Stator lamination having circumferential flow channels, motor, powertrain, and electric vehicle

Abstract

The present application relates to the technical field of motors, and provides a stator lamination having circumferential flow channels, a motor, a powertrain, and an electric vehicle. The stator lamination comprises a plurality of communication holes and a plurality of circumferential flow channels; in the axial direction of a stator, each communication hole and each circumferential flow channel pass through the stator lamination; in the circumferential direction of the stator, the plurality of communication holes are arranged at intervals, the plurality of circumferential flow channels are arranged at intervals, and each circumferential flow channel is communicated with at least two communication holes; and in the radial direction of the stator, the distance between the center of the circumferential flow channel and the center of the stator lamination is greater than the distance between the center of the communication hole and the center of the stator lamination. A cooling working medium can flow in the circumferential direction of the motor after entering the motor, optimizing the heat dissipation effect on the motor.

Description

Stator punching sheet with circumferential flow channel, 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 September 26, 2023, with application number 202311288722.7 and application name "Stator punching, motor, powertrain and electric vehicle with circumferential flow channel", the entire 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 a circumferential flow channel, 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 can be achieved by oil cooling the stator through heat dissipation channels provided on the stator. However, conventional heat dissipation methods for motor stators are currently inadequate, and the cooling effect needs to be improved.

[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 a circumferential flow channel. After the cooling medium enters the motor, it can flow along the circumference of the motor, and the cooling medium can be sprayed toward the end of the stator winding from a specific circumferential angle, thereby optimizing the heat dissipation effect of the motor.

[0008] In a first aspect, an embodiment of the present application provides a stator lamination with a circumferential flow channel, which can be axially stacked to form the stator core of a motor. The stator lamination includes a plurality of connecting holes and a plurality of circumferential flow channels. Along the axial direction of the stator lamination, each connecting hole and each circumferential flow channel penetrates the stator lamination. Along the circumference of the stator lamination, a plurality of connecting holes are arranged at intervals, and a plurality of circumferential flow channels are arranged at intervals, and each circumferential flow channel is connected to at least two connecting holes, so that a cooling medium can flow along the circumference of the stator within the circumferential flow channel. Along the radial direction of the stator lamination, the distance between the center of the circumferential flow channel and the center of the stator lamination is greater than the distance between the center of the connecting hole and the center of the stator lamination. The circumferential flow channel and the connecting hole are both part of the internal channel of the stator. The cooling medium can flow through the circumferential flow channel and the connecting hole to achieve liquid cooling and heat dissipation of the stator. The circumferential flow channel can connect at least two connecting holes, so that the cooling medium can flow circumferentially within the stator. In motor design, the circumferential flow channel is adjusted according to the heat dissipation requirements, so that the cooling medium can flow along the circumference of the stator to a preset angle at the end of the stator, and can be sprayed to the end of the stator winding from a specific circumferential angle, so that the liquid cooling heat dissipation effect of the motor is better.

[0009] In one possible implementation, the stator punch includes a groove extending axially through the stator punch. The outer circumferential surface of the stator punch includes a notch opening, meaning the groove communicates with the outer circumferential surface of the stator punch. In the radial direction of the stator punch, the bottom of the groove communicates with at least two communication holes, with the groove serving as the aforementioned circumferential flow channel. The groove of the stator punch connects the outer circumferential surface of the stator punch with the communication holes, allowing the cooling medium to flow radially along the stator punch.

[0010] In one possible implementation, along the circumference of the stator punching, one communication hole communicates with the bottom of the groove, while another communication hole adjacent to the one communication hole is isolated from the groove. Only one of the two adjacent communication holes communicates with the groove, allowing the coolant in one communication hole to communicate with the outer circumference of the stator punching through the groove, thereby changing the flow direction of the coolant.

[0011] Wherein, along the radial direction of the stator punching sheet, the distance between the communicating hole and the bottom of the groove is greater than the size of the communicating hole, and the communicating hole is closer to the center of the stator punching sheet.

[0012] In one possible implementation, along the circumference of the stator sheet, the size of the circumferential flow channel is larger than the size of the communication hole. The circumferential flow channel can extend along the circumference of the stator sheet to connect at least two communication holes.

