Stator core for cooling winding end part, motor, power assembly and electric vehicle

Abstract

The utility model provides a stator core for cooling winding ends, a motor, a power assembly and an electric vehicle. The stator iron core comprises a plurality of stator punching sheets, and the plurality of stator punching sheets are sequentially and adjacently arranged along the axial direction of the stator iron core to form at least one part of the stator iron core. Each stator punching sheet comprises a central hole and a plurality of cooling holes, and the cooling holes are arranged between the central hole and the outer peripheral surface of the stator punching sheet at intervals. The plurality of stator punching sheets comprise a first punching sheet and a second punching sheet which are adjacently arranged, and each cooling hole of the first punching sheet is used for communicating with a cooling hole of the second punching sheet and cooling the end part of the stator winding, so that a channel for a cooling working medium to flow is formed. Along at least one of the radial direction or the circumferential direction of the stator core, each cooling hole of the first punching sheet is eccentrically arranged relative to the cooling hole of the second punching sheet communicated with the first punching sheet. The stator core can reduce the cross section of a channel for circulation of a cooling working medium and improve the flow velocity of the cooling working medium.

Description

Technical Field

[0001] The present application relates to the technical field of motors, and in particular to a stator core, a motor, a power assembly and an electric vehicle for cooling a winding end. Background Art

[0002] With the development of science and 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.

[0003] During motor operation, heat loss of the stator core is an important heat source of the motor, and the stator can be cooled by oil through a heat dissipation channel arranged on the motor stator. At present, the heat dissipation method of the motor stator in traditional technology is not good, and the cooling effect needs to be improved. Utility Model Content

[0004] The present application provides a stator core, a motor, a power assembly and an electric vehicle for cooling the ends of windings. The stator core can realize oil injection at the ends of the stator and has a relatively high oil injection speed.

[0005] In the first aspect, the present application provides a stator core for cooling the winding end, which can be used in the motor in the field of electric vehicles. The stator core includes a plurality of stator punchings, which are arranged in sequence and adjacent to each other along the axial direction of the stator core to form at least a part of the stator core. Each stator punching includes a center hole and a plurality of cooling holes, and the plurality of cooling holes are arranged at intervals along the circumferential direction of the stator punching, and each cooling hole is arranged at intervals between the center hole and the outer peripheral surface of the stator punching. After the plurality of stator punchings are arranged adjacent to each other along the axial direction of the stator core, the center holes of the plurality of stator punchings are connected to form a receiving hole for accommodating the rotor. The plurality of stator punchings include a first punching and a second punching, and specifically, the first punching is arranged adjacent to the second punching along the axial direction of the stator core. Each cooling hole of the first punching is used to connect a cooling hole of the second punching and to cool the stator winding end to form a channel for the flow of cooling medium. Along at least one direction of the radial direction or the circumferential direction of the stator core, each cooling hole of the first punching plate is eccentrically arranged relative to a cooling hole of the second punching plate connected thereto.

[0006] The stator core reduces the cross-sectional size of the channel for the cooling medium to flow through the staggered arrangement of the cooling holes of the first punching sheet and the cooling holes of the second punching sheet. Under the condition that the flow rate of the cooling medium driven by the oil pump is constant, the flow rate of the cooling medium will increase when the cross-sectional area of ​​the channel is reduced. When the first punching sheet is used as the stator punching sheet at the end of the stator core, the misalignment of the first cooling hole and the second cooling hole allows the cooling medium to have a higher speed when it is ejected, thereby achieving a good liquid cooling heat dissipation effect.

[0007] In one possible implementation, along the radial direction of the stator core, the distance between the cooling hole of the first punch and the center hole is smaller than the distance between the cooling hole of the second punch and the center hole, so that a cooling hole of the first punch is offset along the radial direction of the stator core relative to a cooling hole of the second punch connected thereto.

[0008] In a possible implementation, a cooling hole of a first punch is connected to a cooling hole of a second punch, and another cooling hole of a first punch is connected to another cooling hole of a second punch. Along the circumference of the stator core, the distance between a cooling hole of a first punch and another cooling hole is not equal to the distance between a cooling hole of a second punch and another cooling hole of a first punch, and the distance between a cooling hole of a second punch and another cooling hole is not equal to the distance between a cooling hole of a first punch and another cooling hole of a second punch, so that a cooling hole of a first punch is arranged offset relative to a cooling hole of a second punch connected thereto along the circumference of the stator core.

[0009] In a possible implementation, the diameter of the cooling hole of the first punch is smaller than or equal to the diameter of the cooling hole of the second punch. The reduction in the diameter of the cooling hole of the first punch can further increase the flow rate of the cooling medium when it flows from the cooling hole of the second punch to the cooling hole of the first punch.

[0010] In a possible implementation, the number of cooling holes of the first punching sheet can be set to be smaller than the number of cooling holes of the second punching sheet. When the cooling holes of the first punching sheet are used as axial liquid outlets of the stator core, the number of liquid outlets that are connected can be reduced to increase the flow rate.

[0011] In one possible implementation, the plurality of stator punches include a plurality of second punches and another second punch, and the plurality of second punches are arranged between the second punch and the another second punch along the axial direction of the stator core. Along the axial direction of the stator core, the plurality of cooling holes of a second punch are respectively used to connect the plurality of cooling holes of adjacent second punches, the plurality of cooling holes of another second punch are respectively used to connect the plurality of cooling holes of adjacent second punches, and the plurality of cooling holes of each second punch in the plurality of second punches are respectively used to connect the plurality of cooling holes of adjacent second punches. Between any two adjacent second punches, a cooling hole of a second punch is used to connect the second cooling hole of another second punch to form a channel for the flow of cooling medium. The structure and arrangement of the plurality of second punches can be designed to change the flow direction of the cooling medium.

[0012] In a possible implementation, the spacing between one cooling hole and the center hole of two circumferentially adjacent cooling holes of the second punching sheet is greater than the spacing between the other cooling hole and the center hole. When the stator core includes a plurality of second punching sheets, and the plurality of second punching sheets are rotated a certain angle along the circumference of the stator core and stacked, an oblique flow channel can be formed to direct the cooling medium to the center of the stator core, facilitating the spraying of liquid to the end winding.

[0013] Specifically, between any two connected cooling holes of the second punching sheets, along the radial direction of the stator core, the distance between one cooling hole and the center hole is greater than the distance between the other cooling hole and the center hole.

[0014] In one possible implementation, the plurality of stator punching sheets include a third punching sheet, and the third punching sheet is arranged adjacent to another second punching sheet along the axial direction of the stator core. Along the radial direction of the stator core, the cooling hole of the third punching sheet is connected to the outer peripheral surface of the third punching sheet. Along the axial direction of the stator core, the plurality of cooling holes of the third punching sheet are respectively used to connect to the plurality of cooling holes of another second punching sheet, and the distance between the cooling hole of the third punching sheet and the center hole is less than or equal to the distance between the cooling hole of the second punching sheet and the center hole. The cooling hole of the third punching sheet can guide the cooling medium entering between the housing and the stator core to the second punching sheet.

