Immersion liquid-cooled electric motor, powertrain, and vehicle

Abstract

The present application relates to the technical field of electric motors, and in particular, to an immersion liquid-cooled electric motor, a powertrain, and a vehicle. A stator of the electric motor comprises a stator core, a stator winding, and an annular injection-molded body formed by integral injection molding. The annular injection-molded body comprises a plurality of embedded sections and one exposed section. The one exposed section and the plurality of embedded sections are arranged adjacently in an axial direction of the electric motor. Each embedded section is configured to be embedded in a corresponding winding slot in a radial direction of the electric motor. The one exposed section is exposed from an axial end face in the axial direction of the electric motor. The one exposed section is configured to enclose an accommodating cavity together with an electric motor end cover, a stator sleeve and the axial end face. The accommodating cavity is configured to accommodate a cooling liquid, such that one end of the stator winding is immersed in the cooling liquid. The annular injection-molded body is connected and fixed to the electric motor end cover of an electric motor housing, such that the accommodating cavity is formed between one end of the stator and the housing, and immersion liquid cooling is performed on the end winding of the stator winding, thereby enhancing the cooling effect on the stator winding and increasing the power of the electric motor.

Description

An immersion liquid-cooled electric motor, powertrain, and vehicle

[0001] Cross-reference to related applications

[0002] This application claims priority to Chinese Patent Application No. 202411589685.8, filed on November 7, 2024, entitled "An Immersion Liquid-Cooled Motor, Powertrain and Vehicle", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of motor technology, and more particularly to an immersion liquid-cooled motor, powertrain, and vehicle. Background Technology

[0004] The losses in the stator windings of a motor are a significant source of heat and affect motor efficiency. Circulating oil or water through the stator can lower the winding temperature, thereby reducing heat loss and improving motor efficiency.

[0005] However, current motor cooling methods cannot meet the demands of motor miniaturization and high continuous power requirements. Summary of the Invention

[0006] This application provides an immersion liquid-cooled motor, powertrain, and vehicle. The motor is formed by injection molding a stator core and an annular injection molded body to create a structure that allows the windings to be directly immersed in liquid for cooling, thereby enhancing the cooling effect of the motor and meeting the power requirements of the motor.

[0007] In a first aspect, embodiments of this application provide an immersion liquid-cooled motor. The motor housing includes a stator sleeve and a motor end cover. The stator sleeve is used to fix the stator of the motor, and the motor end cover is used to enclose the stator sleeve to form a motor cavity. The motor cavity is used to accommodate the stator and rotor of the motor. The stator includes a stator core, stator windings, and an integrally injection-molded annular injection-molded body. The stator core includes a central hole and multiple winding slots. The central hole penetrates the stator core along the axial direction of the motor, and the multiple winding slots are arranged circumferentially around the stator. Each winding slot is radially spaced from the center of the stator. The holes are interconnected, wherein: multiple winding slots are used to fix the stator winding and the annular injection molded body, one end of the stator winding is exposed on an axial end face of the stator core along the axial direction of the motor; the annular injection molded body includes multiple embedded sections and one exposed section, one exposed section and the multiple embedded sections are arranged adjacent to each other along the axial direction of the motor, each embedded section is used to embed a winding slot along the radial direction of the motor, one exposed section is exposed on an axial end face along the axial direction of the motor, one exposed section is used to enclose a motor end cover, a stator sleeve and an axial end face to form a receiving cavity, one receiving cavity is used to receive coolant to immerse one end of the stator winding.

[0008] The motor provided in this application embodiment has an annular injection-molded body that is fixedly connected to the motor end cover of the motor housing. This allows a receiving cavity to be formed between one end of the stator and the housing, into which the end of the stator winding can extend. Coolant is filled into the receiving cavity, providing liquid cooling to the portion of the stator winding housed within it, thus achieving direct cooling of the stator winding end. The exposed section of the annular injection-molded body is directly connected and fixed to the housing, which shortens the stator end height and facilitates motor miniaturization. Compared to the existing oil-injection ring end winding cooling scheme, this method has a simpler structure, better cooling effect, reduced production costs, and increased continuous power of the motor.

[0009] In one embodiment, along the circumferential direction of the motor, the width of each winding slot is greater than the width of the slot opening used to connect the center hole of the winding slot, and the embedded segment embedded in each winding slot fills the slot opening of each winding slot. The embedded end is fixed by filling the winding slot opening, which can strengthen the connection and fixation between the annular injection molded body and the stator core.

[0010] In one embodiment, along the radial direction of the motor, the length of an embedded segment embedded in each winding slot is less than or equal to the length of the slot opening. This can save materials, reduce production costs, and reduce the weight of the motor while ensuring the bonding strength between the embedded segment and the winding slot.

[0011] In one embodiment, along the radial direction of the motor, an embedded segment embedded in each winding slot surrounds the stator winding accommodated by the winding slot along the inner wall of the winding slot, which can strengthen the connection and fixation between the embedded segment and the winding slot.

[0012] In one embodiment, an exposed section is used to cover a portion of the axial end face. The outer diameter of the portion of the exposed section covering the axial end face is larger than the diameter of a central hole, which can strengthen the connection and fixation of the annular injection molded body and the stator core along the radial direction of the motor.

[0013] In one embodiment, along the radial direction of the motor, the outer diameter of a portion of an exposed section covering an axial end face is smaller than the distance between the stator winding and the motor axis in each winding slot. This exposed section, arranged radially between the stator winding and the center hole, can increase the creepage distance of the stator winding.

[0014] In one embodiment, the outer diameter of the portion of an exposed section covering an axial end face is greater than the distance between the bottom of each winding slot and the axis of the motor. One end of the stator winding passes through the portion of the exposed section covering an axial end face along the axial direction of the motor and protrudes from an axial end face of the stator core. This exposed section can cover a larger area of ​​the axial end face of the stator core, allowing for a tighter bond and fixation between the annular injection molded body and the stator core.

[0015] In one embodiment, an exposed section covering an axial end face includes multiple through holes spaced apart circumferentially along the motor. Each through hole penetrates the exposed section axially and communicates with a winding slot. Specifically, the size of each through hole is greater than or equal to the size of each winding slot radially along the motor, and the distance between two adjacent through holes circumferentially along the motor is less than or equal to the distance between two adjacent winding slots. The through holes connect the winding slots with the space on the side of the exposed section away from the stator core, thereby allowing the receiving cavity to communicate with the winding slots. Coolant in the receiving cavity can then enter the winding slots to cool the stator windings.

[0016] In one embodiment, along the radial direction of the motor, a portion of an exposed section covering an axial end face includes multiple through holes, each through hole penetrating the portion of the exposed section covering an axial end face along the axial direction of the motor, and each through hole is arranged between two winding slots. The arrangement of through holes can reduce the amount and weight of the annular injection molded part.

[0017] In one embodiment, the exposed section of the annular injection molded body may only have a through hole. Alternatively, the exposed section of the annular injection molded body may also have both a through hole and a through hole. Or, the exposed section of the annular injection molded body may cover the portion between the winding slots on the axial end face of the stator core, in which case the exposed section may only include a through hole.

[0018] In one embodiment, each through hole includes a notch along the radial direction of the motor, the notch of each through hole facing away from a central hole along the radial direction of the motor, and the width of each notch along the circumference of the motor is greater than the width of each winding slot, so that adjacent notches in the circumference can connect to form an exposed section with a smaller radial dimension.

[0019] In one embodiment, the stator core includes one or more liquid cooling channels, and a portion of an exposed section covering an axial end face includes a plurality of liquid cooling holes, each liquid cooling hole being used to connect a receiving cavity and at least one liquid cooling channel, such that the receiving cavity can communicate with the at least one liquid cooling channel to form a liquid cooling system for the motor.