[0013] Along the radial direction of the stator punching sheet, the size of the circumferential flow channel is larger than the size of the communicating hole, and the circumferential flow channel can accommodate more cooling medium than that accommodated by the communicating hole.

[0014] In a second aspect, embodiments of the present application provide a motor, wherein the stator of the motor includes a first punching sheet and at least one stator punching sheet of any one of the types provided in the first aspect. The first punching sheet includes a plurality of conducting holes, each of which extends through the first punching sheet along the axial direction of the stator, and the plurality of conducting holes are spaced apart along the circumferential direction of the stator. Along the axial direction of the stator, the first punching sheet is arranged adjacent to the stator punching sheets, and the conducting holes are connected to the circumferential flow channel or the connecting hole, thereby forming a flow channel extending along the axial direction of the stator for the flow of the cooling medium.

[0015] In one possible implementation, a first punch is arranged between two first punches along the axial direction of the stator. The circumferential flow channel of one stator punch is a groove, and the outer circumferential surface of the stator punch includes a notch of the groove. The circumferential flow channel of the other stator punch is a through hole, and along the circumference of the stator, the through hole is larger than the connecting hole. The connecting hole of the first punch can connect the connecting holes of the two stator punches, or connect the circumferential flow channel, or connect the circumferential flow channel to the connecting hole.

[0016] In one possible implementation, there are two stator punchings, and the two stator punchings are arranged adjacent to each other along the axial direction of the stator. Along the axial direction of the stator, the circumferential flow channel of one stator punching is connected to the circumferential flow channel of another adjacent stator punching, and the connecting hole of one stator punching is connected to the circumferential flow channel of another adjacent stator punching. Along the circumference of the stator, the structure between the two adjacent circumferential flow channels of one stator punching partially blocks the circumferential flow channel of the other adjacent stator punching. The circumferential flow channels of the two stator punchings are staggered along the circumference of the stator and connected in sequence, forming a circumferential liquid cooling channel that is continuous along the circumference of the stator.

[0017] In one possible implementation, the stator includes at least one second punching plate, and the second punching plate includes a plurality of liquid outlet holes, each of which penetrates the second punching plate along the axial direction of the stator, and the plurality of liquid outlet holes are arranged at intervals along the circumference of the stator. Along the axial direction of the stator, the second punching plate is arranged on the side of the above-mentioned other stator punching plate that is away from the first punching plate, and the circumferential flow channel is connected to at least two adjacent liquid outlet holes along the circumference of the stator. The second punching plate is equivalent to the axial end plate of the stator. After the cooling medium is ejected from the liquid outlet, it can fall on the end winding to dissipate heat for the end winding. At least two adjacent liquid outlet holes along the circumference of the stator are connected to the circumferential flow channel, which facilitates the realization of a non-uniform oil injection effect at the end of the stator.

[0018] In one possible implementation, the stator includes at least one third punching plate, and the third punching plate includes a plurality of inner cooling holes and a plurality of outer cooling holes. Along the circumference of the stator, the plurality of inner cooling holes are arranged at intervals, and the plurality of outer cooling holes are arranged at intervals. Along the radial direction of the stator, the distance between the inner cooling hole and the center of the stator is smaller than the distance between the outer cooling hole and the center of the third punching plate. Along the axial direction of the stator, the third punching plate is arranged on the side of one of the stator punching plates facing away from the first punching plate, the outer cooling hole is connected to the circumferential flow channel, and the inner cooling hole is connected to the connecting hole. The inner cooling hole can be considered as the outer cooling channel of the stator, and the inner cooling hole can be considered as the inner cooling channel of the stator. The circumferential flow channel of the stator punching plate can connect the inner and outer cooling channels to achieve double-layer liquid cooling heat dissipation.

[0019] Specifically, the number of the external cooling holes is greater than the number of the circumferential flow channels, and each circumferential flow channel can be communicated with at least one external cooling hole at the same time.

[0020] In some possible implementations, the outer cooling holes are in communication with the outer circumferential surface of the third punching plate along the radial direction of the stator, so that outer cooling of the stator is provided to the circumferential surface of the stator.