[0015] In one possible implementation, the plurality of stator punching sheets include a third punching sheet and a fourth punching sheet, the fourth punching sheet is arranged adjacent to another second punching sheet along the axial direction of the stator core, and the third punching sheet is arranged adjacent to the side of the fourth punching sheet away from another second punching sheet along the axial direction of the stator core. Along the radial direction of the stator core, the cooling hole of the third punching sheet is connected to the outer peripheral surface of the third punching sheet. Along the axial direction of the stator core, the plurality of cooling holes of the fourth punching sheet are respectively used to connect at least one cooling hole of another second punching sheet with at least one cooling hole of the third punching sheet. The cooling hole of the fourth punching sheet can form a collection space between the second punching sheet and the third punching sheet that can accommodate more cooling media, and the liquid outlet provides a more sufficient oil supply to ensure the oil pressure and oil speed sprayed out of the liquid outlet, and can also reduce the assembly precision requirements.

[0016] In one possible implementation, along the circumference of the stator core, the circumferential size of the cooling hole of the fourth punch is greater than the spacing between two adjacent cooling holes of the second punch and the spacing between two adjacent cooling holes of the third punch, so that the cooling hole of the fourth punch can simultaneously connect to multiple cooling holes of the second punch and multiple cooling holes of the third punch.

[0017] In a possible implementation, each cooling hole of the fourth punch is connected to the outer peripheral surface of the fourth punch along the radial direction of the stator core. At least two adjacent cooling holes of the plurality of cooling holes of the fourth punch are connected along the circumferential direction of the stator core. An annular channel for the flow of cooling medium can be formed between the third punch and the second punch.

[0018] In a second aspect, the present application provides a motor, the motor comprising a housing and any one of the stator cores provided in the first aspect. The housing is sleeved on the outer peripheral surface of the stator core, and the housing comprises a liquid inlet, the liquid inlet is used to communicate with at least one cooling hole of the second punching sheet, and the cooling medium can eventually flow to the cooling hole of the second punching sheet after entering the housing.

[0019] In a third aspect, the present application provides a powertrain, which includes a reducer or a transmission and a motor according to the first aspect and any implementation thereof, wherein a motor shaft of the motor is drivingly connected to an input shaft of the reducer or an input shaft of the transmission. Since the motor has good heat dissipation performance, the heat dissipation performance and power performance of the powertrain can be improved.

[0020] In a fourth aspect, the present application provides an electric vehicle. The electric vehicle in the present application includes wheels, a transmission mechanism, and a powertrain according to the second aspect and any implementation thereof. The powertrain drives the wheels through the transmission mechanism. The electric vehicle provided in the present application has good heat dissipation performance and power performance.

[0021] For the technical effects that can be achieved by the above-mentioned second to fourth aspects, please refer to the description of the technical effects that can be achieved by the corresponding design scheme in the above-mentioned first aspect, and this application will not repeat them here. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A schematic diagram of the structure of an electric vehicle provided in an embodiment of the present application;

[0023] Figure 2 A schematic diagram of the structure of a powertrain provided in an embodiment of the present application;

[0024] Figure 3a A schematic diagram of the structure of a housing and a stator core of a motor provided in an embodiment of the present application;

[0025] Figure 3b A schematic diagram of the structure of a housing and a stator core of a motor provided in an embodiment of the present application;

[0026] Figure 4a A schematic structural diagram of a first punching sheet and a second punching sheet of a stator core provided in an embodiment of the present application;

[0027] Figure 4b A schematic structural diagram of a first punching sheet and a second punching sheet of a stator core provided in an embodiment of the present application;

[0028] Figure 5a A schematic diagram of the partial structure of a first punching sheet and a second punching sheet of a stator core provided in an embodiment of the present application;

[0029] Figure 5b A schematic cross-sectional view of a partial structure of a first punching sheet and a second punching sheet of a stator core provided in an embodiment of the present application;

[0030] Figure 6a A schematic diagram of the partial structure of a first punching sheet and a second punching sheet of a stator core provided in an embodiment of the present application;

[0031] Figure 6b A schematic cross-sectional view of a partial structure of a first punching sheet and a second punching sheet of a stator core provided in an embodiment of the present application;

[0032] Figure 7 A schematic diagram of the partial structure of a first punching sheet and a second punching sheet of a stator core provided in an embodiment of the present application;

[0033] Figure 8 A schematic cross-sectional view of a partial structure of a first punching sheet and a plurality of second punching sheets of a stator core provided in an embodiment of the present application;

[0034] Fig. 9 A schematic structural diagram of a second punching sheet of a stator core provided in an embodiment of the present application;

[0035] Fig.10a A schematic cross-sectional view of a partial structure of a plurality of second punching sheets of a stator core provided in an embodiment of the present application;

[0036] Fig.10b A schematic cross-sectional view of a partial structure of a plurality of second punching sheets of a stator core provided in an embodiment of the present application;

[0037] Fig.11 A schematic diagram of a partial structure of stacked multiple second punching sheets of a stator core provided in an embodiment of the present application;

[0038] Fig.12 A schematic cross-sectional view of a partial structure of a plurality of second punching sheets of a stator core provided in an embodiment of the present application;

[0039] Fig.13a A schematic diagram of the structure of a stator core provided in an embodiment of the present application;

[0040] Fig.13b An exploded diagram of a stator core provided in an embodiment of the present application;

[0041] Fig.14a A schematic structural diagram of a second punching sheet and a fourth punching sheet of a stator core provided in an embodiment of the present application;

[0042] Fig.14b A schematic structural diagram of a third punching sheet and a fourth punching sheet of a stator core provided in an embodiment of the present application;

[0043] Fig.15 A schematic diagram of a partial structure of a stator core provided in an embodiment of the present application;

[0044] Fig.16 A schematic diagram of a cooling medium flow path of a stator core provided in an embodiment of the present application;

[0045] Fig.17 An exploded diagram of a stator core provided in an embodiment of the present application;

[0046] Fig.18a A schematic structural diagram of a second punching sheet and a fourth punching sheet of a stator core provided in an embodiment of the present application;

[0047] Fig.18b A schematic structural diagram of a third punching sheet and a fourth punching sheet of a stator core provided in an embodiment of the present application. DETAILED DESCRIPTION

[0048] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings.

[0049] The terms used in the following embodiments are only for the purpose of describing specific embodiments and are not intended to be limiting of the present application. As used in the specification and appended claims of the present application. References to "one embodiment" or "some embodiments" and the like described in this specification mean that one or more embodiments of the present application include specific features, structures or characteristics described in conjunction with the embodiment.

[0050] When the motor is running at high speed, the heat loss of the stator core is the main heat source of the motor. In traditional technology, oil cooling is generally used for the stator of the motor. Specifically, oil can be passed through the back of the stator core, and oil can be sprayed on the end wire package of the stator winding to achieve heat dissipation of the stator. This heat dissipation method has poor heat dissipation effect and cannot meet the high heat dissipation requirements brought about by the increase in motor power density. In addition, this heat dissipation method adds restrictions to the design of the motor, reduces space utilization, and adding other auxiliary oil injection structures will also increase production costs.

[0051] Based on this, the embodiments of the present application provide a stator core, a motor, a powertrain and an electric vehicle for cooling the ends of windings. The stator core can realize oil injection at the ends of the stator and has a relatively high oil injection speed.

