CN117713400A

CN117713400A - Stator punching sheet with cooling holes, motor, power assembly and electric vehicle

Info

Publication number: CN117713400A
Application number: CN202311458791.8A
Authority: CN
Inventors: 孙韬; 汪思学; 皇甫聿昭; 付方圆; 郭琪琦; 罗栋; 侯继宁
Original assignee: Huawei Digital Power Technologies Co Ltd
Current assignee: Huawei Digital Power Technologies Co Ltd
Priority date: 2023-11-03
Filing date: 2023-11-03
Publication date: 2024-03-15

Abstract

The embodiment of the application provides a stator punching sheet with cooling holes, a motor, a power assembly and an electric vehicle. The stator lamination includes a plurality of first cooling holes and a plurality of second cooling holes. The plurality of first cooling holes are arranged at intervals along the circumferential direction of the stator lamination, and the plurality of second cooling holes are arranged at intervals along the circumferential direction of the stator lamination. Of the two first cooling holes adjacent in the circumferential direction of the stator lamination, the distance between one first cooling hole and the center of the stator lamination is greater than the distance between the other first cooling hole and the center of the stator lamination. And in the two second cooling holes adjacent along the circumferential direction of the stator punching sheet, the distance between one second cooling hole and the center of the stator punching sheet is larger than the distance between the other second cooling hole and the center of the stator punching sheet. The first cooling hole and the second cooling hole can be mutually alternative, so that the spraying angle of the end part of the motor is ensured to cover the circumferential range of the motor, and the requirement that circumferential liquid spraying of the motor dissipates heat for the end winding is met.

Description

Stator punching sheet with cooling holes, motor, power assembly and electric vehicle

Technical Field

The application relates to the technical field of motors, in particular to a stator punching sheet with cooling holes, a motor, a power assembly and an electric vehicle.

Background

With the development of technology, the power density of the motor is higher and higher, and the volume is smaller and smaller. The improvement of the power density of the motor brings higher requirements to the heat dissipation of the motor.

In motor operation, stator core heat loss is the important heat source of motor, can carry out the oil cooling heat dissipation to the stator through the heat dissipation passageway that sets up on the motor stator to through the oil spout annular of assembling in stator axial tip to end winding oil spout heat dissipation. In order to achieve miniaturization of the motor, a scheme of radially outgoing wires of a motor winding is proposed in the prior art, but the wiring mode cannot be adapted to the oil cooling heat dissipation scheme of the oil spraying ring.

Disclosure of Invention

The embodiment of the application provides a stator punching sheet with a cooling hole, a motor, a power assembly and an electric vehicle, wherein the stator punching sheet can form a structure for enabling the end part of the motor to spray oil radially along the axial direction of the motor in a stacked mode, and the scheme of radial wire outlet of a motor winding can be adapted.

In a first aspect, the present application provides a stator lamination with cooling holes that may be used to form a stator of an electric machine. The stator punching sheet comprises a plurality of first cooling holes and a plurality of second cooling holes, and each first cooling hole and each second cooling hole penetrate through the stator punching sheet along the axial direction of the stator punching sheet. The plurality of first cooling holes are arranged at intervals along the circumferential direction of the stator lamination, and the plurality of second cooling holes are arranged at intervals along the circumferential direction of the stator lamination. Of the two first cooling holes adjacent in the circumferential direction of the stator lamination, the distance between one first cooling hole and the center of the stator lamination is greater than the distance between the other first cooling hole and the center of the stator lamination. And in the two second cooling holes adjacent along the circumferential direction of the stator punching sheet, the distance between one second cooling hole and the center of the stator punching sheet is larger than the distance between the other second cooling hole and the center of the stator punching sheet.

The stator punching provided by the application can be overlapped along the axial direction of the motor to form a part of the stator core, and both the first cooling hole and the second cooling hole can be used for circulating cooling working media. After a plurality of stator punching sheets are stacked along the axial direction of the motor, if the first cooling holes of two adjacent stator punching sheets are communicated, a first cooling channel can be formed, if the second cooling holes of two adjacent stator punching sheets are communicated, a second cooling channel can be formed, both the first cooling channel and the second cooling channel can be used for circulating cooling working media, and when one cooling channel is blocked, the other cooling channel can be used for alternatively ensuring that the cooling working media can circulate through the plurality of stator punching sheets. The distance between a plurality of first cooling holes of stator punching and the center of the stator changes, the distance between a plurality of second cooling holes of stator punching and the center of the stator changes, after the stator punching is sequentially deflected and overlapped along the circumferential direction of the motor, the cooling channels formed by the communication of the first cooling holes and the cooling channels formed by the communication of the second cooling holes can incline along the radial direction of the stator core, and the circulation direction of cooling liquid is changed. When the stator punching sheets are applied to spraying liquid at the axial end part of the motor, the oil spraying ring structure can be omitted, so that the cooling working medium in the stator is sprayed obliquely to the central shaft direction of the motor along the axial direction of the motor, and the cooling working medium dissipates heat for the end winding. The first cooling hole and the second cooling hole can be mutually alternative, so that the spraying angle of the end part of the motor is ensured to cover the circumferential range of the motor, and the requirement that circumferential liquid spraying of the motor dissipates heat for the end winding is met. The motor with the stator punching sheet has smaller axial dimension and can be suitable for occasions with high requirements on space or power density.

In some possible implementations, the distance between the first cooling hole and the center of the stator plate is smaller than the distance between the second cooling hole and the center of the stator plate in the radial direction of the stator plate. The first cooling holes are arranged between the second cooling holes and the center of the stator lamination, and the second cooling holes are closer to the outer peripheral surface of the stator lamination. Possibly, the first cooling holes and the second cooling holes may be arranged along a radial direction of the stator lamination to form radial double-layer cooling holes, and the cooling channels formed by the first cooling holes and the cooling channels formed by the second cooling holes are within the same angle range in the circumferential direction of the stator.

In other possible implementations, one first cooling hole and one second cooling hole are arranged adjacently along the circumferential direction of the stator lamination. The plurality of first cooling holes form a group of cooling holes along the circumferential direction of the stator punching sheet, and the plurality of second cooling holes form a group of cooling holes. Possibly, the first cooling holes and the adjacent second cooling holes are equidistant from the center of the stator lamination along the radial direction of the stator lamination, and the cooling channels formed by the first cooling holes and the cooling channels formed by the second cooling holes are within the same thickness range of the radial direction of the stator.

In some possible implementations, after the number of the stator laminations is relatively small and the stator laminations are stacked in a circumferential deflection manner, only part of cooling channels corresponding to the first cooling holes are blocked, and then second cooling holes can be configured for the blocked cooling channels, and the second cooling holes can form cooling channels penetrating through all the stator laminations after the stator laminations are stacked in a circumferential deflection manner.

In some possible implementations, the central angle between any two adjacent first cooling holes is the same along the circumferential direction of the stator punching sheet, and the central angle between any two adjacent second cooling holes is an integer multiple of the central angle between any two adjacent first cooling holes. After the stator punching sheets are deflected and overlapped circumferentially, the first cooling holes and the second cooling holes are ensured to be communicated respectively to form two cooling channels.

Specifically, the central angle between the first cooling hole closest to the center of the stator lamination and the second cooling hole closest to the center of the stator lamination is smaller than 180 degrees+α and larger than 180 degrees α along the circumferential direction of the stator lamination, and α is the central angle between any two adjacent first cooling holes along the circumferential direction of the stator, so as to ensure the effect of spraying cooling working medium along the circumferential direction of the stator.

In some possible implementations, the stator plate includes a central bore and a plurality of plate grooves spaced apart along a circumference of the stator plate, each plate groove in communication with the central bore along a radial direction of the stator plate, the central bore and each plate groove extending through the stator plate along an axial direction of the stator plate. When a plurality of stator punching sheets are overlapped along the axial direction of the motor, the center holes of the stator punching sheets can be communicated to form a space for accommodating the rotor of the stator core, and the stator grooves of the stator core can be respectively communicated to form stator grooves of the stator core, and the stator grooves are used for winding stator windings. Along the radial direction of the stator, the distance between the first cooling hole and the central hole and the distance between the second cooling hole and the central hole are larger than the distance between the bottom of the punching groove and the central hole, so that the first cooling hole and the second cooling hole are distributed between the outer peripheral surface of the stator punching and the punching groove, and the influence on the strength of the stator punching is reduced.

In some possible implementations, the first cooling holes and the lamination grooves are offset along the circumference of the stator lamination. And/or the second cooling holes and the punching sheet grooves are arranged in a staggered manner, so that the strength of the stator punching sheet is further improved.

In a second aspect, the present application provides an electric machine, the stator of the electric machine comprising a plurality of first stator laminations, at least one second stator lamination and at least one third stator lamination, the first stator lamination being any one of the stator laminations provided in the first aspect above. Along the axial direction of the stator core, the second stator punching sheet is arranged between the first stator punching sheet and the third stator punching sheet, and the stator core comprises an axial gap between the first stator punching sheet and the third stator punching sheet, and the axial gap is communicated with at least one first cooling hole and at least one second cooling hole. The axial gap can be used for cooling working medium to flow along the circumferential direction or radial direction of the stator so as to convey the cooling working medium to the first cooling hole and the second cooling hole, so that the first cooling hole and the second cooling hole have the possibility of circulating the cooling working medium.

