CN119628325A

CN119628325A - An immersion liquid-cooled motor, powertrain and vehicle

Info

Publication number: CN119628325A
Application number: CN202411589685.8A
Authority: CN
Inventors: 余国权; 丛奇; 石超杰
Original assignee: Huawei Digital Power Technologies Co Ltd
Current assignee: Huawei Digital Power Technologies Co Ltd
Priority date: 2024-11-07
Filing date: 2024-11-07
Publication date: 2025-03-14

Abstract

The application relates to the technical field of motors, in particular to an immersed liquid-cooled motor, a power assembly and a vehicle. The stator of the motor comprises a stator core, a stator winding and an integral injection molding annular injection molding body, wherein the annular injection molding body comprises a plurality of embedded sections and an exposed section, the exposed section and the embedded sections are adjacently arranged along the axial direction of the motor, each embedded section is used for embedding a winding groove along the radial direction of the motor, one exposed section is exposed out of one axial end face along the axial direction of the motor, one exposed section is used for enclosing one motor end cover, one stator sleeve and one axial end face to form an accommodating cavity, and one accommodating cavity is used for accommodating one end of the cooling liquid immersed stator winding. The annular injection molding body is fixedly connected with the motor end cover of the motor shell, a containing cavity is formed between one end part of the stator and the shell, the end winding of the stator winding is immersed and cooled, the cooling effect on the stator winding is enhanced, and the power of the motor is improved.

Description

Submerged liquid cooled motor, power assembly and vehicle

Technical Field

The application relates to the technical field of motors, in particular to an immersed liquid-cooled motor, a power assembly and a vehicle.

Background

Loss of the motor stator windings is an important heat generating source of the motor and affects the motor efficiency. The temperature of the winding can be reduced by oil or water flowing to the motor stator, so that the heat loss of the motor is reduced, and the motor efficiency is improved.

However, the current heat dissipation mode of the motor cannot meet the requirements of miniaturization and high continuous power requirements of the motor.

Disclosure of Invention

The application provides an immersed liquid-cooled motor, a power assembly and a vehicle, wherein the motor forms a structure capable of directly immersing a winding in liquid by injection molding of a stator core and an annular injection molding body, so that the cooling effect of the motor can be enhanced, and the power requirement of the motor is met.

In a first aspect, an embodiment of the application provides an immersed-liquid cooled motor, the motor comprising a stator sleeve and a motor end cover, the stator sleeve being used for fixing a stator of the motor, the motor end cover being used for surrounding a stator sleeve to form a motor cavity, the motor cavity being used for accommodating a stator and a rotor of the motor, the stator comprising a stator core, a stator winding and an integrally injection-molded annular injection body, the stator core comprising a central hole and a plurality of winding slots, the central hole penetrating the stator core in an axial direction of the motor, the winding slots being arranged at intervals in a circumferential direction of the motor stator, each winding slot being in communication with the central hole in a radial direction of the motor stator, wherein the plurality of winding slots are used for fixing the stator winding and the annular injection body, one end of the stator winding being exposed to an axial end face of the stator core in an axial direction of the motor, the annular injection-molded body comprising a plurality of embedded sections and an exposed section being arranged adjacent to each other in an axial direction of the motor, one exposed section being used for surrounding the stator core in an axial direction of the motor to form an exposed end face of the stator and one end cover being used for accommodating an immersed-liquid.

According to the motor provided by the embodiment of the application, the annular injection molding body is fixedly connected with the motor end cover of the motor shell, so that a containing cavity is formed between one end part of the stator and the shell, and the end part of the stator winding can extend into the containing cavity. And the accommodating cavity is filled with cooling liquid, and the cooling liquid can cool the immersed liquid of the stator winding accommodated in the accommodating cavity part, so that the direct cooling of the stator winding end winding is realized. The exposed section of the annular injection molding body is directly connected and fixed with the shell, so that the end part height of the stator can be shortened, and the miniaturization of the motor is facilitated. Compared with the oil spraying ring end winding cooling scheme in the prior art, the oil spraying ring end winding cooling structure is simpler in structure and better in cooling effect, can reduce production cost and improve continuous power of a motor.

In one embodiment, the in-slot width of each winding slot is greater than the slot width of the slot opening of the winding slot for communication with the central bore in the circumferential direction of the motor, and the embedded segment embedded in each winding slot fills the slot opening of each winding slot. The embedded end is fixed in a mode of filling the slot opening of the winding slot, so that the connection and fixation between the annular injection molding body and the stator core can be enhanced.

In one embodiment, along the radial direction of the motor, the length of one embedded section embedded in each winding slot is smaller than or equal to the length of the notch, so that the bonding strength of the embedded section and the winding slot can be ensured, the material is saved, the production cost is reduced, and the weight of the motor is reduced.

In one embodiment, in the radial direction of the motor, an embedded segment embedded in each winding slot surrounds the stator winding accommodated in the winding slot along the inner wall of the winding slot, so that the connection fixation of the embedded segment and the winding slot can be enhanced.

In one embodiment, one exposed section is used for covering a part of the axial end face, and the outer diameter of the part of the exposed section covering the axial end face is larger than the diameter of one central hole, so that the connection fixation of the annular injection molding body and the stator core can be reinforced along the radial direction of the motor.

In one embodiment, an outer diameter of a portion of one of the exposed segments covering one of the axial end faces is smaller than a distance between the stator winding in each winding slot and an axis of the motor in a radial direction of the motor. The exposed section is arranged between the stator winding and the central hole along the radial direction of the motor, so that the creepage distance of the stator winding can be increased.

In one embodiment, the outer diameter of the part of one exposed section covering one axial end face is larger than the distance between the bottom of each winding slot and the axis of the motor, and one end of the stator winding passes through the part of one exposed section covering one axial end face along the axial direction of the motor and is exposed out of one axial end face of the stator core. The exposed section can cover a larger range of the axial end face of the stator core, so that the annular injection molding body and the stator core are combined and fixed more tightly.

In one embodiment, the part of one exposed section covering one axial end surface comprises a plurality of through holes, the through holes are arranged at intervals along the circumferential direction of the motor, each through hole penetrates through one exposed section along the axial direction of the motor and is communicated with one winding slot, wherein the size of each through hole along the radial direction of the motor is larger 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 smaller than or equal to the distance between two corresponding adjacent winding slots. The through holes can communicate the winding slots with the space of the exposed section, which is far away from one side of the stator core, so that the accommodating cavity is communicated with the winding slots, and cooling liquid in the accommodating cavity can enter the winding slots to cool the stator winding.

In one embodiment, a portion of one of the exposed segments covering one of the axial end faces in the radial direction of the motor includes a plurality of through holes each penetrating the portion of one of the exposed segments covering one of the axial end faces in the axial direction of the motor, each of the through holes being arranged between two of the winding slots. The arrangement of the through holes can reduce the dosage and the weight of the annular injection molding body.

In one embodiment, the exposed section of the annular injection molded body may have only through holes. The exposed section of the annular injection molded body may have both the through hole and the through hole, or the exposed section of the annular injection molded body may cover a portion between the winding slots of the axial end face of the stator core, and in this case, the exposed section may include only the through hole.

In one embodiment, each through hole comprises a notch along the radial direction of the motor, the notch of each through hole faces away from a central hole along the radial direction of the motor, the width of each notch along the circumferential direction of the motor is larger than the width of each winding slot, and circumferentially adjacent notches can be communicated to form an exposed section with smaller radial dimension.

In one embodiment, the stator core includes one or more liquid cooling channels, and a portion of the exposed section covering one axial end face includes a plurality of liquid cooling holes, each of the liquid cooling holes being configured to connect one of the receiving cavities and at least one of the liquid cooling channels such that the receiving cavity is capable of communicating with the at least one liquid cooling channel to form a liquid cooling system for the motor.