[0021] In a third aspect, a powertrain is provided, comprising a reducer or transmission, and the motor of the first aspect and any implementation thereof, wherein the motor shaft of the motor is drivingly connected to the input shaft of the reducer or the input shaft of the transmission. Because the motor has excellent heat dissipation performance, the heat dissipation and power performance of the powertrain can be improved.

[0022] In a fourth aspect, an electric vehicle is provided. The electric vehicle in this application includes wheels, a transmission mechanism, and the powertrain according to the second 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.

[0023] For the technical effects that can be achieved in 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

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

[0027] FIG4 is an exploded view of a stator of a motor provided in an embodiment of the present application;

[0028] FIG5a is a schematic structural diagram of a stator punching sheet provided in an embodiment of the present application;

[0029] FIG5 b is a schematic structural diagram of another stator punching sheet provided in an embodiment of the present application;

[0030] FIG6 is a schematic structural diagram of a portion of a stator punching sheet provided in an embodiment of the present application;

[0031] FIG7 a is a schematic structural diagram of a stator core of a stator provided in an embodiment of the present application;

[0032] FIG7 b is an exploded view of a portion of the stator core of the stator provided in an embodiment of the present application;

[0033] FIG8a is a schematic structural diagram of two stator punching sheets provided in an embodiment of the present application;

[0034] FIG8 b is a schematic diagram of a simulated physical structure of a circumferential liquid cooling channel formed by two stator punchings provided in an embodiment of the present application;

[0035] FIG9 a is a schematic structural diagram of two stator punching sheets and a first punching sheet provided in an embodiment of the present application;

[0036] FIG9 b is a schematic cross-sectional view of two stator punching sheets and a first punching sheet provided in an embodiment of the present application;

[0037] FIG9c is an enlarged view of the detail at point A in FIG9b;

[0038] FIG10 a is a schematic structural diagram of a stator punching sheet and a third punching sheet provided in an embodiment of the present application;

[0039] FIG10 b is an enlarged view of the detail at point B in FIG10 a ;

[0040] FIG10c is a schematic structural diagram of two stator punching sheets and a third punching sheet provided in an embodiment of the present application;

[0041] FIG10d is a schematic diagram of a flow channel for a cooling medium formed in a stator according to an embodiment of the present application;

[0042] FIG11a is a schematic structural diagram of two stator punching sheets, two first punching sheets, and a third punching sheet provided in an embodiment of the present application;

[0043] FIG11 b is a schematic cross-sectional view of a partial structure of a stator provided in an embodiment of the present application;

[0044] Figure 11c is an enlarged view of the details at C1 in Figure 11b;

[0045] FIG11d is an enlarged view of the details at C2 in FIG11b;

[0046] FIG12a is a schematic cross-sectional view of a stator provided in an embodiment of the present application;

[0047] FIG12 b is an enlarged view of the detail at D1 in FIG12 a ;

[0048] FIG12c is an enlarged view of the detail at D2 in FIG12a;

[0049] FIG12 d is a schematic diagram of a simulated physical structure of a cooling medium flow channel of a stator provided in an embodiment of the present application.

[0050] Reference numerals:

[0051] 1000-powertrain; 2000-transmission mechanism; 3000-wheel; 100-motor; 200-reducer; 10-stator; 20-stator winding; 30-rotor; 40-motor shaft; 1-housing; 11-radial groove; 13-liquid inlet pipe; 101-liquid inlet; 102-liquid outlet; 2-punching plate; 21-center hole; 22-punching plate groove; 24, 24a, 24b-connecting hole; 25-through hole; 26-groove; 27-conducting hole; 28-liquid outlet; 291-inner cooling hole; 292-outer cooling hole; 2a, 2b-stator punching plate; 2c-first punching plate; 2d-second punching plate; 2e-third punching plate. DETAILED DESCRIPTION

[0052] With the advancement of technology, electric motors are moving towards smaller size and higher power. However, motor heat dissipation is currently one of the bottlenecks limiting the increase in motor power density. When the motor is operating at high speed, heat loss from the stator core is a significant heat source. This can typically be dissipated by cooling the stator core using cooling oil. Specifically, oil is passed through the back of the stator core and sprayed onto the end coils of the stator windings to dissipate the heat. However, current heat dissipation methods are ineffective and cannot meet the high heat dissipation requirements brought about by the increase in motor power density.