In some possible implementations, the second stator lamination includes a plurality of second grooves that communicate with an outer circumferential surface of the second stator lamination in a radial direction of the stator core, the plurality of second grooves being arranged at intervals in a circumferential direction of the stator core. The third stator punching sheet comprises a plurality of first grooves which are communicated with the outer peripheral surface of the third stator punching sheet along the radial direction of the stator core, and the plurality of first grooves are arranged at intervals along the circumferential direction of the stator core. Each second groove communicates with at least one first cooling hole and at least one second cooling hole, and each second groove communicates with at least one first groove. The second groove, the first stator punching sheet and the third stator punching sheet can form the axial clearance, and the first groove, the first cooling hole and the second cooling hole are communicated so that cooling working medium flows to the axial end face of the stator.

In some possible implementations, the slot size of each second groove is larger than the slot bottom size of each second groove along the circumferential direction of the stator, so that the second grooves can accommodate more cooling medium.

In some possible implementations, the outer diameter of the second stator plate is smaller than the outer diameter of the first stator plate and the outer diameter of the third stator plate. The axial clearance can be formed between the outer peripheral surface of the second stator punching sheet and the first stator punching sheet and the third stator punching sheet, and the first groove is communicated with the first cooling hole and the second cooling hole so that cooling working medium flows to the axial end face of the stator.

In some possible implementations, along the axial direction of the stator, one first cooling hole of one first stator punch is in communication with a first cooling hole of another adjacent first stator punch, and one second cooling hole of one first stator punch is in communication with a second cooling hole of another adjacent first stator punch, such that the first cooling holes can form a cooling channel. Along the radial direction of the stator, the distance between one first cooling hole of one first stator punching sheet and the center of the first stator punching sheet is larger than the distance between one first cooling hole of the other first stator punching sheet and the center of the first stator punching sheet, so that the centers of cooling channels formed by the communication of the two first cooling holes deviate along the radial direction of the stator core, and the flow direction of cooling working medium can be changed. When the stator punching sheets are applied to spraying liquid at the axial end part of the motor, cooling liquid can be sprayed obliquely to the central axis direction of the motor along the axial direction of the motor, and heat is dissipated for the end winding.

In a third aspect, the present application provides a powertrain comprising a reducer and any one of the motors provided in the second aspect, wherein an output shaft of the motor is in driving connection with an input shaft of the reducer. The speed reducer can also be a speed changer, and the heat dissipation performance and the power performance of the power assembly can be improved due to the good heat dissipation performance of the motor.

In a fourth aspect, the present application also provides an electric vehicle. The electric vehicle in the present application includes wheels, a transmission mechanism, and the powertrain of the fourth aspect and any implementation thereof. The power assembly drives the wheels through a transmission mechanism. The electric vehicle provided by the application has good heat dissipation performance and power performance.

Drawings

Fig. 1 is a schematic structural diagram of an electric 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 disclosure;

fig. 3a is a schematic view of a part of a stator of an electric machine according to an embodiment of the present disclosure;

fig. 3b is an exploded view of a stator of an electric machine according to an embodiment of the present application;

fig. 4a is a schematic structural diagram of a stator core of an electric motor according to an embodiment of the present disclosure;

FIG. 4b is an enlarged detail view at A1 of FIG. 4 a;

FIG. 4c is an enlarged detail view at A2 of FIG. 4 a;

fig. 5a is an exploded view of a part of the structure of a stator core of an electric motor according to an embodiment of the present application;

fig. 5b is a schematic structural diagram of a first stator punching sheet of a motor according to an embodiment of the present disclosure;

fig. 5c is a schematic structural diagram of a second stator lamination of an electric machine according to an embodiment of the present disclosure;

fig. 5d is a schematic structural diagram of a second stator lamination of an electric machine according to an embodiment of the present disclosure;

fig. 6a is a schematic structural diagram of a portion of a stator core of an electric motor according to an embodiment of the present disclosure;

fig. 6b is a schematic cross-sectional view of a part of a stator core of an electric motor according to an embodiment of the present disclosure;

fig. 7 is a schematic structural diagram of a first stator punching sheet of a motor according to an embodiment of the present application;

fig. 8 is a schematic view of a stacked partial cross-sectional structure of a first stator punching sheet of a motor according to an embodiment of the present application;

fig. 9a is a schematic structural view of stacking first stator laminations of a motor according to an embodiment of the present disclosure;

FIG. 9B is an enlarged detail view at B1 of FIG. 9 a;

FIG. 9c is a schematic view of a partial cross-sectional structure at B1 in FIG. 9 a;

FIG. 9d is an enlarged detail view at B2 of FIG. 9 a;

FIG. 9e is a schematic diagram of a partial cross-sectional structure at B2 in FIG. 9 a;

fig. 9f is a schematic view of a stacked partial cross-sectional structure of a first stator lamination of an electric motor according to an embodiment of the present disclosure;

fig. 10 is a schematic structural diagram of a first stator punching sheet of a motor according to an embodiment of the present application;

fig. 11a is a schematic cross-sectional structure of a stator core of an electric motor according to an embodiment of the present disclosure;

FIG. 11b is an enlarged detail view at C1 of FIG. 11 a;

FIG. 11C is an enlarged detail view at C2 of FIG. 11 a;

fig. 12 is a schematic structural diagram of a first stator punching sheet of a motor according to an embodiment of the present application;

fig. 13a is a schematic structural view of a first stator punching sheet of a motor according to an embodiment of the present disclosure;

fig. 13b is a schematic structural diagram of a stator of an electric motor according to an embodiment of the present disclosure;

fig. 13c is a schematic structural view of stacking first stator laminations of a motor according to an embodiment of the present disclosure;

FIG. 13D is an enlarged detail view at D1 of FIG. 13 c;

FIG. 13e is an enlarged detail view at D2 of FIG. 13 c;

fig. 14 is a schematic structural view of a second stator lamination of an electric machine according to an embodiment of the present disclosure;

fig. 15a is an exploded view of a part of the structure of a stator core of an electric motor according to an embodiment of the present application;

Fig. 15b is a schematic sectional view of a part of a stator core of an electric motor according to an embodiment of the present application.

Detailed Description

The loss of the motor is divided into copper loss, iron loss and mechanical loss. Wherein copper loss is the main loss in the medium-low speed motor. In the motor structure, copper losses are distributed over the end windings of the motor and the core slot inner windings. Because the core has better heat conduction characteristics, the temperature rise of the windings in the slots is often lower than that of the end windings without special cooling. Specifically, oil can be introduced into the back of the stator core, oil is sprayed to the end coil of the stator winding, and the end winding can be cooled well, so that the motor works in a state with higher current density and power density. In the prior art, an oil injection ring is arranged at the axial end part of the motor, oil is injected to an end winding through the oil injection ring, and a stator winding of the motor is led out along the axial direction of the motor to be connected with phase electricity. In a hybrid vehicle, because the space occupied by the engine is extremely high, the axial dimension requirement of the hybrid system on the motor is extremely high, and the arrangement of the system is often limited by a few millimeters and cannot be realized. In order to reduce the axial size of the motor as much as possible, the phase-electricity wires are generally led out from the radial direction of the motor coil, but the radial direction lead-out mode cannot be matched with the oil spraying ring in structure or process, and challenges are presented to the traditional oil cooling heat dissipation mode of the oil spraying ring of the motor.

Based on this, this application embodiment provides a stator punching with cooling hole, motor, power assembly and electric motor car, and wherein first cooling hole and second cooling hole can be the mutual alternative, ensure that the injection angle of motor tip covers the circumference scope of motor, promote the radiating effect, can promote the dynamic performance and the life of motor, power assembly.

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

The terminology used in the following embodiments is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used in the specification and the appended claims, the singular forms "a," "an," "the," and "the" are intended to include, for example, "one or more" such forms of expression, unless the context clearly indicates to the contrary.

Reference in the specification to "one embodiment" or "some embodiments" or the like means that a particular feature, structure, or characteristic described in connection with the embodiment is included in one or more embodiments of the application. Thus, appearances of the phrases "in one embodiment," "in some embodiments," "in other embodiments," and the like in the specification are not necessarily all referring to the same embodiment, but mean "one or more but not all embodiments" unless expressly specified otherwise. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless expressly specified otherwise.

Fig. 1 is a schematic diagram of an electric vehicle according to an embodiment of the present application. Referring to fig. 1, an electric vehicle provided in an embodiment of the present application 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.

Fig. 2 is a schematic diagram of a powertrain provided in an embodiment of the present application. As shown in fig. 2, a powertrain 1000 provided in an embodiment of the present application includes a motor 100 and a decelerator 200. Wherein the motor 100 is in transmission connection with the decelerator 200. The motor 100 is used to drive a transmission 2000 of an electric vehicle through a decelerator 200. The motor 100 includes a stator 10, a rotor 20, and a motor shaft 30. The rotor 20 is coaxially fixed on a motor shaft 30, and the motor shaft 30 is in transmission connection with the speed reducer 200. The stator 10 includes a stator core 1, a stator winding 2, and a housing 3, wherein the stator core 1 is sleeved outside the rotor 30, the stator winding 2 is wound on the stator core 10, and the housing 3 is disposed outside the stator core 10. The speed reducer 200 may be a transmission. The stator core 1, the rotor 30, and the motor shaft 30 are coaxially assembled, and the stator 10 is axially oriented, that is, the motor 100, and the stator 10 is circumferentially oriented, that is, the motor 100, and the stator 10 is radially oriented, that is, the motor 100.