In one embodiment, the exposed section further comprises an annular section, the motor end cover comprises an annular bulge and a bearing groove, the annular bulge surrounds the bearing groove, the annular bulge is used for extending into a central hole of the annular section along the axial direction of the motor, a gap between the outer peripheral surface of the annular boss and the inner peripheral surface of the annular section is used for accommodating a sealing ring, the bearing groove is used for fixing an outer ring of a bearing, and an inner ring of the bearing is used for being in transmission connection with a motor shaft of the motor. The annular section of the exposed section can be matched with the annular bulge in a positioning way to realize the connection and fixation of the annular injection molding body and the motor end cover, so that the axial size of the motor is reduced.

In one embodiment, a length of one annular segment exposed to one axial end face is greater than a length of one annular protrusion protruding from one motor end cover along an axial direction of the motor. The end part of the annular section can be abutted with the motor end cover, and structures such as bonding glue can be added between the end part and the motor end cover, so that the motor end cover is axially and hermetically connected with the annular injection molding body.

In a second aspect, an embodiment of the present application provides a powertrain comprising one of a reducer or a transmission and any one of the motors provided in the first aspect above, wherein an output shaft of the motor is coaxially coupled to an input shaft of the reducer or the transmission.

In a third aspect, an embodiment of the present application provides a vehicle comprising wheels, a transmission, and a powertrain as provided in the second aspect above, the powertrain driving the wheels through the transmission. The vehicle can be an electric vehicle or a hybrid vehicle, and the application of the power assembly is beneficial to ensuring the stable and safe running of the vehicle.

Drawings

Fig. 1 is a schematic structural diagram of a vehicle according to an embodiment of the present application;

FIG. 2 is a schematic diagram of a powertrain according to an embodiment of the present application;

fig. 3a is a schematic structural diagram of a motor according to an embodiment of the present application;

FIG. 3b is an exploded view of a motor according to an embodiment of the present application;

Fig. 3c is a schematic cross-sectional structure of a motor according to an embodiment of the present application;

fig. 4 is a schematic structural view of an annular injection molding body of a motor according to an embodiment of the present application;

fig. 5a is a schematic structural diagram of an annular injection molding body and a stator core of a motor according to an embodiment of the present application;

fig. 5b is a schematic view of a partial cross-sectional structure of an annular injection molding body and winding slots of a motor according to an embodiment of the present application;

Fig. 6 is a schematic structural diagram of a stator of an electric motor according to an embodiment of the present application;

fig. 7 is a schematic cross-sectional view of a part of a stator and a casing of an electric motor according to an embodiment of the present application;

FIG. 8a is an exploded view of a motor according to an embodiment of the present application;

Fig. 8b is a schematic cross-sectional structure of a motor according to an embodiment of the present application;

Fig. 9 is a schematic structural view of an annular injection molding body of a motor according to an embodiment of the present application;

fig. 10a is a schematic structural diagram of an annular injection molding body and a stator core of a motor according to an embodiment of the present application;

fig. 10b is a schematic view of a partial cross-sectional structure of an annular injection molding body and winding slots of a motor according to an embodiment of the present application;

fig. 11 is a schematic structural diagram of a stator of an electric motor according to an embodiment of the present application;

Fig. 12 is a schematic cross-sectional view of a part of a stator and a casing of an electric motor according to an embodiment of the present application;

fig. 13a is a schematic structural view of an annular injection molding body of a motor according to an embodiment of the present application;

Fig. 13b is a schematic cross-sectional view of a portion of a stator and a housing of an electric machine according to an embodiment of the present application;

fig. 14a is a schematic structural view of an annular injection molding body of a motor according to an embodiment of the present application;

Fig. 14b is a schematic cross-sectional view of a portion of a stator and a housing of an electric machine according to an embodiment of the present application;

fig. 15 is a schematic structural view of an annular injection molding body of a motor according to an embodiment of the present application;

Fig. 16 is a schematic structural view of a stator core of an electric motor according to an embodiment of the present application;

FIG. 17 is a schematic structural view of an annular injection molded body of a motor according to an embodiment of the present application;

fig. 18a is a schematic structural diagram of a matching between an annular injection molding body and a stator core of a motor according to an embodiment of the present application;

FIG. 18b is an enlarged detail view at V in FIG. 18 a;

Fig. 19a is a schematic view of a partial cross-sectional structure of an annular injection molding body of a motor and a stator core according to an embodiment of the present application;

fig. 19b is a schematic view of a partial cross-sectional structure of an annular injection molding body of a motor and a stator core according to an embodiment of the present application;

fig. 20 is a schematic cross-sectional view of a portion of a stator and a housing of an electric machine according to an embodiment of the present application.

Reference numerals:

1000-power assembly, 2000-transmission mechanism, 3000-wheels;

100-motor, 200-motor controller, 300-speed reducer;

10-stator, 20-shell, 201-stator sleeve, 202-motor end cover, 2021-annular bulge, 2022-bearing groove, 30-rotor and 301-bearing;

1-stator core, 11-center hole, 12-winding slot, 121-notch, 101-first stator punching sheet, 102-second stator punching sheet, 2-stator winding;

3-ring-shaped injection molding body, 31-embedded section, 32-exposed section, 321-ring section, 322-extension section;

The device comprises a K-liquid outlet, an S-containing cavity, a d-axial end face, a g-through hole, a j-liquid inlet, an n-liquid cooling hole, a t 1-axial liquid cooling channel, a t 2-circumferential liquid cooling channel, a p-through hole, a q 1-axial flow channel and a q 2-radial flow channel.

Detailed Description

In recent years, environmental pollution and energy shortage accelerate the development and utilization of green renewable energy, and electric automobiles are increasingly popular with users due to the advantages of low pollution, low noise, high energy efficiency and the like, and the market share of the electric automobiles is also improved year by year. The stator winding of the driving motor is electrified to generate a rotating magnetic field, and the rotating magnetic field interacts with the rotor magnetic field to generate torque so as to drive the electric automobile to move. The stator winding of the existing driving motor is generally a round wire winding or a flat wire winding, and the cooling mode comprises shell water cooling and oil spraying cooling. Specifically, the water cooling of the casing is to arrange a water channel in the casing outside the stator, and heat of the stator winding is radially transferred to the casing for cooling through the stator core after being insulated by the winding grooves, so that the indirect cooling mode is realized. The oil spray cooling is to arrange oil spray rings or oil pipes at the two side ends of the motor stator winding, and the oil spray cooling is carried out on the end winding to take away the heat of the stator winding, so that the direct cooling mode is realized. Compared with the water cooling of the shell, the thermal resistance between the winding and the cooling liquid is reduced by the oil injection mode at the end part, and the cooling effect and the continuous power can be improved. With the miniaturization of motors and the demand for higher and higher continuous power, the heat dissipation and cooling effects of the motors need to be further improved.

Based on the above, the embodiment of the application provides an immersed liquid-cooled motor, a power assembly and a vehicle, wherein the stator winding of the motor can realize immersed liquid cooling, so that a better liquid cooling effect is achieved, and the miniaturization and continuous power improvement of the motor are facilitated.

In order to make the objects, technical solutions and advantages of the present application more apparent, the present application will be further described in detail with reference to the accompanying drawings.

Fig. 1 is a schematic structural diagram of a vehicle according to an embodiment of the present application, as shown in fig. 1, the vehicle is a wheeled device driven or towed by a power device, and is a pure electric vehicle (pure ELECTRIC VEHICLE/battery ELECTRIC VEHICLE, pure EV/battery EV), a Hybrid ELECTRIC VEHICLE (HEV), a Range Extended ELECTRIC VEHICLE (REEV), a plug-in hybrid ELECTRIC VEHICLE (PHEV), or the like. The vehicle includes a powertrain 1000, a transmission 2000, and wheels 3000. Powertrain 1000 drives wheels 3000 via a transmission 2000. Wherein the powertrain 1000 is configured to convert electrical energy into mechanical energy. The transmission mechanism 2000 is used for connecting the power assembly 1000 and the wheels 3000 in a transmission manner. Of course, the vehicle also includes a frame that supports the environmental loads inside and outside the vehicle and a battery for powering the powertrain 1000.

