cover further includes the second annular wall. The second annular wall may surround the outer circumference of the first annular wall and may be connected to the stator core. This allows the receiving structure to be an annular groove, effectively receiving the winding end and coolant, thereby enhancing 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 securing a stator core. The stator housing is longer than the stator core in the axial direction of the drive motor, and the outer diameter of the stator core in 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 cap for fixed connection to the stator housing. An end face of the end cap is aligned opposite an end face of one end of the stator core in the axial direction of the drive motor. For a drive motor having a stator housing and an end cap, a cooling hood can be used to contain coolant and winding ends, thereby 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 secure the first annular wall. The first annular wall may be a separate component that is fixedly connected to the inner circumferential surface of the stator housing. This implementation has a simple and reliable structure, facilitates 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 secure the second annular wall or to serve as the second annular wall. The second annular wall may be a separate component, or it may be part of the inner circumferential surface of the stator housing, or it may be integrated with the stator housing. This implementation has a simple and reliable structure, facilitates 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 cover 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 the other end of the first annular wall away from the stator core along the axial direction of the drive motor and fix 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 annular wall and the second annular wall can be fixedly connected to the end face of the end cover. This implementation has a simple and reliable structure, facilitates the assembly of the cooling cover, and ensures the performance of the cooling cover.

[0012] In one implementation of the first aspect, the cooling shroud includes an axial bottom wall. Along the axial direction of the drive motor, the axial bottom wall, a winding end, and an end surface of one end of the stator core are sequentially arranged. In this implementation, by including the axial bottom wall in the cooling shroud, the axial bottom wall can be connected or disconnected to the first annular wall, and the axial bottom wall can be connected or disconnected to the second annular wall. This formed containment structure effectively accommodates the winding end and coolant, thereby enhancing the immersion liquid cooling effect of the winding end.

[0013] In one implementation of the first aspect, one end surface of the end cover serves as the axial bottom wall of the cooling shroud. The axial bottom wall itself is part of the end cover, or in other words, the axial bottom wall and the end cover are integrated into one piece. This implementation has a simple and reliable structure, facilitates assembly of the cooling shroud, and ensures the performance of the cooling shroud.

[0014] In an implementation of the first aspect, the outer peripheral surface of the axial bottom wall is used to fixedly connect to the second annular wall, and the end surface of the axial bottom wall facing the stator core is used to fixedly connect to the first annular wall of the cooling cover. The second annular wall can be an independent component, or integrated with other shells (such as stator shells). The first annular wall can be an independent component, or integrated with other shells. 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 surface of the axial bottom wall. The accommodation structure formed in this way can well accommodate the winding end and the coolant, which is beneficial to improving the immersion liquid cooling heat dissipation effect of the winding end. This implementation method can be simple and reliable in design, realize the structural design of the cooling cover, and ensure the performance of the cooling cover.

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

[0016] In one implementation of the first aspect, the drive motor includes multiple stator cooling channels, each of which includes multiple coolant outlets. The multiple coolant outlets are spaced apart along the circumference of the drive motor on an end surface of one end of the stator core, and the radial distance between each coolant outlet and the axis of the drive motor is greater than the outer diameter of a winding end. The outer diameter of the second annular wall is greater than the radial distance between at least some of the coolant outlets and the axis of the drive motor. For drive motors with stator cooling channels, the second annular wall is positioned farther from the motor axis, while the coolant outlets are positioned closer to the motor axis, thereby facilitating the flow of coolant into the housing structure of the cooling shroud via the stator cooling channels.

[0017] In one implementation of the first aspect, the second annular wall includes an opening, and the opening is used to connect to the housing flow channel of the drive motor; wherein the opening faces the axis of the drive motor, and the opening, a winding end, and the end face of one end of the stator core are arranged in sequence along the axial direction of the drive motor. By providing an opening on the second annular wall, the receiving structure and the housing flow channel can be connected, so that the coolant cooling the winding end can flow through the housing flow channel to other links to be cooled, so that the heat dissipation of the stator winding is no longer the heat dissipation end point of the entire powertrain, and the coolant can be recycled and reused. In addition, without increasing the flow rate of the drive pump, more coolant can be allowed to flow through the stator winding at the same time, thereby enhancing the heat dissipation of the stator winding.

[0018] In one implementation of the first aspect, the axial bottom wall includes an opening, and the opening is used to connect to the housing flow channel of the drive motor; wherein the opening faces an end face of the stator core, and is arranged in sequence along the axial opening of the drive motor and a winding end, and 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, so that the coolant for cooling the winding end can flow through the housing flow channel to other links to be cooled, so that the heat dissipation of the stator winding is no longer the heat dissipation end point of the entire powertrain, and the coolant can be recycled and reused. In addition, without increasing the flow rate of the drive pump, more coolant can be allowed to flow through the stator winding at the same time, thereby enhancing the heat dissipation of the stator winding.

[0019] In a second aspect, an embodiment of the present application provides a power assembly, including a reducer and the drive motor, wherein the input shaft of the reducer is used to be fixedly connected to the motor shaft of the drive motor.

[0020] In the embodiment of the present application, the cooling cover of the drive motor is designed to include a first annular wall that surrounds one end of the stator core, thereby creating a containment structure that can accommodate the winding ends and coolant, immersing the winding ends in the coolant and achieving immersion-type liquid cooling of the winding ends. Therefore, the embodiment of the present application allows the heat of the stator winding to be quickly absorbed and removed by the coolant, greatly improving the heat dissipation effect of the stator winding and enhancing the temperature uniformity of the drive motor cooling, which is beneficial to improving the performance of the drive motor and powertrain.

[0021] On the third aspect, an embodiment of the present application provides an electric vehicle, comprising a frame and the powertrain, wherein the frame is used to fix the powertrain. In an embodiment of the present application, by designing the cooling cover of the drive motor, the cooling cover includes a first annular wall enclosing one end of the stator core, and a receiving structure can be constructed. The receiving structure can accommodate the winding end and the coolant therein, immersing the winding end in the coolant, and realizing immersion liquid cooling of the winding end. Therefore, the embodiment of the present application can enable the heat of the stator winding to be quickly absorbed and carried away by the coolant, greatly improving the heat dissipation effect of the stator winding, and enhancing the temperature uniformity of the drive motor cooling, which is beneficial to improving the performance of the drive motor, the powertrain and the entire vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] FIG1 is a schematic structural diagram of an electric vehicle according to an embodiment of the present application;

[0023] FIG2 is a schematic diagram of the framework structure of the powertrain according to an embodiment of the present application;

[0024] FIG3 is a schematic diagram of the three-dimensional structure of a stator core according to an embodiment of the present application;

[0025] FIG4 is a schematic diagram of the axial structure of the stator core in FIG3 ;

[0026] FIG5 is a schematic diagram of the three-dimensional structure of the cooling cover in Example 1 of the present application from one viewing angle;

[0027] FIG6 is a schematic diagram of the three-dimensional structure of the cooling cover in Example 1 of the present application from another perspective;

[0028] 7 is a schematic cross-sectional view of the assembly structure of the cover, stator core, stator winding, etc. in Example 1 of the present application;

[0029] FIG8 is a schematic diagram of a partially enlarged structure of point A in FIG7 ;

[0030] FIG9 is another partial enlarged structural schematic diagram of point A in FIG7;

[0031] 10 is a schematic cross-sectional view of the assembly structure of the cover, stator core, stator winding, etc. in Example 2 of the present application;

[0032] FIG11 is a schematic diagram of the three-dimensional structure of the cooling cover in Example 3 of the present application from one viewing angle;

[0033] FIG12 is a schematic diagram of the three-dimensional structure of the cooling cover in Example 3 of the present application from another perspective;

[0034] 13 is a schematic cross-sectional view of the assembly structure of the cover, stator core, stator winding, etc. in Example 3 of the present application;

[0035] FIG14 is a schematic diagram of the three-dimensional structure of the cooling cover in Example 4 of the present application from one viewing angle;

[0036] FIG15 is a schematic diagram of the three-dimensional structure of the cooling cover in the fourth embodiment of the present application from another perspective;

[0037] FIG16 is a schematic cross-sectional view of the assembly structure of the cover, stator core, stator winding, etc. in the fourth embodiment of the present application;

[0038] FIG17 is a schematic diagram of the topological architecture of the assembly flow passage of the powertrain in the fifth embodiment of the present application;

[0039] FIG18 is a schematic cross-sectional view of the assembly flow channel based on the topological structure shown in FIG17 ;

[0040] FIG19 is a schematic diagram of the topological architecture of the assembly flow passage of the powertrain in the sixth embodiment of the present application;

[0041] FIG20 is a schematic cross-sectional view of the flow channel assembly based on the topological structure shown in FIG19 ;

[0042] FIG21 is a schematic diagram of the topological architecture of the assembly flow passage of the powertrain in the seventh embodiment of the present application;

[0043] FIG22 is a schematic cross-sectional view of the assembly flow channel based on the topological structure shown in FIG21;

[0044] FIG23 is a schematic diagram of the topological architecture of the assembly flow path of the powertrain in the eighth embodiment of the present application;

[0045] FIG24 is a schematic cross-sectional view of the assembly flow channel based on the topological structure shown in FIG23;

[0046] FIG25 is a schematic diagram of the topological architecture of the assembly flow path of the powertrain in the ninth embodiment of the present application;

[0047] FIG26 is a schematic cross-sectional view of the assembly flow channel based on the topological structure shown in FIG25 . DETAILED DESCRIPTION

[0048] For ease of understanding, the relevant technical terms involved in the embodiments of this application are explained and described below.