The motor 100 provided in the embodiment of the present application is a motor with a stator liquid cooling winding, and specifically refers to a motor with a cooling medium for dissipating heat of a stator 10, which can simultaneously spray the cooling medium to an end winding of a stator winding 20 for dissipating heat. Referring to fig. 2 and 3a, the end of the stator 10 includes at least one liquid inlet 101 and a plurality of liquid outlets 102 communicating with the external space in the circumferential direction of the motor 100. The stator 10 is provided with a channel for cooling working medium to flow through, the liquid inlet 101 and the liquid outlet 102 are respectively communicated with the channel, the cooling working medium is injected into the channel in the stator 10 through the liquid inlet 101, and liquid is sprayed to the end winding through the liquid outlet 102. The shell 1 comprises a liquid inlet pipe 13, and the liquid inlet pipe 13 is a hollow pipe. One end of the liquid inlet pipe 31 is fixed on the outer peripheral surface of the shell 3, and the liquid inlet pipe 31 is communicated with a channel for cooling working medium circulation in the shell 3. An end port of the liquid inlet pipe 31 facing away from the outer peripheral surface of the housing 3 forms a liquid inlet 101. In the axial direction of the motor 100, a liquid outlet 102 is provided at an end portion of the stator core 1. The stator 10 is substantially annular in shape as a whole, and has a plurality of stator teeth 103 on the inner side of the stator core 1. Stator slots 104 are formed between any two adjacent stator teeth 103 along the circumferential direction of the stator core 10, and the stator winding 20 may be wound around the stator teeth 103. The stator winding 20 is energized, and the center of the stator 10 forms a magnetic field in which the rotor 30 can rotate about the axis of the motor shaft 40. Specifically, a part of the stator winding 20 is accommodated in the stator slot 104, and the part of the stator winding 20 protrudes from an axial end face of the stator 10 in the axial direction of the stator 10. When the stator 10 is cooled by the cooling medium, the cooling medium can be sprayed from the liquid outlet 102 to the end windings of the stator windings 20, so as to realize liquid cooling and heat dissipation of the end windings. For ease of illustration, the stator windings 20 are hidden in fig. 3 a.

Illustratively, as shown in fig. 3b, which is an exploded view of the stator core 1 and the housing 3 of the stator 10, the stator core 1 is formed by a plurality of punched sheets 11 adjacently aligned in the axial direction of the stator 10. The casing 3 is cylindrical, the inner wall of the casing 3 comprises a radial groove 32, the radial groove 32 is formed by grooves arranged on the inner wall of the casing 32, the radial groove 32 extends along the circumferential direction of the casing 1, and the groove bottom of the radial groove 32 is communicated with the liquid inlet 101 through the liquid inlet pipe 31. The outer circumferential surface of the stator core 1 includes a plurality of axial grooves 103, each axial groove 103 extending in the axial direction of the stator 10. When the casing 3 is sleeved on the outer peripheral surface of the stator core 1, the radial grooves 32 of the casing 3 can be communicated with the axial grooves 103, and the cooling medium entering from the liquid inlet 101 can flow along the circumferential direction of the stator 10 along the radial grooves 32 of the casing 3 and enter the axial grooves 103, and the cooling medium in the axial grooves 103 flows along the axial direction of the stator 10. The stator core 1 is formed by a plurality of punched sheets 11 adjacently aligned in the axial direction of the stator 10. The punched sheet 11 located at the axial end face of the stator 10 may be regarded as an end plate structure of the stator 10, and the liquid outlet 102 is formed in the punched sheet 11 located at the axial end of the stator core 1. Each of the punched sheets 11 includes a central hole 111 and a plurality of punched sheet grooves 112, and the number of punched sheet grooves 112 is plural. The central hole 111 is located in the central position of the punching sheet 11, and each punching sheet groove 112 extends in the radial direction of the punching sheet 11 and communicates with the central hole 111 to form the stator groove 104 in fig. 3a, and the bottom of the punching sheet groove 112 is directed away from the center of the punching sheet 11. The plurality of punch grooves 112 are arranged at intervals along the circumferential direction of the punch 11. In the axial direction of the stator 10, a central hole 111 and each radial groove 112 extend through the punched sheet 11, respectively. After the plurality of punched pieces 11 are adjacently arranged in the circumferential direction of the stator 10, the center holes 111 of the plurality of punched pieces 11 can communicate with each other to form a space for accommodating the rotor 30. The radial grooves 112 of the plurality of punching sheets 11 can be respectively communicated, and the structure between any two radial grooves 112 can be overlapped along the axial direction of the stator 10 to form the stator teeth 103 of the stator 10. Between any two adjacent stator teeth 103, i.e. stator slots 104, in the circumferential direction of the stator 10.

Fig. 4a shows a structure of a stator core 1, and the stator core 1 provided in the embodiment of the present application includes a plurality of punched sheets 11, where the plurality of punched sheets 11 includes a plurality of first stator punched sheets 11a, at least one second stator punched sheet 11b, and at least one third stator punched sheet 11c. Illustratively, the second stator lamination 11b is arranged between the first stator lamination 11a and the third stator lamination 11c in the axial direction of the stator core 1. At least one second stator lamination 11b and a plurality of first stator laminations 11a are respectively arranged at both ends of the third stator lamination 11c in the axial direction of the stator 10.

Fig. 4b shows an enlarged detail view at A1 in fig. 4 a. The plurality of first stator laminations 11a are located at the axial end of the stator core 1, the first stator laminations 11a include a plurality of first cooling holes 1131 and a plurality of second cooling holes 1132 penetrating the first stator laminations 11a along the axial direction of the stator 10, the first cooling holes 1131 and the second cooling holes 1132 are all communicated with channels inside the stator 10 for cooling medium to circulate, and the cooling medium can pass through the first cooling holes 1131 and the second cooling holes 1132. For the first stator lamination 11a located at the axial end of the stator 10, the port of the first cooling hole 1131 facing away from the second stator lamination 1b and the port of the second cooling hole 1132 facing away from the second stator lamination 1b form the liquid outlet 102. Referring to fig. 4a and 4b together, a plurality of first cooling holes 1131 are arranged at intervals along the circumferential direction of the stator 10, and a plurality of second cooling holes 1132 are arranged at intervals. The first cooling holes 1131 are distributed over substantially one circumferential turn of the first stator plate 11a, and the second cooling holes 1132 are also distributed over substantially one circumferential turn of the first stator plate 11a. The first cooling holes 1131 and the punching grooves 112 are arranged in a staggered manner, or the second cooling holes 1132 and the punching grooves 112 are arranged in a staggered manner, or the first cooling holes 1131 and the second cooling holes 1132 are arranged in a staggered manner with the punching grooves 112 along the circumferential direction of the first stator punching 11a, so as to ensure the structural strength of the first stator punching 11a.

Fig. 4c shows an enlarged detail view at A2 in fig. 4 a. As shown in fig. 4c, the outer circumferential surface of the second stator lamination 11b includes a plurality of first grooves 114, and the first grooves 114 extend in the axial direction of the stator 10 and penetrate the second stator lamination 11b. The plurality of first grooves 114 are arranged at intervals in the circumferential direction of the stator 10, and the groove widths of the respective first grooves 114 may be the same or different, and the groove depths may be the same or different. Illustratively, the number of the second stator laminations 11b is plural, and the first grooves 114 of the outer circumferential surfaces of the plural second stator laminations 11b may be respectively communicated in the axial direction of the stator 10, so that the above-described axial grooves 103 may be formed.

With continued reference to fig. 4c, the stator core 1 includes an axial gap Q between the first stator punch 11a and the third stator punch 11c, the axial gap Q communicates with at least one first groove 114, and the axial gap Q communicates with at least one first cooling hole 1131 and at least one second cooling hole 1132. When the axial gap Q communicates the first cooling hole 1131 and the second cooling hole 1132 with the at least one first groove 114, the cooling medium in the first groove 114 may be delivered to the first cooling hole 1131 and the second cooling hole 1132 through the axial gap Q. When the first cooling holes 1131 of the plurality of first stator laminations 11a are respectively communicated along the axial direction of the stator 10, and the second cooling holes 1132 of the plurality of first stator laminations 11a are respectively communicated along the axial direction of the stator 10, the cooling medium can be conveyed to the axial end face of the stator core 1 and sprayed out from the liquid outlet 102. The axial gap Q may play a role in collecting the cooling medium, so that the cooling medium may be closer to the center of the stator 10 along the radial direction of the stator 10, so that the cooling medium may be conveniently sprayed to the end winding through the first cooling hole 1131 and the second cooling hole 1132. The converging action of the axial gap Q also provides a more adequate liquid supply for the injection of the cooling medium at the circumferential end of the stator 10, ensuring adequate injection pressure and injection speed. The axial gap Q has various implementation modes, has lower requirement on assembly precision and is easier to realize.

