Stator lamination having cooling holes, motor, powertrain, and electric vehicle

Abstract

Embodiments of the present application provide a stator lamination having cooling holes, a motor, a powertrain, and an electric vehicle. The stator lamination comprises a plurality of first cooling holes and a plurality of second cooling holes. The plurality of first cooling holes are spaced apart in the circumferential direction of the stator lamination, and the plurality of second cooling holes are spaced apart in the circumferential direction of the stator lamination. In two adjacent first cooling holes 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. In two adjacent second cooling holes in the circumferential direction of the stator lamination, the distance between one second cooling hole and the center of the stator lamination is greater than the distance between the other second cooling hole and the center of the stator lamination. The first cooling holes and the second cooling holes can be alternatives to each other, ensuring that the angle of spraying to the end of the motor covers the circumferential range of the motor, so as to satisfy the requirement for spraying in the circumferential direction of the motor to dissipate heat from an end winding.

Description

Stator punching sheet with cooling holes, motor, powertrain and electric vehicle

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office of the People's Republic of China on November 3, 2023, with application number 202311458791.8 and application name "Stator punching, motor, powertrain and electric vehicle with cooling holes", all contents of which are incorporated by reference into this application. Technical Field

[0003] The present application relates to the field of motor technology, and in particular to a stator punching sheet with cooling holes, a motor, a power assembly, and an electric vehicle. Background Art

[0004] With the development of technology, the power density of motors is getting higher and higher, while the size is getting smaller and smaller. The increase in motor power density has put forward higher requirements for motor heat dissipation.

[0005] During motor operation, heat loss from the stator core is a significant source of heat. This heat can be dissipated through oil cooling via heat dissipation channels within the stator. Oil spray rings, mounted at the axial ends of the stator, spray oil onto the end windings to dissipate the heat. To miniaturize the motor, existing technologies have proposed radially routing the motor windings, but this wiring arrangement is not compatible with the aforementioned oil spray ring oil cooling solution.

[0006] Summary of the Invention

[0007] The embodiments of the present application provide a stator punching, a motor, a powertrain and an electric vehicle with cooling holes. The stator punchings are stacked axially along the motor to form a structure that allows radial oil injection at the motor end, which can adapt to the solution of radial output of the motor winding.

[0008] In a first aspect, the present application provides a stator punching with cooling holes, which can be used to form the stator of an electric motor. The stator punching includes a plurality of first cooling holes and a plurality of second cooling holes. Along the axial direction of the stator punching, each first cooling hole and each second cooling hole passes through the stator punching. The plurality of first cooling holes are arranged at intervals along the circumference of the stator punching, and the plurality of second cooling holes are arranged at intervals along the circumference of the stator punching. Of two first cooling holes adjacent to each other along the circumference of the stator punching, the distance between one first cooling hole and the center of the stator punching is greater than the distance between the other first cooling hole and the center of the stator punching. Of two second cooling holes adjacent to each other along the circumference of the stator punching, the distance between one second cooling hole and the center of the stator punching is greater than the distance between the other second cooling hole and the center of the stator punching.

[0009] The stator punchings provided in the present application can be stacked along the axial direction of the motor to form a part of the stator core, and the first cooling hole and the second cooling hole can both be used to circulate the cooling medium. After a plurality of stator punchings are stacked along the axial direction of the motor, if the first cooling holes of two adjacent stator punchings are connected, a first cooling channel can be formed, and if the second cooling holes of two adjacent punchings are connected, a second cooling channel can be formed. Both the first cooling channel and the second cooling channel can be used to circulate the cooling medium. When one of the cooling channels is blocked, the other cooling channel can be used as an alternative to ensure that the cooling medium can flow through a plurality of stator punchings. The distance between the plurality of first cooling holes of the stator punchings and the center of the stator changes, and the distance between the plurality of second cooling holes of the stator punchings and the center of the stator changes. After the plurality of stator punchings are deflected and stacked in sequence along the circumference of the motor, the cooling channel formed by the connection of the first cooling holes and the cooling channel formed by the connection of the second cooling holes can be tilted along the radial direction of the stator core to change the flow direction of the coolant. When these multiple stator punchings are used for spraying liquid at the axial ends of the motor, the oil spray ring structure can be omitted, allowing the cooling medium in the stator to be sprayed out along the motor's axial direction toward the motor's central axis at an angle, dissipating heat from the end windings. The first cooling hole and the second cooling hole can serve as alternatives to each other, ensuring that the spray angle at the motor end covers the motor's circumferential range, meeting the motor's requirement for circumferential liquid spraying to dissipate heat from the end windings. Motors with these stator punchings have a smaller axial dimension and are suitable for applications with high space or power density requirements.

[0010] In some possible implementations, along the radial direction of the stator punching, the distance between the first cooling hole and the center of the stator punching is smaller than the distance between the second cooling hole and the center of the stator punching. The first cooling hole is arranged between the second cooling hole and the center of the stator punching, and the second cooling hole is closer to the outer circumference of the stator punching. Possibly, the first cooling hole and the second cooling hole can be arranged along the radial direction of the stator punching to form a radial double layer of 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 angular range in the stator circumferential direction.

[0011] In other possible implementations, a first cooling hole and a second cooling hole are arranged adjacent to each other circumferentially along the stator punching sheet. A plurality of first cooling holes form a group of cooling holes, and a plurality of second cooling holes form a group of cooling holes circumferentially along the stator punching sheet. Alternatively, a first cooling hole and an adjacent second cooling hole may be equidistant from the center of the stator punching sheet in a radial direction, and the cooling channels formed by the first cooling holes and the cooling channels formed by the second cooling holes may be within the same thickness range in the stator radial direction.

[0012] In some possible implementations, the number of stator punchings is relatively small. After the multiple stator punchings are circumferentially deflected and stacked, only some of the cooling channels corresponding to the first cooling holes are blocked. Second cooling holes can be configured for these blocked cooling channels. These second cooling holes can form cooling channels that pass through all stator punchings after the stator punchings are circumferentially deflected and stacked.

[0013] In some possible implementations, along the circumference of the stator punching, the central angle between any two adjacent first cooling holes is the same, 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 multiple stator punchings are circumferentially deflected and stacked, the first cooling holes and the second cooling holes are respectively connected to form two cooling channels.

[0014] Specifically, along the circumference of the stator punching, the central angle between the first cooling hole closest to the center of the stator punching and the second cooling hole closest to the center of the stator punching is less than 180°+α and greater than 180°-α, where α is the central angle between any two adjacent first cooling holes along the circumference of the stator, so as to ensure the effect of spraying the cooling medium along the circumference of the stator.

[0015] In some possible implementations, a stator punching includes a center hole and a plurality of punching grooves, wherein the plurality of punching grooves are spaced apart along the circumference of the stator punching, each punching groove is connected to the center hole in the radial direction of the stator punching, and the center hole and each punching groove extend through the stator punching in the axial direction of the stator punching. When the plurality of stator punchings are stacked along the axial direction of the motor, the center holes of the plurality of stator punchings can be connected to form a space in the stator core for accommodating the rotor, and the plurality of punching grooves can be connected to form stator slots in the stator core, which are used to wind the stator winding. In the radial direction of the stator, the distance between the first cooling hole and the center hole and the distance between the second cooling hole and the center hole are greater than the distance between the bottom of the punching groove and the center 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, thereby reducing the impact on the strength of the stator punching.

[0016] In some possible implementations, along the circumference of the stator punching sheet, the first cooling holes and the punching sheet grooves are staggered, and / or the second cooling holes and the punching sheet grooves are staggered, further improving the strength of the stator punching sheet.

[0017] In a second aspect, the present application provides a motor, wherein the stator of the motor includes a plurality of first stator punchings, at least one second stator punching, and at least one third stator punching, wherein the first stator punching is any one of the stator punchings provided in the first aspect above. Along the axial direction of the stator core, the second stator punching is arranged between the first stator punching and the third stator punching, and the stator core includes an axial gap between the first stator punching and the third stator punching, and the axial gap is connected to at least one first cooling hole and at least one second cooling hole. The axial gap can allow the cooling medium to flow circumferentially or radially along the stator to transport the cooling medium to the first cooling hole and the second cooling hole, so that the cooling medium can flow through both the first cooling hole and the second cooling hole.

[0018] In some possible implementations, the second stator punching sheet includes a plurality of second grooves, the second grooves are connected to the outer peripheral surface of the second stator punching sheet along the radial direction of the stator core, and the plurality of second grooves are spaced apart along the circumferential direction of the stator core. The third stator punching sheet includes a plurality of first grooves, the first grooves are connected to 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 spaced apart along the circumferential direction of the stator core. Each second groove is connected to at least one first cooling hole and at least one second cooling hole, and each second groove is connected to at least one first groove. The above-mentioned axial gap can be formed between the second groove and the first stator punching sheet and the third stator punching sheet, connecting the first groove with the first cooling hole and the second cooling hole, so that the cooling medium can flow to the axial end face of the stator.