[0020] In one embodiment, an exposed section further includes an annular section, and a motor end cover includes an annular protrusion and a bearing groove. The annular protrusion surrounds the bearing groove, wherein: the annular protrusion is used to extend into the central hole of the annular section along the axial direction of the motor; the gap between the outer circumferential surface of the annular protrusion and the inner circumferential surface of the annular section is used to accommodate a sealing ring; the bearing groove is used to fix the outer ring of a bearing, and the inner ring of the bearing is used to drive the motor shaft of the motor. The annular section of the exposed section can be positioned and engaged with the annular protrusion to achieve the connection and fixation of the annular injection molded body and the motor end cover, reducing the axial dimension of the motor.

[0021] In one embodiment, along the axial direction of the motor, the length of an annular segment protruding from an axial end face is greater than the length of an annular protrusion protruding from a motor end cover. The end of the annular segment can abut against the motor end cover, and adhesive or other structures can be added between them to achieve an axially sealed connection between the motor end cover and the annular injection molded body.

[0022] Secondly, embodiments of this application provide a powertrain that includes a reducer or a transmission and any of the motors provided in the first aspect above, wherein the output shaft of the motor is coaxially connected to the input shaft of the reducer or the transmission.

[0023] Thirdly, embodiments of this application provide a vehicle including wheels, a transmission mechanism, and a powertrain as described in the second aspect above. The powertrain drives the wheels through the transmission mechanism. This vehicle can be an electric vehicle or a hybrid vehicle. The application of the aforementioned powertrain helps ensure the smooth and safe operation of the vehicle. Attached Figure Description

[0024] Figure 1 is a structural schematic diagram of a vehicle provided in an embodiment of this application;

[0025] Figure 2 is a structural schematic diagram of a powertrain provided in an embodiment of this application;

[0026] Figure 3a is a schematic diagram of the structure of a motor provided in an embodiment of this application;

[0027] Figure 3b is an exploded view of an electric motor provided in an embodiment of this application;

[0028] Figure 3c is a cross-sectional structural diagram of a motor provided in an embodiment of this application;

[0029] Figure 4 is a schematic diagram of the structure of a ring-shaped injection molded body of an electric motor provided in an embodiment of this application;

[0030] Figure 5a is a schematic diagram of the structure of an annular injection molded body and stator core of an electric motor provided in an embodiment of this application;

[0031] Figure 5b is a partial cross-sectional view of the annular injection-molded body of an electric motor and the winding slot provided in an embodiment of this application;

[0032] Figure 6 is a schematic diagram of the stator structure of an electric motor provided in an embodiment of this application;

[0033] Figure 7 is a simplified cross-sectional view of a stator and housing of an electric motor according to an embodiment of this application;

[0034] Figure 8a is an exploded view of an electric motor provided in an embodiment of this application;

[0035] Figure 8b is a cross-sectional structural diagram of a motor provided in an embodiment of this application;

[0036] Figure 9 is a schematic diagram of the structure of a ring-shaped injection molded body of a motor provided in an embodiment of this application;

[0037] Figure 10a is a schematic diagram of the structure of an annular injection molded body and stator core of an electric motor provided in an embodiment of this application;

[0038] Figure 10b is a partial cross-sectional view of the annular injection-molded body of an electric motor and the winding slot provided in an embodiment of this application;

[0039] Figure 11 is a schematic diagram of the stator structure of an electric motor provided in an embodiment of this application;

[0040] Figure 12 is a simplified cross-sectional view of a stator and housing of an electric motor according to an embodiment of this application;

[0041] Figure 13a is a schematic diagram of the structure of an annular injection molded body of a motor provided in an embodiment of this application;

[0042] Figure 13b is a simplified cross-sectional view of a stator and housing of an electric motor according to an embodiment of this application;

[0043] Figure 14a is a schematic diagram of the structure of an annular injection molded body of a motor provided in an embodiment of this application;

[0044] Figure 14b is a simplified cross-sectional view of a stator and housing of an electric motor according to an embodiment of this application;

[0045] Figure 15 is a schematic diagram of the structure of an annular injection molded body of a motor provided in an embodiment of this application;

[0046] Figure 16 is a schematic diagram of the structure of a stator core of an electric motor provided in an embodiment of this application;

[0047] Figure 17 is a schematic diagram of the structure of an annular injection molded body of a motor provided in an embodiment of this application;

[0048] Figure 18a is a schematic diagram of the structure of a ring-shaped injection molded body of an electric motor and a stator core according to an embodiment of this application;

[0049] Figure 18b is a magnified view of the details at point V in Figure 18a;

[0050] Figure 19a is a partial cross-sectional view of the structure of the annular injection molded body of an electric motor and the stator core provided in an embodiment of this application.

[0051] Figure 19b is a partial cross-sectional view of the structure of the annular injection molded body of an electric motor and the stator core provided in an embodiment of this application.

[0052] Figure 20 is a simplified cross-sectional view of a stator and housing of an electric motor provided in an embodiment of this application.

[0053] Reference numerals: 1000-Powertrain; 2000-Transmission mechanism; 3000-Wheel; 100-Motor; 200-Motor controller; 300-Reducer; 10-Stator; 20-Housing; 201-Stator sleeve; 202-Motor end cover; 2021-Annular protrusion; 2022-Bearing slot; 30-Rotor; 301-Bearing; 1-Stator core; 11-Center hole; 12-Winding slot; 121-Slot opening; 101-First stator lamination; 102-Second stator lamination; 2-Stator winding; 3-Annular injection molded body; 31-Embedded section; 32-Exposed section; 321-Annular section; 322-Extension section; K - Liquid outlet; S - Receiving cavity; d - Axial end face; g - Through hole; j - Liquid inlet; n - Liquid cooling hole; t1 - Axial liquid cooling channel; t2 - Circumferential liquid cooling channel; p - Through hole; q1 - Axial flow channel; q2 - Radial flow channel. Detailed Implementation

[0054] In recent years, environmental pollution and energy shortages have accelerated the development and utilization of green and renewable energy. Electric vehicles, with their advantages of low pollution, low noise, and high energy efficiency, are becoming increasingly popular with users, and their market share is increasing year by year. The stator windings of a drive motor generate a rotating magnetic field when energized, which interacts with the rotor magnetic field to produce torque, thus driving the electric vehicle. Existing drive motor stator windings are generally round or flat wire windings, and their cooling methods include housing water cooling and oil spray cooling. Specifically, housing water cooling involves arranging water channels inside the housing outside the stator. The heat from the stator windings is transferred radially to the housing through the stator core after being insulated by the winding slots, thus providing indirect cooling. Oil spray cooling involves arranging oil spray rings or oil pipes at both ends of the motor stator windings to spray oil onto the end windings, carrying away the heat from the stator windings, thus providing direct cooling. Compared to housing water cooling, end oil spraying reduces the thermal resistance between the windings and the coolant, improving cooling efficiency and continuous power. With the increasing demand for miniaturization of motors and higher continuous power, there is a need to further improve the heat dissipation and cooling effect of motors.

[0055] Based on this, embodiments of this application provide an immersion liquid-cooled motor, powertrain, and vehicle. The stator windings of the motor can be immersed in liquid cooling, thereby achieving a better liquid cooling effect, which is beneficial for the miniaturization of the motor and the improvement of continuous power.

[0056] To make the objectives, technical solutions, and advantages of this application clearer, the application will now be described in further detail with reference to the accompanying drawings.

[0057] Figure 1 is a structural schematic diagram of a vehicle provided in an embodiment of this application. As shown in Figure 1, the vehicle is a wheeled device driven or towed by a power unit, such as a pure electric vehicle (pure EV / battery EV), a hybrid electric vehicle (HEV), a range-extended electric vehicle (REEV), or a plug-in hybrid electric vehicle (PHEV). The vehicle includes a powertrain 1000, a transmission mechanism 2000, and wheels 3000. The powertrain 1000 drives the wheels 3000 through the transmission mechanism 2000. The powertrain 1000 converts electrical energy into mechanical energy. The transmission mechanism 2000 connects the powertrain 1000 and the wheels 3000. The vehicle also includes a frame to withstand the loads of the internal and external environment and a battery for supplying power to the powertrain 1000.