Fig. 5a shows a schematic view of one first stator lamination 11a, one second stator lamination 11b and one third stator lamination 11c of the stator core 1 arranged at intervals in the axial direction of the stator 10. As shown in fig. 5a, the second stator plate 11b is arranged between the first stator plate 11a and the third stator plate 11c, and the radial dimensions of the first stator plate 11a, the second stator plate 11b, and the third stator plate 11c are the same. The outer circumferential surface of the second stator plate 11b includes a second groove 115, when the first stator plate 11a, the second stator plate 11b, and the third stator plate 11c are adjacently arranged along the axial direction of the stator 10, one axial end surface of the second stator plate 11b contacts the first stator plate 11a, the other axial end surface of the second stator plate 11b contacts the third stator plate 11c, and the above-mentioned axial gap Q may be formed between the first stator plate 11a, the second groove 115, and the third stator plate 11 c. The outer diameters of the first stator punching sheet 11a, the second stator punching sheet 11b and the third stator punching sheet 11c are the same, so that the outer peripheral surfaces of the plurality of punching sheets are conveniently welded and fixed to form the stator core 1.

Based on fig. 5a, please refer to the structure of the first stator punching 11a shown in fig. 5 b. As shown in fig. 5b, the number of first cooling holes 1131 is the same as the number of second cooling holes 1132. The plurality of first cooling holes 1131 are spaced apart along the circumferential direction of the stator 10, and the plurality of second cooling holes 1132 are spaced apart along the circumferential direction of the stator 10. In the radial direction of the stator 10, a first cooling hole 1131 and a second cooling hole 1132 are arranged at intervals, and the first cooling hole 1131 is arranged between the second cooling hole 1131 and the center hole 111. One first cooling hole 1131 and one second cooling hole 1132 arranged in the radial direction of the stator 10 may be regarded as a group of cooling holes in which a distance H11 between the first cooling hole 1131 and the center O of the stator 10 is smaller than a distance H12 between the second cooling hole 1132 and the center O of the stator 10. Wherein, the distance H11 between the first cooling hole 1131 and the center O of the stator 10 is greater than the distance H0 between the bottom of the slot of the punching groove 112 and the center O of the stator 10, so that the first cooling hole 1131 and the second cooling hole 1131 are distributed at the part of the first stator punching 11a near the outer peripheral surface, and the structural strength of the first stator punching 11a is ensured. The first and second cooling holes 1131 and 1132 are illustratively circular, and the radial dimension of the first cooling hole 1131 is close to the radial dimension of the second cooling hole 1132 along the circumferential direction of the stator 10. The centers of the first and second cooling holes 1131 and 1132 may not be necessarily arranged at strict intervals in the radial direction of the stator 10 based on the influence of the manufacturing process. In fig. 5b, the first cooling holes 1131 and the second cooling holes 1132 are uniformly distributed along the circumferential direction of the stator 10, and the included angle between any two adjacent first cooling holes 1131 is equal, and the included angle between any two adjacent second cooling holes 1132 is equal. The number of first cooling holes 1131 may be a factor of the number of stator teeth of the stator 10. For example, for a 48 slot stator 10, the number of first cooling holes 1131 may be 48, 24, 16, 8, etc. The spacing angle of any two first cooling holes 1131 adjacent in the circumferential direction of the stator 10 is also 7.5 °, 15 °, 22.5 °, 45 °, etc., depending on the number. The number of the second cooling holes 1132 may be the same as or different from the number of the first cooling holes 1131. The first cooling holes 1131 and the second cooling holes 1132 arranged in the radial direction of the stator 10 are regarded as one cooling hole group, the number of which is half of the number of the lamination grooves 112, one cooling hole group for each two adjacent lamination grooves 112. The first cooling holes 1131 and the second cooling holes 1132 respectively deflect a certain angle relative to the stator punching groove 112 in the circumferential direction, so that the first cooling holes 1131 and the second cooling holes 1132 respectively and the stator punching groove 112 are arranged in a staggered manner along the circumferential direction of the stator 10, and the structural strength of the first stator punching 11a is further improved.

Based on fig. 5a, please refer to the structure of the second stator lamination 11b shown in fig. 5c, the second stator lamination 11b is a gear-shaped lamination structure. As shown in fig. 5c, the second groove 115 is exemplarily rectangular, and a distance H2 between a groove bottom of the second groove 115 and a center O of the stator 10 is equal to or less than a distance H11 between the first cooling hole 1131 and the center O of the stator 10 in fig. 5b, or a radial dimension obtained by subtracting the first cooling hole 1131 from the distance H2 between the groove bottom of the second groove 115 and the center O of the stator 10 is smaller than the distance H11 between the first cooling hole 1131 and the center O of the stator 10. When the first stator lamination 11a and the second stator lamination 11b are adjacently arranged, the second groove 115 can be at least partially communicated with the first cooling hole 1131 and the second cooling hole 1132 along the axial direction of the stator 10. The second groove 115 has a size larger than that of a set of cooling holes in the circumferential direction of the stator 10, and the first cooling holes 1131 and the second cooling holes 1132 of the set of cooling holes are arranged at intervals in the radial direction of the stator 10. Wherein the second grooves 115 may be simultaneously in communication with the plurality of sets of cooling holes.

Based on fig. 5d, please refer to the structure of the third stator punching sheet 11c shown in fig. 5 d. As shown in fig. 5d, a plurality of first grooves 114 are spaced apart along the circumferential direction of the stator 10. The distance between any two first grooves 114 may not be equal in the circumferential direction of the stator 10. When the third stator plate 11c is arranged adjacent to the second stator plate 11b, only a portion of the first grooves 114 of the plurality of first grooves 114 will communicate with the second grooves 115. Wherein the second grooves 115 may simultaneously communicate with one or more of the first grooves 114.

Fig. 6a shows a schematic view of a first stator segment 11a, a second stator segment 11b and a third stator segment 11c arranged adjacent to each other in the axial direction of the stator 10. As shown in fig. 6a, the second stator plate 11b is sandwiched between the first stator plate 11a and the second stator plate 11 c. With reference to the schematic partial cross-sectional structure shown in fig. 6b, the second groove 115 of the second stator lamination 11b forms the axial gap Q with the first stator lamination 11a and the third stator lamination 11 c. In the axial direction of the stator 10, one end of the second groove 115 communicates with a set of cooling holes, that is, the second groove 115 communicates with both a first cooling hole 1131 and a second cooling hole 1132. The other end of the second recess 115 communicates with at least one first recess 114.

Fig. 7 illustrates a schematic structural view of the first stator lamination 11a described above in the axial direction of the stator 10. As shown in fig. 7, of the two first cooling holes 1131 adjacent in the circumferential direction of the stator 10, a distance H112 between one first cooling hole 1131 and the center O of the stator 10 is greater than a distance H111 between the other first cooling hole 1131 and the center O of the stator 10. Illustratively, the distance between the plurality of first cooling holes 1131 and the center O of the stator 10 gradually increases or decreases. For example, the plurality of first cooling holes 1131 are distributed along an asymptote whose base circle is the radius of the distance between the nearest first cooling hole 1131 to the center O of the stator 10 and the center O of the stator 10. The first cooling hole 1131 closest to the center O of the stator 10 is taken as a first cooling hole 1131 in the clockwise or counterclockwise direction, and the distances between the plurality of first cooling holes 1131 behind the first cooling hole 1131 and the center O of the stator 10 are gradually increased. Wherein, the distance between the kth+1th first cooling hole 1131 and the center O of the stator 10 is greater than the distance between the kth first cooling hole 1131 and the center O of the stator 10.

With continued reference to fig. 7, a distance H122 between one of the two second cooling holes 1132 and the center O of the stator 10 is greater than a distance H121 between the other second cooling hole 1132 and the center O of the stator 10, among the two second cooling holes 1132 adjacent in the circumferential direction of the stator 10. Illustratively, the distance between the plurality of second cooling holes 1132 and the center O of the stator 10 gradually increases or decreases. For example, the plurality of second cooling holes 1132 are distributed along an asymptote whose base circle is the radius of the distance between the nearest second cooling hole 1132 to the center O of the stator 10 and the center O of the stator 10. The second cooling holes 1132 closest to the center O of the stator 10 are taken as first second cooling holes 1132 in the clockwise or counterclockwise direction, and the distances between the plurality of second cooling holes 1132 behind the first second cooling holes 1132 and the center O of the stator 10 are gradually increased. Wherein, the distance between the (k+1) th second cooling hole 1132 and the center O of the stator 10 is greater than the distance between the (k) th second cooling hole 1132 and the center O of the stator 10.

The plurality of first stator laminations 11a are adjacently aligned in the axial direction of the stator 10. As shown in fig. 8, in each of the first stator laminations 11a, the first cooling holes 1131, which are equal in distance from the center O of the stator 10, respectively communicate in the axial direction of the stator 10 to form first cooling passages W1, and the second cooling holes 1132, which are equal in distance from the center O of the stator 10, respectively communicate in the axial direction of the stator 10 to form second cooling passages W2. The first cooling passage W1 and the second cooling passage W2 penetrate through the structure of the stacked plurality of first stator laminations 11a in the axial direction of the stator 10, respectively, and guide the cooling medium in the second groove 115 of the second stator lamination 11b to the axial end portion of the stator 10. The group of cooling holes of the plurality of stator punching sheets 11a can form two cooling channels, so that double-layer cooling and heat dissipation of the stator 10 are realized, and the heat dissipation effect is improved.