Fig. 2 is a schematic structural diagram of a powertrain 1000 according to an embodiment of the present application. As shown in fig. 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 direct current supplied from a battery into alternating current and to deliver the alternating current to the motor 100. In one embodiment, powertrain 1000 further includes a speed reducer 300, and the power output of motor 100 is drivingly connected to wheels 3000 of the vehicle through speed reducer 300. Among other things, the speed reducer 300 may also be referred to as a transmission. The motor 100 of the electric vehicle is typically a permanent magnet synchronous or an ac asynchronous motor.

During operation of the motor, the resistance created by the current flowing through the flat wire windings of the motor 100 causes energy losses, which are converted to heat, resulting in a constant increase in the temperature of the flat wire windings. If the flat wire winding cannot be cooled in time, the service life of the flat wire winding is not damaged, the working efficiency of the motor is reduced, and the safety accident risk caused by electrical faults is also caused.

Fig. 3a shows a housing 20 of a motor 100 according to an embodiment of the present application, and a stator 10 and a rotor 30 accommodated in the housing 20, wherein a part of the stator 10 and the rotor 30 are accommodated in the housing 20 and not shown, and a rotor shaft of the rotor 30 extends out of the housing 20 along an axial direction of the motor for outputting power. It will be appreciated that the rotor shaft of the rotor 30 also corresponds to the motor shaft of the motor 100. For ease of illustration, the axial direction (axial) of the motor 100 is referred to by the abbreviation a.

Fig. 3b is an exploded view of the motor 100. As shown in fig. 3b, the housing 20 of the motor 100 includes a stator sleeve 201 and a motor end cap 202. In one embodiment, the stator sleeve 201 is a cylindrical structure with an opening at one end, the motor end cover 202 is similar to a circular plate, and the motor end cover 202 is used for being matched and fixed with the opening end of the stator sleeve 201 to form a motor cavity in a surrounding manner. In some embodiments, the housing 20 may include a stator sleeve 201 and two motor end covers 202, where the stator sleeve 201 is a cylindrical structure with two open ends, and the two motor end covers 202 may be respectively fixed at the two open ends of the stator sleeve 201 in a matching manner to form a motor cavity.

Based on the illustration of fig. 3b, a part of the stator 10 and the rotor 30 may be accommodated in the housing 20, which is a motor cavity. The stator 10 comprises a stator core 1, a stator winding 2 and an annular injection molding body 3, wherein the stator winding 2 can be a flat wire winding or a round wire winding, the specific structural form of the stator winding 2 is not limited, and the stator winding 2 is simplified and illustrated. The annular injection molding body 3 is an integral injection molding structure. Wherein the stator winding 2 and the annular injection-molded body 3 are fixed to the stator core 1. The rotor 30 is rotatably mounted to the housing 20 at both ends in the axial direction of the motor about the axis of the motor 100, and the stator 10 can form a magnetic field capable of driving the rotor 30 to rotate.

In the embodiment of the application, 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 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.

In one embodiment, the surface of the motor end cap 202 facing the stator sleeve 201 includes an annular protrusion 2021 and a bearing groove 2022, the annular protrusion 2021 surrounding the bearing groove 2022. The annular projection 2021 is used for cooperation with the stator 10 in the axial direction of the motor, and the bearing groove 2022 is used for driving the rotor shaft of the rotor 30 via a bearing 301. Specifically, an outer race of the bearing 301 is fixed within the bearing groove 2022, and an inner race of the bearing 301 is drivingly connected to a rotor shaft of the rotor 30.

When the motor 100 is assembled, as shown in a schematic cross-sectional structure of the motor 100 in fig. 3c, 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 gluing or the like, and both axial ends of the rotor 30 are rotatably mounted to the motor end cover 202 and the stator sleeve 201 through bearings 301, respectively. The housing 20 may provide some protection for the stator 10 and rotor 30 and may also provide positioning and support for the installation of the stator 10 and rotor 30. In the axial direction of the motor, one axial end portion of the stator 10 is adjacent to one motor end cap 202 in the axial direction of the motor, and the other axial end portion of the stator 10 is adjacent to an end of the stator sleeve 201 remote from the motor end cap 202 in the axial direction of the motor. One end of the annular injection molding body 3 of the stator 10 is connected with the annular protrusion 2021 of the motor end cover 202, so that one end of the stator 10 and the motor end cover 202 are enclosed to form a containing cavity R, and the containing cavity R can contain cooling liquid to submerge the end part of the side of the liquid cooling stator winding 2. The accommodating cavity R can perform immersion liquid cooling on the end part of the stator winding 2, thereby improving the winding cooling effect of the motor 100, improving the efficiency of the motor 100 and the safety performance of equipment using the motor 100. In one embodiment, the cooling fluid is any one of glycol-based cooling oil, synthetic oil, and mineral oil.

In some embodiments, the other end of the annular injection molding body 3 of the stator 10 is connected with the stator sleeve 201, so that the other end of the stator 10 and the motor end cover 202 are enclosed to form another accommodating cavity R, and the accommodating cavity R can accommodate cooling liquid to submerge the end part of the other side of the liquid-cooled stator winding 2, thereby performing submerging liquid cooling on the two ends of the stator winding 2 respectively.

According to the motor 100 provided by the embodiment of the application, the space capable of carrying out immersion liquid cooling on the end part of the stator winding 2 is formed at the end part of the stator 10, so that the structure of carrying out end part cooling by an oil injection ring and the like is omitted, the height of the end part of the stator 10 can be shortened, and the motor 100 is beneficial to realizing miniaturization. Compared with the prior art, the structure is simpler, the cooling effect is better, the manufacturing cost can be reduced, and the continuous power of the motor 100 is improved.

It will be appreciated that in the axial direction of the machine, one end of the stator winding 2 is a welded end and the other end is a crossover end, the welded end of the stator winding 2 being generally used for the sink run. In order to adapt to the different configurations of the two ends of the stator winding 2, the shape of the corresponding motor end cap 202 and the stator sleeve 201 need to be adjusted accordingly, which is not described in detail here.

The following embodiments will take an example of a solution in which a motor end cover 202 cooperates with a stator 10 to form a receiving cavity S, and the motor 100 according to the embodiments of the present application can submerge an end portion of a stator winding 2.

Fig. 4 shows a structure of an annular injection molded body 3 of a stator 10 according to an embodiment of the present application. As shown in fig. 4, the annular injection body 3 has an annular structure that can be fitted to the stator core 1. In one embodiment, the annular injection molding body 3 comprises two exposed sections 32 and a plurality of embedded sections 31 connected between the two exposed sections 32. With reference to one end of the annular injection molding body 3 in the axial direction of the motor, the annular injection molding body 3 includes one exposed section 32 and a plurality of embedded sections 31 arranged adjacently in the axial direction of the motor, the one exposed section 32 is cylindrical, and the plurality of embedded sections 31 are formed on one side of the one exposed section 32 in the axial direction of the motor. The annular injection body 3 includes a plurality of insert segments 31 arranged at intervals along the circumferential direction of the motor. The outer diameter of each embedded segment 31 is substantially identical to the outer diameter of the exposed segment 32 in the radial direction of the motor. In the production of the electric motor 100, the annular injection molded body 3 is formed by integral injection molding, and the exposed section 32 and the plurality of insert sections 31 are of integral construction, the construction being divided here only for the sake of structural description. The exposed section 32 is annular, and the exposed section 32 may be regarded as an annular section.