[0049] In the description of the embodiments of the present application, unless otherwise specified, "plurality" refers to two or more.

[0050] The terms "first", "second", etc. are used for descriptive purposes only and should not be understood to suggest or imply relative importance or to implicitly indicate the quantity of the technical features indicated. Features qualified as "first" or "second" may explicitly or implicitly include one or more of such features.

[0051] The directional terms mentioned in the embodiments of this application, such as "upper," "lower," "front," "back," "left," "right," "inner," "outer," "side," "top," and "bottom," are merely references to directions in the accompanying drawings. These directional terms are intended to better and more clearly illustrate and understand the embodiments of this application, and are not intended to explicitly or implicitly indicate that the devices or components referred to must have a specific orientation, be constructed or operate in a specific orientation, and are therefore not to be construed as limiting the embodiments of this application.

[0052] The embodiments of the present application provide an electric vehicle, including but not limited to an electric sedan, an electric SUV (Sport Utility Vehicle), an electric bus, an electric motorcycle, etc. The electric vehicle can be a pure electric vehicle, a hybrid vehicle, or a fuel cell vehicle, etc.

[0053] FIG1 schematically shows an electric vehicle 1 , which may include a vehicle frame 2 , a thermal management system 3 , and a powertrain 4 , etc. The thermal management system 3 and the powertrain 4 may be mounted on the vehicle frame 2 .

[0054] The powertrain 4 is a system composed of a series of components for generating power and transmitting the power to the road surface. The powertrain 4 can drive the wheels to rotate. Schematically, the electric vehicle 1 can also include a power battery, which is used to provide electrical energy to the powertrain 4. The powertrain 4 converts the electrical energy into mechanical energy and drives the wheels to rotate. The thermal management system 3 is used to perform thermal management of the entire vehicle. Thermal management can include heat dissipation (for example, heat dissipation of the power battery and powertrain), heating (for example, heating the power battery and drive motor), air conditioning, temperature control (for example, monitoring and regulating the operating temperature of the power battery and drive motor), heat distribution (for example, ensuring the temperature stability and balance of the power battery and drive motor), and other processes. The heat exchanger in the powertrain 4 can be connected to the thermal management system 3, and the powertrain 4 can exchange heat with the thermal management system 3 through the heat exchanger.

[0055] FIG2 illustrates the framework structure of the power assembly 4 . It is understood that the positions and connections of the various components in FIG2 are merely schematic and do not limit the actual structure.

[0056] As shown in Figure 2, the power assembly 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 the embodiment of the present application, the drive motor 6 may be a radial motor.

[0057] In one embodiment, the powertrain 4 can be an integrated powertrain, and the drive motor 6, the motor controller 7, and the reducer 8 can be assembled in the same assembly housing. The drive motor accommodating chamber of the housing of the powertrain 4 is used to accommodate the drive motor 6. The controller accommodating chamber of the housing of the powertrain 4 is used to accommodate the motor controller 7. The reducer accommodating chamber of the housing of the powertrain 4 is used to accommodate the reducer 8. For convenience of naming, the housing portion that accommodates the drive motor 6 can be called a motor housing, the housing portion that accommodates the motor controller 7 can be called a motor controller housing, and the housing portion that accommodates the reducer 8 can be called a reducer housing.

[0058] In one embodiment, the power assembly 4 may also be a split power assembly, wherein one or more of the drive motor 6, the motor controller 7 and the reducer 8 has a separate housing.

[0059] As shown in Figure 2, motor controller 7 is used to control drive motor 6. Motor controller 7 receives direct current (DC) from the power battery and outputs alternating current (AC) to drive motor 6. The motor shaft of drive motor 6 is drivingly connected to the input shaft of reducer 8, which transmits power from drive motor 6 to the wheels.

[0060] As shown in FIG2 , a drive pump 9 is mounted in the pump housing of the powertrain 4. The drive pump is used to drive the coolant to circulate between the internal flow channel of the powertrain 4 housing, the coolant flow channel of the drive motor 6, and the coolant flow channel of the reducer 8. In one embodiment, the coolant can be cooling oil.

[0061] As shown in FIG2 , heat exchanger 5 is mounted on the housing of powertrain 4 and is connected to at least one of the internal flow passages of the housing of powertrain 4, the coolant flow passages of drive motor 6, or the coolant flow passages of reducer 8. Heat exchanger 5 is used to dissipate heat from high-temperature coolant flowing out of at least one of the internal flow passages of the housing of powertrain 4, the coolant flow passages of drive motor 6, or the coolant flow passages of reducer 8.

[0062] As shown in Figure 2 and Figure 1 , the coolant absorbs heat and rises in temperature after flowing through 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. The heated coolant then exchanges heat with the thermal management system 3 through the heat exchanger 5, thereby cooling it down. Thus, the coolant circulates within the powertrain 4, providing cyclic cooling for the powertrain 4. This cyclic cooling process will be further described below.

[0063] As shown in FIG2 , a filter 10 is mounted on the housing of the powertrain 4. The filter 10 is used to filter foreign matter and impurities from at least one of the internal flow passages of the housing of the powertrain 4, the coolant flow passages of the drive motor 6, or the coolant flow passages of the reducer 8. In one embodiment, the filter 10 is located upstream of the drive pump 9. In one embodiment, the filter 10 is located downstream of the drive pump 9. In one example, the filter 10 is located between the drive pump 9 and the heat exchanger 5.

[0064] It is understood that the powertrain 4 shown in FIG2 is only one embodiment of the powertrain 4 provided in the embodiments of the present application. The powertrain 4 may include more or fewer components as needed. In another embodiment, the powertrain 4 may not include the filter 10.

[0065] In the drive motor 6 and powertrain 4 provided in the embodiment of the present application, by improving the heat dissipation design of the stator winding of the drive motor 6, not only can the stator winding be fully dissipated, but the coolant of the stator winding can also be used to cool other heat-generating components of the powertrain 4, thereby realizing the recycling and reuse of the coolant. In addition, in the drive motor 6 and powertrain 4 provided in the embodiment of the present application, 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 heat output generated to electrical energy consumed), achieving energy saving and cost reduction. This will be described in detail below.

[0066] In the embodiment of the present application, the axial, circumferential, and radial directions are defined based on the motor shaft of the drive motor 6. 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.

[0067] In an embodiment of the present application, the drive motor 6 includes a stator core and a stator winding. The stator core is used to fix the stator winding. One winding end of the stator winding along the axial direction of the drive motor 6 is exposed at one end of the stator core, and the inner diameter of one winding end of the stator winding along the radial direction of the drive motor 6 is larger than the inner diameter of the stator core.

[0068] Figures 3 and 4 illustrate a schematic structure of the stator core 61 in the drive motor 6. As shown in Figures 3 and 4, the end faces of the stator core 61 along the axial direction are end face 61c and end face 61e, respectively. A plurality of wire slots 61a are provided on the inner circumference of the stator core 61. These wire slots 61a can be evenly spaced along the circumference. Each wire slot 61a can pass through two opposite end faces 61c and 61e of the stator core 61. Each wire slot 61a can form an opening on the inner circumference of the stator core 61. A conductor can be wound in each wire 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 at the end faces of the stator core 61 along the axial direction. These two ends can be referred to as the first winding end and the second winding end, respectively (to be described below). The first winding end and the second winding end are both winding ends. The inner circumferential surface of the winding end in the wire slot 61 a may be sunken a certain distance relative to the opening of the wire slot 61 a , so that the inner diameter of the winding end is larger than the inner diameter of the stator core 61 .