[0019] In some possible implementations, along the circumference of the stator, the slot opening size of each second slot is larger than the slot bottom size of each second slot, so that the second slot can accommodate more cooling medium.

[0020] In some possible implementations, the outer diameter of the second stator punching is smaller than the outer diameters of the first stator punching and the outer diameters of the third stator punching. The aforementioned axial gap can be formed between the outer circumferential surface of the second stator punching and the first and third stator punchings, connecting the first groove with the first and second cooling holes, allowing the cooling medium to flow to the axial end surface of the stator.

[0021] In some possible implementations, along the axial direction of the stator, a first cooling hole of a first stator punch is connected to the first cooling hole of another adjacent first stator punch, and a second cooling hole of a first stator punch is connected to the second cooling hole of another adjacent first stator punch, so that the first cooling holes can form a cooling channel. Along the radial direction of the stator, the distance between a first cooling hole of a first stator punch and the center of the first stator punch is greater than the distance between a first cooling hole of another first stator punch and the center of the first stator punch. Then, the center of the cooling channel formed by the connection of the two first cooling holes is offset along the radial direction of the stator core, which can change the flow direction of the cooling medium. When the multiple stator punches are used as the axial end spray of the motor, the coolant can be sprayed obliquely along the axial direction of the motor toward the central axis of the motor to dissipate heat for the end winding.

[0022] In a third aspect, the present application provides a powertrain comprising a reducer and any of the motors provided in the second aspect, wherein the output shaft of the motor is connected to the input shaft of the reducer. The reducer can also be a transmission. Because the motor has excellent heat dissipation performance, it can improve the heat dissipation and power performance of the powertrain.

[0023] In a fourth aspect, the present application further provides an electric vehicle. The electric vehicle includes wheels, a transmission mechanism, and a powertrain according to the fourth aspect and any implementation thereof. The powertrain drives the wheels via the transmission mechanism. The electric vehicle provided in this application has excellent heat dissipation and power performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] FIG1 is a schematic structural diagram of an electric vehicle provided in an embodiment of the present application;

[0025] FIG2 is a schematic structural diagram of a powertrain provided in an embodiment of the present application;

[0026] FIG3 a is a schematic diagram of a partial structure of a stator of a motor provided in an embodiment of the present application;

[0027] FIG3 b is an exploded view of a stator of a motor provided in an embodiment of the present application;

[0028] FIG4 a is a schematic structural diagram of a stator core of a motor provided in an embodiment of the present application;

[0029] FIG4b is an enlarged view of the details at A1 in FIG4a;

[0030] FIG4c is an enlarged view of the details at A2 in FIG4a;

[0031] FIG5 a is an exploded view of a portion of the stator core of a motor provided in an embodiment of the present application;

[0032] FIG5 b is a schematic structural diagram of a first stator punching sheet of a motor provided in an embodiment of the present application;

[0033] FIG5c is a schematic structural diagram of a second stator punching sheet of a motor provided in an embodiment of the present application;

[0034] FIG5 d is a schematic structural diagram of a second stator punching sheet of a motor provided in an embodiment of the present application;

[0035] FIG6 a is a schematic diagram of a partial structure of a stator core of a motor provided in an embodiment of the present application;

[0036] FIG6 b is a schematic cross-sectional view of a portion of the structure of a stator core of a motor provided in an embodiment of the present application;

[0037] FIG7 is a schematic structural diagram of a first stator punching sheet of a motor provided in an embodiment of the present application;

[0038] FIG8 is a schematic diagram of a partially stacked cross-sectional structure of a first stator punching sheet of a motor provided by an embodiment of the present application;

[0039] FIG9a is a schematic diagram of the stacked structure of first stator sheets of a motor provided by an embodiment of the present application;

[0040] FIG9b is an enlarged view of the detail at B1 in FIG9a;

[0041] FIG9c is a schematic diagram of a partial cross-sectional structure at point B1 in FIG9a;

[0042] FIG9 d is an enlarged view of the detail at B2 in FIG9 a ;

[0043] FIG9e is a schematic diagram of a partial cross-sectional structure at point B2 in FIG9a;

[0044] FIG9f is a schematic diagram of a partially stacked cross-sectional structure of a first stator punching sheet of a motor provided by an embodiment of the present application;

[0045] FIG10 is a schematic structural diagram of a first stator punching sheet of a motor provided in an embodiment of the present application;

[0046] FIG11a is a schematic cross-sectional view of a stator core of a motor provided in an embodiment of the present application;

[0047] FIG11b is an enlarged view of the details at C1 in FIG11a;

[0048] FIG11c is an enlarged view of the details at C2 in FIG11a;

[0049] FIG12 is a schematic structural diagram of a first stator punching sheet of a motor provided in an embodiment of the present application;

[0050] FIG13a is a schematic structural diagram of a first stator punching sheet of a motor provided in an embodiment of the present application;

[0051] FIG13 b is a schematic structural diagram of a stator of a motor provided in an embodiment of the present application;

[0052] FIG13c is a schematic structural diagram of stacked first stator sheets of a motor provided by an embodiment of the present application;

[0053] FIG13d is an enlarged view of the detail at D1 in FIG13c;

[0054] FIG13e is an enlarged view of the detail at D2 in FIG13c;

[0055] FIG14 is a schematic structural diagram of a second stator punching sheet of a motor provided in an embodiment of the present application;

[0056] FIG15a is an exploded view of a portion of the stator core of a motor provided by an embodiment of the present application;

[0057] FIG15 b is a schematic cross-sectional view of a portion of the structure of a stator core of a motor provided in an embodiment of the present application.

[0058] Reference numerals:

[0059] 1000-powertrain; 2000-transmission mechanism; 3000-wheel;

[0060] 100-motor; 200-reducer;

[0061] 10- stator; 101- liquid inlet; 102- liquid outlet; 103- stator teeth; 104- stator slots; 20- rotor; 30- motor shaft;

[0062] 1- stator core; 11- punching sheet; 11a- first stator punching sheet; 11b- second stator punching sheet; 11c- third stator punching sheet; 111- center hole; 112- punching sheet groove; 1131, 1131a, 1131b, 1131c, 1131d, 1131w, 1131v- first cooling hole; 1132, 1132a, 1132b, 1132c, 1132d- second cooling hole; 1131q- first starting hole; 1132q- second starting hole; 114- first groove; 115- second groove; 2- stator winding; 3- housing; 31- liquid inlet pipe; 32- radial groove. DETAILED DESCRIPTION

[0063] Motor losses are divided into copper losses, iron losses, and mechanical losses. Copper losses are the primary loss in medium- and low-speed motors. Within the motor structure, copper losses are distributed across the motor's end windings and the windings within the core slots. Because the core has excellent thermal conductivity, the temperature rise of the windings within the slots is often lower than that of the end windings without special cooling. Specifically, oil can be passed through the back of the stator core and sprayed onto the end coils of the stator windings. This effectively cools the end windings and allows the motor to operate at higher current and power densities. Traditionally, an oil spray ring is installed at the axial end of the motor, through which oil is sprayed onto the end windings. The stator windings of the motor then run axially to connect to the phase power. In hybrid vehicles, due to the space occupied by the engine, the hybrid system places extremely high demands on the axial dimensions of the motor. This limits the system layout to a few millimeters and makes it impossible to achieve savings. In order to minimize the axial size of the motor, the phase wires are generally routed radially out of the motor winding. However, this radial routing method is not compatible with the oil spray ring in terms of structure or process, posing a challenge to the traditional oil cooling method of the motor oil spray ring.

[0064] Based on this, the embodiments of the present application provide a stator punching sheet, a motor, a powertrain and an electric vehicle with cooling holes, wherein the first cooling hole and the second cooling hole can be alternatives to each other, ensuring that the injection angle at the end of the motor covers the circumferential range of the motor, improving the heat dissipation effect, and improving the power performance and service life of the motor and powertrain.

[0065] In order to make the purpose, technical solutions and advantages of this application clearer, this application will be further described in detail below with reference to the accompanying drawings.

[0066] The terms used in the following embodiments are only for the purpose of describing specific embodiments and are not intended to limit the present application. As used in the specification and appended claims of this application, the singular expressions "a", "an", "said", "above", "the", and "this" are intended to also include expressions such as "one or more", unless the context clearly indicates otherwise.