Fig. 5a is a schematic diagram of a matching structure of the annular injection molding body 3 and the stator core 1 shown in fig. 4. As shown in fig. 5a, the stator core 1 includes one center hole 11 and a plurality of winding slots 12, the one center hole 11 being for accommodating a rotor of the motor 100. In the axial direction of the motor, the one central hole 11 and each winding slot 12 penetrate through the stator core 1, the plurality of winding slots 12 are arranged at intervals in the circumferential direction of the motor, and the plurality of winding slots 12 are used for fixing the annular injection molded body 3 and the stator winding 2. During the manufacturing process of the motor 100, the annular injection body 3 is integrally injection-molded and fixed to the stator core 1 by an in-mold injection molding process. Each embedded section 31 of the annular injection molding body 3 is embedded into one winding slot 12 along the axial direction of the motor and fixed, and one exposed section 32 is exposed on one axial end surface d of the stator core 1 along the axial direction of the motor. The exposed section 32 protrudes from the one axial end face d of the stator core 1 in the axial direction of the motor. In 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 surface d of the stator core 1, and the combination and fixation of the annular injection molding body 3 and the stator core 1 are enhanced.

Fig. 5b shows a partial sectional structure of the insert section 31 of the annular injection molded body 3 after it has been inserted into the winding slot 12 in the radial direction of the motor. As shown in fig. 5b, the width of each winding slot 12 is larger than the width of the slot 121 of the winding slot 12 for connecting with the central hole 11, the embedded section 31 may be filled only in the opening 121 of the winding slot 12 for connecting with the central hole 11 to achieve fixation, and the embedded section 31 and the winding slot 12 may enclose a space for accommodating the stator winding 2. When the stator winding 2 is accommodated in the winding slot 12, an insulating material such as insulating paper is required to be disposed between the stator winding 2 and the inner wall of the winding slot 12. The embedded section 31 fills the notch 121 of the winding slot 12 along the radial direction of the motor, and on the premise of isolating the winding slot 12 from the central hole 11, the material can be saved, the weight of the motor 100 can be reduced, and the miniaturization of the motor 100 can be realized. For convenience of illustration, the circumferential direction (circumferential) of the motor 100 is referred to by the abbreviation C.

In one embodiment, the embedded sections 31 of the annular injection molding body 3 do not protrude from the central hole 11 of the stator core 1 along the radial direction of the motor, each embedded section 31 is embedded into the winding slot 12 along the axial direction of the motor during injection molding, and the embedded sections 31 do not extend into the central hole 11 to affect the assembly of the stator 10 and the rotor.

Fig. 6 illustrates the structure of the stator 10, and as shown in fig. 6, the stator winding 2 is wound around the stator core 1 and then protrudes from one axial end surface d of the stator core 1. In the axial direction of the motor, the height of the end windings of the stator winding 2 exposed to the one axial end face d is lower than the height of the exposed section 32 exposed to the axial end face d. In 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 and the axis of the motor 100 in each winding slot 12. The stator winding 2 is not affected when the exposed section 32 is coupled to the housing 20. In some embodiments, the structure of the stator winding 2, the annular injection-molded body 3 of the other axial end face d of the stator core 1 may be similar to that shown in fig. 6.

Fig. 7 is a schematic sectional view of a part of the structure of an electric motor 100 according to an embodiment of the present application, which is formed to pass through a winding slot 12 of a stator core 1 and an embedded section 31 embedded in the winding slot 12 in the radial direction of the motor, and the rotor 30 is not shown. As shown in fig. 7, taking one winding slot 12 as an example, one insert section 31 of the annular injection molded body 3 is inserted into a notch of the winding slot 12 in the radial direction of the motor for enclosing a space for accommodating the stator winding 2, the exposed section 32 exposes an axial end face d of the stator core 1, and a division between the insert section 31 and the exposed section 32 is shown in broken lines. The stator winding 2 is partially accommodated in the winding slot 12 and extends out of one axial end d of the stator core 1 in the axial direction of the motor. The portion of the stator winding 2 exposed to the one axial end surface d of the stator core 1 can be regarded as an end winding of the stator winding 2, and the stator winding 2 is isolated from the winding grooves 12 and the embedded segments 31 by the insulating paper 4. The exposed segments 32 are arranged between the stator winding 2 and the central bore 11 in the radial direction of the machine, the outer diameter of the exposed segments 32 being smaller than the distance between the stator winding 2 and the axis of the machine 100, the exposed segments 32 not affecting the extension of the ends of the stator winding 2 out of the stator core 1. The exposed section 32 is used for isolating the stator winding 2 and the central hole 11, and the exposed section 32 extends for a certain height along the axial direction of the motor, so that the creepage distance between the central hole 11 and the stator winding 2 can be increased, and the safety of the motor 100 is improved. In 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 exposing the axial end face d of the stator core 1, and when the exposed section 32 is engaged with the motor end cover 202, the motor end cover 202 does not contact the end of the stator winding 2.

With continued reference to fig. 7, an annular projection 2021 of the motor end cap 202 extends into the inner ring of an exposed section 32 in the axial direction of the motor, the exposed section 32 being disposed adjacent to the annular projection 2021 in the radial direction of the motor. The inner peripheral surface of the exposed section 32 is for being fitted and fixed with the outer peripheral surface of the annular projection 2021 in the radial direction of the motor. In some embodiments, the distance between the outer circumferential surface of the one annular boss 2021 and the axis of the motor 100 is smaller than the distance between the inner circumferential surface of the exposed section 32 and the axis of the motor 100, and the gap between the outer circumferential surface of the one annular boss 2021 and the inner circumferential surface of the one annular section 321 is used for accommodating a sealing ring, so as to enhance the sealing and fixing effect therebetween. A housing cavity S is formed between the motor end cover 202 and one axial end surface d of the stator core 1, and the end portion of the stator winding 2 extends out of the winding slot 12 in the axial direction of the motor and then extends into the housing cavity S through the exposed section 32.

In some embodiments, the length of the exposed section 32 exposed at one axial end face d is greater than the length of one annular boss 2021 protruding from one motor end cap 202 in the axial direction of the motor. The end of the exposed section 32 facing the motor end cover 202 is abutted against the motor end cover 202, so that the annular injection molding body 3 and the motor end cover 202 are axially connected. The length of the portion of the stator winding 2 passing through the one exposed section 32 is smaller than the length of the annular boss 321, and the motor end cover 202 does not contact the end of the stator winding 2, so that the function of the stator winding 2 can be ensured. In some embodiments, a material such as an adhesive may be filled between the motor end cap 202 and the end of the exposed section 32 facing the motor end cap 202 to enhance sealing fixation therebetween in the axial direction of the motor.

Fig. 8a illustrates an exploded view of another motor 100, in which motor 100 the structure of the ring-shaped injection-molded body 3 is different from the structure of the ring-shaped injection-molded body 3 of the motor 100 shown in fig. 3 b.

When the motor 100 is assembled, as shown in a schematic cross-sectional structure of the motor 100 in fig. 8b, along the axial direction of the motor, one end of the annular injection molding body 3 of the stator 10, which is exposed out of the axial end face d of the stator core 1, is connected with the annular protrusion 2021 of the motor end cover 202, so that one end of the stator 10 and the motor end cover 202 are enclosed to form a containing cavity S, which can contain a cooling liquid to submerge the end portion of the side of the liquid-cooled stator winding 2. In one embodiment, the portion of the annular injection-molded body 3 that exposes the axial end face d of the stator core 1 in the axial direction of the motor extends in the radial direction of the motor, so that the annular injection-molded body 3 can partially cover the axial end face d of the stator core 1. The part of the stator winding 2 exposed to the stator core 1 passes through the annular injection-molded body 3 into the accommodation chamber S.