[0053] Based on this, the embodiments of the present application provide a stator punching, motor, powertrain and electric vehicle with a circumferential flow channel, in which the cooling medium can be sprayed toward the end of the stator winding from a specific circumferential angle, thereby optimizing the heat dissipation effect of the motor and thereby improving the power performance and service life of the powertrain.

[0054] 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.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] FIG2 is a schematic diagram of a powertrain according to an embodiment of the present application. As shown in FIG2 , a motor 100 is used to drive a transmission mechanism 2000 of an electric vehicle via a reducer 200. The motor 100 includes a stator 10, a stator winding 20, a rotor 30, and a motor shaft 40. The rotor 30 is coaxially fixed to the motor shaft 40, and the motor shaft 40 is connected to the reducer 200 in a transmission manner. The stator 10 is sleeved on the outside of the rotor 30, and the stator winding 20 is wound on the stator 10. The stator winding 20 has a portion located inside the stator 10 and a portion located outside the stator 10. The portion of the stator winding 20 located outside the stator slot protrudes from the axial side of the stator 10. When power is supplied to the stator winding 20, a magnetic field is formed in the center of the stator 10, and the rotor 30 can rotate around the axis of the motor shaft 40 in the magnetic field. The reducer 200 may also be a transmission. It should be understood that the axial direction of the stator 10 is also the axial direction of the motor 100 , the radial direction of the stator 10 is also the radial direction of the motor 100 , and the circumferential direction of the stator 10 is also the circumferential direction of the motor 100 .

[0059] The motor 100 provided in the embodiment of the present application is a motor with a stator liquid-cooled winding, specifically referring to a motor that the cooling medium used to dissipate heat for the stator 10 can simultaneously spray the cooling medium to the end windings of the stator winding 20 to dissipate heat. As shown in Figure 3, the stator 10 includes a housing 1 and a plurality of punching sheets 2, and the plurality of punching sheets 2 are arranged along the axial direction of the stator 10 to form a stator core. Each punching sheet 2 includes a center hole 21 and a plurality of punching sheet grooves 22, and the number of the punching sheet grooves 22 is multiple. The center hole 21 is located at the center of the punching sheet 2, and each punching sheet groove 22 extends radially along the punching sheet 2 and is connected to the center hole 21, and the bottom of the punching sheet groove 22 is away from the center of the punching sheet 2. Along the circumference of the punching sheet 2, a plurality of punching sheet grooves 22 are arranged at intervals. When multiple punching sheets 2 are stacked along the axial direction of the stator 10, the center holes 21 of the multiple punching sheets 2 can be connected to each other to form a space for accommodating the rotor 30, and the punching grooves 22 of the multiple punching sheets 2 are respectively connected to form stator slots, and the structure between any two punching grooves 22 can be superimposed to form the stator teeth of the stator 10.

[0060] The shell 1 includes a liquid inlet pipe 13, which is a hollow tube. One end of the liquid inlet pipe 13 is fixed to the outer peripheral surface of the shell 1, and the end of the liquid inlet pipe 13 facing away from the outer peripheral surface of the shell 1 forms a liquid inlet 101. The axial end face of the stator 10 includes a plurality of liquid outlets 102, and the liquid outlets 102 are specifically formed on the punching sheet 2 located at the axial end of the stator 10. For example, 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 10 has a channel for the circulation of 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 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 10. When the cooling medium flows in the stator 10 , it can dissipate heat from the stator winding 20 through the stator 10 . After the cooling medium is ejected from the liquid outlet 102 , it can be sprayed onto the stator winding 20 located at the end of the stator 10 .