[0058] Figure 2 is a schematic diagram of the powertrain 1000 provided in an embodiment of this application. As shown in Figure 2, the powertrain 1000 includes a motor 100 and a motor controller 200, wherein the motor 100 is a flat-wire motor. The motor controller 200 is used to convert the DC power supplied by the battery into AC power and deliver the AC power to the motor 100. In one embodiment, the powertrain 1000 also includes a reducer 300, and the power output end of the motor 100 is connected to the vehicle wheels 3000 through the reducer 300. The reducer 300 can also be called a transmission. The motor 100 of an electric vehicle is typically a permanent magnet synchronous or AC asynchronous motor.

[0059] During motor operation, the resistance generated by the current flowing through the flat wire winding of the motor causes energy loss, which is converted into heat, causing the temperature of the flat wire winding to rise continuously. If the flat wire winding cannot be cooled in time, it will not only damage the service life of the flat wire winding and reduce the working efficiency of the motor, but also pose a risk of electrical failure and safety accidents.

[0060] Figure 3a shows the motor 100 housing 20 and the stator 10 and rotor 30 housed within the housing 20 according to an embodiment of this application. Parts of the stator 10 and rotor 30 are concealed within the housing 20 and are not shown. The rotor shaft of the rotor 30 extends out of the housing 20 along the axial direction of the motor for power output. It can be understood that the rotor shaft of the rotor 30 is also equivalent to the motor shaft of the motor 100. For ease of illustration, the axial direction of the motor 100 is referred to by the abbreviation A.

[0061] Figure 3b is an exploded view of the motor 100. As shown in Figure 3b, the housing 20 of the motor 100 includes a stator sleeve 201 and a motor end cover 202. In one embodiment, the stator sleeve 201 is a cylindrical structure with one open end, and the motor end cover 202 is similar to a circular plate. The motor end cover 202 is used to cooperate and fix with the open end of the stator sleeve 201 to enclose and form a motor cavity. In some embodiments, the housing 20 may include one stator sleeve 201 and two motor end covers 202. The stator sleeve 201 is a cylindrical structure with both ends open, and the two motor end covers 202 may also be respectively cooperated and fixed at the two end openings of the stator sleeve 201 to enclose and form a motor cavity.

[0062] As shown in Figure 3b, a portion of the stator 10 and rotor 30 can be accommodated within the motor cavity of the housing 20. The stator 10 includes a stator core 1, a stator winding 2, and an annular injection-molded body 3. The stator winding 2 can be a flat wire winding or a round wire winding. This application does not limit the specific structural form of the stator winding 2; a simplified schematic diagram of the stator winding 2 is provided here. The annular injection-molded body 3 is an integral injection-molded structure. The stator winding 2 and the annular injection-molded body 3 are fixed to the stator core 1. The rotor 30 is rotatably mounted on the housing 20 at both ends along the axial direction of the motor 100. The stator 10 can generate a magnetic field capable of driving the rotor 30 to rotate.

[0063] In this embodiment, the axial direction of the stator, the axial direction of the stator core, and the axial direction of the motor refer to the same direction; the circumferential direction of the stator, the circumferential direction of the stator core, and the circumferential direction of the motor refer to the same direction; and the radial direction of the stator, the radial direction of the stator core, and the radial direction of the motor refer to the same direction.

[0064] In one embodiment, the surface of the motor end cover 202 facing the stator sleeve 201 includes an annular protrusion 2021 and a bearing groove 2022, with the annular protrusion 2021 surrounding the bearing groove 2022. The annular protrusion 2021 engages with the stator 10 along the motor's axial direction, while the bearing groove 2022 is used to drively connect the rotor shaft of the rotor 30 via a bearing 301. Specifically, the outer ring of the bearing 301 is fixed within the bearing groove 2022, and the inner ring of the bearing 301 is drively connected to the rotor shaft of the rotor 30.

[0065] When the motor 100 is assembled, as shown in Figure 3c, which is a cross-sectional view of the motor 100, the outer circumferential surface of the stator core 1 of the stator 10 is fixed to the inner wall of the stator sleeve 201 by means of adhesive or other methods. The two axial ends of the rotor 30 are rotatably mounted on the motor end cover 202 and the stator sleeve 201 respectively by bearings 301. The housing 20 can provide a certain degree of protection for the stator 10 and the rotor 30, and also provides positioning and support for the installation of the stator 10 and the rotor 30. Along the axial direction of the motor, one axial end of the stator 10 is adjacent to a motor end cover 202 along the axial direction of the motor, and the other axial end of the stator 10 is adjacent to the end of the stator sleeve 201 away from the motor end cover 202 along the axial direction of the motor. In this embodiment, one end of the annular injection-molded body 3 of the stator 10 is connected to the annular protrusion 2021 of the motor end cover 202, so that one end of the stator 10 and the motor end cover 202 can form a receiving cavity R. This receiving cavity R can contain coolant to immerse and liquid-cool the end of the stator winding 2 on that side. This receiving cavity R can immerse and liquid-cool the end of the stator winding 2, thereby improving the winding cooling effect of the motor 100, increasing the efficiency of the motor 100, and improving the safety performance of the equipment using the motor 100. In one embodiment, the coolant is any one of ethylene glycol-based cooling oil, synthetic oil, and mineral oil.

[0066] In some embodiments, the other end of the annular injection-molded body 3 of the stator 10 is connected to the stator sleeve 201, so that the other end of the stator 10 and the motor end cover 202 can form another receiving cavity R, which can contain coolant to immerse the end of the liquid-cooled stator winding 2 on the other side, thereby immersing both ends of the stator winding 2 in liquid cooling.

[0067] The motor 100 provided in this application embodiment forms a space at the end of the stator 10 that allows for immersion liquid cooling of the end of the stator winding 2. This eliminates the need for end cooling structures such as oil injection rings, shortens the end height of the stator 10, and facilitates miniaturization of the motor 100. Compared to the prior art, the structure is simpler, the cooling effect is better, manufacturing costs can be reduced, and the continuous power of the motor 100 can be increased.

[0068] It should be understood that, along the axial direction of the motor, one end of the stator winding 2 is a welded end, and the other end is a cross-line end. The welded end of the stator winding 2 is generally used for busbar routing. In order to adapt to the different structures at both ends of the stator winding 2, the shapes of the corresponding motor end cover 202 and stator sleeve 201 need to be adjusted accordingly, which will not be described in detail here.

[0069] The following embodiments will take a motor end cover 202 and a stator 10 to form a receiving cavity S as an example to illustrate the technical solution provided in this application that the motor 100 can immerse the end of the stator winding 2.

[0070] Figure 4 illustrates the structure of an annular injection-molded body 3 of a stator 10 according to an embodiment of this application. As shown in Figure 4, the annular injection-molded body 3 has an annular structure that can be adapted to the stator core 1. In one embodiment, the annular injection-molded body 3 includes two exposed sections 32 and a plurality of embedded sections 31 connected between the two exposed sections 32. Taking one end of the annular injection-molded body 3 along the axial direction of the motor as a reference, the exposed section 32 and the plurality of embedded sections 31 of the annular injection-molded body 3 are arranged adjacent to each other along the axial direction of the motor. The exposed section 32 is cylindrical, and the plurality of embedded sections 31 are formed on one side of the exposed section 32 along the axial direction of the motor. The plurality of embedded sections 31 of the annular injection-molded body 3 are arranged at intervals along the circumference of the motor. Along the radial direction of the motor, the outer diameter of each embedded section 31 is substantially consistent with the outer diameter of the exposed section 32. In the manufacturing of the motor 100, the annular injection-molded body 3 is integrally injection molded, and the exposed section 32 and the plurality of embedded sections 31 are an integral structure. The structural division here is only for structural illustration. Among them, the exposed section 32 is ring-shaped, and can be considered as a ring-shaped section.