Fig. 9 shows a structure of an annular injection molded body 3 of a stator 10 according to an embodiment of the present application. As shown in fig. 9, the annular injection body 3 includes two exposed sections 32 and a plurality of insert sections 31 connected between the two exposed sections 32. The annular injection body 3 includes a plurality of insertion sections 31 arranged at intervals in the circumferential direction of the motor, each insertion section 31 being for insertion into one winding slot 12 of the stator core 1 in the axial direction of the motor. In one embodiment, each embedded segment 31 is in the shape of a pipe. With reference to one end of the annular injection molded body 3 in the axial direction of the motor, the exposed section 32 includes an annular section 321 and an extending section 322, the extending section 322 extends in the radial direction of the motor and is connected with each embedded section 31, the annular section 321 extends in the axial direction of the motor, and a step is formed between the outer peripheral surface of the annular section 321 and the surfaces of the extending section 322 facing away from the plurality of embedded sections 31. The circumferentially enclosed channel of each embedded segment 31 communicates with the outer peripheral surface side of the annular segment 321.

In one embodiment, the extension 322 of the exposed section 32 includes a plurality of through holes g arranged at intervals along the circumferential direction of the motor, each through hole g penetrating the extension 322 in the axial direction of the motor to communicate with the inner space of one of the embedded sections 31.

Fig. 10a is a schematic diagram of a mating structure of the annular injection molding body 3 and the stator core 1 shown in fig. 9. As shown in fig. 10a, the annular injection body 3 is integrally injection-molded and fixed to the stator core 1 by an in-mold injection molding process, each of the embedded sections 31 of the annular injection body 3 is embedded in one of the winding slots 12 in the axial direction of the motor and fixed, and one of the exposed sections 32 is exposed to one of the axial end faces d of the stator core 1 in the axial direction of the motor. Taking one axial end surface d of the stator core 1 as an example, the annular section 321 of the exposed section 32 extends in the axial direction of the motor to expose the axial end surface d of the stator core 1, and the extending section 322 of the exposed section 32 extends in the radial direction of the motor and partially covers the axial end surface d of the stator core 1. In the axial direction of the motor, the height of the annular section 321 exposing the axial end face d of the stator core 1 is greater than the height of the extending section 322 exposing the axial end face d of the stator core 1. In the radial direction of the motor, the outer diameter of the extension 322 is larger than the distance between the groove bottom of the winding groove 12 and the axis of the motor 100 and is smaller than or equal to the radial dimension of the outer circumferential surface of the stator core 1, and it is also considered that the outer circumferential surface of the extension 322 is located between the outer circumferential surface of the stator core 1 and the groove bottom of the winding groove 12. Fig. 10b shows a partial sectional structure of the insert section 31 of the annular injection molded body 3 after it has been inserted into the winding slot 12 in the radial direction of the motor. As shown in fig. 10b, after one of the embedded segments 31 of the annular injection body 3 is embedded in one of the winding slots 12 of the corresponding stator core 1, the embedded segment 31 extends along the slot wall of the winding slot 12 to cover the inner wall of the winding slot 12 and fill the opening 121 of the winding slot 12 for communicating with the center hole 11. The channel defined by the embedded segments 31 is isolated from the central bore 11, and the space defined by the embedded segments 31 is used for accommodating the stator winding 2.

In one embodiment, referring to fig. 10a and 10b in combination, the size of each through hole g is greater than or equal to the size of each winding slot 12 in the radial direction of the motor, and the distance between two adjacent through holes g in the circumferential direction of the motor is less than or equal to the distance between the corresponding two adjacent winding slots 12. The larger-sized through-hole g can be provided to communicate with the inner space of one of the embedded sections 31 while avoiding the stator winding 2 protruding from the winding slot 12.

In one embodiment, after an embedding 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 formed by the surrounding of the embedding 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 section 32 in the radial direction of the motor may be larger than or equal to the size of the embedded section 31, and the distance between two adjacent through holes p in the circumferential direction of the motor may be smaller than or equal to the distance between two corresponding adjacent embedded sections 31, which may also satisfy the requirement of avoiding the stator winding 2 protruding in the winding slot 12.

Fig. 11 illustrates the structure of the stator 10, and as shown in fig. 1, when the stator winding 2 is wound around the stator core 1, the stator winding 2 protrudes through the insertion section 31 beyond one axial end surface d of the stator core 1, and the end of the stator winding 2 is exposed through the through hole g of the extension section 322. In 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 holes g do not hinder the extension of the stator winding 2. The distance between two adjacent through holes g is smaller than or equal to the distance between two corresponding adjacent winding slots 12 along the circumferential direction of the motor. In the axial direction of the motor, the height of the end windings of the stator winding 2 exposed to the one axial end face d is lower than the height of the annular section 321 of the exposed section 32 exposed to the axial end face d. In some embodiments, the structure of the stator winding 2, the annular injection-molded body 3 of the other axial end face d of the stator core 1 may be similar to that shown in fig. 11. In this stator 10, the embedded segments 31 may act as insulation barriers between the stator winding 2 and the winding slots 12 of the stator core 1, without the need for additional insulation material such as insulation paper.

Fig. 12 is a schematic sectional view of a part of the structure of an electric motor 100 according to an embodiment of the present application, which is formed to pass through a winding slot 12 of a stator core 1 and an embedded section 31 embedded in the winding slot 12 in the radial direction of the motor, and a rotor 30 is not shown. As shown in fig. 12, taking one winding slot 12 as an example, one embedded section 31 of the annular injection molded body 3 is embedded in the winding slot 12 in the radial direction of the motor and covers the inner wall of the winding slot 12, and the inner wall of the embedded section 31 encloses a space for accommodating the stator winding 2. The stator winding 2 is exposed in the axial direction of the motor through the extension 322 of the embedded segment 31, the exposed segment 32. The portion of the one axial end surface d of the stator core 1 where the stator winding 2 is exposed can be regarded as an end winding of the stator winding 2. In the radial direction of the machine, the annular segments 321 of the exposed segments 32 are arranged between the stator windings 2 and the central bore 11, the outer diameter of the annular segments 321 being smaller than the distance between the stator windings 2 and the axis of the machine 100, the exposed segments 32 not affecting the extension of the ends of the stator windings 2 out of the stator core 1. In 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 exposing the axial end face d of the stator core 1, and when the exposed section 32 is engaged with the motor end cover 202, the motor end cover 202 does not contact the end of the stator winding 2. The distance between the outer circumferential surface of the extension 322 and the axis of the motor 100 is greater than the groove bottom of the winding groove 12, and the extension 322 may cover a portion of the axial end surface d of the stator core 1 in the axial direction of the motor.

With continued reference to fig. 12, an annular projection 2021 of the motor end cap 202 extends into the inner ring of an exposed section 32 in the axial direction of the motor, the exposed section 32 being disposed adjacent to the annular projection 2021 in the radial direction of the motor. The inner peripheral surface of the exposed section 32 is for being fitted and fixed with the outer peripheral surface of the annular projection 2021 in the radial direction of the motor. A housing cavity S is formed between the motor end cover 202 and one axial end surface d of the stator core 1, and the end portion of the stator winding 2 extends out of the winding slot 12 in the axial direction of the motor and then extends into the housing cavity S through the exposed section 32. When the accommodation chamber S accommodates a cooling liquid, the cooling liquid can submerge the end windings of the stator winding 2.

Other forms of construction of the annular injection-molded body 3 are possible, taking into account the manufacturing process and the production costs.

In one embodiment, as shown in fig. 13a, the plurality of embedded segments 31 of the annular injection molded body 3 are the plurality of embedded segments 31 of the annular injection molded body 3 shown in fig. 9 of the above embodiment, and each embedded segment 31 is used for being embedded into one winding slot 12 along the radial direction of the motor and covering the inner wall of the winding slot 12. The exposed section 32 included in the annular injection molded body 3 is the exposed section 32 shown in fig. 4 of the above embodiment, and the exposed section 32 corresponds to one annular section. In the radial direction of the motor, the outer diameter of each embedded section 31 is larger than the outer diameter of the annular section 321. The space formed by the surrounding of each embedded section 31 is communicated with the space on the outer peripheral surface side of each exposed section 32 along the axial direction of the motor.