[0061] As shown in Figure 4, the stator 10 has a structure in which the shell 1 is separated from the multiple punching sheets 2. Multiple punching sheets 2 are stacked axially along the stator 10 to form a stator core, and the shell 1 is circumferentially sealed around the stator core. Each punching sheet 2 includes a center hole 21 and multiple punching sheet grooves 22. The multiple punching sheet grooves 22 are arranged at intervals along the circumference of the stator 10 and are connected to the center hole 21. The shell 1 is cylindrical, and the inner wall of the shell 1 includes a first radial groove 11. The radial groove 11 is formed by a groove provided on the inner wall of the shell 1. The radial groove 11 extends along the circumference of the shell 1, and the bottom of the radial groove 11 is connected to the liquid inlet 101 through the liquid inlet pipe 13. When the shell 1 sealing sleeve is arranged on the outer peripheral surface of the stator core composed of multiple punching sheets 2, and the outer peripheral surface of the stator core includes a flow channel, the radial groove 11 is connected to the flow channel on the outer peripheral surface of the stator core. It should be understood that the axial direction of the stator 10 is also the axial direction of the punching sheet 2 , the radial direction of the stator 10 is also the radial direction of the punching sheet 2 , and the circumferential direction of the stator 10 is also the circumferential direction of the punching sheet 2 .

[0062] The plurality of punchings 2 include a stator punching 2a as shown in FIG5a . The stator punching 2a includes a plurality of connecting holes 24 and a plurality of through-holes 25. Along the axial direction of the stator 10, each connecting hole 24 and each through-hole 25 respectively penetrates the stator punching 2a. Along the circumference of the stator 10, the plurality of connecting holes 24 are spaced apart, and the plurality of through-holes 25 are spaced apart. Each through-hole 25 is connected to at least two connecting holes 24. Along the radial direction of the stator 10, the distance h1 between the center of the through-hole 25 and the center O of the stator punching 2a is greater than the distance h2 between the center of the connecting hole 24 and the center O of the stator punching 2a. Along the radial direction of the stator 10, the size of the through-hole 25 is greater than the size of the connecting hole 24, providing a larger accommodation space. The connecting holes 24 and through-holes 25 are part of the internal flow path of the stator 10, allowing cooling medium to pass through the connecting holes 24 and through-holes 25. Along the circumference of the stator 10, the size of each through-hole 25 is greater than the size of the connecting hole 24. When the cooling medium enters the through-hole 25, it can flow in the through-hole 25 along the circumference of the stator 10. Along the axial direction perpendicular to the stator 10, the through-hole 25 is closed on all sides. In the stator punching 2a shown in Figure 5a, along the circumference of the stator 10, multiple through-holes 25 are spaced and distributed throughout the circumference of the stator 10, and a connecting hole 24 is provided between any two adjacent through-holes 25. Along the circumference of the stator 10, the aperture of the through-hole 25 is larger than the structural dimension between any two through-holes 25. The distance between the through-hole 25 and the center hole 21 is smaller than the distance between the outer peripheral surface of the stator punching 2a and the center hole 21.

[0063] The plurality of punching sheets 2 include another stator punching sheet 2b shown in FIG5b, which includes a groove 26 that penetrates the stator punching sheet 2b in the axial direction of the stator 10, and the outer peripheral surface of the stator punching sheet 2b includes a notch of the groove 26. In the radial direction of the stator 10, the bottom of the groove 26 is connected to at least two connecting holes 24. For ease of understanding, FIG5b illustrates that one of the connecting holes 24 is connected to the groove 26, and the connecting hole 24 and the groove 26 are separated by a dotted line. In the radial direction of the stator 10, the distance between the side wall of the connecting hole 24 close to the stator punching sheet 2b and the bottom of the groove 26 is greater than the size of the connecting hole 24, and the bottom of the groove 26 is connected to the connecting hole 24 through a radial flow channel J. For ease of understanding, the radial flow channel J and the bottom of the groove 26 are separated by a dotted line. Along the radial direction of the stator 10, the distance h3 between the center of the groove 26 and the center O of the stator punching 2a is greater than the distance h2 between the center of the connecting hole 24 and the center O of the stator punching 2a. The groove 26 and the through hole 25 are part of the internal flow channel of the stator 10, and the cooling medium can pass through the connecting hole 24 and the groove 26. Along the circumference of the stator 10, the size of each groove 26 is larger than the size of the connecting hole 24. When the cooling medium enters the groove 26, it can flow in the groove 26 along the circumference of the stator 10. Along the radial direction of the stator 10, the size of the groove 26 is larger than the size of the connecting hole 24, and the groove 26 has a larger accommodating space. For example, as shown in Figure 5b, along the circumference of the stator 10, a connecting hole 24b is connected to the bottom of the groove 26, and another connecting hole 24a adjacent to the one connecting hole 24b is isolated from the groove 26. In the stator punching 2b shown in Figure 5b, one groove 26 is connected to three connecting holes 24 respectively. Multiple grooves 26 are distributed along the circumference of the stator 10. The structure between any two adjacent grooves 26 is convex, and the edge of the convex shape is the edge of the circumferential surface of the stator punching 2b. When the stator 10 is assembled, the structure between two adjacent grooves 26 in the radial direction of the stator 10 is used for welding to the outer circumference of the other punching 2.