In other embodiments, as shown in fig. 9a, the plurality of first stator laminations 11a are arranged in another arrangement, the first cooling holes 1131 of the plurality of first stator laminations 11a are arranged in a staggered manner along the respective circumferential directions of the stator 10, and the second cooling holes 1132 are arranged in a staggered manner along the respective circumferential directions of the stator 10.

Fig. 9B illustrates an enlarged detail view at B1 in fig. 9a, and fig. 9c illustrates a partial cross-sectional schematic view at B1 in fig. 9 a. Referring also to fig. 9a, 9b and 9c, two axially adjacent first stator laminations 11a can be rotated relative to the center circumference of the stator 10 by a set angle, which is the angle between two adjacent first cooling holes 1131 of the same first stator lamination 11 a. It is considered that two adjacent set angles are circumferentially offset from each other by a central angle between two cooling hole groups. The one first cooling hole 1131 of the former first stator plate 11a is offset from the one first cooling hole 1131 of the latter first stator plate 11a in the radial direction of the stator 10, and the distances between the two first cooling holes 1131 and the center O of the stator 10 are not equal. Specifically, in the radial direction of the stator 10, between two first cooling holes 1131 communicating in two adjacent first stator laminations 11a, the distance between one first cooling hole 1131 of one first stator lamination 11a and the center O of the stator 10 is greater than the distance between one first cooling hole 1131 of the other first stator lamination 11a and the center O of the stator 10.

With continued reference to fig. 9b and 9c, each first stator punch 11a is defined as a first cooling hole 1131 closest to the center O of the stator 10, and a first cooling hole 1131 farthest from the center O of the stator is defined as a first cooling hole 1131b. The first cooling hole 1131a of the first stator plate 11a can communicate with the first cooling hole 1131 of any one of the remaining first stator plates 11a, thereby forming a passage penetrating the plurality of first stator plates 11a. The cross section shown in fig. 9c passes through the first cooling holes 1131b, and the first cooling holes 1131b of the first stator plate 11a are blocked by the axial end faces of the adjacent first stator plates 11a. The second cooling holes 1132 of the same set of cooling holes as the first cooling holes 1131a can communicate with the second cooling holes 1132 of any one of the remaining first stator punches 11a, forming channels penetrating the plurality of first stator punches 11a. The second cooling holes 1132 of the same set of cooling holes as the first cooling holes 1131b can communicate with the second cooling holes 1132 of any one of the remaining first stator punches 11a, forming channels penetrating the plurality of first stator punches 11a. It is set that the plurality of first cooling holes 1131 communicate to form a first cooling passage W1, and the plurality of second cooling holes 1132 communicate to form a second cooling passage W2. The first cooling passages W1 corresponding to the first cooling holes 1131a are blocked, and the second cooling passages W2 corresponding to the second cooling holes 1132 of the same group of cooling holes as the first cooling holes 1131a penetrate the plurality of first stator punches 11a.

Fig. 9d illustrates an enlarged detail view at B2 in fig. 9a, and fig. 9e illustrates a partial cross-sectional schematic view at B2 in fig. 9 a. Referring to fig. 9a, 9d and 9e together, two axially adjacent first stator laminations 11a can be rotated relative to the center of the stator 10 by a set angle, which is the angle between two adjacent second cooling holes 1132 of the same first stator lamination 11a. It is considered that two adjacent set angles are circumferentially offset from each other by a central angle between two cooling hole groups. The one second cooling hole 1132 of the former first stator plate 11a is offset from the one second cooling hole 1132 of the latter first stator plate 11a in the radial direction of the stator 10, and the distances between the two second cooling holes 1132 and the center O of the stator 10 are not equal. Specifically, in the radial direction of the stator 10, between two second cooling holes 1132 communicating in two adjacent first stator laminations 11a, the distance between one second cooling hole 1132 of one first stator lamination 11a and the center O of the stator 10 is greater than the distance between one second cooling hole 1132 of the other first stator lamination 11a and the center O of the stator 10.

With continued reference to fig. 9d and 9e, the second cooling hole 1132 of each first stator punch 11a closest to the center O of the stator 10 is defined as a second cooling hole 1132a, and the second cooling hole 1132 farthest from the center O of the stator is defined as a second cooling hole 1132b. The second cooling holes 1132a of the first stator laminations 11a can communicate with the second cooling holes 1132 of any one of the remaining first stator laminations 11a, thereby forming channels through the plurality of first stator laminations 11a. The cross section shown in fig. 9e passes through the second cooling holes 1132b, and the second cooling holes 1132b of the first stator plate 11a are blocked by the axial end faces of the adjacent first stator plates 11a. The first cooling holes 1131 of the same group of cooling holes as the second cooling holes 1132b can communicate with the first cooling holes 1131 of any one of the remaining first stator punches 11a, forming passages penetrating the plurality of first stator punches 11a. The first cooling holes 1131 of the same group of cooling holes as the second cooling holes 1132a can communicate with the first cooling holes 1131 of any one of the remaining first stator punches 11a, forming passages penetrating the plurality of first stator punches 11a. The second cooling passages W2 corresponding to the second cooling holes 1132b are blocked, and the first cooling passages W1 corresponding to the first cooling holes 1131 of the same group of cooling holes as the second cooling holes 1132b penetrate the plurality of first stator punches 11a.

In addition, when the plurality of first stator laminations 11a are axially aligned, one first cooling hole 1131 is always blocked between any two adjacent first stator laminations 11a, so that the first cooling channels W1 are blocked and cannot be communicated. Similarly, in the middle of any two adjacent first stator laminations 11a, one second cooling hole 1132 is always blocked and the second cooling channel W2 is blocked and cannot be communicated. Taking the example of the plurality of first cooling holes 1131 of one stator plate 11a, when the first cooling channel W1 is blocked by a certain first stator plate 11a, the first stator plate 11a blocking the first cooling channel W1 may be one of the first stator plates 11a for the first cooling holes 1131 of different angular positions, and is not limited to the first stator plates 11a along the axial sides of the stator 10. Fig. 9f illustrates a case where the first cooling holes 1131 of the two first stator punches 11a located between the first stator punch 11a and the last first stator punch 11a are not communicated, resulting in blocking of the first cooling passages W1.

As can be seen from fig. 9a to 9f, the plurality of first stator laminations 11a are sequentially deflected and stacked in the axial direction of the stator 10 such that the m-th first cooling hole 1131 of one of the first stator laminations 11a communicates with the m+1th first cooling hole 1131 of the other first stator lamination 11a, and the n-th second cooling hole 1132 of one of the first stator laminations 11a communicates with the n+1th second cooling hole 1132 of the other first stator lamination 11a. Wherein, m and n are integers greater than or equal to 1, and the direction of the first cooling channel W1 formed by the communicating first cooling holes 1131 is inclined because the (m+1) th first cooling hole 1131 is offset outwards or inwards along the radial direction of the stator 10 relative to the (m) th first cooling hole 1131. The (n+1) th second cooling hole 1132 is offset outwardly or inwardly in the radial direction of the stator 10 with respect to the (n) th second cooling hole 1132, and the second cooling holes 1132 in communication with each other are inclined in the direction of the second cooling passage W2 formed. Both the first cooling channel W1 and the second cooling channel W2 can be used for cooling working medium circulation, and the inclined channel can change the circulation direction of the cooling working medium. In a specific arrangement, the arrangement manner of the plurality of first stator laminations 11a may be set, so that the first cooling channel W1 and the second cooling channel W2 incline toward the axis of the stator 10 along the direction in which the second stator laminations 11b point to the first stator laminations 11a, and then the cooling fluid ejected from the first cooling channel W1 and the second cooling channel W2 can be ejected toward the end winding to cool the end winding.

Among the plurality of first stator laminations 11a of the stator 10 provided in the embodiment of the present application, one first cooling hole 1131 of the former first stator lamination 11a is offset from one first cooling hole 1131 of the latter first stator lamination 11a along the radial direction of the stator 10, and the distances between the two first cooling holes 1131 and the center O of the stator 10 are different. The one first cooling hole 1131 of the previous first stator punch 11a communicates with the one first cooling hole 1131 of the next first stator punch 11a, and may form an inclined first cooling passage W1. The one second cooling hole 1132 of the former first stator plate 11a is offset from the one second cooling hole 1132 of the latter first stator plate 11a in the radial direction of the stator 10, and the distance between the two second cooling holes 1132 and the center O of the stator 10 is not the same. The second cooling hole 1132 of the previous first stator plate 11a communicates with the second cooling hole 1132 of the next first stator plate 11a to form an inclined second cooling passage W2. In such an arrangement structure of the first stator laminations 11a, with reference to the cooling hole group, a certain first cooling hole 1131 may be blocked by the axial end face of the adjacent first stator laminations 11a, resulting in a structure in which the first cooling channel W1 is blocked and cannot pass through the stacked formation of the plurality of first stator laminations 11a, and thus the cooling medium cannot be guided from the second groove 115 of the second stator lamination 11b to the axial end face of the stator 10. Alternatively, a certain second cooling hole 1132 may be blocked by the axial end face of the adjacent first stator plate 11a, so that the second cooling channel W2 is blocked and cannot penetrate through the structure formed by stacking the plurality of first stator plates 11a, and thus cannot guide the cooling medium from the second groove 115 of the second stator plate 11b to the axial end face of the stator 10. Fig. 9c illustrates a case where one of the plurality of second cooling holes 1132 in the cooling hole group is blocked by one first stator punching 11a, so that the second cooling channel W2 is blocked, and the plurality of first cooling holes 1131 are sequentially communicated with each other along the axial direction of the stator 10 to form a first cooling channel W1 that is inclined and penetrates. Fig. 9e illustrates that one of the plurality of first cooling holes 1131 in the cooling hole group is blocked by one first stator punching 11a, so that the first cooling channel W1 is blocked, and the plurality of second cooling holes 1132 are sequentially communicated with each other along the axial direction of the stator 10 to form a second cooling channel W2 which is inclined and penetrates.