[0071] Figure 5a is a schematic diagram of the mating structure between the annular injection-molded body 3 shown in Figure 4 and the stator core 1. As shown in Figure 5a, the stator core 1 includes a central hole 11 and multiple winding slots 12. The central hole 11 is used to accommodate the rotor of the motor 100. Along the axial direction of the motor, the central hole 11 and each winding slot 12 penetrate the stator core 1. The multiple winding slots 12 are arranged at intervals along the circumference of the motor and are used to fix the annular injection-molded body 3 and the stator windings 2. During the manufacturing process of the motor 100, the annular injection-molded body 3 is integrally injection-molded and fixed to the stator core 1 by in-mold injection molding. Each embedded segment 31 of the annular injection-molded body 3 is embedded and fixed in a winding slot 12 along the axial direction of the motor, and an exposed segment 32 is exposed on an axial end face d of the stator core 1 along the axial direction of the motor. Along the axial direction of the motor, the exposed segment 32 protrudes from the axial end face d of the stator core 1. Along the radial direction of the motor, the outer diameter of the exposed section 32 is larger than the diameter of the central hole 11 of the stator core 1. The exposed section 32 can partially cover the axial end face d of the stator core 1, thereby strengthening the connection and fixation between the annular injection molded body 3 and the stator core 1.

[0072] Figure 5b shows a partial cross-sectional structure of the embedded section 31 of the annular injection-molded body 3 after it is embedded radially into the winding slot 12 of the motor. As shown in Figure 5b, the width inside each winding slot 12 is greater than the width of the slot opening 121 of the winding slot 12 used to connect to the center hole 11. The embedded section 31 can be fixed only by filling the opening 121 of the winding slot 12 used to connect to the center hole 11. The embedded section 31 and the winding slot 12 can enclose a space for accommodating the stator winding 2. When the stator winding 2 is accommodated in the winding slot 12, insulating paper or other insulating materials need to be placed between the stator winding 2 and the inner wall of the winding slot 12. The embedded section 31 fills the slot opening 121 of the winding slot 12 radially along the motor. Under the premise of isolating the winding slot 12 from the center hole 11, it can save materials and reduce the weight of the motor 100, which is conducive to the miniaturization of the motor 100. For ease of illustration, the circumferential direction of the motor 100 is referred to by the abbreviation C.

[0073] In one embodiment, the embedded section 31 of the annular injection molded body 3 does not protrude from the center hole 11 of the stator core 1 along the radial direction of the motor. Each embedded section 31 is embedded in the winding slot 12 along the axial direction of the motor during injection molding. The embedded section 31 will not extend into the center hole 11 and affect the assembly of the stator 10 and the rotor.

[0074] Figure 6 illustrates the structure of the stator 10. As shown in Figure 6, the stator winding 2 is wound around the stator core 1 and extends out of one axial end face d of the stator core 1. Along the axial direction of the motor, the height at which the end winding of the stator winding 2 protrudes from this axial end face d is lower than the height at which the exposed section 32 protrudes from this axial end face d. Along the radial direction of the motor, the outer diameter of the portion of the exposed section 32 covering the axial end face d of the stator core 1 is smaller than the distance between the stator winding 2 in each winding slot 12 and the axis of the motor 100. When the exposed section 32 is connected to the housing 20, it does not affect the stator winding 2. In some embodiments, the structure of the stator winding 2 and the annular injection-molded body 3 at the other axial end face d of the stator core 1 can be similar to the structure shown in Figure 6.

[0075] Figure 7 is a partial structural cross-sectional view of the motor 100 provided in this embodiment of the application. The cross-section passes radially through a winding slot 12 of a stator core 1 and an embedded section 31 embedded in the winding slot 12. The rotor 30 is not shown here. As shown in Figure 7, taking a winding slot 12 as an example, an embedded section 31 of the annular injection molded body 3 is embedded radially into the slot opening of the winding slot 12 to enclose a space for accommodating the stator winding 2. The exposed section 32 exposes the axial end face d of the stator core 1. The division between the embedded section 31 and the exposed section 32 is shown by a dashed line. The stator winding 2 is partially accommodated in the winding slot 12 and extends axially from one axial end face d of the stator core 1. The portion of the stator winding 2 exposed on the axial end face d of the stator core 1 can be considered as the end winding of the stator winding 2. The stator winding 2 is isolated from the winding slot 12 and the embedded section 31 by insulating paper 4. Along the radial direction of the motor, exposed sections 32 are arranged between the stator winding 2 and the center hole 11. The outer diameter of the exposed sections 32 is smaller than the distance between the stator winding 2 and the axis of the motor 100. The exposed sections 32 do not affect the end of the stator winding 2 extending out of the stator core 1. By using the exposed sections 32 to isolate the stator winding 2 and the center hole 11, and by extending a certain height along the axial direction of the motor, the creepage distance between the center hole 11 and the stator winding 2 can be increased, thereby improving the safety of the motor 100. Along the axial direction of the motor, the height of the exposed sections 32 protruding from the axial end face d of the stator core 1 is greater than the height of the stator winding 2 protruding from the axial end face d of the stator core 1. When the exposed sections 32 are engaged with the motor end cover 202, the motor end cover 202 will not contact the end of the stator winding 2.

[0076] Referring to Figure 7, an annular protrusion 2021 of the motor end cover 202 extends axially into the inner ring of an exposed section 32. The exposed section 32 and the annular protrusion 2021 are arranged adjacent to each other radially. The inner circumferential surface of the exposed section 32 is used to engage and fix the annular protrusion 2021 with the outer circumferential surface of the annular protrusion 2021 radially. In some embodiments, the distance between the outer circumferential surface of the annular protrusion 2021 and the axis of the motor 100 is less than the distance between the inner circumferential surface of the exposed section 32 and the axis of the motor 100. The gap between the outer circumferential surface of the annular protrusion 2021 and the inner circumferential surface of the annular section 321 is used to accommodate a sealing ring, enhancing the sealing and fixing effect between them. A receiving cavity S is formed between the motor end cover 202 and an axial end face d of the stator core 1. The end of the stator winding 2 extends axially from the winding slot 12 and passes through the exposed section 32 into the receiving cavity S.

[0077] In some embodiments, along the motor axial direction, the length of the exposed section 32 protruding from an axial end face d is greater than the length of an annular protrusion 2021 protruding from a motor end cover 202. The end of the exposed section 32 facing the motor end cover 202 abuts against the motor end cover 202, realizing the axial connection between the annular injection molded body 3 and the motor end cover 202. The length of the stator winding 2 passing through the exposed section 32 is less than the length of the annular protrusion 321, so the motor end cover 202 will not contact the end of the stator winding 2, thereby ensuring the function of the stator winding 2. In some embodiments, adhesive or other materials can be filled between the motor end cover 202 and the end of the exposed section 32 facing the motor end cover 202 to enhance the sealing and fixation between them along the motor axial direction.

[0078] Figure 8a illustrates an exploded view of another type of motor 100, in which the annular injection body 3 structure differs from the annular injection body 3 structure of the motor 100 shown in Figure 3b.

[0079] When the motor 100 is assembled, as shown in Figure 8b, a cross-sectional view of the motor 100 is provided. Along the motor's axial direction, one end of the annular injection-molded body 3 of the stator 10, protruding from the axial end face d of the stator core 1, connects to the annular protrusion 2021 of the motor end cover 202. This allows one end of the stator 10 and the motor end cover 202 to enclose a receiving cavity S, which can contain coolant to immerse the end of the liquid-cooled stator winding 2 on that side. In one embodiment, the portion of the annular injection-molded body 3 protruding from the axial end face d of the stator core 1 along the motor's axial direction extends radially along the motor, allowing the annular injection-molded body 3 to partially cover the axial end face d of the stator core 1. The portion of the stator winding 2 protruding from the stator core 1 passes through the annular injection-molded body 3 and enters the receiving cavity S.