[0067] References to "one embodiment" or "some embodiments" in this specification mean that a particular feature, structure, or characteristic described in conjunction with that embodiment is included in one or more embodiments of the present application. Thus, phrases such as "in one embodiment," "in some embodiments," "in other embodiments," and "in yet other embodiments" appearing in various places in this specification do not necessarily refer to the same embodiment, but rather mean "one or more but not all embodiments," unless otherwise specifically emphasized. The terms "including," "comprising," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0068] Figure 1 is a schematic diagram of an electric vehicle provided in accordance with an embodiment of the present application. Referring to Figure 1 , the electric vehicle provided in accordance with an embodiment of the present application includes a powertrain 1000, a transmission mechanism 2000, and wheels 3000. Powertrain 1000 drives wheels 3000 via transmission mechanism 2000. Powertrain 1000 is used to convert electrical energy into mechanical energy. Transmission mechanism 2000 is used to provide a transmission connection between powertrain 1000 and wheels 3000.

[0069] FIG2 is a schematic diagram of a powertrain provided in an embodiment of the present application. As shown in FIG2 , the powertrain 1000 provided in an embodiment of the present application includes a motor 100 and a reducer 200. The motor 100 and the reducer 200 are transmission-connected. The motor 100 is used to drive a transmission mechanism 2000 of an electric vehicle through the reducer 200. The motor 100 includes a stator 10, a rotor 20, and a motor shaft 30. The rotor 20 is coaxially fixed to the motor shaft 30, and the motor shaft 30 is transmission-connected to the reducer 200. The stator 10 includes a stator core 1, a stator winding 2, and a housing 3. The stator core 1 is sleeved on the outside of the rotor 20, the stator winding 2 is wound on the stator core 1, and the housing 3 is arranged outside the stator core 1. The reducer 200 may also be a transmission. The stator core 1 , the rotor 20 and the motor shaft 30 are coaxially assembled. The axial direction of the stator 10 is also the axial direction of the motor 100 , the circumferential direction of the stator 10 is also the circumferential direction of the motor 100 , and the radial direction of the stator 10 is also the radial direction of the motor 100 .

[0070] The motor 100 provided in the embodiment of the present application is a motor with liquid-cooled stator windings. Specifically, the cooling medium used to dissipate heat from the stator 10 can be simultaneously sprayed onto the end windings of the stator winding 2 to dissipate heat. Referring to Figures 2 and 3a, along the circumference of the motor 100, the end of the stator 10 includes at least one liquid inlet 101 and multiple liquid outlets 102 connected to the external space. The stator 10 has a channel for the circulation of the cooling medium. The liquid inlet 101 and the liquid outlet 102 are respectively connected to the channel. The cooling medium is injected into the channel within the stator 10 through the liquid inlet 101, and the liquid is sprayed onto the end windings through the liquid outlet 102. The housing 3 includes a liquid inlet pipe 31, which is a hollow tube. One end of the liquid inlet pipe 31 is fixed to the outer circumferential surface of the housing 3, and the liquid inlet pipe 31 is connected to the channel for the circulation of the cooling medium within the housing 3. The end of the liquid inlet pipe 31 facing away from the outer circumferential surface of the housing 3 forms the liquid inlet 101. Along the axial direction of the motor 100, the liquid outlet 102 is provided at the end of the stator core 1. The stator 10 is generally annular, and a plurality of stator teeth 103 are provided on the inner side of the stator core 1. Along the circumference of the stator core 1, stator slots 104 are formed between any two adjacent stator teeth 103, and the stator winding 2 can be wound on the stator teeth 103. When power is supplied to the stator winding 2, a magnetic field is formed at the center of the stator 10, and the rotor 20 can rotate around the axis of the motor shaft 30 in the magnetic field. Specifically, part of the stator winding 2 is accommodated in the stator slots 104, and part of the stator winding 2 protrudes from the axial end face of the stator 10 along the axial direction of the stator 10. When the stator 10 is cooled by liquid cooling, the cooling medium can be sprayed from the liquid outlet 102 to the end windings of the stator winding 2, thereby achieving liquid cooling and heat dissipation of the end windings. For the convenience of illustration, the stator winding 2 is hidden in Figure 3a.

[0071] For example, as shown in FIG3b , which shows 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 punchings 11 arranged adjacent to each other in the axial direction of the stator 10. The housing 3 is cylindrical, and the inner wall of the housing 3 includes radial grooves 32. The radial grooves 32 are formed by grooves provided on the inner wall of the housing 3. The radial grooves 32 extend along the circumference of the housing 3, and the bottom of the radial grooves 32 is connected to 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 of which extends along the axial direction of the stator 10. When the housing 3 is sleeved on the outer circumferential surface of the stator core 1, the radial grooves 32 of the housing 3 can be connected to the plurality of axial grooves 103. The cooling medium entering from the liquid inlet 101 can flow along the radial grooves 32 of the housing 3 along the circumference of the stator 10 and enter the plurality of axial grooves 103. 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 punching sheets 11 arranged adjacent to each other along the axial direction of the stator 10. The punching sheet 11 located at the axial end face of the stator 10 can be considered as the end plate structure of the stator 10, and the liquid outlet 102 is formed on the punching sheet 11 located at the axial end of the stator core 1. Each punching sheet 11 includes a center hole 111 and a plurality of punching sheet grooves 112, and the number of punching sheet grooves 112 is multiple. The center hole 111 is located at the center of the punching sheet 11, and each punching sheet groove 112 extends along the radial direction of the punching sheet 11 and is connected to the center hole 111 to form the stator slot 104 in Figure 3a, and the bottom of the punching sheet groove 112 is away from the center of the punching sheet 11. Along the circumference of the punching sheet 11, a plurality of punching sheet grooves 112 are arranged at intervals. Along the axial direction of the stator 10, the center hole 111 and each punching sheet groove 112 pass through the punching sheet 11 respectively. After the multiple punching sheets 11 are arranged adjacently along the circumference of the stator 10, the center holes 111 of the multiple punching sheets 11 can be interconnected to form a space for accommodating the rotor 20. The multiple punching grooves 112 of the multiple punching sheets 11 can be connected to each other, and the structure between any two punching grooves 112 can be stacked along the axial direction of the stator 10 to form the stator teeth 103 of the stator 10. Along the circumference of the stator 10, the space between any two adjacent stator teeth 103 is a stator slot 104.

[0072] Figure 4a shows the structure of the stator core 1. The stator core 1 provided in the embodiment of the present application includes a plurality of punchings 11, which include a plurality of first stator punchings 11a, at least one second stator punching 11b, and at least one third stator punching 11c. For example, along the axial direction of the stator core 1, the second stator punching 11b is arranged between the first stator punching 11a and the third stator punching 11c. Along the axial direction of the stator 10, at least one second stator punching 11b and a plurality of first stator punchings 11a are arranged at both ends of the third stator punching 11c.

[0073] FIG4 b shows an enlarged view of the details at A1 in FIG4 a . A plurality of first stator punchings 11 a are located at the axial end of the stator core 1 . The first stator punchings 11 a include a plurality of first cooling holes 1131 and a plurality of second cooling holes 1132 that penetrate the first stator punchings 11 a in the axial direction of the stator 10 . The first cooling holes 1131 and the second cooling holes 1132 are both connected to the channels for the circulation of the cooling medium inside the stator 10 , and the cooling medium can pass through the first cooling holes 1131 and the second cooling holes 1132 . For the first stator punchings 11 a located at the axial end of the stator 10 , the ports of the first cooling holes 1131 facing away from the second stator punchings 11 b and the ports of the second cooling holes 1132 facing away from the second stator punchings 11 b form the aforementioned liquid outlet 102 . Referring to FIG4 a and FIG4 b together, along the circumference of the stator 10 , the plurality of first cooling holes 1131 are arranged at intervals, and the plurality of second cooling holes 1132 are arranged at intervals. The first cooling holes 1131 are distributed over substantially one circumference of the first stator punching 11a, and the second cooling holes 1132 are also distributed over substantially one circumference of the first stator punching 11a. Along the circumference of the first stator punching 11a, the first cooling holes 1131 and the punching grooves 112 are staggered, or the second cooling holes 1132 and the punching grooves 112 are staggered, or both the first cooling holes 1131 and the second cooling holes 1132 are staggered with the punching grooves 112, to ensure the structural strength of the first stator punching 11a.

[0074] Figure 4c shows an enlarged view of the details at A2 in Figure 4a. As shown in Figure 4c, the outer circumferential surface of the second stator punching sheet 11b includes a plurality of first grooves 114, which extend in the axial direction of the stator 10 and penetrate the second stator punching sheet 11b. Along the circumference of the stator 10, the plurality of first grooves 114 are spaced apart, 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. For example, there are multiple second stator punching sheets 11b, and the first grooves 114 on the outer circumferential surfaces of the plurality of second stator punching sheets 11b may be connected in the axial direction of the stator 10, thereby forming the aforementioned axial groove 103.