[0064] With reference to Figures 5a and 5b, some of the punching sheets 2 in the motor 100 provided in the embodiment of the present application include a circumferential flow channel, which can be the through hole 25 shown in Figure 5a, or the groove 26 in Figure 5b. Along the circumference of the stator 10, the size of the circumferential flow channel is larger than the size of the connecting hole 24. The cooling medium entering the circumferential flow channel can flow in the circumferential flow channel along the circumference of the stator 10. According to the cooling requirements of the end windings of the motor 100, the number, shape and size of the circumferential flow channels can be designed to achieve liquid spray cooling of the stator winding ends of the motor 100. In specific applications, the stator 10 of the motor 100 can include at least one stator punching sheet 2a and at least one stator punching sheet 2b at the same time, or can include only at least one stator punching sheet 2a, or can include only at least one stator punching sheet 2b, so as to achieve circumferential flow of the cooling medium in the stator 10.

[0065] FIG6 illustrates a stator 10 having multiple punchings 2, including a first punching 2c and at least two stator punchings, which are the stator punchings 2a or 2b described above. For example, the two stator punchings in FIG6 are stator punchings 2a and 2b, respectively, with the first punching 2c arranged between the stator punchings 2a and 2b along the axial direction of the stator 10. The first punching 2c includes a plurality of through-holes 27, each of which extends through the first punching 2c along the axial direction of the stator 10, and the plurality of through-holes 27 are spaced apart along the circumference of the stator 10. Along the axial direction of the stator 10, the first punching 2c is arranged adjacent to the stator punchings, and the through-holes 27 are connected to the circumferential flow channel or the connecting hole 24. Specifically, between the first punching 2c and the stator punching 2a, the through-holes 27 can be connected to the connecting hole 24, or the through-holes 27 can be connected to the through-hole 25 serving as the circumferential flow channel. Between the first punch 2c and the stator punch 2b, the conduction hole 27 can be connected to the connecting hole 24, or the conduction hole 27 can be connected to the groove 26 serving as a circumferential flow channel. The first punch 2c is arranged between the stator punch 2a and the stator punch 2b, and can guide the cooling medium flowing through the stator punch 2a to the stator punch 2b. The number of through holes 25 and the number of connecting holes 24 in the stator punch 2a are less than the number of conduction holes 27 in the first punch 2c, and the number of grooves 26 and the number of connecting holes 24 in the stator punch 2b are less than the number of conduction holes 27 in the first punch 2c. For example, the number of conduction holes 27 in the first punch 2c is half the number of punch grooves 22, and each conduction hole 27 is arranged in the radial direction of the stator 10 at intervals from a punch groove 22, with one conduction hole 27 corresponding to each punch groove 22.