[0080] Figure 9 illustrates the structure of an annular injection-molded body 3 of a stator 10 according to an embodiment of this application. As shown in Figure 9, the annular injection-molded body 3 includes two exposed sections 32 and a plurality of embedded sections 31 connected between the two exposed sections 32. The plurality of embedded sections 31 included in the annular injection-molded body 3 are arranged at intervals along the circumference of the motor, and each embedded section 31 is used to be embedded in a winding slot 12 of the stator core 1 along the axial direction of the motor. In one embodiment, each embedded section 31 is in the shape of a pipe. Taking one end of the annular injection-molded body 3 along the axial direction of the motor as a reference, the exposed section 32 includes an annular section 321 and an extension section 322. The extension section 322 extends radially along the motor and connects to each embedded section 31. The annular section 321 extends axially along the motor, and a step is formed between the outer peripheral surface of the annular section 321 and the surface of the extension section 322 facing away from the plurality of embedded sections 31. Along the circumference of the motor, the channel formed by the enclosure of each embedded section 31 communicates with one side of the outer peripheral surface of the annular section 321.

[0081] In one embodiment, the extension 322 of the exposed section 32 includes a plurality of through holes g, which are spaced apart circumferentially along the motor, and each through hole g passes through the extension 322 axially along the motor to communicate with the internal space of an embedded section 31.

[0082] Figure 10a is a schematic diagram of the mating structure between the annular injection molded body 3 shown in Figure 9 and the stator core 1. As shown in Figure 10a, the annular injection molded body 3 is integrally injection molded and fixed to the stator core 1 through an in-mold injection molding process. Each embedded segment 31 of the annular injection molded body 3 is embedded and fixed in a winding slot 12 along the axial direction of the motor, and an exposed segment 32 is exposed along the axial direction of the motor at one axial end face d of the stator core 1. Taking one axial end face d of the stator core 1 as an example, the annular segment 321 of the exposed segment 32 extends along the axial direction of the motor to expose the axial end face d of the stator core 1, and the extension segment 322 of the exposed segment 32 extends radially along the motor and partially covers the axial end face d of the stator core 1. Along the axial direction of the motor, the height of the annular segment 321 exposed above the axial end face d of the stator core 1 is greater than the height of the extension segment 322 exposed above the axial end face d of the stator core 1. Along the radial direction of the motor, the outer diameter of the extension segment 322 is greater than the distance between the bottom of the winding slot 12 and the axis of the motor 100 and less than or equal to the radial dimension of the outer circumferential surface of the stator core 1. Alternatively, the outer circumferential surface of the extension segment 322 can be considered to be located between the outer circumferential surface of the stator core 1 and the bottom of the winding slot 12. Figure 10b shows a partial cross-sectional structure of the embedded segment 31 of the annular injection molded body 3 after it is embedded into the winding slot 12 along the radial direction of the motor. As shown in Figure 10b, when an embedded segment 31 of the annular injection molded body 3 is embedded into a corresponding winding slot 12 of the stator core 1, the embedded segment 31 extends along the slot wall of the winding slot 12, covering the inner wall of the winding slot 12 and filling the opening 121 of the winding slot 12 for connecting the central hole 11. The channel formed by the embedded segment 31 is isolated from the central hole 11, and the space formed by the embedded segment 31 is used to accommodate the stator winding 2.

[0083] In one embodiment, referring to Figures 10a and 10b, along the radial direction of the motor, the size of each through-hole g is greater than or equal to the size of each winding slot 12, and the distance between two adjacent through-holes g along the circumferential direction of the motor is less than or equal to the distance between two corresponding adjacent winding slots 12. The larger through-hole g, while connecting the internal space of an embedded section 31, can avoid the stator winding 2 protruding from the winding slot 12.

[0084] In one embodiment, after an embedded segment 31 is embedded in a winding slot 12 and covers the slot wall of the winding slot 12, the cross-sectional dimension of the space enclosed by the embedded segment 31 is smaller than the cross-sectional dimension of the winding slot 12. Here, the size of the through hole p of the exposed segment 32 along the radial direction of the motor can be greater than or equal to the size of the embedded segment 31, and the distance between two adjacent through holes p along the circumferential direction of the motor can be less than or equal to the distance between two corresponding adjacent embedded segments 31, which can also meet the requirement of avoiding the stator winding 2 protruding from the winding slot 12.

[0085] Figure 11 illustrates the structure of the stator 10. As shown in Figure 1, when the stator winding 2 is wound around the stator core 1, the stator winding 2 extends through the embedded section 31 and protrudes from one axial end face d of the stator core 1. The end of the stator winding 2 is exposed through the through hole g of the extension section 322. Along the radial direction of the motor, the size of each through hole g is greater than or equal to the size of each winding slot 12, and the through hole g does not obstruct the extension of the stator winding 2. Along the circumferential direction of the motor, the distance between two adjacent through holes g is less than or equal to the distance between two corresponding adjacent winding slots 12. Along the axial direction of the motor, the height at which the end winding of the stator winding 2 protrudes from one axial end face d is lower than the height at which the annular section 321 of the exposed section 32 protrudes from the axial end face d. In some embodiments, the structure of the stator winding 2 and the annular injection-molded body 3 at the other axial end face d of the stator core 1 can be similar to the structure shown in Figure 11. In this stator 10, the embedded section 31 can act as an insulating material between the stator winding 2 and the winding slot 12 of the stator core 1, without the need for additional insulating materials such as insulating paper.

[0086] Figure 12 is a partial structural cross-sectional view of the motor 100 provided in an embodiment of this application. The cross-section passes radially through a winding slot 12 of a stator core 1 and an embedded section 31 embedded in the winding slot 12. The rotor 30 is not shown here. As shown in Figure 12, taking a winding slot 12 as an example, an embedded section 31 of the annular injection-molded body 3 is embedded radially into the winding slot 12 and covers the inner wall of the winding slot 12. The inner wall of the embedded section 31 encloses a space for accommodating the stator winding 2. The stator winding 2 passes axially through the embedded section 31 and is exposed by an extension 322 of the exposed section 32. The portion of the stator winding 2 exposed on the axial end face d of the stator core 1 can be considered as the end winding of the stator winding 2. Along the radial direction of the motor, the annular segment 321 of the exposed section 32 is arranged between the stator winding 2 and the center hole 11. The outer diameter of the annular segment 321 is smaller than the distance between the stator winding 2 and the axis of the motor 100, and the exposed section 32 does not affect the end of the stator winding 2 extending out of the stator core 1. Along the axial direction of the motor, the height of the exposed section 32 protruding from the axial end face d of the stator core 1 is greater than the height of the stator winding 2 protruding from the axial end face d of the stator core 1. When the exposed section 32 mates with the motor end cover 202, the motor end cover 202 will not contact the end of the stator winding 2. The distance between the outer peripheral surface of the extension section 322 and the axis of the motor 100 is greater than the bottom of the winding slot 12, and the extension section 322 can cover a portion of the axial end face d of the stator core 1 along the axial direction of the motor.

[0087] Referring to Figure 12, an annular protrusion 2021 of the motor end cover 202 extends axially into the inner ring of an exposed section 32. The exposed section 32 and the annular protrusion 2021 are arranged adjacent to each other radially. The inner circumferential surface of the exposed section 32 is used to engage and fix the annular protrusion 2021 radially with the outer circumferential surface of the annular protrusion 2021. A receiving cavity S is formed between the motor end cover 202 and an axial end face d of the stator core 1. The end of the stator winding 2 extends axially from the winding slot 12 and passes through the exposed section 32 into the receiving cavity S. When the receiving cavity S is filled with coolant, the coolant can immerse and liquid cool the end winding of the stator winding 2.