[0075] Continuing with Figure 4c, the stator core 1 includes an axial gap Q between the first stator punching 11a and the third stator punching 11c. The axial gap Q is connected to at least one first groove 114. Simultaneously, the axial gap Q is connected to at least one first cooling hole 1131 and at least one second cooling hole 1132. When the axial gap Q connects the first cooling hole 1131 and the second cooling hole 1132 to the at least one first groove 114, the cooling medium in the first groove 114 can be transported to the first cooling hole 1131 and the second cooling hole 1132 via the axial gap Q. When the first cooling holes 1131 of the plurality of first stator punchings 11a are connected along the axial direction of the stator 10, and the second cooling holes 1132 of the plurality of first stator punchings 11a are connected along the axial direction of the stator 10, the cooling medium can be transported to the axial end surface of the stator core 1 and ejected from the liquid outlet 102. The axial gap Q serves to collect the cooling medium, allowing it to be radially closer to the center of the stator 10, facilitating its spraying from the first cooling holes 1131 and the second cooling holes 1132 toward the end windings. The collecting effect of the axial gap Q also provides a more sufficient supply of liquid for the spraying of the cooling medium at the circumferential ends of the stator 10, ensuring sufficient injection pressure and velocity. Axial gap Q can be implemented in a variety of ways, requiring less assembly precision and being easier to implement.

[0076] Figure 5a shows a schematic diagram of a stator core 1 comprising a first stator lamination 11a, a second stator lamination 11b, and a third stator lamination 11c arranged axially spaced apart from each other in the stator 10. As shown in Figure 5a, the second stator lamination 11b is arranged between the first stator lamination 11a and the third stator lamination 11c. The first, second, and third stator laminations 11a, 11b, and 11c have the same radial dimensions. The outer circumference of the second stator lamination 11b includes a second groove 115. When the first, second, and third stator laminations 11a, 11b, and 11c are adjacently arranged axially in the stator 10, one axial end face of the second stator lamination 11b contacts the first stator lamination 11a, and the other axial end face of the second stator lamination 11b contacts the third stator lamination 11c. This creates the aforementioned axial gap Q between the first stator lamination 11a, the second groove 115, and the third stator lamination 11c. The first stator punching sheet 11 a , the second stator punching sheet 11 b and the third stator punching sheet 11 c have the same outer diameter, which facilitates welding and fixing the outer circumferences of the plurality of punching sheets to form the stator core 1 .

[0077] Based on Figure 5a , please refer to the structure of the first stator punching 11a shown in Figure 5b . As shown in Figure 5b , the number of first cooling holes 1131 is the same as the number of second cooling holes 1132 . Multiple first cooling holes 1131 are spaced apart along the circumference of the stator 10 , and multiple second cooling holes 1132 are spaced apart along the circumference of the stator 10 . In the radial direction of the stator 10 , one first cooling hole 1131 and one second cooling hole 1132 are spaced apart, with the first cooling hole 1131 positioned between the second cooling hole 1132 and the center hole 111 . The first cooling hole 1131 and the second cooling hole 1132 arranged radially along the stator 10 can be considered a group of cooling holes. In a group of cooling holes, the distance H11 between the first cooling hole 1131 and the center O of the stator 10 is smaller than the distance H12 between the second cooling hole 1132 and the center O of the stator 10 . 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 punch groove 112 and the center O of the stator 10. This allows the first cooling holes 1131 and the second cooling holes 1132 to be distributed near the outer circumference of the first stator punch 11a, ensuring the structural strength of the first stator punch 11a. The first cooling holes 1131 and the second cooling holes 1132 are illustratively circular, and along the circumference of the stator 10, the radial dimensions of the first cooling hole 1131 and the second cooling holes 1132 are similar. Due to manufacturing process factors, the centers of the first cooling holes 1131 and the second cooling holes 1132 do not need to be strictly spaced apart along the radial direction of the stator 10. In Figure 5b, the first cooling holes 1131 and the second cooling holes 1132 are evenly distributed along the circumference of the stator 10, with the included angles between any two adjacent first cooling holes 1131 being equal, and the included angles between any two adjacent second cooling holes 1132 being equal. The number of first cooling holes 1131 can be a factor of the number of stator teeth of the stator 10. For example, for a stator 10 with 48 slots, the number of first cooling holes 1131 can be 48, 24, 16, 8, etc. The spacing angle between any two first cooling holes 1131 adjacent to each other along the circumference of the stator 10 also changes to 7.5°, 15°, 22.5°, 45°, etc. according to the number. The number of second cooling holes 1132 can be the same as or different from the number of first cooling holes 1131. The first cooling holes 1131 and the second cooling holes 1132 arranged radially along the stator 10 are regarded as a cooling hole group. The number of this cooling hole group is half the number of the punching grooves 112, and every two adjacent punching grooves 112 correspond to one cooling hole group. Among them, the first cooling hole 1131 and the second cooling hole 1132 are respectively deflected at a certain angle relative to the punching groove 112 in the circumferential direction, so that the first cooling hole 1131 and the second cooling hole 1132 are respectively staggered with the punching groove 112 along the circumferential direction of the stator 10, further improving the structural strength of the first stator punching 11a.

[0078] Based on Figure 5a , please refer to the structure of the second stator punching 11b shown in Figure 5c . This second stator punching 11b has a gear-shaped punching structure. As shown in Figure 5c , the second groove 115 is illustratively rectangular. The distance H2 between the bottom of the second groove 115 and the center O of the stator 10 is less than or equal to the distance H11 between the first cooling hole 1131 and the center O of the stator 10 in Figure 5b . Alternatively, the distance H2 between the bottom of the second groove 115 and the center O of the stator 10 minus the radial dimension of the first cooling hole 1131 is less than the distance H11 between the first cooling hole 1131 and the center O of the stator 10. When the first stator punching 11a and the second stator punching 11b are arranged adjacent to each other, the second groove 115 can at least partially communicate with the first cooling hole 1131 and the second cooling hole 1132 along the axial direction of the stator 10. Along the circumference of the stator 10, the size of the second groove 115 is larger than the size of a group of cooling holes, in which the first cooling holes 1131 and the second cooling holes 1132 are arranged at intervals along the radial direction of the stator 10. The second groove 115 can be connected to multiple groups of cooling holes at the same time.

[0079] Based on Figure 5d, please refer to the structure of the third stator sheet 11c shown in Figure 5d. As shown in Figure 5d, multiple first grooves 114 are spaced apart along the circumference of the stator 10. Along the circumference of the stator 10, the distance between any two first grooves 114 may not be equal. When the third stator sheet 11c is arranged adjacent to the second stator sheet 11b, only some of the multiple first grooves 114 will communicate with the second grooves 115. The second grooves 115 can simultaneously communicate with one or more first grooves 114.

[0080] Figure 6a shows a schematic diagram of a first stator punching 11a, a second stator punching 11b, and a third stator punching 11c arranged adjacent to each other in the axial direction of the stator 10. As shown in Figure 6a, the second stator punching 11b is clamped between the first stator punching 11a and the third stator punching 11c. Combined with the partial cross-sectional structural schematic diagram shown in Figure 6b, the above-mentioned axial gap Q is formed between the second groove 115 of the second stator punching 11b and the first stator punching 11a and the third stator punching 11c. Along the axial direction of the stator 10, one end of the second groove 115 is connected to a group of cooling holes, that is, the second groove 115 is simultaneously connected to a first cooling hole 1131 and a second cooling hole 1132. The other end of the second groove 115 is connected to at least one first groove 114.

[0081] FIG7 illustrates a schematic structural diagram of the first stator punching 11a along the axial direction of the stator 10. As shown in FIG7 , of two adjacent first cooling holes 1131 along the circumferential direction of the stator 10, the distance H112 between one first cooling hole 1131 and the center O of the stator 10 is greater than the distance H111 between the other first cooling hole 1131 and the center O of the stator 10. Exemplarily, 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, where the base circle of the asymptote is the distance between the first cooling hole 1131 closest to the center O of the stator 10 and the center O of the stator 10 as the radius. In a clockwise or counterclockwise direction, starting with the first cooling hole 1131 closest to the center O of the stator 10 as the first first cooling hole 1131, the distances between the plurality of first cooling holes 1131 and the center O of the stator 10 gradually increase. The distance between the k+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 .

[0082] Continuing with FIG. 7 , between two adjacent second cooling holes 1132 along the circumference of the stator 10, the distance H122 between one second cooling hole 1132 and the center O of the stator 10 is greater than the distance H121 between the other second cooling hole 1132 and the center O of the stator 10. Exemplarily, 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, where the base circle of the asymptote is the distance between the second cooling hole 1132 closest to the center O of the stator 10 and the center O of the stator 10 as the radius. In a clockwise or counterclockwise direction, starting with the second cooling hole 1132 closest to the center O of the stator 10 as the first second cooling hole 1132, the distances between the plurality of second cooling holes 1132 and the center O of the stator 10 gradually increase. The distance between the k+1th second cooling hole 1132 and the center O of the stator 10 is greater than the distance between the kth second cooling hole 1132 and the center O of the stator 10 .