In the stator 10 provided by the embodiment of the application, the stator core 1 capable of spraying liquid axially can be formed by splicing the three punching sheets 11, and the stator core 1 can spray cooling working medium in the stator 10 to the end winding along the axial end face of the stator 10. The number of the types of the punching sheet 11 is small, the manufacturing cost is low, and the large-scale production and assembly are facilitated. The plurality of first stator punching sheets 11a can serve as a structure of oil injection at the end part of the stator 10, an oil injection ring is omitted, the motor 100 with the stator 10 can be connected with phase electricity in a radial outgoing line mode, the axial size of the motor 100 is reduced, the axial space of the motor 100 is utilized to the greatest extent, and occasions with high requirements on space or power density can be adapted.

As can be seen from the above embodiments, specifically, the structure of each first stator punching sheet 11a is the same. When the plurality of first stator punching sheets 11a are axially arranged and any two adjacent first stator punching sheets 11a are rotationally staggered in the circumferential direction, one first cooling hole 1131 is always blocked in the middle of any two adjacent first stator punching sheets 11a, so that the first cooling channel W1 is blocked and cannot be communicated. Similarly, in the middle of any two adjacent first stator laminations 11a, one second cooling hole 1132 is always blocked and the second cooling channel W2 is blocked and cannot be communicated. The number of the first stator punching sheets 11a may be limited, and the arrangement manner of the first cooling holes 1131 and the second cooling holes 1132 may be adjusted, so that at least one cooling channel corresponding to one cooling hole in each cooling hole group may penetrate through all the first stator punching sheets 11a. The number and the stacking angle of the first stator punching sheets 11a are adjusted, so that at least one cooling channel corresponding to the first cooling holes 1131 and the second cooling holes 1132 in any one cooling hole group is a structure penetrating through the stacking of a plurality of first stator punching sheets 11a, and at the angle corresponding to the cooling hole group, the stator 10 is provided with a channel communicating the second groove 115 and the liquid outlet 102, so that the motor 100 can spray cooling working medium to the end winding along the circumferential direction of the stator 10, and the end winding is cooled by spraying the cooling working medium without dead zones in the circumferential range of the stator 10.

Illustratively, as shown in fig. 10, on any one of the first stator laminations 11a, a plurality of the first cooling holes 1131 are arranged at intervals along the circumferential direction of the stator 10, and the included angle between any two circumferentially adjacent first cooling holes 1131 is the same. The plurality of second cooling holes 1133 are arranged at intervals along the circumferential direction of the stator 10, and the included angle between any two circumferentially adjacent second cooling holes 1133 is the same. The number of the first cooling holes 1131 and the number of the second cooling holes 1132 are the same, and one first cooling hole 1131 corresponds to one second cooling hole 1132 in the radial direction of the stator 10, and the first cooling hole 1131 is located between the second cooling hole 1132 and the center hole 111. It is set that one of the plurality of first cooling holes 1131 closest to the center of the stator 10 in the radial direction of the stator 10 is a first start hole 1131q, and one of the plurality of second cooling holes 1132 closest to the center of the stator 10 in the radial direction of the stator 10 is a second start hole 1132q. Along the circumferential direction of the stator 10, the angle between the first start hole 1131q and the second start hole 1132q is β,180- α < β <180+α, and α is the interval angle between any two circumferentially adjacent first cooling holes 1131. For example, the first start hole 1131q is 180 ° inclined from the second start hole 1132q. The plurality of first stator laminations 11a are sequentially arranged in a staggered manner along the circumferential direction of the stator 10, and at least one cooling channel corresponding to one cooling hole in any one of the first cooling holes 1131 and the second cooling holes 1132 corresponding to the radial direction of the stator 10 is penetrated.

Fig. 11a shows a schematic sectional structure of the stator core 1, fig. 11b shows an enlarged detail view at C1 in fig. 11a, and fig. 11C shows an enlarged detail view at C2 in fig. 11 a. The stator core 1 includes a plurality of first stator laminations 11a, one second stator lamination 11b, and a plurality of third stator laminations 11c, the second stator lamination 11b being arranged between the plurality of first stator laminations 11a and the plurality of third stator laminations 11c in the axial direction of the stator 10. The outer peripheral surface of the second stator plate 11b includes a second groove 115, and an axial gap Q is formed between the second groove 115 and the first and third stator plates 11a, 11 c. The axial gap Q communicates with at least one cooling hole group of the first stator punching 11a and at the same time communicates with at least one first groove 114 of the third stator punching 11c, so that the cooling medium in the first groove 114 can be led to the first cooling hole 1131 and/or the second cooling hole 1132 and ejected from the axial end face of the stator 10.

Referring also to fig. 11a to 11c, the cross section passes through two of the cooling hole groups of the plurality of first stator laminations 11a on the left side. The axial gap Q corresponding to each cooling hole group is communicated with the first groove 114 of the third stator punching 11c, and the cooling medium in the first groove 114 can enter the axial gap Q. The plurality of first stator laminations 11a are divided into two parts in the axial direction of the stator 10, wherein one part of the first stator laminations 11a is arranged between the other part of the first stator laminations 11a and the second stator laminations 11 b. A portion of the first stator laminations 11a adjacent to the second stator laminations 11b are arranged in a stacked manner as shown in fig. 8, and another portion of the first stator laminations 11b are arranged in a stacked manner as shown in fig. 9c and 9 e. After the plurality of first stator punching sheets 11a are sequentially arranged, the first cooling channel W1 formed by the first cooling holes 1131 includes a straight line segment portion and an inclined line segment portion, and the second cooling channel W2 formed by the second cooling holes 1132 also includes a straight line segment portion and an inclined line segment portion. Wherein the diagonal cooling channels are inclined in the axial direction of the stator 10 towards the location of the end windings.

In connection with one of the cooling hole sets illustrated in fig. 11a and 11b, the first cooling channel W1 corresponding to the first cooling hole 1131 of the cooling hole set is blocked by one of the first stator laminations 11a, and the second cooling channel W2 corresponding to the second cooling hole 1132 penetrates through the plurality of first stator laminations 11a. The cooling medium in the first groove 114 can flow into the second cooling channel W2 through the axial gap Q, reach the liquid outlet 102 through the second cooling channel W2 and spray out, and spray and dissipate heat for the end winding.

In connection with another set of cooling holes illustrated in fig. 11a and 11c, a first cooling channel W1 corresponding to a first cooling hole 1131 of the set of cooling holes penetrates the plurality of first stator laminations 11a, and a second cooling channel W2 corresponding to a second cooling hole 1132 penetrates the plurality of first stator laminations 11a. The cooling medium in the first groove 114 can flow into the first cooling channel W1 and the second cooling channel W2 through the axial gap Q, reach the liquid outlet 102 through the first cooling channel W1 and the second cooling channel W2, and spray and dissipate heat of the end winding through liquid spraying.

It should be appreciated that when the distance between any two circumferentially adjacent first cooling holes 1131 of the first stator punching 11a changes, the trend of the first cooling passages W1 is inclined along the circumferential direction of the stator 10, so that the cooling medium is eccentrically deflected along the circumferential direction of the stator 10. Similarly, when the distance between any two circumferentially adjacent second cooling holes 1132 of the first stator punching 11a changes, the trend of the second cooling passages W2 is inclined along the circumferential direction of the stator 10, so that the cooling medium is eccentrically deflected along the circumferential direction of the stator 10. When the communication manner of the first cooling holes 1131 is inclined at the same time in the circumferential direction or the radial direction of the stator core 10, the manner in which the first cooling holes 1131 of the final stator 10 spray the cooling liquid can realize the rotary spray. When the communication manner of the second cooling holes 1132 is inclined at the same time in the circumferential direction or the radial direction of the stator core 10, the manner in which the second cooling holes 1132 of the final stator 10 spray the cooling liquid can realize the rotary spray. Of course, the injection angle and direction of the cooling liquid may be irregular, and the comparison of the embodiment of the present application is not limited.