[0088] Considering the manufacturing process and production costs, the ring-shaped injection molded body 3 may also have other structural forms.

[0089] In one embodiment, as shown in FIG13a, a ring-shaped injection molded body 3 has multiple embedded segments 31, which are the same as those shown in FIG9 of the above embodiment. Each embedded segment 31 is used to embed into a winding slot 12 along the radial direction of the motor and cover the inner wall of the winding slot 12. The exposed segment 32 included in the ring-shaped injection molded body 3 is the same as those shown in FIG4 of the above embodiment, and the exposed segment 32 is equivalent to an annular segment. Along the radial direction of the motor, the outer diameter of each embedded segment 31 is larger than the outer diameter of the annular segment 321. Along the axial direction of the motor, the space enclosed by each embedded segment 31 is connected to the space on one side of the outer peripheral surface of each exposed segment 32.

[0090] Figure 13b is a simplified cross-sectional view of a portion of the motor 100 including the annular injection-molded body 3. When the annular injection-molded body 3 and the stator core 1 are injection-molded, each embedded section 31 is embedded radially into a winding slot 12 and fixedly covers the inner wall of the winding slot 12. The stator winding 2 accommodated in the winding slot 12 is specifically accommodated within the space enclosed by the embedded section 31. The exposed section 32 is connected and fixed to the motor end cover 202, and a receiving cavity S is formed between the motor end cover 202, the stator sleeve 201 and the axial end face d of the stator core 1. The end of the stator winding 2 passes through the embedded section 31 axially and enters the receiving cavity S.

[0091] In one embodiment, as shown in FIG14a, a ring-shaped injection molded body 3 has multiple embedded segments 31, which are the same as those shown in FIG4 of the above embodiment. Each embedded segment 31 is used to be embedded into the slot 121 of a winding slot 12 along the radial direction of the motor. The exposed segment 32 included in the ring-shaped injection molded body 3 is the same as those shown in FIG9 of the above embodiment. The exposed segment 32 includes an annular segment 321 and an extension segment 322. The extension segment 322 includes multiple through holes g arranged at intervals along the circumference of the motor. Each through hole g passes through the annular segment 321 along the axial direction of the motor. Along the radial direction of the motor, the outer diameter of each embedded segment 31 is equivalent to the outer diameter of the annular segment 321, and the outer diameter of the extension segment 322 is larger than the outer diameter of the embedded segment 31 and the outer diameter of the annular segment 321. Along the axial direction of the motor, the through holes g are connected to the space on one side of the outer peripheral surface of the annular segment 321 and the space on one side of the outer peripheral surface of the embedded segment 31.

[0092] Figure 14b is a partial cross-sectional schematic diagram of the motor 100 including the annular injection molded body 3. When the annular injection molded body 3 is injection molded with the stator core 1, each embedded segment 31 is embedded into the slot 121 of a winding slot 12 along the radial direction of the motor and fixed. The extension segment 322 of the exposed segment 32 covers the axial end face d of the stator core 1 along the radial direction of the motor. Each through hole g is connected to a winding slot 12 along the axial direction of the motor. The exposed segment 32 is connected and fixed to the motor end cover 202, and a receiving cavity S is formed between the motor end cover 202, the stator sleeve 201 and the axial end face d of the stator core 1. The stator winding 2 contained in a winding slot 12 can extend into the receiving cavity S through the through hole g of the extension segment 322.

[0093] In some embodiments, an exposed section 32 of the annular injection molded body 3 covers an axial end face d of the stator core 1. To reduce the amount and weight of the annular injection molded body 3, as shown in Figure 15, the portion of the exposed section 32 of the annular injection molded body 3 covering the axial end face d of the stator core 1 may include one or more through holes p. Each through hole p extends along the axial direction of the motor through a portion of the exposed section 32 covering the axial end face. Unlike the through hole g of the annular injection molded body 3 described above, when the annular injection molded body 3 and the stator core 1 are injection molded, each through hole p here can be arranged between two winding slots 12. In Figure 15, only one through hole p is shown.

[0094] It should be understood that there is no necessary relationship between the through hole p and the through hole g. The exposed section 32 of the annular injection molded body 3 may only have the through hole g, as shown in Figure 9. Alternatively, the exposed section 32 of the annular injection molded body 3 may also have both the through hole p and the through hole g, as shown in Figure 15.

[0095] In some embodiments, the exposed section 32 of the annular injection molded body 3 covers the portion between the winding slots 12 on the axial end face d of the stator core 1. In this case, the exposed section 32 may only include through holes p. Based on this annular injection molded body 3, in one embodiment, each through hole p includes a notch along the radial direction of the motor, the notch of each through hole p facing away from a central hole 11 along the radial direction of the motor, and the notch can communicate with the outer peripheral surface of the exposed section 32 along the radial direction of the motor. Along the circumferential direction of the motor, the width of each notch is greater than the width of each winding slot 12, so adjacent notches in the circumferential direction can connect to form an exposed section 32 with a smaller radial dimension. When adjacent notches along the circumferential direction of the motor are connected, the structure of the exposed section 32 of the annular injection molded body 3 is similar to that shown in FIG. 4. This can be considered as one way of forming the exposed section 32 shown in FIG. 4.

[0096] In one embodiment, the stator core 1 provided in this application embodiment can be circulated with oil or water to cool the stator 10. The stator core 1 forms one or more liquid cooling channels, which can be connected to the receiving cavity S formed between the motor end cover 202 and the stator 10.

[0097] Figure 16 illustrates the structure of a stator core 1 according to an embodiment of this application. As shown in Figure 16, taking the overall structure of the stator core 1 as a reference, the stator core 1 includes a central hole 11 and multiple winding slots 12. Along the axial direction of the motor, the central hole 11 penetrates the stator core 1, meaning that both ends of the central hole 11 are connected to two axial end faces d. Each winding slot 12 penetrates the stator core 1 along the axial direction of the motor, meaning that both ends of each winding slot 12 are connected to two axial end faces d. The multiple winding slots 12 are arranged at intervals along the circumference of the motor, and a stator tooth is formed between any two adjacent winding slots 12. The portion between the bottom of each winding slot 12 and the outer circumferential surface of the stator core 1 is the yoke of the stator. In one embodiment, the distance between any two winding slots 12 is approximately equal along the circumference of the motor, and the structure of the stator core 1 is centrally symmetrical along the circumference of the motor. In another embodiment, each winding slot 12 communicates with the central hole 11 along the radial direction of the motor.

[0098] Referring to Figure 16, the stator core 1 includes a plurality of stator laminations 101 arranged adjacent to each other along the axial direction of the motor. These stator laminations 101 can form liquid cooling channels in the stator core 1. Each stator lamination 101 includes at least one first stator lamination 101 and a plurality of second stator laminations 102, which are arranged adjacent to each other along the axial direction of the motor. The one or more stacked second stator laminations 102 can form one or more axial liquid cooling channels t1, each extending along the axial direction of the motor to two axial end faces d of the stator core 1. The at least one first stator lamination 101 forms a circumferential liquid cooling channel t2, which communicates with the outer circumferential surface of the stator core 1 and extends circumferentially along the motor. One or more axial liquid cooling channels t1 communicate with the circumferential liquid cooling channel t2. Coolant is directed to the one or more axial liquid cooling channels t1 by introducing coolant into the circumferential liquid cooling channel t2. These one or more axial liquid cooling channels t1 direct the coolant to the two axial end faces d of the stator core 1. The plurality of axial liquid cooling channels t1 and the circumferential liquid cooling channel t2 together form the liquid cooling channel of the stator core 1.