[0052] Figure 1 A schematic diagram of an electric vehicle provided in an embodiment of the present application. Figure 1The electric vehicle provided in the embodiment of the present application includes a power assembly 1000, a transmission mechanism 2000 and a wheel 3000. The power assembly 1000 drives the wheel 3000 through the transmission mechanism 2000. The power assembly 1000 is used to convert electrical energy into mechanical energy. The transmission mechanism 2000 is used to transmit and connect the power assembly 1000 and the wheel 3000.

[0053] Figure 2 This is a schematic diagram of a powertrain provided in an embodiment of the present application. Figure 2 As shown, the powertrain 1000 provided in the embodiment of the present application includes a motor 100 and a reducer 200. Among them, the motor 100 and the reducer 200 are connected in transmission. The motor 100 is used to drive the transmission mechanism 2000 of the electric vehicle through the reducer 200. The motor 100 includes a stator core 10, a stator winding 20, a rotor 30, a motor shaft 40 and a housing 50. The rotor 30 is coaxially fixed to the motor shaft 40, and the motor shaft 40 is connected in transmission to the reducer 200. The stator core 10 is sleeved outside the rotor 30, the stator winding 20 is wound on the stator core 10, and the housing 50 is arranged outside the stator core 10. Among them, the reducer 200 can also be a transmission. It should be understood that the axial direction of the stator core 10 is also the axial direction of the motor 100, the radial direction of the stator core 10 is also the radial direction of the motor 100, and the circumferential direction of the stator core 10 is also the circumferential direction of the motor 100.

[0054] 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 for the stator 10 can simultaneously spray the cooling medium to the end windings of the stator windings 20 to dissipate heat.

[0055] Figure 3a The structure of the stator core 10 and the housing 50 of the motor 100 is shown schematically. Figure 3a As shown, the housing 50 includes a liquid inlet pipe 51, which is a hollow pipe. One end of the liquid inlet pipe 51 is fixed to the outer peripheral surface of the housing 50, and one end of the liquid inlet pipe 51 away from the outer peripheral surface of the housing 50 forms a liquid inlet 101. The axial end surface of the stator core 10 includes a plurality of liquid outlets 102, each of which is used to spray a cooling medium to dissipate heat from the end of the stator winding 20.

[0056] Exemplarily, along the circumference of the motor 100, a plurality of liquid outlets 102 are arranged at intervals. The number and arrangement rules of the liquid outlets 102 can be adjusted according to actual cooling requirements and process conditions. The stator core 10 has a channel for the circulation of a cooling medium, and the liquid inlet 101 and the plurality of liquid outlets 102 are respectively connected to the channel. The cooling medium can be injected into the channel in the stator core 10 through the liquid inlet 101, and the cooling medium is sprayed out to the plurality of liquid outlets 102 through the circulation channel in the stator core 10. When the cooling medium circulates in the stator core 10, it can dissipate heat from the stator winding 20 through the stator core 10, and after the cooling medium is sprayed out of the liquid outlet 102, it can be sprayed at the end of the stator winding 20 located at the end of the stator core 10.

[0057] Please continue to refer to Figure 3a As shown, the stator core 10 includes stator teeth 103, winding slots 104 and receiving holes 105. The receiving holes 105 are located at the axial center of the stator core 10 and penetrate the stator core 10 in the axial direction of the stator core 10. There are multiple winding slots 104 and they are spaced apart along the circumferential direction of the stator core 10. Each winding slot 104 is connected to the receiving hole 105 in the radial direction of the stator core 10. Along the circumferential direction of the stator core 10, stator teeth 103 are formed between any two adjacent winding slots 104. The winding slots 104 are used to receive part of the stator winding 20, and the receiving holes 105 are used to receive the rotor 30.

[0058] like Figure 3bThe structure shown is that the stator core 10 is separated from the housing 50. The stator core 10 includes a plurality of stator punchings 1, and the plurality of stator punchings 1 are arranged along the axial direction of the stator core 10. Each stator punching 1 includes a center hole 11 and a plurality of cooling holes 12. The center hole 11 is located at the center of the stator punching 1, and the plurality of cooling holes 12 are arranged at intervals along the circumferential direction of the stator core 10, and each cooling hole 12 is arranged between the center hole 11 and the outer peripheral surface of the stator punching 1 along the radial direction of the stator core 10. Along the axial direction of the stator core 10, the center hole 11 and each cooling hole 12 penetrate the stator punching 1. Exemplarily, each stator punching sheet 1 further includes a plurality of punching sheet grooves 13, which are arranged at intervals along the circumference of the stator core 10 and penetrate the stator punching sheet 1 along the axial direction of the stator core 10, each punching sheet groove 13 is connected to the center hole 11 along the radial direction of the stator core 10, and the bottom of the punching sheet groove 13 is away from the center of the stator punching sheet 1. The liquid outlet 102 of the stator core 10 is specifically formed on the stator punching sheet 1 located at the axial end of the stator core 10, and the stator punching sheet 1 can be considered as the oil injection structure of the stator core 10. When multiple stator punching sheets 1 are stacked along the axial direction of the stator core 10, the central holes 11 of the multiple stator punching sheets 1 can be connected to each other to form a receiving hole 105 of the stator core 10, and the punching grooves 13 of the multiple stator punching sheets 1 are respectively connected to form a winding slot 104, and the structure between any two adjacent punching grooves 13 along the circumferential direction of the stator core 10 can be superimposed to form a stator tooth 103 of the stator core 10. The outer peripheral surface of the stator core 10 includes a plurality of axial grooves 106, which extend along the axial direction of the stator core 10, and the plurality of axial grooves 106 are arranged at intervals along the circumferential direction of the stator core 10.

[0059] The shell 50 is used to circumferentially seal the outside of the stator core 10. The shell 50 is cylindrical. The inner wall of the shell 50 includes a radial groove 52. The radial groove 52 is formed by a groove arranged on the inner wall of the shell 50. The radial groove 52 extends along the circumference of the shell 50. The groove bottom of the radial groove 52 is connected to the liquid inlet 101 through the liquid inlet pipe 51. When the shell 50 sealing sleeve is arranged on the outer peripheral surface of the stator core 10 composed of multiple punchings 1, the radial groove 52 is connected to at least one cooling hole 12 of the stator punching 1 through the axial groove 106 on the outer peripheral surface of the stator core 10. Among them, the corresponding relationship between the number of axial grooves 106 and cooling holes 12 is not limited, as long as there is a cooling hole 12 connected to the radial groove 52 through at least one axial groove 106.

[0060] Figure 4a FIG. 1 shows a partial structure of the stator core 10. Figure 4aAs shown, the plurality of stator punching sheets 1 of the stator core 10 include a first punching sheet 1a and a second punching sheet 1b. Along the axial direction of the stator core 10, a first punching sheet 1a is arranged adjacent to a second punching sheet 1b, the center hole 11 of the first punching sheet 1a is connected to the center hole 11 of the second punching sheet 1b, and each cooling hole 12 of the first punching sheet 1a is used to connect to a cooling hole 12 of the second punching sheet 1b and to cool the end of the stator winding 20.