[0069] In some embodiments, each wire groove 61 a can also be used to circulate cooling liquid (described below).

[0070] In this embodiment, the drive motor 6 includes multiple stator cooling channels, and the stator cooling channels include multiple coolant outlets, wherein: multiple coolant outlets are spaced apart along the circumference of the drive motor 6 on the end surface of one end of the stator core 61, and 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.

[0071] For example, as shown in Figures 3 and 4, a plurality of axial channels 61b can be provided within the stator core 61. These axial channels 61b can be equally spaced circumferentially. Each axial channel 61b can extend axially through both end surface 61c and end surface 61e, forming a coolant outlet on each end surface 61c and end surface 61e. The multiple coolant outlets on each of end surfaces 61c and 61e can be spaced circumferentially around the drive motor 6. Compared to the wire slots 61a, the axial channels 61b can be closer to the outer circumference 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.

[0072] Illustratively, a circumferential channel 61d may be further provided on the outer circumferential surface of the stator core 61. The circumferential channel 61d may be a slot that surrounds the circumference. The circumferential channel 61d is connected to each axial channel 61b.

[0073] In another embodiment, the circumferential channel 61d may also be composed of a plurality of radial holes arranged in sequence along the circumferential direction, the axis of each radial hole is along the radial direction, and one radial hole may be correspondingly connected to one axial channel 61b.

[0074] In the embodiment of the present application, the axial channel 61b and the circumferential channel 61d are all stator cooling channels.

[0075] As shown in FIG. 3 and FIG. 4 , a sealing layer 62 may be provided on the inner circumferential surface of the stator core 61 .

[0076] In one embodiment, the sealing layer 62 can cover all areas of the inner circumference of the stator core 61. The sealing layer 62 can be a single cylindrical component. The sealing layer 62 covers the opening of each wire slot 61a on the inner circumference of the stator core 61, so that the wires in each wire slot 61a are contained in the space enclosed by the slot wall of the wire slot 61a and the sealing layer 62. Schematically, the sealing layer 62 can be integrated with the stator core 61. For example, the sealing layer 62 can be manufactured on the inner circumference of the stator core 61 using an injection molding process. Alternatively, the sealing layer 62 can be manufactured separately and assembled to the stator core 61.

[0077] Different from the above, in another embodiment, there may be multiple sealing layers 62, each of which may be in the shape of an arc plate. These sealing layers 62 may be distributed at equal intervals along the inner circumference of the stator core 61, and one sealing layer 62 may cover the opening of one wire slot 61a.

[0078] The following description will continue by taking the sealing layer 62 as a single cylindrical component as an example.

[0079] In the embodiment of the present application, cooling hoods can be connected to opposite axial ends of the stator core 61 to achieve immersion liquid cooling of the stator winding. The cooling hood is used to contain coolant and a winding end. The cooling hood includes 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 one winding end of the stator winding. The first annular wall is used to enclose one end of the stator core 61 along the axial direction of the drive motor 6 to form a containment structure. The coolant contained in the containment structure is used to immerse and cool the winding end.

[0080] In the embodiment of the present application, one cooling cover is used to accommodate coolant and one winding end, and the other cooling cover is used to accommodate coolant and another winding end.

[0081] In the embodiment of the present application, the first annular wall of the cooling cover is arranged around a circle, and the radial dimension of the first annular wall can be defined as the dimension along the radial direction of the drive motor 6. The first annular wall has a certain thickness, so the inner diameter and outer diameter can be defined, wherein the outer diameter of the first annular wall is the radial dimension of the outer circumference 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, that is, the inner circumference of the winding end, the outer circumference of the first annular wall and the axis of the drive motor 6 can be arranged in sequence along the radial direction of the drive motor 6, and there is a certain distance between the inner circumference of the winding end and the outer circumference of the first annular wall, or there is basically no gap between the inner circumference of the winding end and the outer circumference of the first annular wall.

[0082] In an embodiment of the present application, the first annular wall can be used to enclose one end of the stator core 61, and the cooling cover can form a receiving structure for accommodating a winding end and coolant, thereby achieving immersion cooling of the winding end.

[0083] Several cooling hood design options are described below with examples.

[0084] Figures 5 and 6 show the schematic structure of the cooling cover 63 in the first embodiment of the present application. As shown in Figures 5 and 6, the cooling cover 63 can be a substantially annular cover body.

[0085] The cooling shroud 63 may include a first annular wall 63c, an axial bottom wall 63b, and a second annular wall 63a, which are sequentially connected. The axial bottom wall 63b may be approximately annular and may enclose a first through-hole 63d. The second annular wall 63a and the first annular wall 63c may both protrude from the axial bottom wall 63b and respectively connect the outer and inner edges of the axial bottom wall 63b. 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 enclose an annular groove.

[0086] 7 , along the axial direction of the drive motor, the axial bottom wall 63 b of the cooling cover 63 , one winding end 65 a and the end surface 61 c of one end of the stator core 61 are arranged in sequence.

[0087] In the embodiment of the present application, any one of the axial bottom wall 63b, the first annular wall 63c, and the second annular wall 63a of the cooling cover 63 can be independent of the motor housing or integrated with the motor housing. 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.

[0088] In the first embodiment, a cooling cover 64 may be further provided. The cooling cover 64 may have the same structure as the cooling cover 63 and may be arranged in a mirror image. This will be described below.

[0089] Figure 7 illustrates a cross-sectional view of the assembly of the stator core 61, stator winding 65, sealing layer 62, cooling cover 63, and cooling cover 64 in Example 1. As shown in Figure 7, the stator winding 65 includes a winding end 65a and a winding end 65b, both of which are exposed at one end surface of the stator core 61. The cooling cover 63 and the cooling cover 64 can be located at opposite ends of the stator winding 65 in the axial direction, with the axial bottom wall 63b and the second bottom wall 64b facing away from each other, and the second annular wall 63a and the second annular wall 64a facing each other. The second bottom wall 64b can enclose a second through hole.

[0090] As shown in FIG. 7 , the inner diameter r1 of the second annular wall 63 a in the radial direction of the drive motor 6 is larger than the outer diameter r3 of the first annular wall 63 c and the outer diameter r2 of the one winding end portion 65 a .

[0091] As shown in FIG7 , the outer diameter of the second annular wall along the radial direction of the drive motor 6 is greater than the distance between at least a portion of 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 the coolant outlet of at least a portion of the axial channel 61b and the axis of the drive motor 6. As shown in FIG7 , the second annular wall 63a of the cooling cover 63 can be connected to the end face 61c of the stator core 61. Schematically, the second annular wall 63a can be connected to the end face 61c through a sealing structure, and the sealing structure is made of a material with good sealing performance. The sealing structure can be, for example, a sealing ring. Alternatively, the second annular wall 63a can be directly connected to the end face 61c without passing through a connecting medium. The second annular wall 63a is farther away 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 cover 63 can be connected to the sealing layer 62. Thus, the winding end 65a is enclosed in the first end flow channel 6a, which is surrounded by the cooling cover 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 called a receiving structure.

[0092] As shown in Figure 7, schematically, the second annular wall 64a of the cooling cover 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 through a sealing structure, and the sealing structure is made of a material with good sealing performance. The sealing structure can be, for example, a sealing ring. Alternatively, the second annular wall 64a can be directly connected to the end face 61c without passing through a connecting medium. The second annular wall 64a is farther away 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 cover 64 can be connected to the sealing layer 62. As a result, the winding end 65b is encapsulated in the second end flow channel 6b surrounded by the cooling cover 64, the stator core 61 and the sealing layer 62. The second end flow channel 6b can also be called a containment structure.

[0093] All of the axial passages 61b can communicate with the second end flow passage 6b. Therefore, the second end flow passage 6b can communicate with the first end flow passage 6a through the axial passages 61b.

[0094] Figure 8 is a partially enlarged schematic diagram of the structure at point A in Figure 7 . Figure 8 illustrates one method for connecting the first annular wall 63c of the cooling shroud 63 to the sealing layer 62. As shown in Figure 8 , the first annular wall 63c and the sealing layer 62 can be axially distributed and connected by a sealing structure 66. Sealing structure 66 is made of a material with excellent sealing properties. Illustratively, sealing structure 66 can be a sealing ring.