[0099] The aforementioned circumferential liquid cooling channel t2 can be formed by a single first stator lamination 101 or by a combination of multiple first stator laminations 101. When the stator core 1 includes multiple first stator laminations 101, the structures of the multiple first stator laminations 101 can be the same or different, as long as they can form a circumferential liquid cooling channel t2 that is connected to the axial liquid cooling channel t1.

[0100] In some embodiments, multiple second stator laminations 102 are stacked and arranged between two sets of first stator laminations 101 along the axial direction of the motor. Each set of second stator laminations 102 includes one second stator lamination 102 or multiple stacked first stator laminations 101. Each set of second stator laminations 102 forms one or more axial liquid cooling channels t1. One axial liquid cooling channel t1 formed by one set of second stator laminations 102 communicates with another axial liquid cooling channel t1 formed by another set of second stator laminations 102 through holes on multiple second stator laminations 102. When the coolant enters any one of the axial liquid cooling channels t1 along the circumferential liquid cooling channel t2, the coolant will be divided into two parts along the axial direction of the motor. One part flows along the axial liquid cooling channel t1 formed by one set of second stator laminations 102 to one axial end face d of the stator core 1, and the other part flows along the axial liquid cooling channel t1 formed by another set of second stator laminations 102 to the other axial end face d of the stator core 1.

[0101] When the annular injection molded body 3 is injection molded with the stator core 1 shown in Figure 16, the exposed section 32 of the annular injection molded body 3 has a hole communicating with the axial liquid cooling channel t1 of the stator core 1, so as to guide the coolant to the receiving cavity S at one axial end face d of the stator core 1 for immersion liquid cooling of the end of the stator winding 2. In some embodiments, the channel formed after the embedded section 31 of the annular injection molded body 3 is embedded in the winding slot 12 can communicate with the circumferential liquid cooling channel t2 of the stator core 1, so as to guide the coolant into the winding slot 12 for immersion liquid cooling of the part of the stator winding 2 accommodated in the winding slot 12.

[0102] In some embodiments, Figure 17 shows the structure of an annular injection-molded body 3 of a stator 10 provided in an embodiment of this application. As shown in Figure 17, the annular injection-molded body 3 has a structure similar to that shown in Figure 9. The annular injection-molded body 3 includes a plurality of embedded segments 31 arranged at intervals along the circumference of the motor. Each embedded segment 31 is used to embed into a winding slot 12 of the stator core 1 along the axial direction of the motor and cover the inner wall of the winding slot 12. Each embedded segment 31 is in the shape of a pipe, and each embedded segment 31 encloses to form an axial flow channel q1 extending along the axial direction of the motor. Each embedded segment 31 also includes at least one radial flow channel q2, and each radial flow channel q2 communicates with an axial flow channel q1 along the radial direction of the motor. An exposed section 32 of the annular injection-molded body 3 includes an annular segment 321 and an extension segment 322. The annular segment 321 is used to cooperate with the motor end cover 202 or the stator sleeve 201 to enclose and form a receiving cavity S. The outer diameter of the extension segment 322 is larger than the outer diameter of any embedded segment 31. The extension section 322 includes a plurality of through holes g, which are spaced apart circumferentially along the motor. Each through hole g passes through the extension section 322 axially along the motor to communicate with an axial flow channel q1. The extension section 322 also includes a plurality of liquid cooling holes n, which pass through the extension section 322 axially along the motor to communicate with an axial cooling channel t1 of the stator core 1.

[0103] Figure 18a shows the structure of the stator core 1 and the annular injection molded body 3 of a motor 100 according to an embodiment of this application, and Figure 18b is a detailed enlarged view of point V in Figure 18a. Referring to Figures 18a and 18b together, during the manufacturing process of the motor 100, the structure shown in Figure 18a can be obtained by integrally injection molding the annular injection molded body 3 to the stator core 1 through an in-mold injection molding process.

[0104] Referring to Figures 18a and 18b, the annular injection-molded body 3 includes multiple embedded segments 31 that are respectively embedded into multiple winding slots 12 of the stator core 1 along the axial direction of the motor. One embedded segment 31 is embedded in each winding slot 12. In one embodiment, each embedded segment 31 extends along the inner wall of the corresponding winding slot 12 and covers the inner wall of the winding slot 12, thus shielding the winding slot 12. The labels of the winding slots 12 shown in Figure 18a indicate the locations of the winding slots 12. An exposed segment 32 of the annular injection-molded body 3 exposes an axial end face d of the stator core 1 along the axial direction of the motor, and the extension segment 322 of the exposed segment 32 covers that axial end face d of the stator core 1. In this embodiment, along the radial direction of the motor, the inner diameter of the exposed section 32 is greater than or equal to the inner diameter of a central hole 11 of the stator core 1, and the outer diameter of the extension section 322 is greater than the distance between the bottom of the winding slot 12 and the axis of the motor 100 and less than the outer diameter of the stator core 1. The plurality of liquid cooling holes n are arranged at intervals along the circumference of the motor, and each liquid cooling hole n communicates with one or more axial liquid cooling channels t1 of the stator core 1 along the axial direction of the motor. A circumferential liquid cooling channel t2 can communicate with a liquid cooling hole n through one or more axial liquid cooling channels t1. In one embodiment, each liquid cooling hole n communicates with an axial liquid cooling channel t1, and the diameter of the liquid cooling hole n is greater than or equal to the diameter of the port of the corresponding axial liquid cooling channel t1 located on the axial end face d. In another embodiment, the extension section 322 of the exposed section 32 further includes a plurality of through holes g, each through hole g communicating with an axial flow channel q1 formed by an embedded section 31.

[0105] Referring to Figure 18b, a partial cross-sectional view of the stator core 1 and the annular injection-molded body 3 can be obtained by radially cutting the stator core 1 and the annular injection-molded body 3 at position P1. This cross-section passes through a winding slot 12 of the stator core 1 and an embedded section 31 embedded in the winding slot 12. As shown in Figure 8a, each embedded section 31 is embedded in a winding slot 12 and extends around the inner wall of the winding slot 12. The axial flow channel q1 formed by the embedded section 31 is isolated from the central hole 11 by a part of the structure of the embedded section 31. The axial flow channel q1 extends along the axial direction of the motor to the two axial end faces d of the stator core 1. Each embedded section 31 also includes a radial flow channel q2, which can connect the circumferential liquid cooling channel t2 of the stator core 1 and one or more axial flow channels q2 along the radial direction of the motor. The axial flow channel q1 formed by the embedded section 31 surrounds the stator winding 2 contained in the winding slot 12. When the coolant in the circumferential liquid cooling channel t2 enters the axial flow channel q1 formed by the embedded section 31 along the radial flow channel q2, the coolant can immerse the stator winding 2 contained in the winding slot 12 in the axial flow channel q1 for liquid cooling.

[0106] In one embodiment, each axial flow channel q1 extends along the axial direction of the motor to the exposed section 32 and communicates with a through hole g of the extension section 322. The axial flow channel q1 can communicate with the space on the side of the extension section 322 away from the axial end face d through the through hole g. The coolant can flow along the axial flow channel q1 to the side of the extension section 322 away from the axial end face d.

[0107] Referring to Figure 18b, a partial cross-sectional view of the stator core 1 and the annular injection molded body 3 can be obtained by cutting along the radial direction of the motor at position P2, as shown in Figure 19b. This cross-section passes through an axial liquid cooling channel t1 of the stator core 1 and a liquid cooling hole n of the annular injection molded body 3. As shown in Figure 19b, the axial liquid cooling channel t1 extends along the axial direction of the motor to the two axial end faces d of the stator core 1, and the axial liquid cooling channel t1 is connected to the liquid cooling hole n along the axial direction of the motor. Along the radial direction of the motor, a circumferential liquid cooling channel t2 extends to communicate with the axial liquid cooling channel t1.