After the plurality of first stator punching sheets 11a provided in the embodiment of the present application are arranged in a staggered manner along the circumferential direction of the stator 10, the first cooling channels W1 formed by communicating the first cooling holes 1131 may be used to spray the cooling medium in the stator 10 out of the axial end of the stator 10. When the first cooling channels W1 corresponding to a part of the first cooling holes 1131 cannot pass through all the first stator punching sheets 11a, the cooling medium in the stator 10 can be ejected out of the axial end of the stator 10 through the second cooling channels W2 formed by the communication of the second cooling holes 1132, and the second cooling holes 1132 can be regarded as an auxiliary structure of the first cooling holes 1131.

In some embodiments, taking the first stator laminations 11a with a certain number of first cooling holes 1131 as an example, when the plurality of first stator laminations 11a are arranged in a staggered manner along the circumferential direction of the stator 10, the smaller the number of first stator laminations 11a, the smaller the number of first cooling channels W1 corresponding to the first cooling holes 1131 are blocked. Therefore, the number of the second cooling holes 1132 may be reduced as needed, so that the second cooling holes 1132 are correspondingly provided in the first cooling holes 1131 corresponding to the blocked first cooling passages W1 in the plurality of first stator punches 11a, and the second cooling holes 1132 in the plurality of first stator punches 11a may be communicated to form the second cooling passages W2 penetrating all the first stator punches 11a. When the first cooling channels W1 corresponding to the first cooling holes 1131 are blocked, the second cooling channels W2 corresponding to the second cooling holes 1132 can pass through all the first stator punching sheets 11a. As shown in fig. 12, the number of second cooling holes 1132 is smaller than the number of first cooling holes 1131. A second cooling hole 1132 is provided at a side of a part of the first cooling holes 1131w away from the central hole 111, and the second cooling holes 1132 are not provided at an angle of the rest of the first cooling holes 1131 v. After the plurality of first stator laminations 11a shown in fig. 12 are arranged in a staggered manner along the circumferential direction of the stator 10, there may be a situation that the first cooling channels W1 formed corresponding to part of the first cooling holes 1131W are not penetrated, and the second cooling channels W2 formed corresponding to the second cooling holes 1132 can penetrate through all the first stator laminations 11a, so that the cooling medium in the stator 10 can still be guided to the axial end face of the stator 10 at the angle.

In the above embodiment, the second cooling holes 1132 are disposed on the side of the first cooling holes 1131 away from the center hole 111 in the radial direction of the stator 10, and the second cooling holes 1132 are closer to the outer peripheral surface of the first stator plate 11 a. Possibly, the second cooling hole 1132 may also be provided between the first cooling hole 1131 and the center hole 111. In the circumferential direction of the stator 10, it is sufficient to ensure that there is one first cooling hole 1131 and/or one second cooling hole 1132 at an angle at which the cooling medium needs to be injected. That is, the first cooling hole 1131 and the second cooling hole 1132 may be interchanged in position. Of course, the number of cooling holes may also be further increased, for example, a third cooling hole, a fourth cooling hole, etc. may be further added, so that the stator 10 may eventually be circumferentially sprayed with liquid.

In other embodiments, as shown in fig. 13a, in one set of cooling holes, the first cooling holes 1131 and the second cooling holes 1132 are adjacently arranged along the circumferential direction of the stator 10. In any one of the cooling hole groups, the distance H1 between the first cooling hole 1131 and the center O of the stator 10 and the distance H2 between the second cooling hole 1132 and the center O of the stator 10 may be the same or different, the first cooling hole 1131 is located between the outer circumferential surface of the first stator punch 11a and the bottom of the punch groove 112, and the second cooling hole 1132 is also located between the outer circumferential surface of the first stator punch 11a and the bottom of the punch groove 112. The apertures of the first cooling holes 1131 and the second cooling holes 1132 may be the same or different. An included angle between any two adjacent first cooling holes 1131 and second cooling holes 1132 is greater than 0 ° and smaller than α in the circumferential direction of the stator 10, and α is a central angle between any two adjacent first cooling holes 1131 in the circumferential direction of the stator.

Specifically, the plurality of first cooling holes 1131 are distributed at intervals along the circumferential direction of the stator 10, and the included angles between any two circumferentially adjacent first cooling holes 1131 are equal. The distances between the plurality of first cooling holes 1131 and the center O of the stator 10 gradually increase or decrease. For example, the plurality of first cooling holes 1131 are distributed along an asymptote whose base circle is the radius of the distance between the nearest first cooling hole 1131 to the center O of the stator 10 and the center O of the stator 10. The first cooling hole 1131 closest to the center O of the stator 10 is taken as a first cooling hole 1131 in the clockwise or counterclockwise direction, and the distances between the plurality of first cooling holes 1131 behind the first cooling hole 1131 and the center O of the stator 10 are gradually increased. Wherein, the distance between the kth+1th first cooling hole 1131 and the center O of the stator 10 is greater than the distance between the kth first cooling hole 1131 and the center O of the stator 10. Similarly, the plurality of second cooling holes 1132 are distributed at intervals along the circumferential direction of the stator 10, and the included angles between any two circumferentially adjacent second cooling holes 1132 are equal. The distances between the plurality of second cooling holes 1132 and the center O of the stator 10 gradually increase or decrease. For example, the plurality of second cooling holes 1132 are distributed along an asymptote whose base circle is the radius of the distance between the nearest second cooling hole 1132 to the center O of the stator 10 and the center O of the stator 10. The second cooling holes 1132 closest to the center O of the stator 10 are taken as first second cooling holes 1132 in the clockwise or counterclockwise direction, and the distances between the plurality of second cooling holes 1132 behind the first second cooling holes 1132 and the center O of the stator 10 are gradually increased. Wherein, the distance between the (k+1) th second cooling hole 1132 and the center O of the stator 10 is greater than the distance between the (k) th second cooling hole 1132 and the center O of the stator 10.

The plurality of first cooling holes 1131 in the first stator plate 11a shown in fig. 13a are arranged in a similar manner to the plurality of first cooling holes 1131 in the first stator plate 11a shown in fig. 7, and the plurality of second cooling holes 1132 are arranged in a similar manner. The difference is only that the relative positions between the first cooling holes 1131 and the second cooling holes 1132 in one set of cooling holes are changed. Accordingly, the first stator punching 11a shown in fig. 13a is arranged in a certain arrangement to form a part of the axial end portion of the stator 10, and the resulting structure of the stator 10 can be referred to as shown in fig. 13 b. As shown in fig. 13b, the plurality of first stator laminations 11a are divided into two groups, which are respectively located at both axial ends of the stator core 1. For the first stator lamination 11a located at the axial end of the stator 10, the port of the first cooling hole 1131 facing away from the second stator lamination 1b and the port of the second cooling hole 1132 facing away from the second stator lamination 1b form the liquid outlet 102.

As shown in fig. 13c, the plurality of first stator laminations 11a may be rotationally offset along the circumferential direction of the stator 10, such that the first cooling holes 1131 of each first stator lamination 11a are offset along the respective circumferential directions of the stator 10, and the second cooling holes 1132 are offset along the respective circumferential directions of the stator 10. The arrangement of the first cooling holes 1131 and the second cooling holes 1132 may be as shown in fig. 9c and fig. 9e, so that after the plurality of first stator punching sheets 11a are axially arranged and any two adjacent first stator punching sheets 11a are rotationally displaced circumferentially, at least one cooling channel corresponding to one cooling hole in each cooling hole group can penetrate through all the first stator punching sheets 11a. The number and the stacking angle of the first stator punching sheets 11a are adjusted, so that at least one cooling channel corresponding to the first cooling holes 1131 and the second cooling holes 1132 in any one cooling hole group is a structure penetrating through the stacking of a plurality of first stator punching sheets 11a, and at the angle corresponding to the cooling hole group, the stator 10 is provided with a channel communicating the second groove 115 and the liquid outlet 102, so that the motor 100 can spray cooling working medium to the end winding along the circumferential direction of the stator 10, and the end winding is cooled by spraying the cooling working medium without dead zones in the circumferential range of the stator 10.

Specifically, fig. 13D illustrates a detail enlargement at D1 in fig. 13c, and fig. 13e illustrates a detail enlargement at D2 in fig. 13 c. Referring to fig. 13c, 13d and 13e together, two axially adjacent first stator laminations 11a can be rotated relative to the center of the stator 10 by a set angle, which is the angle between two adjacent first cooling holes 1131 of the same first stator lamination 11a. The first cooling hole 1131 of the previous first stator punching 11a is offset from the first cooling hole 1131 of the next first stator punching 11a along the radial direction of the stator 10, and the second cooling hole 1132 of the previous first stator punching 11a is offset from the second cooling hole 1132 of the next first stator punching 11a along the radial direction of the stator 10, so that at least one cooling channel corresponding to one cooling hole in any one cooling hole group can penetrate through all the first stator punching 11a. In the two sets of cooling holes illustrated in fig. 13d, the cooling channels corresponding to the first cooling holes 1131 can penetrate all of the first stator punches 11a. The cooling channels corresponding to the second cooling holes 1132c in one cooling hole group can penetrate through all the first stator punching sheets 11a, and the cooling channels corresponding to the second cooling holes 1132d in the other cooling hole group can be blocked. In the two sets of cooling holes illustrated in fig. 13e, the cooling channels corresponding to the second cooling holes 1132 can penetrate all of the first stator punches 11a. The cooling channels corresponding to the first cooling holes 1131c in one cooling hole group can penetrate through all the first stator punching sheets 11a, and the cooling channels corresponding to the first cooling holes 1131d in the other cooling hole group can be blocked.