[0061] like Figure 4a The cooling holes 12 can be used for cooling medium to flow through, and when the cooling medium flows through the cooling holes 12, the cooling medium can dissipate heat to the stator punching 1. The cooling holes 12 connected to the two first punchings 1a and the second punchings 1b can be connected for cooling medium to flow. For the convenience of illustration, the cooling holes 12 of the first punching 1a and the cooling holes 12 of the second punching 1b are both circular holes, and the aperture size is the same.

[0062] like Figure 4b As shown, taking any two connected cooling holes 12 of the first punch 1a and the second punch 1b as an example, the cooling hole 12 of the first punch 1a is set as cooling hole 12a, and the cooling hole 12 of the second punch 1b is set as cooling hole 12b, and the cooling hole 12a and the cooling hole 12b are connected along the axial direction of the stator core 10. The cooling hole 12a and the cooling hole 12b are eccentrically arranged along the radial direction of the stator core 10, so that the distance from the cooling hole 12a to the center hole 11 is not equal to the distance from the cooling hole 12b to the center hole 11. The center holes 11 of the first punch 1a and the second punch 1b are equal in shape and size. It can also be considered that the spacing h1 between the cooling hole 12a and the center Oa of the first punch 1a is not equal to the spacing h2 between the cooling hole 12b and the center Ob of the second punch 1b.

[0063] Figure 5aThe schematic diagram shows a structure in which the cooling hole 12a of the first punching plate 1a is connected to the cooling hole 12b of the second punching plate 1b. For example, when observed along the axial direction of the stator core 10, the first punching plate 1a and the second punching plate 1b are stacked along the axial direction of the stator core 10, the center holes 11 of the first punching plate 1a and the second punching plate 1b are connected and overlapped, the center Oa of the first punching plate 1a and the center Ob of the second punching plate 1b overlap as the center O, and the multiple punching grooves 13 of the first punching plate 1a and the multiple punching grooves 13 of the second punching plate 1b are respectively connected and overlapped. In a group of connected cooling holes 12a and cooling holes 12b, the spacing h1 between the cooling hole 12a and the center O is smaller than the spacing h2 between the cooling hole 12b and the center O, and the cooling hole 12a is eccentrically arranged with the cooling hole 12b along the radial direction of the stator core 10. Along the radial direction of the stator core 10, the cooling hole 12a is offset from the cooling hole 12b by a distance p toward the center O of the stator core 10, and the distance p is the difference between the spacing h1 and the spacing h2. It should be understood that the cooling hole 12a and the cooling hole 12b need to be connected, and at the same time, offset along the radial direction of the stator core 10. Taking the circular cooling hole 12a and the cooling hole 12b at the center of the circle as an example, the offset distance of the cooling hole 12a relative to the cooling hole 12b is not greater than the radial dimension of any cooling hole 12a, so that the cooling hole 12a and the cooling hole 12b along the axial projection of the stator core 10 partially overlap.

[0064] The cooling hole 12a of the first punch 1a and the cooling hole 12b of the second punch 1b are connected to each other for the flow of cooling medium. The cooling hole 12a is offset relative to the cooling hole 12b, which changes the structure of the flow channel of the cooling hole 12a and the cooling hole 12b. Specifically, Figure 5b As shown, when the coolant flows from the cooling hole 12b to the cooling hole 12a, the cross-sectional area that the coolant can occupy when flowing in the cooling hole 12b can refer to the area shown in area A2. After the cooling hole 12a is offset relative to the cooling hole 12b along the radial direction of the stator core 10, when the coolant enters the cooling hole 12a from the cooling hole 12b, the cross-sectional area of ​​the channel for the flow of the coolant suddenly changes to the area shown in area A1, and area A2 is larger than area A1. The shaded area A', that is, the part where area A2 is larger than area A1, the coolant located in the cooling hole 12b cannot pass through the shaded area A', resulting in the cross-sectional area of ​​the channel for the flow of the coolant suddenly changing from area A2 to area A1, and the flow cross-sectional area becomes smaller. When the oil pump power is the same, the flow direction of the coolant is the same, and the rate at which the coolant enters the cooling hole 12a will increase. In other words, the flow rate of the coolant can be changed by the offset design of the cooling hole 12a and the cooling hole 12b.

[0065] In some embodiments, the cooling hole 12a of the first punching sheet 1a is connected to the cooling hole 12b of the second punching sheet 1b, and the cooling holes 12a and the cooling holes 12b are staggered along the circumferential direction of the stator core 10. For example, Figure 6aAs shown, a first punching sheet 1a includes two adjacent cooling holes 12a, namely, a cooling hole 12a1 and another cooling hole 12a2. A second punching sheet 1b includes two adjacent cooling holes 12b, namely, a cooling hole 12b1 and another cooling hole 12b2. The first punching sheet 1a and the second punching sheet 1b are arranged adjacent to each other along the axial direction of the stator core 10, so as to Figure 5a Taking the radial position shown by the dashed line as an example, the cooling holes 12a1 are connected with the cooling holes 12b1 and offset by a distance q, and the cooling holes 12a2 are connected with the cooling holes 12b2 and offset by a distance q. Along the circumference of the stator core 10, the distance between the cooling holes 12a1 and the cooling holes 12a2 is not equal to the distance between the cooling holes 12b1 and the cooling holes 12a2.

[0066] Figure 6b The cross-sectional structure of two circumferentially adjacent cooling holes 12a of the first punching sheet 1a and two circumferentially adjacent cooling holes 12a of the second punching sheet 1b is shown. For example, along the circumference of the stator core 10, the cooling hole 12a1 is offset to the left by a distance q relative to the cooling hole 12b1, and the cooling hole 12a2 is offset to the left by a distance q relative to the cooling hole 12b2. The distance between the cooling hole 12a1 and the cooling hole 12a2 is m1, and the distance between the cooling hole 12b1 and the cooling hole 12a2 is m2, and m1>m2.

[0067] by Figure 6b For example, when the cooling medium flows from the cooling hole 12b1 to the cooling hole 12a1, the cross-sectional area that the cooling medium can occupy when flowing in the cooling hole 12b1 can be referred to as shown in the area A2. After the cooling hole 12a1 is offset relative to the cooling hole 12b1 along the circumferential direction of the stator core 10, when the cooling medium enters the cooling hole 12a1 from the cooling hole 12a1, the cross-sectional area of ​​the channel for the cooling medium to flow suddenly changes to the area shown in the area A1, and the area A2 is larger than the area A1. The shaded area A' is the part where the area A2 is larger than the area A1. The cooling medium located in the cooling hole 12b1 cannot pass through the shaded area A', resulting in the cross-sectional area of ​​the channel for the cooling medium to flow suddenly changing from the area A2 to the area A1, and the flow cross-sectional area becomes smaller. Under the same flow rate, the rate at which the cooling medium enters the cooling hole 12a1 will increase. In other words, the flow rate of the cooling medium can be changed by the offset design of the cooling hole 12a1 and the cooling hole 12b1.

[0068] In some possible embodiments, the cooling hole 12a of the first punch 1a can be offset relative to the cooling hole 12b of the second punch 1b along the circumferential and radial directions of the stator core 10, so that when the cooling medium flows between the cooling hole 12a and the cooling hole 12b, the flow velocity changes due to the change in the flow cross-section.