[0066] Figure 7a shows a stator core portion of a stator 10, and Figure 7b shows an exploded view of the partial structure of the stator 10 shown in Figure 7a. The multiple punching sheets 2 of the stator 10 include a first punching sheet 2c, a second punching sheet 2d, a third punching sheet 2e and a plurality of stator punching sheets, and the plurality of stator punching sheets specifically include two stator punching sheets 2a and at least one stator punching sheet 2b. Along the axial direction of the stator 10, the first punching sheet 2c is arranged between the stator punching sheet 2a and the stator punching sheet 2b, the second punching sheet 2d is arranged adjacent to the side of the two stator punching sheets 2a facing away from the first punching sheet 2c, and the third punching sheet 2e is arranged adjacent to the side of the stator punching sheet 2b facing away from the first punching sheet 2c. Among them, the second punching sheet 2d is located at the axial end of the stator 10 and can serve as the end cover of the stator 10. The liquid outlet 102 is located on the side surface of the second punching sheet 2d facing away from the stator punching sheet 2a. The number of the first punching sheets 2c can be one or more, the number of the second punching sheets 2d can be one or more, the number of the third punching sheets 2e can be one or more, and the number of the stator punching sheets 2b can also be one or more.

[0067] Referring to Figures 7a and 7b, the second punch 2d includes a plurality of liquid outlet holes 28, each of which passes through the second punch 2d in the axial direction of the stator 10, and the plurality of liquid outlet holes 28 are arranged at intervals along the circumference of the stator 10. Along the axial direction of the stator 10, the end of the liquid outlet hole 28 away from the stator punch 2a is the liquid outlet 102 of the stator 10. The second punch 2d is arranged on the side of the stator punch 2a away from the first punch 2c, and the circumferential flow channel formed by the through hole 25 of the stator punch 2a is connected to at least two adjacent liquid outlet holes 28 along the circumference of the stator 10. The position and number of the liquid outlet holes 28 can be adjusted according to the layout direction of the motor 100 and the hot spot position of the winding, so that the cooling medium can be sprayed into the hottest area of ​​the end winding to improve the heat dissipation efficiency.

[0068] The third punch 2e includes multiple inner cooling holes 291 and multiple outer cooling holes 292. The inner cooling holes 291 and the outer cooling holes 292 are arranged at intervals along the circumference of the stator. The outer cooling holes 292 communicate with the outer circumferential surface of the third punch 2e. The number of outer cooling holes 292 is greater than the number of through-holes 25 in the stator punch 2a, and the number of outer cooling holes 292 is also greater than the number of grooves 26 in the stator punch 2b.

[0069] Along the radial direction of the stator 10, the distance between the inner cooling hole 291 and the center of the third punch 2e is smaller than the distance between the outer cooling hole 292 and the center of the third punch 2e. The cooling medium is passed through the outer cooling hole 292 to dissipate heat from the outer peripheral surface of the third punch 2e, and the cooling medium is passed through the inner cooling hole 291 to dissipate heat from the inside of the third punch 2e. In other words, the inner cooling hole 291 and the outer cooling hole 292 can form two inner and outer cooling channels on the third punch 2e that are arranged along the radial direction of the stator 10, which can improve the liquid cooling heat dissipation effect of the third punch 2e. Along the axial direction of the stator 10, the third punch 2e is arranged on the side of the stator punch 2b away from the first punch 2c. The outer cooling hole 292 is connected to the circumferential flow channel formed by the groove 26 of the stator punch 2b, and the inner cooling hole 291 is connected to the connecting hole 24 of the stator punch 2b. When the stator punching 2b is arranged adjacent to the third punching 2e, the groove 26 of the stator punching 2b is connected to at least one external cooling hole 292 of the third punching 2e, and the connecting hole 24 of the stator punching 2b is connected to the internal cooling hole 291 of the third punching 2e, then the stator punching 2b can be connected to the internal cooling hole 291 and multiple external cooling holes 292 of the third punching 2e.

[0070] As shown in FIG7b , two stator punchings 2a are illustrated. Each stator punching 2a includes a plurality of communication holes 24 and a plurality of through-holes 25. For example, along the circumference of the stator 10, one communication hole 24 is arranged between any two adjacent through-holes 25. Along the circumference of the stator 10, the number of through-holes 25 in the stator punching 2a is less than the number of internal cooling holes 291 in the third punching 2e and the number of guide holes 27 in the first punching 2c.