[0083] Multiple first stator punchings 11a are arranged adjacent to each other along the axial direction of the stator 10. As shown in Figure 8, in each first stator punching 11a, first cooling holes 1131 that are equidistant from the center O of the stator 10 are connected along the axial direction of the stator 10 to form a first cooling channel W1, and second cooling holes 1132 that are equidistant from the center O of the stator 10 are connected along the axial direction of the stator 10 to form a second cooling channel W2. The first cooling channel W1 and the second cooling channel W2 respectively penetrate the stacked structure of multiple first stator punchings 11a along the axial direction of the stator 10, and guide the cooling medium in the second groove 115 of the second stator punching 11b to the axial end of the stator 10. A group of cooling holes in multiple first stator punchings 11a can form two cooling channels, achieving double-layer cooling and heat dissipation of the stator 10 and improving the heat dissipation effect.

[0084] In other embodiments, as shown in FIG9 a , the plurality of first stator punching sheets 11 a are arranged in another arrangement, wherein the first cooling holes 1131 of the plurality of first stator punching sheets 11 a are staggered along the circumferential directions of the stator 10 , and the second cooling holes 1132 are staggered along the circumferential directions of the stator 10 .

[0085] Figure 9b illustrates an enlarged view of the details at B1 in Figure 9a, and Figure 9c illustrates a partial cross-sectional schematic diagram at B1 in Figure 9a. Referring to Figure 9a, Figure 9b, and Figure 9c, two axially adjacent first stator punches 11a can be rotated circumferentially relative to the center of the stator 10 by a set angle. The set angle is the angle between two adjacent first cooling holes 1131 of the same first stator punch 11a. It can be considered that the two adjacent set angles are the central angles between two circumferentially staggered cooling hole groups. A first cooling hole 1131 of the preceding first stator punch 11a and a first cooling hole 1131 of the succeeding first stator punch 11a are offset radially from the stator 10, and the distances between the two first cooling holes 1131 and the center O of the stator 10 are unequal. Specifically, along the radial direction of the stator 10, between two connected first cooling holes 1131 in two adjacent first stator punches 11a, the distance between one first cooling hole 1131 of one first stator punch 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 punch 11a and the center O of the stator 10.

[0086] Continuing with Figures 9b and 9c, the first cooling hole 1131 closest to the center O of the stator 10 in each first stator punching 11a is defined as first cooling hole 1131a, and the first cooling hole 1131 farthest from the center O of the stator is defined as first cooling hole 1131b. The first cooling hole 1131a of the first first stator punching 11a can communicate with the first cooling hole 1131 of any remaining first stator punching 11a, thereby forming a channel that penetrates the plurality of first stator punchings 11a. The cross-section shown in Figure 9c passes through first cooling hole 1131b, where the first cooling hole 1131b of the first first stator punching 11a is blocked by the axial end face of the adjacent first stator punching 11a. Second cooling holes 1132 in the same cooling hole group as first cooling holes 1131a can communicate with the second cooling holes 1132 of any remaining first stator punching 11a, thereby forming a channel that penetrates the plurality of first stator punchings 11a. The second cooling holes 1132 in the same cooling hole group as the first cooling holes 1131b can communicate with the second cooling holes 1132 of any remaining first stator punching 11a, forming a channel that penetrates the multiple first stator punchings 11a. It is assumed that the multiple first cooling holes 1131 are connected to form a first cooling channel W1, and the multiple second cooling holes 1132 are connected to form a second cooling channel W2. The first cooling channel W1 corresponding to the first cooling hole 1131a is blocked, and the second cooling channel W2 corresponding to the second cooling hole 1132 in the same cooling hole group as the first cooling hole 1131a penetrates the multiple first stator punchings 11a.

[0087] Figure 9d illustrates an enlarged view of the details at B2 in Figure 9a, and Figure 9e illustrates a partial cross-sectional schematic diagram at B2 in Figure 9a. Referring to Figure 9a, Figure 9d, and Figure 9e, two axially adjacent first stator punches 11a can be rotated circumferentially relative to the center of the stator 10 by a set angle. The set angle is the angle between two adjacent second cooling holes 1132 of the same first stator punch 11a. It can be considered that the two adjacent set angles are the central angles between two circumferentially staggered cooling hole groups. A second cooling hole 1132 of the preceding first stator punch 11a and a second cooling hole 1132 of the succeeding first stator punch 11a are offset radially from the stator 10, and the distances between the two second cooling holes 1132 and the center O of the stator 10 are unequal. Specifically, along the radial direction of the stator 10, between two connected second cooling holes 1132 in two adjacent first stator punches 11a, the distance between one second cooling hole 1132 of one first stator punch 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 punch 11a and the center O of the stator 10.

[0088] Continuing with Figures 9d and 9e, the second cooling hole 1132 closest to the center O of the stator 10 in each first stator punch 11a is defined as second cooling hole 1132a, and the second cooling hole 1132 farthest from the center O of the stator is defined as second cooling hole 1132b. The second cooling hole 1132a of the first first stator punch 11a can communicate with the second cooling hole 1132 of any remaining first stator punch 11a, thereby forming a channel that penetrates the multiple first stator punches 11a. The cross-section shown in Figure 9e passes through the second cooling hole 1132b, and the second cooling hole 1132b of the first first stator punch 11a is blocked by the axial end face of the adjacent first stator punch 11a. The first cooling holes 1131 in the same cooling hole group as the second cooling holes 1132b can communicate with the first cooling holes 1131 of any remaining first stator punch 11a, thereby forming a channel that penetrates the multiple first stator punches 11a. The first cooling holes 1131 in the same cooling hole group as the second cooling holes 1132a can communicate with the first cooling holes 1131 of any remaining first stator punching 11a, forming a channel that penetrates the multiple first stator punchings 11a. The second cooling channel W2 corresponding to the second cooling hole 1132b is blocked, and the first cooling channel W1 corresponding to the first cooling hole 1131 in the same cooling hole group as the second cooling hole 1132b penetrates the multiple first stator punchings 11a.

[0089] In addition, when multiple first stator punches 11a are arranged axially, there is always a first cooling hole 1131 between any two adjacent first stator punches 11a that is blocked, resulting in the first cooling channel W1 being blocked and unable to communicate. Similarly, there is always a second cooling hole 1132 between any two adjacent first stator punches 11a that is blocked, resulting in the second cooling channel W2 being blocked and unable to communicate. Taking the multiple first cooling holes 1131 of a first stator punch 11a as an example, when the first cooling channel W1 is blocked by a first stator punch 11a, for first cooling holes 1131 at different angular positions, the first stator punch 11a that blocks the first cooling channel W1 may be one of the first stator punches 11a, and is not limited to the first stator punches 11a on both sides of the axial direction of the stator 10. FIG9 f illustrates a situation where the first cooling holes 1131 of two first stator punches 11 a between the first first stator punch 11 a and the last first stator punch 11 a are not connected, resulting in blockage of the first cooling channel W1 .

[0090] 9a to 9f , it can be seen that the multiple first stator punchings 11a are sequentially rotated and stacked along the axial direction of the stator 10, so that the m-th first cooling hole 1131 of one first stator punching 11a is connected to the m+1-th first cooling hole 1131 of another first stator punching 11a, and the n-th second cooling hole 1132 of one first stator punching 11a is connected to the n+1-th second cooling hole 1132 of another first stator punching 11a. Wherein, m and n are both integers greater than or equal to 1. Because the m+1-th first cooling hole 1131 is offset outward or inward relative to the m-th first cooling hole 1131 in the radial direction of the stator 10, the direction of the first cooling channel W1 formed by the connected first cooling holes 1131 is inclined. The n+1th second cooling hole 1132 is offset radially outward or inward from the nth second cooling hole 1132 along the stator 10, and the direction of the second cooling channel W2 formed by the interconnected second cooling holes 1132 is inclined. Both the first cooling channel W1 and the second cooling channel W2 can be used for the circulation of cooling medium, and the inclined channels can change the circulation direction of the cooling medium. In a specific configuration, a plurality of first stator punchings 11a can be arranged so that the first cooling channel W1 and the second cooling channel W2 are inclined toward the axis of the stator 10 along the direction from the second stator punching 11b to the first stator punching 11a. Then, the cooling medium ejected from the first cooling channel W1 and the second cooling channel W2 can be sprayed toward the end winding to cool the end winding.