[0069] As shown in the above embodiment, if the first punching sheet 1a is set as the stator punching sheet 1 at the axial end of the stator core 10, the cooling hole 12a of the first punching sheet 1a is equivalent to the liquid outlet 102 at the end of the stator core 10. The cooling medium flows from the cooling hole 12b of the second punching sheet 1b to the cooling hole 12a of the first punching sheet 1a and is sprayed out. The offset setting of the cooling hole 12a relative to the cooling hole 12b can increase the spraying speed of the cooling medium. For the stator core 10, in the design of the stator punching sheet 1, the stator punching sheet 1 at the axial end does not need to be designed with a small-aperture oil injection hole to increase the oil injection rate. The offset of the cooling hole 12a of the first punching sheet 1a and the cooling hole 12b of the second punching sheet 1b can reduce the aperture of the oil injection channel and increase the oil injection flow rate.

[0070] It should be understood that when the first punching sheet 1a is set as the stator punching sheet 1 at the axial end of the stator core 10, the cooling hole 12a of the first punching sheet 1a is equivalent to the liquid outlet 102 at the end of the stator core 10. The cooling hole 12a of the first punching sheet 1a is offset toward the center of the stator core 10 relative to the cooling hole 12b of the connected second punching sheet 1b, and the cooling medium can be guided to the stator winding 20 located at the end of the stator core 10, so as to realize the liquid spray cooling of the end winding.

[0071] Taking the cooling hole 12a of the first punching plate 1a and the cooling hole 12b of the second punching plate 1b as an example, which are connected and offset in the radial direction of the stator core 10, in some embodiments, as Figure 7 As shown, the diameter of the cooling hole 12a of the first punch 1a is smaller than or equal to the diameter of the cooling hole 12b of the second punch 1b. The rate at which the cooling medium is ejected from the cooling hole 12a will be further increased.

[0072] It should be understood that when the first punching sheet 1a is set as the stator punching sheet 1 at the axial end of the stator core 10, the number of the first punching sheet 1a can be one, and the effect of increasing the injection rate can be achieved by cooperating with one first punching sheet 1a and an adjacent second punching sheet 1b. Of course, there can also be two or three first punching sheets 1a, but not too many. The number of second punching sheets 1b can be multiple, and multiple second punching sheets 1b are arranged adjacent to each other along the axial direction of the stator core 10, and multiple cooling holes 12b of multiple second punching sheets 1b are respectively connected to form a channel for the circulation of cooling medium.

[0073] For example, Figure 8 As shown, the plurality of stator punching sheets 1 include a plurality of second punching sheets 1b and another second punching sheet 1b, and the plurality of second punching sheets 1b are arranged between the one second punching sheet 1b and the another second punching sheet 1b along the axial direction of the stator core 10. For example, Figure 8As shown, a first punching sheet 1a and a plurality of second punching sheets 1b are arranged adjacent to each other in the axial direction of the stator core 10. Among the plurality of second punching sheets 1b, the second punching sheet 1b-1 is arranged adjacent to the first punching sheet 1a, and the second punching sheet 1b-2 is the second punching sheet 1b farthest from the first punching sheet 1a. For example, two second punching sheets 1b-3 are arranged between the second punching sheet 1b-1 and the second punching sheet 1b-2. The cooling holes 12b of the plurality of second punching sheets 1b are connected in sequence, and the cooling holes 12b of the second punching sheet 1b-1 are connected to the cooling holes 12a of the first punching sheet 1a and are offset and misaligned.

[0074] like Fig. 9 In the example of a second punching plate 1b, the distances between the multiple cooling holes 12b and the center O of the second punching plate 1b vary along the circumference of the stator core 10. Exemplarily, for two cooling holes 12b adjacent to each other along the circumference of the stator core 10, the distance h22 between the latter cooling hole 12b and the center O of the second punching plate 1b in the clockwise direction is greater than the distance h21 between the former cooling hole 12b and the center O of the second punching plate 1b. Exemplarily, the distances between the multiple cooling holes 12b of the second punching plate 1b and the center O gradually increase. For example, the multiple cooling holes 12b are distributed along an asymptote, and the base circle of the asymptote takes the distance between the cooling hole 12b closest to the center O of the second punching plate 1b and the center O as the radius.

[0075] For each second punch 1b, in the clockwise direction, the cooling hole 12b closest to the center O of the second punch 1b is the first cooling hole 12b, and the distances between the multiple cooling holes 12b after the first cooling hole 12b and the center O of the second punch 1b gradually increase. Among them, the distance between the k+1th cooling hole 12b and the center O of the second punch 1b is greater than the distance between the kth cooling hole 12b and the center O of the second punch 1b.

[0076] Multiple Fig. 9 When the second punching sheets 1b are arranged adjacent to each other along the axial direction of the stator core 10, between two adjacent second punching sheets 1b, the multiple cooling holes 12b of the previous second punching sheet 1b are respectively connected with the multiple cooling holes 12b of the next second punching sheet 1b.

[0077] In one arrangement, Fig.10a As shown, the distance between the two connected cooling holes 12b and the center of the second punching plate 1b is equal. In this structure, each second punching plate 1b is connected to the cooling holes 12b with equal distances from the center in sequence to form a cooling channel D for the flow of cooling medium, and the cooling channel D is parallel to the axial direction of the stator core 10.

[0078] In one arrangement, Fig.10bAs shown, the distances between the two connected cooling holes 12b and the center of the second punch 1b are not equal. Along the radial direction of the stator core 10, between the two cooling holes 12b connected between two adjacent second punches 1b, the distance between the cooling hole 12b of one second punch 1b and the center of the second punch 1b is greater than the distance between the cooling hole 12b of the other second punch 1b and the center of the second punch 1b. The center of the cooling channel formed by the two cooling holes 12b is offset along the radial direction of the second punch 1b, causing the cooling channel to tilt and changing the flow direction of the coolant. In this structure, the cooling channel D formed by the connected cooling holes 12b is set at an angle to the axial direction of the stator core 10. When a group of cooling holes 12b of multiple second punches 1b are connected in sequence to form a cooling channel D that runs through all the second punches 1b, the cooling hole 12b of the second punch 1b-1 adjacent to the first punch 1a is closest to the center of the second punch 1b, and the cooling hole 12b of the second punch 1b-2 farthest from the first punch 1a is farthest from the center of the second punch 1b. The inclined cooling channel D is inclined toward the axial direction of the stator core 10, so that the cooling medium can be inclined to the end winding.

[0079] Fig.10b The arrangement of the cooling holes 12b of the plurality of second punching sheets 1b shown can be achieved by Fig.11 The multiple second punching sheets 1b shown are implemented. Fig.11 As shown, the local structure of multiple second punching plates 1b, the cooling hole 12b closest to the center O of each second punching plate 1b is defined as cooling hole 12b-1, and the cooling hole 12b farthest from the center of the second punching plate 1b is defined as cooling hole 12b-2. Along the circumference of the second punching plate 1c, any two adjacent second punching plates 1b are relatively deflected by a set angle, and the set angle is the central angle between the two cooling holes 12b.