[0108] Referring further to a partial cross-sectional structural diagram of an electric motor 100 shown in Figure 20, in one embodiment, the stator sleeve 201 includes a liquid inlet j extending radially through the stator sleeve 201. This liquid inlet j communicates radially with the circumferential liquid cooling channel t2 of the stator core 1. Coolant entering from the liquid inlet j can partially enter the axial liquid cooling channel t1 of the stator core 1 along the circumferential liquid cooling channel t2, and partially enter the axial flow channel q1 via the radial flow channel p2 of the annular injection molding body 3. Coolant in both the axial liquid cooling channel t1 and the axial flow channel q1 can enter the receiving cavity S to immerse and liquid cool the end windings of the stator winding 2. Coolant in the axial flow channel q1 can immerse and liquid cool the stator winding 2 contained within the axial flow channel q1.

[0109] In one embodiment, the motor end cover 202 further includes one or more outlets K for discharging coolant from a receiving cavity S. Along the radial direction of the motor, the axial distance between each outlet K and the motor end cover 202 is greater than the outer diameter of the annular protrusion 2021. The coolant in the receiving cavity S can be ejected through the outlets K on the motor end cover 202.

[0110] As shown in Figure 20, the stator 10 and the housing 20 of the motor 100 can form a relatively sealed chamber for immersion liquid cooling of the stator winding 2. Specifically, each embedded section 31 of the annular injection molded body 3 can be embedded in a winding slot 12 to form an axial flow channel q1, which can immerse the stator winding 2 contained in the winding slot 12 for liquid cooling. The exposed section 32 of the annular injection molded body 3 can be connected and fixed to the motor end cover 202 of the housing 20, thereby forming a receiving cavity S between the stator sleeve 201, the motor end cover 202, the exposed section 32, and an axial end face d of the stator core 1. This receiving cavity S can immerse the end of the stator winding 2 exposed from the stator core 1 for liquid cooling.

[0111] It should be understood that in the actual structure, the axial flow channel q1 and the axial liquid cooling channel t2 are misaligned along the circumference of the motor. Therefore, the axial liquid cooling channel t2 and the liquid cooling hole n connected to the axial liquid cooling channel t2 in Figure 20 are shown as dashed lines only to illustrate the flow direction of the coolant in the motor 100.

[0112] In summary, the motor 100 provided in this application embodiment, through the cooperation of the motor 100 housing 20 and the stator 10, can form a sealed chamber capable of immersing the stator winding 2 in liquid cooling, achieving good cooling of the stator winding 2 and thus improving the continuous power of the motor 100. Specifically, the annular injection molded body 3 and the stator core 1 are integrally injection molded, and the exposed section 32 of the annular injection molded body 3 is directly connected and fixed to the housing 20, which can shorten the end height of the stator and facilitate motor miniaturization. Compared with the oil injection ring end winding cooling scheme in the prior art, the structure is simpler, the cooling effect is better, production costs can be reduced, and the continuous power of the motor can be improved.

[0113] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A liquid-cooled immersion motor, characterized in that, The motor housing includes a stator sleeve and a motor end cover. The stator sleeve is used to fix the stator of the motor, and the motor end cover is used to enclose the stator sleeve to form a motor cavity, which is used to accommodate the stator and rotor of the motor. The stator includes a stator core, stator windings, and an integrally injection-molded annular injection-molded body. The stator core includes a central hole and multiple winding slots. The central hole extends through the stator core along the axial direction of the motor. The multiple winding slots are arranged at circumferential intervals along the stator. Each winding slot communicates with the central hole along the radial direction of the stator. The plurality of winding slots are used to fix the stator winding and the annular injection molded body, and one end of the stator winding is exposed on one axial end face of the stator core along the axial direction of the motor. The annular injection-molded body includes an embedded section and an exposed section. The exposed section and the embedded section are arranged adjacent to each other along the axial direction of the motor. The embedded section is used to embed into the plurality of winding slots along the radial direction of the motor. The exposed section is exposed on the axial end face along the axial direction of the motor. The exposed section is used to enclose the motor end cover, the stator sleeve and the axial end face to form a receiving cavity. The receiving cavity is used to receive coolant that submerges one end of the stator winding.

2. The motor as described in claim 1, characterized in that, Along the circumference of the motor, the width of each winding slot is greater than the width of the slot opening for connecting the central hole, and the embedded segment embedded in each winding slot fills the slot opening of each winding slot.

3. The motor as described in claim 2, characterized in that, Along the radial direction of the motor, the length of the embedded segment in each winding slot is less than or equal to the length of the slot opening.

4. The motor as described in claim 2, characterized in that, Along the radial direction of the motor, the embedded segment in each of the winding slots surrounds the stator winding accommodated by the winding slot along the inner wall of the winding slot.

5. The motor as described in any one of claims 1-4, characterized in that, The exposed section is used to cover a portion of the axial end face, and the outer diameter of the portion of the exposed section covering the axial end face is larger than the diameter of the central hole.

6. The motor as described in claim 5, characterized in that, Along the radial direction of the motor, the outer diameter of the portion of the exposed section covering the axial end face is smaller than the distance between the stator winding in each winding slot and the axis of the motor.

7. The motor as described in claim 5, characterized in that, The outer diameter of the portion of the exposed section covering the axial end face is greater than the distance between the bottom of each winding slot and the axis of the motor. One end of the stator winding passes through the portion of the exposed section covering the axial end face along the axis of the motor and is exposed on an axial end face of the stator core.

8. The motor as described in claim 7, characterized in that, The portion of the exposed section covering the axial end face includes a plurality of through holes, which are spaced apart circumferentially along the motor. Each through hole passes through the exposed section axially along the motor and communicates with a winding slot, wherein: The size of each through hole along the radial direction of the motor is greater than or equal to the size of each winding slot, and the distance between two adjacent through holes along the circumferential direction of the motor is less than or equal to the distance between two corresponding adjacent winding slots.

9. The motor as described in claim 7, characterized in that, Along the radial direction of the motor, the portion of the exposed section covering the axial end face includes a plurality of through holes, each of the through holes extending along the axial direction of the motor through the portion of the exposed section covering the axial end face, and each of the through holes being arranged between two winding slots.

10. The motor as described in claim 9, characterized in that, Along the radial direction of the motor, each of the through holes includes a notch, the notch of each of the through holes being oriented radially away from the central hole of the motor, and the width of each notch along the circumference of the motor being greater than the width of each of the winding slots.

11. The motor according to any one of claims 1-10, characterized in that, The stator core includes one or more liquid cooling channels, and the portion of the exposed section covering the axial end face includes a plurality of liquid cooling holes, each of the liquid cooling holes being used to connect the receiving cavity and at least one of the liquid cooling channels.

12. The motor according to any one of claims 1-11, characterized in that, The exposed section further includes an annular section, and the motor end cover includes an annular protrusion and a bearing groove, the annular protrusion surrounding the bearing groove, wherein: The annular protrusion is used to extend into the center hole of the annular segment along the axial direction of the motor, and the gap between the outer peripheral surface of the annular protrusion and the inner peripheral surface of the annular segment is used to accommodate a sealing ring. The bearing groove is used to fix the outer ring of a bearing, and the inner ring of a bearing is used to drive the motor shaft of the motor.

13. The motor as described in claim 12, characterized in that, Along the axial direction of the motor, the length of the annular segment protruding from the axial end face is greater than the length of the annular boss protruding from the motor end cover.

14. A powertrain, characterized in that, The powertrain includes a reduction gear or a transmission and an electric motor as described in any one of claims 1-13; The output shaft of the motor is coaxially connected to the input shaft of the reducer or the transmission.

15. A vehicle, characterized in that, The vehicle includes wheels, a transmission mechanism, and a powertrain as described in claim 14, the powertrain driving the wheels via the transmission mechanism.

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