[0095] Unlike FIG8 , in another embodiment, as shown in FIG9 , the first annular wall 63c and the sealing layer 62 can be radially distributed and connected via a sealing structure 66. In the embodiment shown in FIG9 , 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. Accordingly, the connection area between the first annular wall 63c and the sealing layer 62 is relatively large, thereby improving the sealing performance 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.

[0096] The connection between the first annular wall 64 c of the cooling cover 64 and the sealing layer 62 may also be carried out in the manner described above, which will not be described in detail here.

[0097] In this embodiment, both the first end flow channel 6a and the second end flow channel 6b can serve as coolant flow channels, and can communicate with the drive pump 9, filter 10, heat exchanger 5, and other flow channels in the powertrain 4. Both the first end flow channel 6a and the second end flow channel 6b can flow into and contain coolant. As a result, the ends of the stator winding 65 can be immersed in the coolant in the first end flow channel 6a and the second end flow channel 6b, respectively, achieving immersion liquid cooling. The above will be further explained below.

[0098] In this embodiment, the cooling cover 63, the cooling cover 64 and the motor housing can be independent of each other, and the cooling cover 63 and the cooling cover 64 are not directly connected to the motor housing. Schematically, the drive motor 6 can be a hanging ear type motor, and the outer periphery of the stator core 61 can have a stator hanging ear. The cooling cover 63 and the cooling cover 64 can both form a cover body hanging ear, and the cover body hanging ear is assembled with the stator hanging ear, and the stator hanging ear is then fixed to the motor housing, so that the cooling cover 63, the cooling cover 64 and the stator core 61 are fixed to the same position of the motor housing. In one embodiment, the cooling cover 63, the cooling cover 64 and the motor housing are independent of each other, but the cooling cover 63 and the cooling cover 64 are both connected to the motor housing, which will be explained below.

[0099] As shown in Figure 10, the drive motor 6 includes a stator housing 6x, which is used to secure a 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 cap, which is fixedly connected to the stator housing 6x. One end face of the end cap, along the axial direction of the drive motor 6, is aligned opposite an end face of one end of the stator core 61.

[0100] As shown in Figure 10, the stator housing 6x surrounds the outer circumference of the stator core 61 and is used to secure the stator core 61. Along the axial direction of the drive motor 6, one end (e.g., the left end) of the stator housing 6x, one end (e.g., the left end) of the stator core 61, the other end (e.g., the right end) of the stator core 61, and the other end (e.g., the right end) of the stator housing 6x can be arranged in sequence. The end caps can include a first end cap 67 and a second end cap 68. The outer circumference of the end caps is fixedly connected to the inner circumference of the stator housing 6x, or the end faces of the end caps are fixedly connected to the end faces of the stator housing 6x.

[0101] FIG10 illustrates an 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 the second embodiment.

[0102] The first end cap 67 and the second end cap 68 both belong to the motor housing. The first end cap 67 can be located on the side of the cooling cover 63 facing away from the cooling cover 64. The first end cap 67 can be assembled with the cooling cover 63, for example, by means of threaded connectors. The first end cap 67 can press against the cooling cover 63, thereby forming a sealed connection between the cooling cover 63, the stator core 61, and the sealing layer 62. The second end cap 68 can be located on the side of the cooling cover 64 facing away from the cooling cover 63. The second end cap 68 can be assembled with the cooling cover 64, for example, by means of threaded connectors. The second end cap 68 can press against the cooling cover 64, thereby forming a sealed connection between the cooling cover 64, the stator core 61, and the sealing layer 62.

[0103] In one embodiment, the inner circumferential surface of the stator housing is used to secure the first annular wall. The first annular wall may be a separate component that is 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 may extend radially to form a connecting wall that connects to the first annular wall to form a receiving structure. This embodiment allows for assembly of the cooling shroud with a simple and reliable structure, ensuring the performance of the cooling shroud.

[0104] In one embodiment, the inner circumferential surface of the stator housing is used to secure or serve as the second annular wall. The second annular wall can be a separate component that is fixedly connected to the inner circumferential surface of the stator housing. Alternatively, the stator housing and the second annular wall can be integrated into one piece, with at least a portion of the stator housing serving as the second annular wall. This allows for a simple and reliable structure to be used to manufacture the cooling shroud, enabling the cooling shroud to accommodate coolant and winding ends.

[0105] Referring to Figure 10, in one embodiment, one end surface of the end cover 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.

[0106] In this embodiment, the first annular wall and the second annular wall of the cooling cover can be independent components, and at least one of the two can be fixedly connected to an end face of the end cover. The axial bottom wall in the cooling cover can be an independent component, or can be integrated with the end cover. Taking the end cover 67 as an example: one end face of the end cover 67 (for example, the right end face) can be used to fix the end of the first annular wall facing away from the stator core 61, or one end face of the end cover 67 (for example, the right end face) can be used to fix the end of the second annular wall facing away from the stator core 61, or one end face of the end cover 67 (for example, the right end face) can be used to fix the end of the first annular wall facing away from the stator core 61 and the end of the second annular wall facing away from the stator core 61.

[0107] In one embodiment of the present application, the cooling cover 63, the cooling cover 64 and the motor housing can be integrated into one, which will be explained below.

[0108] Figures 11 and 12 illustrate the structure of the cooling cover 63 in the third embodiment. As shown in Figures 11 and 12, the cooling cover 63 can be a roughly annular cover body. The cooling cover 63 can include an axial bottom wall 63b, a second annular wall 63a and a first annular wall 63c. Among them, the axial bottom wall 63b can be approximately annular, and a first through hole 63d can be opened thereon, and the first through hole 63d can be used to install the motor shaft; the second annular wall 63a and the first annular wall 63c can both be protruded on the axial bottom wall 63b, and the second annular wall 63a can be located on the outer periphery of the first annular wall 63c, and the second annular wall 63a can be at a certain distance from the edge of the axial bottom wall 63b.

[0109] As shown in FIG. 13 , the axial bottom wall 63 b may be integrated with the end cover of the drive motor 6 , and one end surface of the end cover is used as the axial bottom wall 63 b of the cooling cover 63 .

[0110] FIG13 illustrates an assembled cross-sectional structure of the stator core 61 , the stator winding 65 , the sealing layer 62 , the cooling cover 63 , and the cooling cover 64 in the third embodiment, wherein the structures of the cooling cover 64 and the cooling cover 63 may be identical.

[0111] As shown in Figure 13, the cooling cover 63 can serve as the first end cover, and the cooling cover 64 can serve as the second end cover. The connection method of the cooling cover 63, the cooling cover 64, the stator core 61 and the sealing layer 62 can be as described above and will not be repeated here. In Example 3, by combining the cover body and the end cover of the drive motor into one, the structure can be made compact, the assembly process is simplified, and the assembly accuracy is improved. In other embodiments, at least a portion of the cooling cover 63 can also be the circumferential side shell of the motor housing (a shell that surrounds the motor in the circumferential direction, and the end cover can be assembled with the circumferential side shell in the axial direction), and at least a portion of the cooling cover 64 can also be the circumferential side shell of the motor housing. The circumferential side shell can also be called a stator housing.

[0112] In the fourth embodiment of the present application, unlike the third embodiment, 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.

[0113] Figures 14 and 15 illustrate the structure of the cooling cover 63 of the fourth embodiment. As shown in Figures 14 and 15, the cooling cover 63 may include an axial bottom wall 63b and a first annular wall 63c. The axial bottom wall 63b may be approximately annular, and may enclose a first through hole 63d, which may be used to allow the motor shaft to pass through; the first annular wall 63c may be protruding from the axial bottom wall 63b, and the first annular wall 63c may be at a certain distance from the edge of the axial bottom wall 63b, and the first annular wall 63c surrounds the outer periphery of the first through hole 63d. Comparing Figures 14 and 11, it can be seen that compared with the third embodiment, the cooling cover 63 of the fourth embodiment may not have a first annular wall.

[0114] Figure 16 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 Example 4, wherein the structure of the cooling cover 64 can be consistent with that of the cooling cover 63.