[0080] After the plurality of second punching sheets 1b are deflected and stacked in sequence, the cooling channel D formed by the connected cooling holes 12b can be tilted along the radial direction of the stator core 10, thereby changing the flow direction of the coolant. Specifically, with the cooling hole 12b closest to the center of the second punching sheet 1b as a reference, after the plurality of second punching sheets 1b are arranged adjacently, the kth cooling hole 12b of one of the second punching sheets 1b is connected to the k+1th cooling hole 12b of another second punching sheet 1b, where k is an integer greater than or equal to 1, and the direction of the channel formed by the connected cooling holes 12b is tilted, thereby changing the flow direction of the coolant.

[0081] like Fig.11As shown at N1, N1 is the position of the cooling hole 12b-2 of the first second punch 1b that is farthest from the center of the second punch 1b. A cooling hole 12b-2 of the first second punch 1b can be connected to the last cooling hole 12b of the last second punch 1b, so that the cooling holes 12b of multiple second punches 1b at this position are connected in sequence to form a cooling channel. Here, since the kth cooling hole 12b of the i+1th second punch 1b is connected to the k+1th cooling hole 12b of the i-th second punch 1b, the direction of the cooling channel here is inclined along the radial direction of the stator core 10, and the cooling medium can be deflected radially outward or inward along the stator core 10 when circulating.

[0082] like Fig.11 As shown in N2, N2 is the position of the cooling hole 12b-1 of the first second punch 1b that is closest to the center of the second punch 1b. If the cooling hole 12b-1 of the first second punch 1b is blocked by the second second punch 1b, a cooling channel that runs through all the second punches 1b cannot be formed. When multiple second punches 1b are arranged axially, there is always a cooling hole 12b blocked between any two adjacent second punches 1b, resulting in the cooling channel being blocked and unable to communicate. It should be understood that when a cooling channel is blocked by a second punch 1b, for cooling holes 12b at different angular positions, the second punch 1b that blocks the cooling channel may be one of the second punches 1b, and is not limited to the second punches 1b on both sides. Fig.12 The example illustrates a situation where the cooling holes 12b of the two second punching sheets 1b are not connected between the first second punching sheet 1b-1 and the last second punching sheet 1b-2, resulting in blockage of the outer cooling channel.

[0083] It should be understood that when the distance between any two circumferentially adjacent cooling holes 12b of the second punching sheet 1b changes, the direction of the cooling channel will be tilted along the circumference of the stator core 10, causing the cooling medium to deflect eccentrically along the circumference of the stator core 10. When the connection mode of the cooling hole 12b is tilted simultaneously in the circumferential or radial direction of the stator core 10, the stator core 10 can finally spray the coolant in a rotating manner. Of course, the spray direction of the coolant can be irregular, and the embodiment of the present application is not limited thereto. Two axially adjacent second punching sheets 1b can be circumferentially rotated relative to the center of the stator core 10 by a set angle, and the set angle is the angle between two adjacent cooling holes 12b of the same second punching sheet 1b.

[0084] like Fig.13aThe stator core 10 shown in the figure includes a plurality of stator sheets 1, including a first sheet 1a, a second sheet 1b, a third sheet 1c and a fourth sheet 1d. Specifically, the stator core 10 includes a fourth sheet 1d, a second sheet 1b and a third sheet 1c arranged at the axial ends of the third sheet 1c. The second sheet 1b is a combination of a plurality of second sheets 1b, which can be specifically the stator core 10 in the above embodiment. Figure 8 The fourth punching sheet 1d is arranged between the plurality of second punching sheets 1b and the third punching sheet 1c. It can be considered that the first punching sheet 1a is circumferentially connected to the stator core 10. Figure 8 The second punching sheet 1b-1 is arranged adjacent to the stator core 10, and the fourth punching sheet 1d is arranged adjacent to the stator core 10 in the axial direction. Figure 8 Another second punching sheet 1b-2 is arranged adjacently, and the third punching sheet 1c is arranged adjacently on the side of the fourth punching sheet 1d away from another second punching sheet 1b-2 along the axial direction of the stator core 10. When there is one fourth punching sheet 1d, the fourth punching sheet 1d is arranged between the second punching sheet 1b and the third punching sheet 1c. The center holes 11 of the first punching sheet 1a, the second punching sheet 1b, the third punching sheet 1c and the fourth punching sheet 1d overlap along the axial projection of the stator core 10, and the distances from the outer peripheral surfaces of the first punching sheet 1a, the second punching sheet 1b, the third punching sheet 1c and the fourth punching sheet 1d to the center hole 11 are equal.

[0085] Fig.13b An exploded view of the stator core 10 is shown. Along the radial direction of the stator core 10, the cooling hole 12c of the third punch 1c is connected to the outer peripheral surface of the third punch 1c. It can be considered that the cooling hole 12c of the third punch 1c is at least a part of the axial groove 106 of the stator core 10. Along the axial direction of the stator core 10, the multiple cooling holes 12d of the fourth punch 1d are respectively used to connect at least one cooling hole 12b of another second punch 1b-2 with at least one cooling hole 12c of the third punch 1c. Exemplarily, the cooling hole 12d of the fourth punch 1d is connected to the outer peripheral surface of the fourth punch 1d along the radial direction of the stator core 10, and each cooling hole 12d of the fourth punch 1d is used to connect one cooling hole 12b of the second punch 1b with at least one cooling hole 12c of the third punch 1c. The number of cooling holes 12d of the fourth punching plate 1d may be smaller than the number of cooling holes 12 of the second punching plate 1b and the number of cooling holes 12 of the third punching plate 1c.

[0086] Fig.14aThe structure in which the second punching sheet 1b and the fourth punching sheet 1d are arranged and stacked is shown. Along the axial direction of the stator core 10, the orthographic projection of the cooling hole 12d of the fourth punching sheet 1d on the second punching sheet 1b covers the cooling hole 12b of the second punching sheet 1b. Along the circumferential direction of the stator core 10, the circumferential dimension of the cooling hole 12d of the fourth punching sheet 1d is larger than the circumferential dimension of the cooling hole 12b of the second punching sheet 1b. Along the radial direction of the stator core 10, the radial dimension of the cooling hole 12d of the fourth punching sheet 1d is larger than the radial dimension of the cooling hole 12b of the second punching sheet 1b.

[0087] Fig.14b The structure in which the third punching sheet 1c and the fourth punching sheet 1d are arranged and stacked is shown. Along the axial direction of the stator core 10, the cooling hole 12d of the fourth punching sheet 1d covers at least one cooling hole 12c of the third punching sheet 1c in the orthographic projection of the third punching sheet 1c. Along the circumferential direction of the stator core 10, the circumferential dimension of the cooling hole 12d of the fourth punching sheet 1d is larger than the circumferential dimension of the cooling hole 12c of the third punching sheet 1c. Along the radial direction of the stator core 10, the radial dimension of the cooling hole 12d of the fourth punching sheet 1d is larger than the radial dimension of the cooling hole 12c of the third punching sheet 1c.