[0091] In the multiple first stator punching sheets 11a of the stator 10 provided in the embodiment of the present application, a first cooling hole 1131 of the previous first stator punching sheet 11a and a first cooling hole 1131 of the next first stator punching sheet 11a are offset 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 not equal. When a first cooling hole 1131 of the previous first stator punching sheet 11a is connected to a first cooling hole 1131 of the next first stator punching sheet 11a, an inclined first cooling channel W1 can be formed. A second cooling hole 1132 of the previous first stator punching sheet 11a and a second cooling hole 1132 of the next first stator punching sheet 11a are offset along 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. When a second cooling hole 1132 of a first stator punch 11a is connected to a second cooling hole 1132 of a subsequent first stator punch 11a, an inclined second cooling channel W2 can be formed. In this arrangement structure of the first stator punches 11a, with reference to the cooling hole group, a first cooling hole 1131 may be blocked by the axial end face of an adjacent first stator punch 11a, resulting in the first cooling channel W1 being blocked and unable to pass through the structure formed by the stacking of multiple first stator punches 11a, and thus unable to guide the cooling medium from the second groove 115 of the second stator punch 11b to the axial end face of the stator 10. Alternatively, a second cooling hole 1132 may be blocked by the axial end face of an adjacent first stator punch 11a, resulting in the second cooling channel W2 being blocked and unable to pass through the structure formed by the stacking of multiple first stator punches 11a, and thus unable to guide the cooling medium from the second groove 115 of the second stator punch 11b to the axial end face of the stator 10. Figure 9c illustrates a case where one of the multiple second cooling holes 1132 in a cooling hole group is blocked by a first stator punching 11a, thereby blocking the second cooling channel W2, while the multiple first cooling holes 1131 are sequentially connected along the axial direction of the stator 10 to form an inclined and penetrating first cooling channel W1. Figure 9e illustrates a case where one of the multiple first cooling holes 1131 in a cooling hole group is blocked by a first stator punching 11a, thereby blocking the first cooling channel W1, while the multiple second cooling holes 1132 are sequentially connected along the axial direction of the stator 10 to form an inclined and penetrating second cooling channel W2.

[0092] In the stator 10 provided in the embodiment of the present application, three types of punching sheets 11 can be spliced ​​together to form a stator core 1 capable of axially spraying liquid. The stator core 1 can spray the cooling medium in the stator 10 toward the end winding along the axial end face of the stator 10. There are few types of punching sheets 11, and the manufacturing cost is low, which is conducive to large-scale production and assembly. The multiple first stator punching sheets 11a can serve as a structure for spraying oil at the end of the stator 10, eliminating the oil injection ring, so that the motor 100 with the stator 10 can radially output wires to connect the phase electricity, reduce the axial size of the motor 100, and maximize the use of the axial space of the motor 100, which can be adapted to occasions with high space or power density requirements.

[0093] Based on the above embodiments, it can be seen that, specifically, the structure of each first stator punch 11a is the same. When multiple first stator punches 11a are arranged axially and any two adjacent first stator punches 11a are circumferentially rotated and misaligned, there is always a first cooling hole 1131 between any two adjacent first stator punches 11a that is blocked, resulting in the first cooling channel W1 being blocked and unable to communicate. Similarly, there is always a second cooling hole 1132 between any two adjacent first stator punches 11a that is blocked, resulting in the second cooling channel W2 being blocked and unable to communicate. The number of first stator punches 11a can be limited, and the arrangement of the first cooling holes 1131 and the second cooling holes 1132 can be adjusted so that the cooling channel corresponding to at least one cooling hole in each cooling hole group can pass through all the first stator punches 11a. The number and stacking angle of the first stator punching sheets 11a are adjusted so that in any group of cooling hole groups, at least one of the cooling channels corresponding to the first cooling holes 1131 and the second cooling holes 1132 passes through the stacked structure of multiple first stator punching sheets 11a. At the angle corresponding to this group of cooling hole groups, the stator 10 has a channel connecting the second groove 115 and the liquid outlet 102, so that the motor 100 can spray the cooling medium toward the end winding along the circumference of the stator 10, thereby realizing the dead-zone-free spraying of the cooling medium in the circumferential range of the stator 10 to cool the end winding.

[0094] For example, as shown in FIG10 , on any first stator punching 11a, a plurality of first cooling holes 1131 are arranged at intervals along the circumference of the stator 10, with the angle between any two circumferentially adjacent first cooling holes 1131 being the same. A plurality of second cooling holes 1132 are arranged at intervals along the circumference of the stator 10, with the angle between any two circumferentially adjacent second cooling holes 1132 being the same. The number of first cooling holes 1131 and second cooling holes 1132 is the same, and one first cooling hole 1131 corresponds to one second cooling hole 1132 in the radial direction of the stator 10. The first cooling hole 1131 is located between the second cooling hole 1132 and the center hole 111. It is assumed that the first cooling hole 1131, which is closest to the center of the stator 10 in the radial direction of the stator 10, is the first starting hole 1131q, and the second cooling hole 1132, which is closest to the center of the stator 10 in the radial direction of the stator 10, is the second starting hole 1132q. Along the circumference of the stator 10, the angle between the first starting hole 1131q and the second starting hole 1132q is β, where 180-α<β<180+α, where α is the angle between any two circumferentially adjacent first cooling holes 1131. For example, the first starting hole 1131q and the second starting hole 1132q form an angle of 180°. Multiple first stator punchings 11a are arranged in a staggered manner along the circumference of the stator 10. In any group of first cooling holes 1131 and second cooling holes 1132 corresponding in the radial direction of the stator 10, the cooling channel corresponding to at least one cooling hole is continuous.

[0095] Figure 11a shows a schematic cross-sectional view of the stator core 1, Figure 11b shows an enlarged view of the details at C1 in Figure 11a, and Figure 11c shows an enlarged view of the details at C2 in Figure 11a. The stator core 1 includes a plurality of first stator laminations 11a, a second stator lamination 11b, and a plurality of third stator laminations 11c. The second stator lamination 11b is arranged axially between the plurality of first stator laminations 11a and the plurality of third stator laminations 11c of the stator 10. The outer circumferential surface of the second stator lamination 11b includes a second groove 115, which forms an axial gap Q between the second groove 115 and the first and third stator laminations 11a and 11c. The axial gap Q is connected to at least one cooling hole group of the first stator punch 11a, and is also connected to at least one first groove 114 of the third stator punch 11c, so that the cooling medium in the first groove 114 can be conducted to the first cooling hole 1131 and / or the second cooling hole 1132 and ejected from the axial end face of the stator 10.

[0096] Referring to Figures 11a to 11c , this cross-section passes through two cooling hole groups in the left-side plurality of first stator punchings 11a. The axial gap Q corresponding to each cooling hole group communicates with the first groove 114 of the third stator punching 11c, allowing the coolant within the first groove 114 to enter the axial gap Q. The plurality of first stator punchings 11a are divided into two sections along the axial direction of the stator 10, with one section of the first stator punchings 11a arranged between another section of the first stator punchings 11a and the second stator punchings 11b. A section of the first stator punchings 11a adjacent to the second stator punchings 11b is arranged in the stacking arrangement shown in Figure 8, while another section of the first stator punchings 11a is arranged in the stacking arrangement shown in Figures 9c and 9e. After the plurality of first stator punchings 11a are arranged in sequence, the first cooling channel W1 formed by the first cooling holes 1131 includes a straight segment and an oblique segment. The second cooling channel W2 formed by the second cooling holes 1132 also includes a straight segment and an oblique segment. The oblique cooling channel is inclined along the axial direction of the stator 10 toward the location of the end winding.

[0097] In conjunction with the example of one cooling hole group shown in Figures 11a and 11b, the first cooling channel W1 corresponding to the first cooling hole 1131 of the cooling hole group is blocked by one of the first stator punchings 11a, and the second cooling channel W2 corresponding to the second cooling hole 1132 runs through multiple first stator punchings 11a. The cooling medium in the first groove 114 can flow into the second cooling channel W2 through the axial gap Q, and then reach the liquid outlet 102 through the second cooling channel W2 to be sprayed out, thereby dissipating the heat of the end winding.

[0098] 11a and 11c illustrate another cooling hole group. The first cooling channel W1 corresponding to the first cooling hole 1131 of this cooling hole group penetrates the plurality of first stator laminations 11a, and the second cooling channel W2 corresponding to the second cooling hole 1132 penetrates the plurality of first stator laminations 11a. The cooling medium within the first groove 114 can flow through the axial gap Q into the first cooling channel W1 and the second cooling channel W2, and then reach the liquid outlet 102 through the first cooling channel W1 and the second cooling channel W2, where it is sprayed to dissipate heat from the end windings.

[0099] It should be understood that when the distance between any two circumferentially adjacent first cooling holes 1131 of the first stator punching 11a changes, the direction of the first cooling channel W1 will be tilted along the circumference of the stator 10, causing the cooling medium to deflect eccentrically along the circumference 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 direction of the second cooling channel W2 will be tilted along the circumference of the stator 10, causing the cooling medium to deflect eccentrically along the circumference of the stator 10. When the connection mode of the first cooling holes 1131 is tilted simultaneously in the circumferential direction or radial direction of the stator core 1, the way in which the first cooling holes 1131 of the stator 10 spray coolant can ultimately achieve rotational spraying. When the connection mode of the second cooling holes 1132 is tilted simultaneously in the circumferential direction or radial direction of the stator core 1, the way in which the second cooling holes 1132 of the stator 10 spray coolant can ultimately achieve rotational spraying. Of course, the spray angle and direction of the coolant may also be irregular, which is not limited in the embodiment of the present application.