[0115] As shown in Figure 16, the circumferential shell 671 surrounds the outer circumference of the stator core 61, and the circumferential shell 671 can be connected to the outer circumferential surface of the stator core 61. The axial bottom wall 63b of the cooling cover 63 can be connected to the circumferential shell 671, and the circumferential 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 circumferential shell 671 can serve as the first annular wall of the cooling cover 63. The second bottom wall 64b of the cooling cover 64 can be connected to the circumferential shell 671, and the circumferential 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 circumferential shell 671 can serve as the second annular wall of the cooling cover 64.

[0116] As shown in Figure 16, the circumferential shell 671 may have an inlet 671b near the bottom, which may communicate with the second end flow channel 6b and allow coolant to enter the second end flow channel 6b. The circumferential shell 671 may have an outlet 671a near the top, which may communicate with the first end flow channel 6a and allow coolant to flow out of the first end flow channel 6a.

[0117] Referring to FIG7 , in one embodiment, the outer circumferential surface of the axial bottom wall 63b of the cooling cover 63 is fixedly connected to the second annular wall 63a, and the end surface of the axial bottom wall 63b facing the stator core 61 is fixedly connected to the first annular wall 63c of the cooling cover 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.

[0118] Referring to Figures 13 and 7 , in one embodiment, the axial bottom wall 63b of the cooling cover 63, which faces the end surface of the stator core 61, is fixedly connected to the second annular wall 63a of the cooling cover 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, with the stator housing.

[0119] Based on the description of the above embodiments, it can be understood that in the embodiments of the present 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 can be independent of the motor housing. Moreover, the types of the bottom wall, the first annular wall, and the second annular wall can be freely combined according to product requirements. For example:

[0120] For example, in another embodiment, the first annular wall and the axial bottom wall can be integrated with the motor housing, and the second annular wall can be independent of the motor housing and assembled with the axial bottom wall. The first annular wall can be part of the circumferential shell, and the axial bottom wall can be part of the first end cover.

[0121] Alternatively, in another embodiment, the first annular wall and the second annular wall may be integrated with the motor housing, while the axial bottom wall is independent of the motor housing and assembled with the first and second annular walls. The first annular wall may be part of the circumferential housing, and the second annular wall may be part of the first end cover; alternatively, the first annular wall and the second annular wall may both be part of the first end cover.

[0122] Alternatively, in another embodiment, the second annular wall is integrally formed with the motor housing, 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.

[0123] Alternatively, in another embodiment, the second annular wall and the axial bottom wall are both integrated with the motor housing, and the first annular wall is independent of the motor housing and assembled with the axial bottom wall. The second annular wall and the axial bottom wall may both be part of the first end cover.

[0124] Alternatively, in another embodiment, the axial bottom wall is integrated with the motor housing, the first annular wall and the second annular wall are independent of the motor housing, and 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 cover.

[0125] The above embodiments each describe different types of cooling covers. The cooling cover 63 and the cooling cover 64 in each embodiment can be of the same type. In another embodiment, the cooling cover 63 and the cooling cover 64 can be of different types, and the types of cooling cover 63 and cooling cover 64 can be arbitrarily combined as needed. For example, the cooling cover 63 can be of the type shown in Figure 7, and the cooling cover 64 can be of the type shown in Figure 10 or Figure 13; alternatively, the cooling cover 63 can be of the type shown in Figure 10, and the cooling cover 64 can be of the type shown in Figure 7 or Figure 13.

[0126] The above description explains the first end flow channel 6a and the second end flow channel 6b constructed by designing cooling shrouds 63 and 64. The following describes the positions of first end flow channel 6a and second end flow channel 6b within the assembly flow channel of powertrain 4, and explains the principle of immersion heat dissipation of stator winding 65 and the heat dissipation principle of the entire powertrain 4.

[0127] In the embodiment of the present application, the first end flow channel 6a and the second end flow channel 6b can both be located in the middle section of the assembly flow channel of the powertrain 4 but 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.

[0128] FIG17 is a schematic diagram of the topological architecture of the assembly flow channel of the powertrain 4 in the fifth embodiment of the present application. FIG17 illustrates the key parts of the assembly flow channel, but not the entire assembly flow channel. As shown in FIG17 , the assembly flow channel may include flow channels inside the drive pump, heat exchanger, stator core, housing (including cooling cover and cooling cover), motor shaft, rotor and reducer, etc., as well as flow channels between the above components. Among them, the assembly flow channel is surrounded by a physical structure. For example, the assembly flow channel may include a pipe, a flow channel groove on the housing, etc. The assembly flow channel is represented by a solid line with an arrow in FIG17 . The dotted line with an arrow in FIG17 indicates that the coolant is transported between the bottom shell and the above components by spraying, leaking, gear stirring, etc. Among them, spraying can be, for example, the coolant sprayed out of the bottom shell through a nozzle. Leakage can be, for example, natural leakage to the bottom shell at the joint of the physical flow channel or the installation position of the internal sensor. Gear agitation is when part of the gear in the reducer is immersed in the coolant in the bottom shell, and the coolant is transported from the bottom shell to the inside of the reducer through the agitation of the gear.

[0129] As shown in Figure 17, the stator core has a stator cooling channel, the cooling cover participates in the formation of the end flow channel (including the first end flow channel and the second end flow channel), and the motor shaft, rotor and reducer participate in the formation of other flow channels. Among them, the other flow channels may include a first channel and a second channel. The first channel is the flow channel in the drive motor other than the end flow channel and the stator cooling channel, such as the motor shaft channel in the motor shaft, the motor bearing accommodating cavity, the rotor channel in the rotor, etc. The second channel is the flow channel in the reducer, such as the gear shaft flow channel in the reducer, etc.

[0130] As shown in Figure 17, the driving pump extracts high-temperature coolant from the bottom shell and pumps the high-temperature coolant into the heat exchanger. Low-temperature coolant flows out of the heat exchanger. The low-temperature coolant can flow into the stator cooling channel, the end channel, and other channels in parallel. Among them, the low-temperature coolant can flow into the other channel along channel R1, flow into the stator cooling channel along channel R2, and flow into the end channel 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 channel along channel R4. The coolant in the end channel can flow into the bottom shell by spraying or leaking (the coolant can flow out from the first end channel or the second end channel and enter the bottom shell). The coolant in the end channel can also flow into the other channel along channel R5. The coolant in the other channel can flow into the bottom shell by spraying or leaking. For the reducer in the other channel, the gears in the reducer can transport the coolant from the bottom shell to the inside of the reducer by stirring.

[0131] The topology shown in FIG17 can realize circulating liquid cooling of the powertrain.

[0132] FIG18 is a schematic diagram of the cross-sectional structure of the assembly flow channel based on the topological structure shown in FIG17 . As shown in FIG18 , the power assembly 4 can be an integrated power assembly, and the drive motor 6 and the reducer 8 can be assembled in the same assembly casing. Schematically, the cooling cover 63 and the cooling cover 64 can be combined into one with the motor casing of the drive motor 6. Since the motor casing of the drive motor 6 also belongs to the assembly casing, it can be considered that the cooling cover 63 and the cooling cover 64 are combined into one with the assembly casing. FIG18 illustrates the bottom casing 41, the peripheral side casing 42, the cooling cover 63 and the cooling cover 64 in the assembly casing, but does not illustrate the reducer casing of the reducer 8.

[0133] It should be understood that the powertrain 4 shown in FIG18 is merely illustrative and does not limit the actual structure. For example, FIG18 shows the cross-sectional shape of the drive motor 6 and the cross-sectional shape of the reducer 8 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.

[0134] As shown in FIG18 , the motor shaft 69 can be mounted on the assembly housing via a motor bearing 701 fixed to the assembly housing (e.g., the cooling cover 63 and the cooling cover 64). The rotor 71 can surround and be fixed to the outer periphery of the motor shaft 69, and the sealing layer 62, the stator winding 65, and the stator core 61 surround the outer periphery of the rotor 71. The rotor 71, the sealing layer 62, the stator winding 65, and the stator core 61 are located between the cooling cover 63 and the cooling cover 64. One end (e.g., the right end) of the motor shaft 69 can extend out of the cooling cover 64 and be fixedly connected to the input shaft 84 of the reducer 8.

[0135] As shown in Figure 18, 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 the gear 86 may be fixed to the outer periphery of the gear shaft 88 and mesh with the gear 85. The gear shaft 81 may be mounted on the assembly housing via the gear bearing 83, and the gear 82 may be fixed to the outer periphery of the gear shaft 81 and mesh with the gear 86. Gear 85, gear 86, and gear 82 are all located outside the cooling cover 63 and the cooling cover 64. For example, the above three gears may all be located on the side of the cooling cover 64 facing away from the cooling cover 63.