Fig. 13b is a schematic cross-sectional view of a part of the structure of the motor 100 including the annular injection molded body 3. When the annular injection molding body 3 and the stator core 1 are injection molded, each embedded section 31 is embedded into one winding slot 12 along the radial direction of the motor and is fixed by covering the inner wall of the winding slot 12, and the stator winding 2 accommodated in the winding slot 12 is specifically accommodated in a space formed by surrounding the embedded sections 31. The exposed section 32 is fixedly connected with the motor end cover 202, and a containing cavity S is formed among the motor end cover 202, the stator sleeve 201 and the axial end surface d of the stator core 1, and the end part of the stator winding 2 penetrates out of the embedded section 31 along the axial direction of the motor and then enters the containing cavity S.

In one embodiment, as shown in fig. 14a, the plurality of embedded segments 31 of the annular injection molded body 3 are the plurality of embedded segments 31 of the annular injection molded body 3 shown in fig. 4 of the above embodiment, and each embedded segment 31 is used for being embedded into the notch 121 of one winding slot 12 along the radial direction of the motor. The exposed section 32 included in the annular injection molding body 3 is the exposed section 32 shown in fig. 9 of the above embodiment, and the exposed section 32 includes an annular section 321 and an extension section 322. The extension section 322 includes a plurality of through holes g arranged at intervals along the circumferential direction of the motor, each through hole g penetrating the annular section 321 in the axial direction of the motor. In the radial direction of the motor, the outer diameter of each embedded section 31 is equal to the outer diameter of the annular section 321 in size, and the outer diameter of the extending section 322 is larger than the outer diameter of the embedded section 31 and the outer diameter of the annular section 321. The through-hole g communicates with the space on the outer peripheral surface side of the annular section 321 and the space on the outer peripheral surface side of the insertion section 31 in the axial direction of the motor.

Fig. 14b is a schematic cross-sectional view of a part of the structure of the motor 100 including the annular injection molded body 3. When the annular injection molding body 3 is injection molded with the stator core 1, each of the embedded sections 31 is embedded in the notch 121 of one of the winding slots 12 in the radial direction of the motor and fixed, the extension section 322 of the exposed section 32 covers the axial end face d of the stator core 1 in the radial direction of the motor, and each of the through holes g communicates with one of the winding slots 12 in the axial direction of the motor. The exposed section 32 is fixedly connected to the motor end cover 202, and a receiving space S is formed between the motor end cover 202, the stator sleeve 201 and the axial end surface d of the stator core 1, into which the stator winding 2 received in one winding slot 12 can be inserted through the through-hole g of the extension section 322.

In some embodiments, in order to reduce the amount and weight of the annular injection molding body 3, the portion of the annular injection molding body 3 where the exposed section 32 covers the axial end face d of the stator core 1 may include one or more through holes p, each of which penetrates a portion of the exposed section 32 covering the axial end face in the axial direction of the motor, as shown in fig. 15. Unlike the through-hole g of the annular injection body 3 described above, each through-hole p may be arranged between two winding slots 12 here when the annular injection body 3 is injection-molded with the stator core 1. In fig. 15, only one through hole p is illustrated.

It should be understood that there is no necessary relationship between the through-holes p and the through-holes g, and the exposed section 32 of the annular injection-molded body 3 may have only the through-holes g, as shown in fig. 9. Alternatively, the exposed section 32 of the annular injection-molded body 3 may have both a through-hole p and a through-hole g, as shown in fig. 15.

In some embodiments, the exposed section 32 of the annular injection body 3 covers the portion between the winding slots 12 of the axial end face d of the stator core 1, and at this time, the exposed section 32 may include only the through hole p. Based on such an annular injection-molded body 3, in one embodiment, each through-hole p includes a notch in the radial direction of the motor, the notch of each through-hole p facing away from a central hole 11 in the radial direction of the motor, which notch can communicate with the outer peripheral surface of the exposed section 32 in the radial direction of the motor. The width of each notch is greater than the width of each winding slot 12 in the circumferential direction of the motor, and circumferentially adjacent notches may communicate to form exposed segments 32 of smaller radial dimension. When the adjacent gaps in the circumferential direction of the motor are communicated, the exposed section 32 of the annular injection molding body 3 is similar in structure to that shown in fig. 4. This is believed to be one way of forming the exposed section 32 shown in fig. 4.

In one embodiment, the stator core 1 provided in the embodiment of the present application may be used for cooling the stator 10 by passing oil or water, and the stator core 1 is formed with one or more liquid cooling channels, and the one or more liquid cooling channels may be in communication with the accommodating cavity S formed between the motor end cover 202 and the stator 10.

Fig. 16 shows a structure of a stator core 1 according to an embodiment of the present application. As shown in fig. 16, the stator core 1 includes one center hole 11 and a plurality of winding slots 12, referring to the overall structure of the stator core 1. In the axial direction of the motor, the one center hole 11 penetrates the stator core 1 in the axial direction of the motor, that is, both ends of the one center hole 11 are respectively communicated to the two axial end faces d. Each winding slot 12 penetrates the stator core 1 in the axial direction of the motor, i.e., both ends of each winding slot 12 are respectively communicated to the two axial end faces d. The plurality of winding slots 12 are arranged at intervals along the circumferential direction of the motor, one tooth portion of the stator is formed between any two adjacent winding slots 12, and a portion between the slot bottom of each winding slot 12 and the outer circumferential surface of the stator core 1 is a yoke portion of the stator. In one embodiment, the distance between any two winding slots 12 is approximately equal along the circumferential direction of the motor, and the structure of the stator core 1 is symmetrical along the circumferential center of the motor. In one embodiment, each winding slot 12 communicates with the central bore 11 in the radial direction of the motor.

With continued reference to fig. 16, the stator core 1 includes a plurality of stator laminations 101 arranged adjacent to each other along the axial direction of the motor, and the plurality of stator laminations 101 can form a liquid cooling channel in the stator core 1. The plurality of stator laminations 101 includes at least one first stator lamination 101 and a plurality of second stator laminations 102, the at least one first stator lamination 101 and the at least one second stator lamination 102 being arranged adjacent in the axial direction of the motor. The one second stator lamination 102 or a plurality of stacked second stator laminations 102 can form one or more axial liquid cooling channels t1, each axial liquid cooling channel t1 extending along the axial direction of the motor to both axial end faces d of the stator core 1. The at least one first stator punching sheet 101 can form a circumferential liquid cooling channel t2, the circumferential liquid cooling channel t2 is communicated with the outer circumferential surface of the stator core 1 and extends along the circumferential direction of the motor, the one or more axial liquid cooling channels t1 are all communicated with the circumferential liquid cooling channel t2, cooling liquid can be led to the one or more axial liquid cooling channels t1 by introducing cooling liquid into the circumferential liquid cooling channel t2, and the one or more axial liquid cooling channels t1 can lead the cooling liquid to two axial end surfaces d of the stator core 1. The plurality of axial liquid cooling passages t1 and the circumferential liquid cooling passage t2 here form liquid cooling passages of the stator core 1.

The circumferential liquid cooling channel t2 may be formed by one first stator punching sheet 101, or may be formed by combining a plurality of first stator punching sheets 101. When the stator core 1 includes the plurality of first stator laminations 101, the structures of the plurality of first stator laminations 101 may be the same or different as long as the circumferential liquid cooling passage t2 communicating with the axial liquid cooling passage t1 can be formed.