[0100] Specifically, after the plurality of first stator punchings 11a provided in the embodiment of the present application are arranged in a staggered manner along the circumference of the stator 10, the first cooling channel W1 formed by the first cooling holes 1131 can be used to eject the cooling medium in the stator 10 out of the axial end of the stator 10. When the first cooling channel W1 corresponding to a portion of the first cooling holes 1131 cannot penetrate all of the first stator punchings 11a, the cooling medium in the stator 10 can be ejected out of the axial end of the stator 10 through the second cooling channel W2 formed by the second cooling holes 1132. The second cooling holes 1132 can be regarded as an auxiliary structure for the first cooling holes 1131.

[0101] In some embodiments, taking the example of a first stator punching 11a having a certain number of first cooling holes 1131, when multiple first stator punchings 11a are staggered along the circumference of the stator 10, the fewer the number of first stator punchings 11a, the fewer first cooling channels W1 corresponding to the first cooling holes 1131 are blocked. Therefore, the number of second cooling holes 1132 can be reduced as needed, so that the first cooling holes 1131 corresponding to the blocked first cooling channels W1 in the multiple first stator punchings 11a are each provided with a corresponding second cooling hole 1132. These second cooling holes 1132 in the multiple first stator punchings 11a can be connected to form a second cooling channel W2 that passes through all the first stator punchings 11a. When the first cooling channels W1 corresponding to these 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 punchings 11a. As shown in FIG. 12 , the number of second cooling holes 1132 is less than the number of first cooling holes 1131. Some of the first cooling holes 1131w are provided with second cooling holes 1132 on the side away from the center hole 111, while the remaining first cooling holes 1131v are not provided with second cooling holes 1132 at the angles thereof. After the plurality of first stator punchings 11a shown in FIG12 are arranged in a staggered manner along the circumference of the stator 10, the first cooling channels W1 formed corresponding to some of the first cooling holes 1131w may not be connected, while the second cooling channels W2 formed corresponding to the second cooling holes 1132 can pass through all of the first stator punchings 11a, ensuring that the stator 10 can still guide the cooling medium within the stator 10 to the axial end face of the stator 10 at this angle.

[0102] It should be noted that in the above embodiment, the second cooling hole 1132 is arranged on the side of the first cooling hole 1131 away from the center hole 111 along the radial direction of the stator 10, and the second cooling hole 1132 is closer to the outer peripheral surface of the first stator punching 11a. Possibly, the second cooling hole 1132 can also be arranged between the first cooling hole 1131 and the center hole 111. Along the circumference of the stator 10, it is sufficient to ensure that there is a first cooling hole 1131 and / or a second cooling hole 1132 at the angle where the cooling medium needs to be sprayed. In other words, the above-mentioned first cooling hole 1131 and second cooling hole 1132 can be interchanged. Of course, the number of cooling holes can continue to increase, for example, by adding a third cooling hole, a fourth cooling hole, etc., so that the stator 10 can eventually spray liquid circumferentially.

[0103] In other embodiments, as shown in FIG13a , within a cooling hole group, first cooling holes 1131 and second cooling holes 1132 are arranged adjacent to each other along the circumference of the stator 10. Within any cooling hole group, 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. Along the circumference of the stator 10, the angle between any two adjacent first cooling holes 1131 and second cooling holes 1132 is greater than 0° and less than α, where α is the central angle between any two adjacent first cooling holes 1131 along the circumference of the stator.

[0104] Specifically, the plurality of first cooling holes 1131 are spaced apart along the circumference of the stator 10, with the angle between any two circumferentially adjacent first cooling holes 1131 being 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, with the base circle of the asymptote being the distance between the first cooling hole 1131 closest to the center O of the stator 10 and the center O of the stator 10 as the radius. In a clockwise or counterclockwise direction, starting with the first cooling hole 1131 closest to the center O of the stator 10, the distances between the plurality of first cooling holes 1131 and the center O of the stator 10 gradually increase. The distance between the k+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, multiple second cooling holes 1132 are spaced apart along the circumference of the stator 10, with the angle between any two circumferentially adjacent second cooling holes 1132 being equal. The distances between the multiple second cooling holes 1132 and the center O of the stator 10 gradually increase or decrease. For example, the multiple second cooling holes 1132 are distributed along an asymptote, with the base circle of the asymptote being the distance between the second cooling hole 1132 closest to the center O of the stator 10 and the center O of the stator 10 as its radius. In a clockwise or counterclockwise direction, starting with the second cooling hole 1132 closest to the center O of the stator 10 as the first second cooling hole 1132, the distances between the multiple second cooling holes 1132 following the first second cooling hole 1132 and the center O of the stator 10 gradually increase. The distance between the k+1th second cooling hole 1132 and the center O of the stator 10 is greater than the distance between the kth second cooling hole 1132 and the center O of the stator 10.

[0105] The arrangement of the multiple first cooling holes 1131 in the first stator punching 11a shown in FIG13a is similar to that of the multiple first cooling holes 1131 in the first stator punching 11a shown in FIG7 , and the arrangement of the multiple second cooling holes 1132 is also similar. The only difference is that the relative positions of the first cooling holes 1131 and the second cooling holes 1132 in a cooling hole group have changed. Therefore, by arranging the first stator punchings 11a shown in FIG13a in a certain arrangement to form a portion of the axial end structure of the stator 10, the resulting structure of the stator 10 can be shown in FIG13b . As shown in FIG13b , the multiple first stator punchings 11a are divided into two groups, one at each axial end of the stator core 1. For the first stator punchings 11a located at the axial end of the stator 10, the end of the first cooling hole 1131 facing away from the second stator punching 11b and the end of the second cooling hole 1132 facing away from the second stator punching 11b form the aforementioned liquid outlet 102.

[0106] As shown in FIG13c , the plurality of first stator punchings 11a can be arranged in a circumferential rotational staggered manner along the stator 10, so that the first cooling holes 1131 of the first stator punchings 11a are respectively arranged in a circumferential staggered manner along the stator 10, and the second cooling holes 1132 are respectively arranged in a circumferential staggered manner along the stator 10. The arrangement of the first cooling holes 1131 and the second cooling holes 1132 can refer to FIG9c and FIG9e , so that after the plurality of first stator punchings 11a are axially arranged and any two adjacent first stator punchings 11a are circumferentially rotationally staggered, the cooling channel corresponding to at least one cooling hole in each cooling hole group can pass through all the first stator punchings 11a. The number and stacking angle of the first stator punching sheets 11a are adjusted so that in any group of cooling hole groups, at least one of the cooling channels corresponding to the first cooling holes 1131 and the second cooling holes 1132 passes through the stacked structure of multiple first stator punching sheets 11a. At the angle corresponding to this group of cooling hole groups, the stator 10 has a channel connecting the second groove 115 and the liquid outlet 102, so that the motor 100 can spray the cooling medium toward the end winding along the circumference of the stator 10, thereby realizing the dead-zone-free spraying of the cooling medium in the circumferential range of the stator 10 to cool the end winding.

[0107] Specifically, FIG13d illustrates an enlarged view of the detail at D1 in FIG13c, and FIG13e illustrates an enlarged view of the detail at D2 in FIG13c. Referring to FIG13c, FIG13d, and FIG13e together, two axially adjacent first stator punches 11a can be rotated circumferentially relative to the center of the stator 10 by a set angle, which is the angle between two adjacent first cooling holes 1131 in the same first stator punch 11a. A first cooling hole 1131 in the preceding first stator punch 11a is offset from a first cooling hole 1131 in the succeeding first stator punch 11a along the radial direction of the stator 10, and a second cooling hole 1132 in the preceding first stator punch 11a is offset from a second cooling hole 1132 in the succeeding first stator punch 11a along the radial direction of the stator 10, ultimately ensuring that, in any cooling hole group, the cooling channel corresponding to at least one cooling hole can penetrate all first stator punches 11a. In the two cooling hole groups shown in FIG13d , the cooling channels corresponding to the first cooling holes 1131 can penetrate all the first stator punchings 11a. In one cooling hole group, the cooling channels corresponding to the second cooling holes 1132c can penetrate all the first stator punchings 11a, while the cooling channels corresponding to the second cooling holes 1132d in the other cooling hole group are blocked. In the two cooling hole groups shown in FIG13e , the cooling channels corresponding to the second cooling holes 1132 can penetrate all the first stator punchings 11a. In one cooling hole group, the cooling channels corresponding to the first cooling holes 1131c can penetrate all the first stator punchings 11a, while the cooling channels corresponding to the first cooling holes 1131d in the other cooling hole group are blocked.