[0136] As shown in FIG18 , a housing flow channel 63f may be provided within the cooling cover 63. The housing flow channel 63f may communicate with the motor shaft channel 69a within the motor shaft 69. The motor shaft channel 69a may communicate with the rotor channel 71a within the rotor 71. The coolant flowing out of the heat exchanger 5 may flow through the housing flow channel 63f, the motor shaft channel 69a, and the rotor channel 71a in sequence, thereby removing heat from the motor shaft 69 and the rotor 71. The coolant flowing out of the rotor channel 71a may fall into the bottom shell 41. Referring to FIG18 and FIG17 , the housing flow channel 63f may correspond to the flow channel R1 in FIG17 .

[0137] As shown in FIG18 , a housing flow channel 42a may be provided within the peripheral shell 42, and a housing flow channel 64g may be provided within the cooling cover 64. Housing flow channels 42a, 64g, and gear shaft flow channel 88a within the gear shaft 88 may be sequentially connected. Referring to FIG18 and FIG17 , housing flow channels 42a and 64g may also correspond to flow channel R1 in FIG17 .

[0138] As shown in FIG18 , a housing flow channel 63g may also be provided within the cooling cover 63. The housing flow channel 63g, the housing flow channel 42a, the circumferential channel 61d, and the axial channel 61b of the stator core 61 (both the circumferential channel 61d and the axial channel 61b are stator cooling channels) may be sequentially connected. Coolant flowing out of the heat exchanger 5 may sequentially flow through the housing flow channel 63g, the housing flow channel 42a, the circumferential channel 61d, and the axial channel 61b, entering the interior of the stator core 61, thereby removing heat from the stator core 61 and the stator winding 65. In conjunction with FIG18 and FIG17 , the housing flow channel 63g and the housing flow channel 42a may correspond to the flow channel R2 in FIG17 .

[0139] As shown in Figure 18, since the first end flow channel 6a and the second end flow channel 6b are both connected to the axial channel 61b, the coolant entering the axial channel 61b can flow leftward into the first end flow channel 6a and rightward into the second end flow channel 6b, respectively. In other words, the axial channel 61b can divide the coolant into 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. Combining Figures 18 and 17, 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 the flow of coolant along flow channel R4 in Figure 17.

[0140] In this embodiment, the second annular wall includes an opening, and the opening is used to communicate with the housing flow passage of the drive motor 6, and the opening faces the axis of the drive motor 6. An example will be given below to illustrate.

[0141] As shown in Figure 18, the first end flow channel 6a may have an opening 6c. Opening 6c may be formed, for example, on the second annular wall 63a of the cooling shroud 63 and located radially closer to the bottom shell 41. Through opening 6c, the shell flow channel 63g, the shell flow channel 42a, and the first end flow channel 6a can be sequentially connected. The second end flow channel 6b may have an opening 6d. Opening 6d may be formed, for example, on the second annular wall 64a of the cooling shroud 64 and located radially closer to the bottom shell 41. Through opening 6d, the shell flow channel 63g, the shell flow channel 42a, and the second end flow channel 6b can be sequentially connected. Therefore, the coolant flowing out of the heat exchanger 5 can flow sequentially through the shell flow channel 63g, the shell flow channel 42a, and the opening 6c, entering the first end flow channel 6a; the coolant flowing out of the heat exchanger 5 can flow sequentially through the shell flow channel 63g, the shell flow channel 42a, and the 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 the axial channel 61b. Therefore, the coolant can remove heat from the stator core 61 and the stator winding 65. As shown in Figure 18 and Figure 17, the shell flow channel 63g and the shell flow channel 42a can correspond to the flow channel R3 in Figure 17.

[0142] For example, as shown in FIG18 , the first end flow channel 6a may have an opening 6e. The opening 6e may be formed, for example, on the second annular wall 63a of the cooling shroud 63 and located at an end radially away from the bottom shell 41. From the perspective of FIG18 , the position of the opening 6e is higher than the position of the opening 6c. The coolant in the first end flow channel 6a may flow out from the opening 6e and fall into the bottom shell 41. The second end flow channel 6b may have an opening 6f. The opening 6f may be formed, for example, on the second annular wall 64a of the cooling shroud 64 and located at an end radially away from the bottom shell 41. From the perspective of FIG18 , the position of the opening 6f is higher than the position of the opening 6d.

[0143] In this embodiment, by adding covers (including cooling covers 63 and cooling covers 64) at opposite ends of the stator winding 65, covering the inner circumference of the stator core 61 with a sealing layer 62, and sealingly connecting the cover to the stator core 61 and the sealing layer 62, and constructing end flow channels (including a first end flow channel 6a and a second end flow channel 6b), the stator winding 65 can be immersed in the end flow channels, and the stator winding 65 is cooled using an immersion liquid cooling method, so that the heat of the stator winding 65 can be quickly absorbed and carried away by the coolant, thereby greatly improving the heat dissipation effect of the stator winding 65 and enhancing the temperature uniformity of the cooling of the drive motor 6, which is conducive to improving the rated power output of the drive motor 6 and extending the duration of its peak power. For example, in low-temperature and low-flow application scenarios (such as scenarios where the electric drive actively heats up), immersion liquid cooling can prevent the conductors of the stator winding 65 from overheating, ensuring that the drive motor 6 has good temperature uniformity.

[0144] In this embodiment, because the outlet of the end flow channel (e.g., openings 6e and 6f) 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 unlikely to overflow when the drive pump 9 is stopped and the fluid circuit is stationary and not circulating. Furthermore, when the fluid circuit is stationary and not circulating, the coolant in the end flow channel will not flow back due to the characteristics of the drive pump 9. The above design ensures that the end flow channel is always filled with coolant, ensuring that the stator winding 65 is always immersed in the coolant.

[0145] In this embodiment, since the coolant in the end flow channel is not easy to leak into the air gap between the stator and the rotor 71, the wear between the stator and the rotor 71 (such as oil grinding) can be reduced or avoided, thereby reducing the energy consumption of the drive motor 6.

[0146] In this embodiment, the sealing layer 62 is designed to prevent coolant from leaking from the stator core 61 when it flows between the first end flow channel 6a and the second end flow channel 6b of the stator core 61. In other embodiments, the sealing layer 62 may not be provided, and the second annular wall 63a and the first annular wall 63c of the cooling cover 63 are both connected to the stator core 61, and the cooling cover 63 and the stator core 61 form the first end flow channel 6a. Similarly, the second annular wall 64a and the first annular wall 64c of the cooling cover 64 are both connected to the stator core 61, and the cooling cover 64 and the stator core 61 form the second end flow channel 6b.

[0147] As shown in Figure 18, a shell flow channel 42b can also be provided in the peripheral shell 42, and a shell flow channel 64d, a shell flow channel 64e, and a shell flow channel 64f can also be provided in the cooling cover 64. Through the opening 6f of the second end flow channel 6b, the second end flow channel 6b, the shell flow channel 42b, and the shell flow channel 64e can be connected in sequence, and the shell flow channel 64d and the shell flow channel 64f can both be connected to the shell flow channel 64e. The shell flow channel 64d can be connected to the accommodating cavity of the motor bearing 702. The shell flow channel 64f can be connected to the gear shaft flow channel 81a in the gear shaft 81. The coolant flowing out from the opening 6f of the second end flow channel 6b can flow through the shell flow channel 42b and the shell flow channel 64d into the accommodating cavity of the motor bearing 702 to dissipate heat from the motor bearing 702. The coolant flowing out of the opening 6f of the second end flow channel 6b can also flow through the shell flow channel 42b, the shell flow channel 64e and the shell flow channel 64f into the gear shaft flow channel 81a, dissipating heat for the gear shaft 81 and the gear bearing 83. That is, the coolant flowing out of the opening 6f of the second end flow channel 6b will be diverted to the motor bearing 702 and the gear shaft flow channel 81a. The coolant can flow in from the opening at the intersection of the shell flow channel 64f and the shell flow channel 64e and fall into the bottom shell 41 (three curves are used to represent the falling coolant). In combination with Figures 18 and 17, the flow of the coolant in the shell flow channel 42b, the shell flow channel 64d and the motor bearing 702, as well as the flow of the coolant in the shell flow channel 42b, the shell flow channel 64e, the shell flow channel 64f and the gear shaft flow channel 81a, can all correspond to the flow of the coolant along the flow channel R5 in Figure 17.