In some embodiments, a plurality of second stator laminations 102 are stacked in the axial direction of the electric machine and then arranged between two sets of first stator laminations 101, each set of second stator laminations 102 comprising one second stator lamination 102 or a plurality of stacked first stator laminations 101. Each set of second stator laminations 102 forms one or more axial liquid cooling channels t1, and one axial liquid cooling channel t1 formed by one set of second stator laminations 102 communicates with one axial liquid cooling channel t1 formed by another set of second stator laminations 102 through holes on the plurality of second stator laminations 102. After the cooling liquid enters any one of the axial liquid cooling channels t1 along the circumferential liquid cooling channel t2, the cooling liquid is divided into two parts along the axial direction of the motor, one part flows to one axial end surface d of the stator core 1 along the axial liquid cooling channel t1 formed by one group of the second stator punching sheets 102, and the other part flows to the other axial end surface d of the stator core 1 along the axial liquid cooling channel t1 formed by the other group of the second stator punching sheets 102.

When the annular injection molded body 3 is injection molded with the stator core 1 shown in fig. 16, the exposed section 32 of the annular injection molded body 3 has a hole communicating with the axial liquid cooling passage t1 of the stator core 1 to guide the cooling liquid to the end immersion liquid cooling of the stator winding 2 by the accommodation chamber S at one axial end face d of the stator core 1. In some embodiments, the channels formed by the embedded segments 31 of the annular injection molding body 3 after being embedded in the winding slots 12 can be communicated with the circumferential liquid cooling channels t2 of the stator core 1 so as to guide the cooling liquid into the winding slots 12 for partially immersing the stator windings 2 in the liquid cooling liquid in the winding slots 12.

In some embodiments, fig. 17 is a structure of an annular injection molding body 3 of a stator 10 according to an embodiment of the present application. As shown in fig. 17, the annular injection body 3 has a similar structure to the annular injection body 3 shown in fig. 9. The annular injection molding body 3 includes a plurality of insert sections 31 arranged at intervals along the circumferential direction of the motor, each insert section 31 being for being inserted into one winding slot 12 of the stator core 1 in the axial direction of the motor and covering the inner wall of the winding slot 12, each insert section 31 being in the shape of a pipe, each insert section 31 enclosing an axial flow passage q1 extending in the axial direction of the motor. Each embedded segment 31 further comprises at least one radial flow channel q2, each radial flow channel q2 being in radial communication with one axial flow channel q1 along the machine's radial direction. One exposed section 32 of the annular injection molded body 3 includes an annular section 321 and an extension section 322, the annular section 321 being adapted to cooperate with the motor end cap 202 or the stator sleeve 201 for enclosing to form the accommodation chamber S. The outer diameter of extension 322 is greater than the outer diameter of any one of the embedded segments 31. The extension 322 includes a plurality of through holes g arranged at intervals in the circumferential direction of the motor, each through hole g penetrating the one extension 322 in the axial direction of the motor to communicate with one axial flow passage q1. The extension 322 further includes a plurality of liquid cooling holes n, each of which penetrates the extension 322 in the axial direction of the motor for communication with one axial cooling passage t1 of the stator core 1.

Fig. 18a is a structure of a stator core 1 and an annular injection molding body 3 of an electric motor 100 according to an embodiment of the present application, and fig. 18b is an enlarged detail view of V in fig. 18 a. Referring to fig. 18a and 18b together, in the process of manufacturing the motor 100, the annular injection body 3 is integrally injection-molded to the stator core 1 by an in-mold injection molding process, so that the structure shown in fig. 18a can be obtained.

Referring also to fig. 18a and 18b, the annular injection molded body 3 includes a plurality of insert segments 31 that are respectively inserted into a plurality of winding slots 12 of the stator core 1 in the axial direction of the motor, and one insert segment 31 is inserted into each winding slot 12. In one embodiment, each embedded segment 31 extends along and covers the inner wall of the corresponding winding slot 12, the embedded segment 31 shields the winding slot 12, and the reference numeral of the winding slot 12 shown in fig. 18a points to the location of the winding slot 12. The annular injection body 3 includes one exposed section 32 exposing one axial end face d of the stator core 1 in the axial direction of the motor, and an extension section 322 of the one exposed section 32 covers the one axial end face d of the stator core 1. Wherein, in the radial direction of the motor, the inner diameter of the exposed section 32 is larger than or equal to the inner diameter of one central hole 11 of the stator core 1, and the outer diameter of the extended section 322 is larger than the distance between the bottom of the winding slot 12 and the axis of the motor 100 and smaller than the outer diameter of the stator core 1. The plurality of liquid cooling holes n are arranged at intervals along the circumferential direction of the motor, each liquid cooling hole n is communicated with the axial liquid cooling channels t1 of one or more stator cores 1 along the axial direction of the motor, and the circumferential liquid cooling channels t2 can be communicated with one liquid cooling hole n through one or more axial liquid cooling channels t 1. In one embodiment, each liquid cooling hole n is communicated with one axial liquid cooling channel t1, and the aperture of the liquid cooling hole n is greater than or equal to the aperture of the port of the corresponding axial liquid cooling channel t1 located at the axial end surface d. In one embodiment, the extension 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 one of the embedded sections 31.

In connection with fig. 18b, a partial cross-sectional structure of fig. 19a, which cross-section passes through one winding slot 12 of the stator core 1 and one embedded segment 31 embedded in the winding slot 12, can be obtained by cutting the stator core 1 and the annular injection molded body 3 in the radial direction of the motor at the position indicated by P1. As shown in fig. 8a, each of the embedded segments 31 is embedded in one of the winding slots 12, the embedded segments 31 extend around the inner wall of the winding slot 12, and the axial flow channel q1 defined by the embedded segments 31 is isolated from the central hole 11 by a part of the structure of the embedded segments 31. The axial flow passage q1 extends to both axial end surfaces d of the stator core 1 in the axial direction of the motor. Each embedded segment 31 further comprises a radial flow channel q2, the radial flow channel q2 being capable of communicating the circumferential liquid cooling channel t2 of the stator core 1 with one or more axial flow channels q2 in the radial direction of the motor. The axial flow channel q1 formed by enclosing the embedded section 31 is enclosed outside the stator winding 2 accommodated in the winding slot 12, and when the cooling liquid in the circumferential liquid cooling channel t2 enters the axial flow channel q1 formed by enclosing the embedded section 31 along the radial flow channel q2, the cooling liquid can perform immersion liquid cooling on the stator winding 2 accommodated in the winding slot 12 in the axial flow channel q 1.

In one embodiment, each axial flow channel q1 extends to the one exposed section 32 in the axial direction of the motor and communicates with one through hole g of the extending section 322, through which the axial flow channel q1 may communicate with a space on a surface side of the extending section 322 facing away from the axial end face d, and the coolant may flow along the axial flow channel q1 toward the surface side of the extending section 322 facing away from the axial end face d.

In connection with fig. 18b, cutting the stator core 1 and the annular injection body 3 in the radial direction of the motor at the position indicated by P2 can obtain a partially sectioned schematic structure shown in fig. 19b, which section passes through one axial liquid cooling passage t1 of one stator core 1 and one liquid cooling hole n of the annular injection body 3. As shown in fig. 19b, one axial liquid cooling passage t1 extends from the axial direction of the motor to the two axial end surfaces d of the stator core 1, and one axial liquid cooling passage t1 communicates with one liquid cooling hole n in the axial direction of the motor. Along the radial direction of the motor, the circumferential liquid cooling channel t2 extends to be communicated with the axial liquid cooling channel t 1.