[0088] Combination Fig.14a and Fig.14b As shown, Fig.15 FIG. 1 shows a partial structure of the stator core 10. Fig.15 As shown, along the axial direction of the stator core 10, the first punch 1a, the second punch 1b, the fourth punch 1d and the third punch 1c are arranged adjacent to each other in sequence, and the cooling hole 12d of the fourth punch 1d can connect a cooling hole 12b of the second punch 1b with at least one cooling hole 12c of the third punch 1c. Among them, the circumferential size of the cooling hole 12d of the fourth punch 1d can be greater than the spacing between two adjacent cooling holes 12b of the second punch 1b, so that one cooling hole 12d of the fourth punch 1d can be connected to two cooling holes 12b of the second punch 1b at the same time. The circumferential size of the cooling hole 12d of the fourth punch 1d can be greater than the spacing between two adjacent cooling holes 12c of the third punch 1c, so that one cooling hole 12d of the fourth punch 1d can be connected to two cooling holes 12c of the third punch 1c at the same time.

[0089] Fig.16 FIG. 1 shows a schematic cross-sectional view of a portion of the structure of the housing 50 and the stator core 10 of the motor 100. Fig.16As shown, for example, a cooling medium is introduced into the liquid inlet 101 of the motor 100, and the cooling medium enters the radial groove 52 of the shell 50 through the liquid inlet pipe 51 of the shell 50 and flows in the radial groove 52 along the circumference of the stator core 10, and then enters the multiple cooling holes 12c on the outer peripheral surface of the third punching plate 1c. The cooling medium in each cooling hole 12c flows along the axial direction of the stator core 10 to the cooling holes 12d of the fourth punching plate 1d on both sides of the third punching plate 1c. The cooling medium in each cooling hole 12d can pass through the cooling channel formed by the multiple cooling holes 12b of the multiple second punching plates 1b to flow to the cooling hole 12a of the first punching plate 1a and spray out and drip on the end of the stator winding 20. Since the cooling hole 12a of the first punch 1a is offset relative to the cooling hole 12b of the adjacent second punch 1b along at least one of the circumferential or radial directions of the stator core 10, the cross-sectional size of the channel for the circulation of the cooling medium is reduced, so that the cooling medium ejected from the cooling hole 12a of the first punch 1a has a higher speed.

[0090] In some embodiments, the cooling holes 12d of the fourth punch 1d can be realized in the form of two circumferential connections or multiple circumferential connections. Along the circumference of the stator core 10, at least two adjacent cooling holes 12d among the multiple cooling holes 12d of the fourth punch 1d are connected. In the fourth punch 1d of this structure, the cooling holes 12d of the fourth punch 1d can be simultaneously connected to the cooling holes 12b of the multiple second punches 1b and the cooling holes 12c of the multiple third punches 1c. When the cooling medium in the multiple cooling holes 12 of the third punch 1c flows into the cooling hole 12d of the same fourth punch 1d, the cooling medium can flow in the cooling hole 12d along the circumference of the stator core 10, thereby flowing to the multiple cooling holes 12b of the second punch 1b.

[0091] In the stator core 10 with the fourth punch 1d, the cooling hole 12d of the fourth punch 1d can guide the cooling medium in the third punch 1c to the cooling hole 12b of the second punch 1b which is closer to the center of the stator core 10, so as to facilitate guiding the cooling medium to the end winding. When the cooling hole 12d of the fourth punch 1d is larger in size, the cooling hole 12d of the fourth punch 1d can form a collection space between the second punch 1b and the third punch 1c that can accommodate more cooling medium. The cooling medium is collected here to provide a more sufficient oil supply for the liquid outlet 102, thereby ensuring the oil pressure and oil speed sprayed out of the liquid outlet 102. In addition, the setting of the fourth punch 1d makes it unnecessary for the cooling hole 12b of the second punch 1b and the cooling hole 12c of the third punch 1c to strictly correspond along the axial direction of the stator core 10, thereby reducing the assembly precision requirements.

[0092] Fig.17An exploded view of a stator core 10 is shown, wherein the fourth punch 1d is annular, and the distance from the outer circumference of the fourth punch 1d to the center is smaller than the distance from the outer circumference of the second punch 1b to the center and the distance from the outer circumference of the third punch 1c to the center. The center hole 11 of the second punch 1b, the center hole 11 of the third punch 1c, and the center hole 11 of the fourth punch 1d coincide along the axial projection of the stator core 10. It can also be considered that the distance from the outer circumference of the fourth punch 1d to the center hole 11 is smaller than the distance from the outer circumference of the second punch 1b to the center hole 11 and the distance from the outer circumference of the third punch 1c to the center hole 11. The fourth punch 1d of this structure is Fig.13b The structure of the plurality of cooling holes 12d of the fourth punching sheet 1d is shown as being connected along the circumferential direction of the stator core 10. The cooling holes 12d at this time can be considered to disappear after being connected. The fourth punching sheet 1d can be arranged and fixed between the second punching sheet 1b and the third punching sheet 1c by bonding.

[0093] Fig.18a The structure in which the second punching sheet 1b and the fourth punching sheet 1d are arranged and stacked is shown. Along the axial direction of the stator core 10, the orthographic projection of the outer peripheral surface of the fourth punching sheet 1d on the second punching sheet 1b is located between the cooling hole 12b of the second punching sheet 1b and the bottom of the punching sheet groove 13.

[0094] Fig.18b The third punching sheet 1c and the fourth punching sheet 1d are stacked in an arranged manner. Along the axial direction of the stator core 10, the orthographic projection of the outer peripheral surface of the fourth punching sheet 1d on the third punching sheet 1c is located between the cooling hole 12c of the third punching sheet 1c and the bottom of the punching sheet groove 13.

[0095] based on Fig.18a and Fig.18b In the structure shown, when the fourth punching plate 1d is arranged between the second punching plate 1b and the third punching plate 1c, an annular channel surrounding the circumference of the stator core 10 can be formed between the surface of the third punching plate 1c facing the second punching plate 1b, the outer peripheral surface of the fourth punching plate 1d, and the surface of the second punching plate 1b facing the third punching plate 1c, and the annular channel can be used for the cooling medium to flow along the circumference of the stator core 10. All the cooling holes 12c of the third punching plate 1c are connected to the annular channel, and all the cooling holes 1b of the second punching plate 1b are also connected to the annular channel. The cooling medium can reach the annular channel through the cooling holes 12c of the third punching plate 1c, and flow along the circumference of the stator core 10 and then be transported to each cooling hole 12b of the second punching plate 1b.

[0096] In some embodiments, when the cooling medium can flow along the circumference of the stator core 10, when the stator punching sheet 1 at the axial end of the stator core 10 where the first punching sheet 1a is used for oil injection, the number of cooling holes 12a of the first punching sheet 1a can be reduced, so that a part of the cooling medium cannot be sprayed out from certain cooling holes 12a of the first punching sheet 1a, and can only flow along the circumference of the stator core 10 to the cooling holes 12a at other positions of the first punching sheet 1a for spraying, thereby further improving the spraying speed.