[0148] As shown in Figure 18 , coolant can flow out of gear shaft flow channel 81a and gear shaft flow channel 88a and fall into bottom housing 41. The lower portion of gear 86 can be immersed in the coolant within bottom housing 41. As gear 86 rotates, all circumferential portions of gear 86 can be coated with coolant. Gear 86 can also transfer coolant to gears 85 and 82, thereby dissipating heat from gears 86, 85, and 82.

[0149] In some conventional solutions, heat dissipation from the stator windings is the final destination for heat dissipation of the entire powertrain. For example, in solutions that use oil injection to dissipate heat from the stator windings, after the cooling oil is sprayed onto the stator windings, it flows back into the oil pan, where it awaits the oil pump to pump it back to the beginning of the oil circuit.

[0150] Unlike this conventional solution, as described above, the coolant within the first end flow channel 6a and the second end flow channel 6b of this embodiment can also enter the other flow channel through flow channel R5, rather than being restricted to falling into the bottom shell 41. Therefore, the first end flow channel 6a and the second end flow channel 6b can serve as the middle section of the assembly flow channel, rather than being located only at the end. As part of the assembly flow channel, the first end flow channel 6a and the second end flow channel 6b transport coolant to the various components that make up the other flow channel. This design means that heat dissipation from the stator winding 65 is no longer the end point of heat dissipation for the entire powertrain 4. After dissipating heat from the stator winding 65, the coolant can continue to dissipate heat from the various components that make up the other flow channel. Therefore, this embodiment allows for the recovery and reuse of coolant. This allows more coolant to flow through the stator winding 65 at the same time without increasing the flow rate of the drive pump 9, thereby enhancing the heat dissipation of the stator winding 65.

[0151] Furthermore, as shown in FIG17 , in this embodiment, the design of the first end flow channel 6a and the second end flow channel 6b allows heat from the stator winding 65 to be collected, preventing it from being directly dissipated into the atmosphere. This heat can be transferred via a heat exchanger to the electric vehicle's thermal management system, which 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, thereby improving COP, saving energy, and reducing costs.

[0152] For example, in a scenario where the drive motor operates in a low-temperature environment, the heat of the stator winding 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 improve COP.

[0153] For example, the heat of the stator winding 65 can be effectively utilized to achieve drive motor heating (using the heat of the drive motor to heat the air conditioner or power battery, etc.), and the drive motor is used to replace at least part of the electric heater, which includes but is not limited to a positive temperature coefficient (PTC) heater. In some embodiments, the drive motor can be used to completely replace the electric heater, which can greatly reduce the dependence on the electric heater, reduce costs, reduce energy consumption, and improve COP. In other embodiments, the drive motor heating can be used as a supplement, and the high-voltage electric heater can be replaced with a low-voltage electric heater, which can also have a certain effect of reducing costs, reducing energy consumption, and improving COP.

[0154] Figure 19 is a schematic diagram of the topological architecture of the assembly flow path of the powertrain 4 in the sixth embodiment of the present application. Comparing Figures 19 and 20, unlike the fifth embodiment, the topological architecture of the sixth embodiment can be without flow path R3, that is, the coolant flowing out of the heat exchanger can be directed away from the housing.

[0155] Figure 20 is a schematic cross-sectional view of the assembly flow channel based on the topological structure shown in Figure 19. Comparing Figure 20 with Figure 18, unlike the fifth embodiment, the end flow channel of the sixth embodiment may not have the opening 6c and the opening 6d.

[0156] The solution of the fifth embodiment may have the same or equivalent technical effects as the fourth embodiment, and will not be described in detail here.

[0157] Unlike the fifth or sixth embodiments described above, in other embodiments, the axial channel 61b within the stator core 61 can be eliminated, allowing the circumferential channel 61d on the stator core 61 to communicate with the wire slot 61a. A gap is formed between the conductive wire within the wire slot 61a and the inner wall of the wire slot 61a, allowing coolant to flow. This allows coolant to enter the wire slot 61a and dissipate heat from the stator core 61. The wire slot 61a can connect the first end flow channel 6a with the second end flow channel 6b, thereby dissipating heat from both ends of the stator winding 65. Alternatively, in other embodiments, the axial channel 61b and the wire slot 61a can be used simultaneously to connect the first end flow channel 6a with the second end flow channel 6b.

[0158] Figure 21 is a schematic diagram of the topological architecture of the assembly flow path of powertrain 4 in Example 7 of the present application. Comparing Figure 21 with Figure 19, in Example 6, the coolant flowing out of the heat exchanger can sequentially pass through flow path R2, the stator core, and flow path R4 to the cooling shroud, where the coolant first flows into the stator core and then enters the two cooling shrouds. However, in Example 7, the coolant flowing out of the heat exchanger sequentially passes through flow path R6, one cooling shroud, flow path R7, the stator core, and flow path R8 to another cooling shroud (e.g., located on the three-phase line side), where the coolant sequentially enters one cooling shroud, the stator core, and the other cooling shroud.

[0159] Figure 22 is a schematic cross-sectional view of the assembly flow channel based on the topological structure shown in Figure 21. Comparing Figure 22 with Figure 20, unlike in Example 6, in Example 7, the stator core 61 may not have the circumferential channel 61d; the circumferential shell 42 may be provided with a housing flow channel 42c, which may communicate with the first end flow channel 6a via an opening 6e; the cooling cover 63 may not have the housing flow channel 63f, but may instead have a housing flow channel 63h, one end of which communicates with the housing flow channel 42c and the other end of which communicates with the motor shaft channel 69a; and the second annular wall 64a of the cooling cover 64 may not have the opening 6f.

[0160] As shown in Figure 22, the drive pump 9, heat exchanger 5, and housing flow channel 42a (hereinafter referred to as the first housing flow channel 42a) are sequentially connected. The coolant flowing out of the heat exchanger 5 can flow through the housing flow channel 42a and opening 6d in sequence, entering the second end flow channel 6b. The housing flow channel 42a and opening 6d correspond to flow channel R6 in Figure 21. In other words, the coolant in the housing flow channel 42a can also flow into the gear shaft flow channel 88a through the housing flow channel 64g. In other words, 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 the second end flow channel 6b and the gear shaft flow channel 88a.

[0161] As shown in Figure 22, the coolant in the second end flow channel 6b can enter the axial channel 61b of the stator core 61 and enter the first end flow channel 6a through axial channel 61b. Axial channel 61b can correspond to flow channels R7 and R8 in Figure 21. The coolant in the first end flow channel 6a can enter the housing flow channels 42c, 42b, and 63h through opening 6e, and enter the motor shaft channel 69a through housing flow channels 63h. Housing flow channels 42b and 63h can correspond to flow channel R5 in Figure 21. In addition, the coolant can also enter housing flow channels 64d, 64e, and 64f from housing flow channel 42b, respectively. Housing flow channels 64d, 64e, and 64f can also correspond to flow channel R5 in Figure 21. That is, the coolant flowing out of opening 6e can be diverted to motor shaft channel 69a, rotor channel 71a, motor bearing 702, and gear shaft channel 81a. In this embodiment, housing channel 42c, housing channel 42b, housing channel 63h, housing channel 64d, housing channel 64e, and housing channel 64f can all be referred to as second housing channel.

[0162] The solution of Example 7 may have the same or equivalent technical effects as Example 6, and will not be described in detail here.

[0163] Figure 23 is a schematic diagram of the topological architecture of the assembly flow path of the powertrain 4 in the eighth embodiment of the present application. Comparing Figure 23 with Figure 21, unlike the seventh embodiment, the topological architecture of the eighth embodiment can be without flow path R1, that is, the coolant flowing out of the heat exchanger can be directly not fed into this other flow path.

[0164] FIG24 is a schematic cross-sectional view of the assembly flow channel based on the topological structure shown in FIG23 . Comparing FIG24 with FIG22 , in Example 7, the shell flow channel 64g connects the shell flow channel 42a and the gear shaft flow channel 88a. Unlike Example 7, in Example 8, the shell flow channel 64g may not be provided, and the shell flow channel 42a (which may be referred to as the first shell flow channel 42a) may be connected to the second end flow channel 6b only through the opening 6d; the shell flow channel 64f may extend downward (i.e., toward the bottom shell 41) and be connected to the gear shaft flow channel 88a, wherein the portion where the shell flow channel 64f overlaps with the motor shaft 69 is blocked by the motor shaft 69.