[0108] Figure 14 illustrates a second stator punching sheet 11b. The second groove 115 on the second stator punching sheet 11b is wider at the top and narrower at the bottom. Specifically, along the circumference of the stator 10, the notch opening of the second groove 115 is larger than the bottom of the second groove 115. In other words, the dimension of the second groove 115 away from the center hole 111 is larger than the dimension of the second groove 115 closer to the center hole 111.

[0109] FIG15 a illustrates another second stator punching 11 b, wherein the radial dimension of the second stator punching 11 b is smaller than the radial dimension of the first stator punching 11 a and the radial dimension of the third stator punching 11 c. For example, in the case where the first cooling holes 1131 are arranged radially between the second cooling holes 1132 and the center hole 111 of the stator 10, the distance between the outer circumference of the second stator punching 11 b and the center of the stator 10 is less than or equal to the distance between the first cooling holes 1131 and the center O of the stator 10. Alternatively, the distance between the outer circumference of the second stator punching 11 b and the center of the stator 10 minus the radial dimension of the first cooling hole 1131 is less than the distance between the first cooling hole 1131 and the center O of the stator 10. When the second stator sheet 11b is arranged between the first stator sheet 11a and the third stator sheet 11c, as shown in Figure 15b, an axial gap Q extending and continuous along the circumference of the stator 10 can be formed between the outer circumferential surfaces of the first stator sheet 11a, the second stator sheet 11b, and the third stator sheet 11c. This axial gap Q is annular, allowing the cooling medium to flow in an annular manner along the circumference of the stator 10 and perform heat exchange, thereby preventing local overheating of the stator 10 from affecting the heat dissipation effect. In this structure, the second stator sheet 11b can be fixed between the first stator sheet 11a and the third stator sheet 11c by bonding to form the stator core 1.

[0110] In some embodiments, grooves can be formed on the outer peripheral surface of the first stator punch 11a so that when the first cooling channel W1 corresponding to the first cooling hole 1131 is blocked, the cooling medium in the first cooling channel W1 can flow out from the grooves on the outer peripheral surface of the first stator punch 11a, thereby preventing the cooling medium from accumulating in the stator 10 to form a heat concentration area.

[0111] Without considering the difficulty of the process and the manufacturing cost, the stator core 1 can also be formed by using punching sheets 11 with different structures. By designing each punching sheet 11 with different structures, the cooling medium in the stator 10 can be guided to the axial end of the stator 10 and sprayed out from the liquid outlet 102, and the liquid spray heat dissipation of the end winding can also be achieved. This application will not discuss this in detail.

[0112] In summary, the stator 10 of the motor 100 provided in the embodiment of the present application does not require an oil spray ring structure, and the cooling medium can be sprayed to the end winding at the axial end of the stator 10 through the cooling channel of the stator 10 itself. The first stator punching 11a having multiple first cooling holes 1131 and multiple second cooling holes 1132 is arranged in a certain arrangement, and the cooling medium in the stator 10 can be sprayed out from the liquid outlet 102 circumferentially distributed on the axial end face of the stator 10, thereby realizing circumferential liquid spraying at the end of the stator 10, thereby realizing efficient cooling of the end winding and achieving a good liquid cooling heat dissipation effect. In some embodiments, compared with traditional oil cooling heat dissipation, the stator 10 of the motor 100 provided in the embodiment of the present application has a lower temperature and a better heat dissipation effect. The oil spray ring is omitted from the structure, which further reduces the cost of the motor 100 and achieves the effect of reducing costs and increasing efficiency. In addition, the motor 100 provided in the embodiment of the present application can be used not only in the drive, generator or electronic air-conditioning compressor of electric vehicles, but also in the fields of household electronic air-conditioning compressors, robot motors, industrial motors, etc., and can be adapted to occasions with high requirements on space or road density.

[0113] Obviously, those skilled in the art may make various changes and modifications to the present application without departing from the scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is intended to include these modifications and variations.

Claims

1. A stator punching sheet with cooling holes, characterized in that: The stator punching sheet includes a plurality of first cooling holes and a plurality of second cooling holes; Along the axial direction of the stator punching sheet, each of the first cooling holes and each of the second cooling holes penetrates 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 first cooling holes adjacent to each other in the circumferential direction of the stator punching sheet, a distance between one of the first cooling holes and the center of the stator punching sheet is greater than a distance between the other first cooling hole and the center of the stator punching sheet; Of the two second cooling holes adjacent to each other in the circumferential direction of the stator punching sheet, a distance between one of the second cooling holes and the center of the stator punching sheet is greater than a distance between the other of the second cooling holes and the center of the stator punching sheet.

2. The stator sheet according to claim 1, characterized in that: Along the radial direction of the stator punching sheet, a distance between the first cooling hole and the center of the stator punching sheet is smaller than a distance between the second cooling hole and the center of the stator punching sheet.

3. The stator sheet according to claim 2, characterized in that: Along the radial direction of the stator punching sheet, the first cooling holes and the second cooling holes are arranged at intervals.

4. The stator sheet according to claim 1, characterized in that: Along the circumferential direction of the stator punching sheet, one first cooling hole and one second cooling hole are arranged adjacent to each other.

5. The stator sheet according to claim 4, characterized in that: Along the radial direction of the stator punching sheet, the first cooling hole and the adjacent second cooling hole are at the same distance from the center of the stator punching sheet.

6. The stator lamination according to any one of claims 1 to 5, characterized in that: The number of the second cooling holes is smaller than the number of the first cooling holes.

7. The stator sheet according to any one of claims 1 to 6, characterized in that: Along the circumferential direction of the stator punching sheet, the central angles between any two adjacent first cooling holes are the same, 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.

8. The stator sheet according to claim 7, characterized in that: Along the circumference of the stator punching sheet, the central angle between the first cooling hole closest to the center of the stator punching sheet and the second cooling hole closest to the center of the stator punching sheet is less than 180°+α and greater than 180°-α, where α is the central angle between any two adjacent first cooling holes along the circumference of the stator.

9. The stator lamination according to any one of claims 1 to 8, characterized in that: The stator punching sheet comprises a central hole and a plurality of punching grooves, wherein the plurality of punching grooves are arranged at intervals along the circumferential direction of the stator punching sheet, each of the punching grooves is connected with the central hole along the radial direction of the stator punching sheet, and the central hole and each of the punching grooves penetrate the stator punching sheet along the axial direction of the stator punching sheet; Along the radial direction of the stator punching sheet, the distance between the first cooling hole and the center of the stator punching sheet is greater than the distance between the groove bottom of the punching sheet groove and the center of the stator punching sheet.

10. The stator sheet according to claim 9, characterized in that: Along the circumferential direction of the stator punching sheet, the first cooling holes and the grooves are arranged in a staggered manner; and / or the second cooling holes and the punching sheet grooves are arranged in a staggered manner.

11. A motor, characterized in that: The stator of the motor comprises a plurality of first stator punching sheets, at least one second stator punching sheet and at least one third stator punching sheet, wherein the first stator punching sheet is the stator punching sheet according to any one of claims 1 to 10; 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 includes an axial gap between the first stator punching sheet and the third stator punching sheet, and the axial gap is connected to at least one of the first cooling holes and at least one of the second cooling holes.

12. The motor according to claim 11, characterized in that The second stator punching sheet comprises a plurality of second grooves, the second grooves are connected with the outer peripheral surface of the second stator punching sheet along the radial direction of the stator core, and the plurality of second grooves are arranged at intervals along the circumferential direction of the stator core; The third stator punching sheet comprises a plurality of first grooves, wherein the first grooves are connected 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 is communicated with at least one of the first cooling holes and one of the second cooling holes, and each of the second grooves is communicated with at least one of the first grooves.

13. The motor according to claim 12, characterized in that Along the circumferential direction of the stator, a slot opening size of each of the second slots is larger than a slot bottom size of each of the second slots.

14. The motor according to claim 11, characterized in that The outer diameter of the second stator punching sheet is smaller than the outer diameter of the first stator punching sheet and the outer diameter of the third stator punching sheet.

15. The motor according to any one of claims 11 to 14, characterized in that: Along the axial direction of the stator, one of the first cooling holes of one of the first stator punching sheets is connected to the first cooling hole of another adjacent first stator punching sheet, and one of the second cooling holes of one of the first stator punching sheets is connected to the second cooling hole of another adjacent first stator punching sheet; Along the radial direction of the stator core, a distance between the first cooling hole of the first stator punching sheet and the center of the first stator punching sheet is greater than a distance between the first cooling hole of the other first stator punching sheet and the center of the first stator punching sheet.

16. A powertrain, characterized in that: It comprises a reducer and a motor as claimed in any one of claims 11 to 14, wherein the output shaft of the motor is drivingly connected to the input shaft of the reducer.

17. An electric vehicle, characterized in that: The invention comprises a wheel, a transmission mechanism and the power assembly as claimed in claim 16, wherein the power assembly drives the wheel through the transmission mechanism.

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