Fig. 14 illustrates a second stator lamination 11b, in which the second groove 115 on the second stator lamination 11b has a shape with a wider upper portion and a narrower lower portion. Specifically, in the circumferential direction of the stator 10, the notch size of the second groove 115 is larger than the groove bottom size of the second groove 115. That is, the second groove 115 has a larger dimension away from the center hole 111 than the second groove 115 has a dimension closer to the center hole 111.

Fig. 15a illustrates another second stator plate 11b, the radial dimension of the second stator plate 11b being smaller than the radial dimension of the first stator plate 11a and the radial dimension of the third stator plate 11 c. Taking the example that the first cooling holes 1131 are arranged between the second cooling holes 1132 and the center hole 111 in the radial direction of the stator 10, the distance between the outer circumferential surface of the second stator lamination 11b and the center of the stator 10 is smaller than or equal to the distance between the first cooling holes 1131 and the center O of the stator 10, or the distance between the outer circumferential surface of the second stator lamination 11b and the center of the stator 10 minus the radial dimension of the first cooling holes 1131 is smaller than the distance between the first cooling holes 1131 and the center O of the stator 10. When the second stator plate 11b is arranged between the first stator plate 11a and the third stator plate 11b, as shown in fig. 15b, an axial gap Q extending in the circumferential direction of the stator 10 and continuous may be formed between the first stator plate 11a, the outer circumferential surface of the second stator plate 11b, and the third stator plate 11 c. The axial gap Q is annular, so that the cooling medium can flow along the circumferential direction of the stator 10 in an annular manner and exchange heat, and the heat dissipation effect is prevented from being affected by local overheating of the stator 10. In this structure, the second stator lamination 11b may be fixed between the first stator lamination 11a and the third stator lamination 11b by bonding to form the stator core 1.

In some embodiments, the outer peripheral surface of the first stator punching 11a may be grooved, so that when the first cooling channel W1 corresponding to the first cooling hole 1131 is plugged, the cooling medium in the first cooling channel W1 may flow out from the groove on the outer peripheral surface of the first stator punching 11a, so as to prevent the accumulation of the cooling medium in the stator 10 to form a heat concentration area.

On the premise of not considering the process difficulty and the manufacturing cost, the stator core 1 can be formed by adopting the punching sheets 11 with different structures, and the cooling working medium in the stator 10 is led to the axial end part of the stator 10 and sprayed out from the liquid outlet 102 by carrying out different structural designs on each punching sheet 11, so that the spray liquid heat dissipation of the end winding can be realized, and the application does not need to be discussed too much.

In summary, the stator 10 of the motor 100 provided in the embodiment of the present application does not need an oil injection ring structure, and can inject the cooling medium to the end windings at the axial end of the stator 10 through the cooling channel of the stator 10 itself. The first stator punching sheets 11a with the plurality of first cooling holes 1131 and the plurality of second cooling holes 1132 are arranged according to a certain arrangement mode, and can spray cooling working media in the stator 10 from the liquid outlets 102 circumferentially distributed on the axial end face of the stator 10, so that circumferential liquid spraying at the end part of the stator 10 can be realized, thereby realizing efficient cooling of the end winding and obtaining good liquid cooling heat dissipation effect. In some embodiments, the stator 10 of the motor 100 provided in the embodiments of the present application has a lower temperature and a better heat dissipation effect than conventional oil-cooled heat dissipation. The oil spraying ring is omitted structurally, the cost of the motor 100 is further reduced, and the effects of cost reduction and efficiency improvement are achieved. In addition, the motor 100 provided in the embodiment of the present application may be applied to a driving of an electric vehicle, a generator, or an electronic air-conditioning compressor, and may also be used in fields such as a household electronic air-conditioning compressor, a motor for a robot, and an industrial motor, and may be adapted to occasions with high requirements on space or road density.

It will be apparent to those skilled in the art that various modifications and variations can be made to the present application without departing from the scope and spirit of the application. Thus, if such modifications and variations of the present application fall within the scope of the claims and the equivalents thereof, the present application is intended to cover such modifications and variations.

Claims

1. A stator lamination having cooling holes, the stator lamination comprising a plurality of first cooling holes and a plurality of second cooling holes;

each first cooling hole and each second cooling hole penetrate through the stator punching sheet along the axial direction of the stator punching sheet;

the plurality of first cooling holes are arranged at intervals along the circumferential direction of the stator punching sheet, and the plurality of second cooling holes are arranged at intervals along the circumferential direction of the stator punching sheet;

of the two adjacent first cooling holes in the circumferential direction of the stator lamination, a distance between one of the first cooling holes and the center of the stator lamination is greater than a distance between the other of the first cooling holes and the center of the stator lamination;

and in two adjacent second cooling holes along the circumferential direction of the stator punching sheet, the distance between one second cooling hole and the center of the stator punching sheet is larger than the distance between the other second cooling hole and the center of the stator punching sheet.

2. The stator plate of claim 1, wherein a distance between the first cooling hole and a center of the stator plate is smaller than a distance between the second cooling hole and the center of the stator plate in a radial direction of the stator plate.

3. The stator core of claim 2 wherein the first cooling holes are spaced apart from the second cooling holes in a radial direction of the stator core.

4. The stator core of claim 1 wherein one of said first cooling holes and one of said second cooling holes are aligned adjacent to each other in a circumferential direction of said stator core.

5. The stator plate of claim 4 wherein the first cooling holes and adjacent second cooling holes are equidistant from the center of the stator plate in the radial direction of the stator plate.

6. The stator plate of any one of claims 1-5 wherein the number of second cooling holes is less than the number of first cooling holes.

7. The stator core according to any one of claims 1 to 6, wherein a central angle between any two adjacent first cooling holes is the same along a circumferential direction of the stator core, and a central angle between any two adjacent second cooling holes is an integer multiple of a central angle between any two adjacent first cooling holes.

8. The stator core of claim 7, wherein a central angle between the first cooling hole closest to a center of the stator core and the second cooling hole closest to the center of the stator core is less than 180 ° + α and greater than 180 ° - α along a circumferential direction of the stator core, the α being a central angle between any two adjacent first cooling holes along the circumferential direction of the stator.

9. The stator plate of any one of claims 1-8, wherein the stator plate comprises a central bore and a plurality of plate grooves spaced apart along a circumference of the stator plate, each plate groove in communication with the central bore in a radial direction of the stator plate, the central bore and each plate groove extending through the stator plate in an axial direction of the stator plate;

and the distance between the first cooling hole and the center of the stator punching sheet is larger than the distance between the bottom of the punching sheet groove and the center of the stator punching sheet along the radial direction of the stator punching sheet.

10. The stator plate of claim 9, wherein the first cooling holes and the grooves are offset along a circumferential direction of the stator plate; and/or the second cooling holes and the punching sheet grooves are arranged in a staggered manner.

11. An electric machine, characterized in that the stator of the electric machine comprises a plurality of first stator laminations, at least one second stator lamination and at least one third stator lamination, the first stator lamination being a stator lamination according to any one of claims 1-10;

the second stator punching sheet is arranged between the first stator punching sheet and the third stator punching sheet along the axial direction of the stator core, the stator core comprises an axial gap between the first stator punching sheet and the third stator punching sheet, and the axial gap is communicated with at least one first cooling hole and at least one second cooling hole.

12. The motor of claim 11, wherein the second stator lamination includes a plurality of second grooves communicating with an outer circumferential surface of the second stator lamination in a radial direction of the stator core, the plurality of second grooves being arranged at intervals in a circumferential direction of the stator core;

the third stator punching sheet comprises a plurality of first grooves, the first grooves are communicated with the outer peripheral surface of the third stator punching sheet along the radial direction of the stator core, and the plurality of first grooves are arranged at intervals along the circumferential direction of the stator core;

Each of the second grooves communicates with at least one of the first cooling holes and one of the second cooling holes, and each of the second grooves communicates with at least one of the first grooves.

13. The motor of claim 12, wherein a slot size of each of the second grooves is larger than a slot bottom size of each of the second grooves in a circumferential direction of the stator.

14. The electric machine of claim 11, wherein an outer diameter of the second stator lamination is smaller than an outer diameter of the first stator lamination and an outer diameter of the third stator lamination.

15. The electric machine of any of claims 11-14, wherein one of said first cooling holes of one of said first stator laminations is in communication with a first cooling hole of another adjacent one of said first stator laminations and one of said second cooling holes of one of said first stator laminations is in communication with a second cooling hole of another adjacent one of said first stator laminations in the axial direction of the stator;

the distance between the first cooling hole of the one first stator punch and the center of the first stator punch is greater than the distance between the first cooling hole of the other first stator punch and the center of the first stator punch along the radial direction of the stator core.

16. A powertrain comprising a decelerator and a motor as claimed in any one of claims 11 to 14, the output shaft of the motor being drivingly connected to the input shaft of the decelerator.

17. An electric vehicle comprising wheels, a transmission, and the powertrain of claim 16, wherein the powertrain drives the wheels through the transmission.