[0097] In some embodiments, the structure of the fourth punching sheet 1d can be omitted. Specifically, the stator core 10 includes a plurality of stator punching sheets 1 including a first punching sheet 1a, a second punching sheet 1b and a third punching sheet 1c. Along the axial direction of the stator core 10, the third punching sheet 1c is arranged adjacent to the above-mentioned other second punching sheet 1b-2. That is to say, the third punching sheet 1c is arranged on the side of the plurality of second punching sheets 1b away from the first punching sheet 1a, and it can be considered that the plurality of second punching sheets 1b are arranged between the first punching sheet 1a and the third punching sheet 1c. Specifically, along the radial direction of the stator core 10, the cooling hole 12 of the third punching sheet 1c is connected to the outer peripheral surface of the third punching sheet 1c, and it can be considered that the cooling hole 12 of the third punching sheet 1c is at least a part of the axial groove 106 of the stator core 10. Along the axial direction of the stator core 10, the plurality of cooling holes 12c of the third punching sheet 1c are respectively used to connect the plurality of cooling holes 12b of the second punching sheet 1b adjacent to the third punching sheet 1c. The distance between the cooling hole 12c of the third punching plate 1c and the center of the third punching plate 1c is greater than or equal to the distance between the cooling hole 12b of the second punching plate 1b and the center of the second punching plate 1b. The center holes 11 of the second punching plate 1b and the third punching plate 1c overlap along the axial projection of the stator core 10, and it can also be considered that the distance between the cooling hole 12c of the third punching plate 1c and the center hole 11 of the third punching plate 1c is greater than or equal to the distance between the cooling hole 12b of the second punching plate 1b and the center hole 11 of the second punching plate 1b.

[0098] In summary, the stator core 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 toward the end winding at the axial end of the stator core 10 through the cooling channel of the stator core 10 itself. The first punching sheet 1a is used as the stator punching sheet 1 at the end of the stator core 10, and the cooling holes 12a of the first punching sheet 1a and the cooling holes 12b of the second punching sheet 1b are arranged in a staggered manner, so that the cooling medium has a higher speed when sprayed out, and a good liquid cooling and heat dissipation effect is achieved. In some embodiments, compared with traditional oil cooling and heat dissipation, the stator core 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.

[0099] The above are only specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A stator core for cooling winding ends, characterized in that: The stator core includes a plurality of stator punchings, each of which includes a center hole penetrating the stator punching in the axial direction of the stator core and a plurality of cooling holes, the plurality of cooling holes are arranged at intervals along the circumferential direction of the stator punching, each of the cooling holes is arranged at intervals between the center hole and the outer peripheral surface of the stator punching, and the plurality of stator punchings include a first punching and a second punching, wherein: Along the axial direction of the stator core, the first punching sheet is arranged adjacent to the second punching sheet, the center hole of the first punching sheet is connected to the center hole of the second punching sheet, and each cooling hole of the first punching sheet is used to connect to one cooling hole of the second punching sheet and to cool the stator winding end; Along at least one of the radial direction and the circumferential direction of the stator core, each cooling hole of the first punching plate is eccentrically arranged relative to a cooling hole of the second punching plate connected thereto.

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

3. The stator core according to claim 1, characterized in that: One cooling hole of the first punch is connected to one cooling hole of the second punch, and another cooling hole of the first punch is connected to another cooling hole of the second punch; Along the circumference of the stator core, the distance between the one cooling hole of the one first punch and the other cooling hole is not equal to the distance between the one cooling hole of the one second punch and the other cooling hole of the one first punch, and the distance between the one cooling hole of the one second punch and the other cooling hole is not equal to the distance between the one cooling hole of the one first punch and the other cooling hole of the one second punch.

4. The stator core according to claim 1, characterized in that: The diameter of the cooling hole of the first punching plate is smaller than or equal to the diameter of the cooling hole of the second punching plate.

5. The stator core according to claim 1, characterized in that: The number of the cooling holes of the first punching plate is smaller than the number of the cooling holes of the second punching plate.

6. The stator core according to any one of claims 1 to 5, characterized in that: The plurality of stator punching sheets include a plurality of second punching sheets and another second punching sheet, wherein the plurality of second punching sheets are arranged between the one second punching sheet and the another second punching sheet along the axial direction of the stator core; Along the axial direction of the stator core, the multiple cooling holes of one second punch are respectively used to connect the multiple cooling holes of adjacent second punches, the multiple cooling holes of another second punch are respectively used to connect the multiple cooling holes of adjacent second punches, and the multiple cooling holes of each second punch in the multiple second punches are respectively used to connect the multiple cooling holes of adjacent second punches.

7. The stator core according to claim 6, characterized in that: For two cooling holes of the second punching sheet that are adjacent in the circumferential direction, a distance between one cooling hole and the center hole is greater than a distance between the other cooling hole and the center hole.

8. The stator core according to claim 7, characterized in that: Between any two connected cooling holes of the second punching sheets, along the radial direction of the stator core, the distance between one cooling hole and the center hole is greater than the distance between another cooling hole and the center hole.

9. The stator core according to claim 7 or 8, characterized in that: The plurality of stator punching sheets include a third punching sheet, and the third punching sheet is arranged adjacent to the other second punching sheet along the axial direction of the stator core, wherein: Along the radial direction of the stator core, the cooling hole of the third punching sheet is connected with the outer peripheral surface of the third punching sheet; Along the axial direction of the stator core, the multiple cooling holes of the third punching sheet are respectively used to communicate with the multiple cooling holes of the other second punching sheet.

10. The stator core according to claim 7 or 8, characterized in that: The plurality of stator punching sheets include a third punching sheet and a fourth punching sheet, the fourth punching sheet is arranged adjacent to the other second punching sheet along the axial direction of the stator core, and the third punching sheet is arranged adjacent to the side of the fourth punching sheet away from the other second punching sheet along the axial direction of the stator core, wherein: Along the radial direction of the stator core, the cooling hole of the third punching sheet is connected with the outer peripheral surface of the third punching sheet; Along the axial direction of the stator core, the plurality of cooling holes of the fourth punching sheet are respectively used to connect at least one cooling hole of the other second punching sheet with at least one cooling hole of the third punching sheet.

11. The stator core according to claim 10, characterized in that: Along the circumferential direction of the stator core, a circumferential dimension of the cooling hole of the fourth punching plate is larger than a distance between two adjacent cooling holes of the second punching plate and a distance between two adjacent cooling holes of the third punching plate.

12. The stator core according to claim 10, characterized in that: Each of the cooling holes of the fourth punching sheet is connected to the outer peripheral surface of the fourth punching sheet along the radial direction of the stator core; Along the circumferential direction of the stator core, at least two adjacent cooling holes among the plurality of cooling holes of the fourth punching sheet are connected.

13. A motor, characterized in that: The motor comprises a housing and a stator core as claimed in any one of claims 1 to 12; The housing is sleeved on the outer peripheral surface of the stator core, and the housing comprises a coolant inlet, which is used to communicate with at least one cooling hole of the second punching sheet.

14. A powertrain, characterized in that: It comprises a reducer or a transmission and the motor as claimed in claim 13, wherein the motor shaft of the motor is drivingly connected to the input shaft of the reducer or the input shaft of the transmission.

15. An electric vehicle, characterized in that: The invention comprises a wheel, a transmission mechanism and a power assembly as claimed in claim 14, wherein the power assembly drives the wheel through the transmission mechanism.

Images