[0165] The solution of Example 8 may have the same or equivalent technical effects as Example 7, and will not be described in detail here.

[0166] Figure 25 is a schematic diagram of the assembly flow path topology of the powertrain 4 in the ninth embodiment of the present application. Comparing Figure 25 with Figure 23, unlike the eighth embodiment, the position of the heat exchanger in the coolant flow path in the ninth embodiment is adjustable. Coolant flowing from the drive pump can flow directly into one cooling hood along flow path R6, while coolant flowing from another cooling hood can flow into the heat exchanger along flow path R9, and coolant flowing from the heat exchanger can flow into the other flow path along flow path R10.

[0167] In this embodiment, the axial bottom wall includes an opening for communicating with the housing flow passage of the drive motor 6. The opening faces the stator core 61. The radial distance between the opening 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 to illustrate this.

[0168] FIG26 is a schematic cross-sectional view of the assembly flow channel based on the topological structure shown in FIG25 . Comparing FIG26 with FIG24 , unlike the eighth embodiment, the ninth embodiment can have a shell flow channel 63i within the cooling hood 63. The shell flow channel 63i can connect the first end flow channel 6a with the heat exchanger 5. The shell flow channel 63i can overlap with the shell flow channel 63h but not connect to it. The axial bottom wall of the cooling hood 63 can be integrated with the end cover. The shell flow channel 63i can be opened on the axial bottom wall (or opened on the end cover). The opening of the shell flow channel 63i toward the first end flow channel 6a is the opening 63x on the axial bottom wall. The opening 63x faces the stator core 61 and connects to the shell flow channel 63i. In 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.

[0169] As shown in Figure 26, a shell flow channel 63j can also be provided within the cooling cover 63. Shell flow channel 63j can connect the heat exchanger 5 with the shell flow channel 42b. Shell flow channel 63j can also connect with shell flow channel 63h. Coolant within the first end flow channel 6a can enter the heat exchanger 5 through shell flow channel 63i. Shell flow channel 63i can correspond to flow channel R9 in Figure 25. Coolant within the heat exchanger 5 can enter the motor shaft channel 69a along shell flow channels 63j and 63h. Coolant within the heat exchanger 5 can also flow along shell flow channels 63j and 42b, and from there enter shell flow channels 64d and 64f, respectively. Shell flow channels 63j and 63h can correspond to flow channel R10 in Figure 25. Shell flow channels 63j, 42b, 64d, and 64f can also correspond to flow channel R10 in Figure 25.

[0170] The solution of Example 9 can have the same or equivalent technical effects as Example 8, and will not be described in detail here.

[0171] In the assembly flow channels of the aforementioned fifth, seventh, and eighth embodiments, the amount of coolant flowing through the housing can be sequentially increased while maintaining the same flow rate of the drive pump 9. Specifically, because the second end flow channel 6b and the first end flow channel 6a in the seventh embodiment are connected in series, the temperature of the winding end 65b of the stator winding 65 within the second end flow channel 6b is inconsistent with the temperature of the winding end 65a of the stator winding 65 within the first end flow channel 6a. Because the second end flow channel 6b, the stator cooling channel, the first end flow channel 6a, and the other flow channels are sequentially connected in series in the eighth embodiment, the coolant flowing out of the heat exchanger 5 is not diverted. Therefore, the amount of coolant in the second end flow channel 6b and the first end flow channel 6a is relatively large, thereby providing better heat dissipation to the winding ends 65b and 65a. To achieve this "sequential series" design, the three-phase line interface can be well sealed.

[0172] Unlike the seventh, eighth, or ninth embodiments described above, in other embodiments, the axial channel 61b within the stator core 61 can be eliminated, and a gap for coolant flow can be formed between the conductive wires within the wire slots 61a and the inner walls of the wire slots 61a. This allows coolant to enter the wire slots 61a and dissipate heat from the stator core 61. The wire slots 61a can connect the first end flow channel 6a with the second end flow channel 6b, thereby dissipating heat from both ends of the stator winding 65. Alternatively, in other embodiments, both the axial channel 61b and the wire slots 61a can be used to connect the first end flow channel 6a with the second end flow channel 6b.

[0173] The above embodiment uses an example in which the cover and motor housing are integrated. It should be understood that this is merely an example. In other embodiments, at least a portion of the cover can be independent of the motor housing. The openings in the cover and the corresponding housing flow passages can be designed to produce an assembly flow passage that meets product requirements.

[0174] In any of the above embodiments, the positions of any inlet and any outlet of each shell flow channel, as well as any inlet and any outlet of each end flow channel, can be designed according to product requirements and are not limited to those shown in the drawings.

[0175] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A drive motor with end - immersed cooling of the stator winding, characterized in that, The drive motor includes: A stator core and a stator winding, where 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 the one winding end of the stator winding is greater than the inner diameter of the stator core; A cooling cover, which is used to accommodate the coolant and the one winding end. The cooling cover includes a first annular wall. Along the radial direction of the drive motor, the outer diameter of the first annular wall is less than or equal to the inner diameter of the one winding end of the stator winding. One end of the first annular wall along the axial direction of the drive motor is used to enclose the one end of the stator core to form a receiving structure, and the coolant received 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 cooling cover includes a second annular wall. Along the radial direction of the drive motor, the inner diameter of the second annular wall is greater than the outer diameter of the first annular wall and the outer diameter of the one winding end.

3. The drive motor according to claim 1 or 2, characterized in that, The drive motor includes: A stator housing, which is used to fix the stator core. Along the axial direction of the drive motor, the length of the stator housing is greater than that of the stator core. Along the radial direction of the drive motor, the outer diameter of the stator core is less than or equal to the inner diameter of the stator housing; An end cover, which is used to fixedly connect the stator housing. One end face of the end cover is arranged opposite to the end face of the one end of the stator core along the axial direction of the drive motor.

4. The drive motor according to claim 3, characterized in that, The inner circumferential surface of the stator housing is used to fix the first annular wall.

5. The drive motor according to claim 4, characterized in that, The inner circumferential surface of the stator housing is used to fix the second annular wall or serve as the second annular wall.

6. The drive motor according to claim 3, characterized in that The one end face of the end cover is used for: Fixing the other end of the first annular wall along the axial direction of the drive motor away from the stator core; or, Fixing the other end of the second annular wall along the axial direction of the drive motor away from the stator core; Or, Fixing the other end of the first annular wall along the axial direction of the drive motor away from the stator core and fixing the other end of the second annular wall along the axial direction of the drive motor away from the stator core.

7. The drive motor according to claim 3, characterized in that, The cooling cover includes an axial bottom wall. Along the axial direction of the drive motor, the axial bottom wall, the one winding end and the end face of the one end of the stator core are arranged in sequence.

8. The drive motor according to claim 7, characterized in that The one end face of the end cover is used to serve as the axial bottom wall of the cooling cover.

9. The drive motor according to claim 7, wherein, The outer circumferential surface of the axial bottom wall is used to fixedly connect the second annular wall, and the end face of the axial bottom wall facing the stator core is used to fixedly connect the first annular wall of the cooling cover.

10. The drive motor according to claim 7, characterized in that, The end face of the axial bottom wall facing the stator core is used to fixedly connect the second annular wall of the cooling cover.

11. The drive motor according to claim 2, characterized in that, The drive motor includes a plurality of stator cooling channels, and the stator cooling channels include a plurality of coolant outlets, where: Along the circumferential direction of the drive motor, the plurality of coolant outlets are spaced apart on the end face of the one end of the stator core. Along the radial direction of the drive motor, the distance between each coolant outlet and the axis of the drive motor is greater than the outer diameter of the one winding end; The outer diameter of the second annular wall in the radial direction of the drive motor is greater than the distance between at least a part of the coolant outlet and the axis of the drive motor.

12. The drive motor according to claim 2, wherein The second annular wall includes an opening for communicating with the housing flow passage of the drive motor, and the opening faces the axis of the drive motor.

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

14. A powertrain, characterized in that, The powertrain includes a reducer and the drive motor according to any one of claims 1-13, and the input shaft of the reducer is used for driving connection with the motor shaft of the drive motor.

15. An electric vehicle, characterized in that, The electric vehicle includes a vehicle frame and the powertrain according to claim 14, and the vehicle frame is used for fixing the powertrain.

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