With further reference to the schematic cross-sectional view of a portion of an electric machine 100 shown in fig. 20. In one embodiment, the stator sleeve 201 includes a fluid inlet j penetrating the stator sleeve 201 in the radial direction of the motor, and the fluid inlet j communicates with the circumferential liquid cooling channel t2 of the stator core 1 in the radial direction of the motor. The cooling liquid entering from the liquid inlet j can enter the axial liquid cooling channel t1 of the stator core 1 along a part of the circumferential liquid cooling channel t2, and enter the axial flow channel q1 through the radial flow channel p2 of the annular injection molding body 3. The cooling liquid in the axial liquid cooling channel t1 and the axial flow channel q1 can enter the accommodating cavity S to perform immersion liquid cooling on the end winding of the stator winding 2, and the cooling liquid in the axial flow channel q1 can perform immersion liquid cooling on the stator winding 2 accommodated in the axial flow channel q1.

In one embodiment, the motor end cap 202 further includes one or more fluid outlets K for directing the cooling fluid from within a receiving chamber S. In the radial direction of the motor, each liquid outlet K is axially spaced from the motor end cap 202 by a distance greater than the outer diameter of the annular boss 2021. The cooling liquid in the accommodating cavity S can be sprayed out through the liquid outlet K on the motor end cover 202.

As can be seen from fig. 20, the stator 10 and the housing 20 of the motor 100 can enclose a relatively airtight chamber for immersion cooling of the stator winding 2. In particular, each embedded segment 31 of the annular injection-molded body 3 may be embedded in one winding slot 12 to enclose an axial flow channel q1, which axial flow channel q1 enables immersion-liquid cooling of the stator winding 2 accommodated in the winding slot 12. The exposed section 32 of the annular injection molded body 3 can be fixedly connected to the motor end cap 202 of the housing 20, so that a receiving space S is formed between the stator sleeve 201, the motor end cap 202, the exposed section 32 and an axial end face d of the stator core 1, which receiving space S can be used for immersion cooling of the exposed end of the stator winding 2 to the stator core 1.

It should be understood that in a practical configuration, the axial flow channel q1 and the axial liquid cooling passage t2 are offset in the circumferential direction of the motor, and thus the axial liquid cooling passage t2 and the liquid cooling hole n communicating with the axial liquid cooling passage t2 are shown in fig. 20 by broken lines, only for illustrating the flow direction of the cooling liquid of the motor 100.

In summary, according to the motor 100 provided by the embodiment of the application, the housing 20 of the motor 100 is matched with the stator 10 to form a sealed cavity capable of carrying out immersion liquid cooling on the stator winding 2, so that good cooling on the stator winding 2 is realized, and further, the continuous power of the motor 100 can be improved. The annular injection molding body 3 and the stator core 1 are integrally injection molded, and the exposed section 32 of the annular injection molding body 3 is directly connected and fixed with the shell 20, so that the end height of the stator can be shortened, and the miniaturization of the motor is facilitated. Compared with the oil spraying ring end winding cooling scheme in the prior art, the oil spraying ring end winding cooling structure is simpler in structure and better in cooling effect, can reduce production cost and improve continuous power of a motor.

The foregoing is merely illustrative embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily think about variations or substitutions within the technical scope of the present application, and the application should be covered. Therefore, the protection scope of the application is subject to the protection scope of the claims.

Claims

1. An immersion liquid cooled motor, wherein the housing of the motor comprises a stator sleeve and a motor end cover, wherein the stator sleeve is used for fixing a stator of the motor, the motor end cover is used for enclosing the stator sleeve to form a motor cavity, and the motor cavity is used for accommodating the stator and a rotor of the motor;

the stator includes stator core, stator winding and integral type injection molding's annular injection molding body, stator core includes a centre bore and a plurality of winding groove, a centre bore is followed the axial of motor runs through stator core, a plurality of winding grooves are followed motor stator's circumference interval arrangement, every the winding groove is followed motor stator's radial with the centre bore intercommunication, wherein:

the plurality of winding grooves are used for fixing the stator winding and the annular injection molding body, and one end of the stator winding is exposed out of one axial end face of the stator core along the axial direction of the motor;

The annular injection molding body comprises an embedded section and an exposed section, the exposed section and the embedded section are adjacently arranged along the axial direction of the motor, the embedded section is used for being embedded into the winding grooves along the radial direction of the motor, the exposed section is exposed out of the axial end face along the axial direction of the motor, the exposed section is used for enclosing the motor end cover, the stator sleeve and the axial end face to form an accommodating cavity, and the accommodating cavity is used for accommodating cooling liquid to submerge one end of the stator winding.

2. The motor of claim 1, wherein an in-slot width of each of the winding slots is greater than a slot width of a slot opening of the winding slot for communication with the central hole in a circumferential direction of the motor, and the embedded section embedded in each of the winding slots fills the slot opening of each of the winding slots.

3. The motor of claim 2, wherein a length of said one embedded segment embedded in each of said winding slots is less than or equal to a length of said slot in a radial direction of said motor.

4. The motor of claim 2, wherein said one embedded segment embedded in each of said winding slots surrounds said stator winding received in said winding slot along an inner wall of said winding slot in a radial direction of said motor.

5. The electric machine of any one of claims 1-4, wherein said one exposed section is adapted to cover a portion of said one axial end face, the portion of said one exposed section that covers said one axial end face having an outer diameter that is greater than the diameter of said one central bore.

6. The motor of claim 5, wherein an outer diameter of a portion of said one exposed section covering said one axial end face is smaller than a distance between the stator winding in each of said winding slots and an axis of said motor in a radial direction of said motor.

7. The motor of claim 5, wherein an outer diameter of a portion of the one exposed section covering the one axial end face is larger than a distance between a bottom of each of the winding grooves and an axis of the motor, and one end of the stator winding is exposed to the one axial end face of the stator core through the portion of the one exposed section covering the one axial end face in an axial direction of the motor.

8. The motor of claim 7, wherein the portion of the one exposed section covering the one axial end face includes a plurality of through holes arranged at intervals in a circumferential direction of the motor, each of the through holes communicating with one of the winding slots through the one exposed section in an axial direction of the motor, wherein:

The size of each through hole is larger than or equal to the size of each winding slot along the radial direction of the motor, and the distance between two adjacent through holes along the circumferential direction of the motor is smaller than or equal to the distance between two corresponding adjacent winding slots.

9. The motor of claim 7, wherein a portion of said one exposed section covering said one axial end face in a radial direction of said motor includes a plurality of through holes each penetrating a portion of said one exposed section covering said one axial end face in an axial direction of said motor, each of said through holes being arranged between two of said winding slots.

10. The motor of claim 9 wherein each of said through holes includes a notch in a radial direction of said motor, said notch of each of said through holes facing away from said one central hole in a radial direction of said motor, a width of each of said notches being greater than a width of each of said winding slots in a circumferential direction of said motor.

11. The electric machine of any one of claims 1-10, wherein the stator core includes one or more liquid-cooled channels and the portion of the one exposed section that covers the one axial end face includes a plurality of liquid-cooled apertures, each of the liquid-cooled apertures for connecting the one receiving cavity and at least one of the liquid-cooled channels.

12. The electric machine of any of claims 1-11, wherein the one exposed section further comprises an annular section, the one electric machine end cap comprising an annular protrusion and a bearing groove, the one annular protrusion encircling the one bearing groove, wherein:

The annular bulge is used for extending into the central hole of the annular section along the axial direction of the motor, and a gap between the outer peripheral surface of the annular boss and the inner peripheral surface of the annular section is used for accommodating a sealing ring;

The bearing groove is used for fixing an outer ring of a bearing, and an inner ring of the bearing is used for being in transmission connection with a motor shaft of the motor.

13. The motor of claim 12 wherein the length of said one annular segment exposed at said one axial end face is greater than the length of said one annular boss exposed at said one motor end cap in the axial direction of said motor.

14. A powertrain comprising one of a speed reducer or a transmission and an electric machine as claimed in any one of claims 1 to 13;

And an output shaft of the motor is coaxially connected with an input shaft of the speed reducer or the speed changer in a transmission way.

15. A vehicle comprising wheels, a transmission, and the powertrain of claim 14, wherein the powertrain drives the wheels through the transmission.