[0071] Figure 8a shows a structure in which two stator punching sheets 2a are arranged along the axial direction of the stator 10. As shown in Figure 8a, along the axial direction of the stator 10, the through-hole 25 of one stator punching sheet 2a is connected to the through-hole 25 of another adjacent stator punching sheet 2a, and the connecting hole 24 of one stator punching sheet 2a is connected to the through-hole 25 of another adjacent stator punching sheet 2a. Along the circumferential direction of the stator 10, the structure between the two adjacent through-holes 25 of one stator punching sheet 2a partially blocks the through-hole 25 of the other adjacent stator punching sheet 2a. Exemplarily, the two stator punching sheets 2a are relatively deflected by a certain angle along the circumferential direction of the stator 10, so that the multiple through-holes 25 of the two stator punching sheets 2a are staggered along the circumferential direction of the stator 10. Exemplarily, along the axial direction of the stator 10, each through-hole 25 of one stator punching sheet 2a is connected to two adjacent through-holes 25 of the other stator punching sheet 2a. After the through holes 25 of the two stator punching sheets 2 a are connected, a circumferentially continuous channel can be formed between the first punching sheet 2 c and the second punching sheet 2 d , and the cooling medium can flow in the channel along the circumference of the stator 10 .

[0072] With reference to Figure 8a, Figure 8b illustrates a simulated physical structure of a circumferentially continuous channel formed by two stator punchings 2a. As shown in Figure 8b, the channel is annular and formed by a plurality of gaps t1 and t2 that alternately connect along the circumference of the stator 10. Gap t1 is the space corresponding to the through-hole 25 of one stator punching 2a, and gap t2 is the space corresponding to the through-hole 25 of the other stator punching 2a. Any two connected gaps t1 and t2 are connected along the axial direction of the stator 10. The channel is formed between the first punching 2c and the second punching 2d.

[0073] Figure 9a shows the structure of two stator punchings 2a and a first punching 2c arranged along the axial direction of the stator 10, Figure 9b shows the cross-sectional structure of the two stator punchings 2a and the first punching 2c, and Figure 9c shows an enlarged view of point A in Figure 9b. Referring to Figures 9a to 9c, the communicating hole 24 of the first punching 2c communicates with the communicating holes 24 of the two stator punchings 2a, or the communicating hole 24 of the first punching 2c communicates with the circumferential channel formed by the through holes 25 of the two stator punchings 2a.

[0074] Figure 10a shows a structure in which the stator punching 2b and the third punching 2e are arranged adjacent to each other. As shown in Figure 10a, along the radial direction of the stator 10, the outer diameter of the stator punching 2b is basically aligned with the outer diameter of the third punching 2e, and the distance between the bottom of the groove 26 and the center hole 21 is less than the distance between the outer surface of the third punching 2e and the center hole 21. Along the axial direction of the stator 10, the outer cooling hole 292 of the third punching 2e is aligned with a groove 26 of the stator punching 2b. In the circumferential direction of the stator 10, the size of the groove 26 is larger than the size of the multiple outer cooling holes 292 and the sum of the sizes of any two outer cooling holes 292. Along the axial direction of the stator 10, the orthographic projection of at least one outer cooling hole 292 of the third punching 2e on the stator punching 2b falls within a groove 26.

[0075] With further reference to the enlarged view at point B in FIG10a shown in FIG10b , the stator punching 2b and the third punching 2e are arranged adjacent to each other in the axial direction of the stator 10. The multiple communication holes 24 of the stator punching 2b are respectively connected to the multiple inner cooling holes 291 of the third punching 2e to form a liquid-cooling channel in the inner layer of the stator 10. The multiple inner cooling holes 291 of the third punching 2e are respectively connected to the multiple communication holes 24 of the stator punching 2b in the axial direction of the stator 10. The outer cooling holes 292 of the third punching 2e are part of the outer liquid-cooling channel of the stator 10. The outer cooling holes 292 can be connected to some of the communication holes 24 of the stator punching 2b through the groove 26, so that the inner and outer liquid-cooling channels of the stator 10 can be connected. As shown in Figure 10b, the cooling medium in the outer cooling hole 292 flows into the groove 26 along the axial direction of the stator 10 and can flow along the circumferential direction of the stator 10, and then flows into the connecting hole 24 through the radial flow channel J and enters the inner cooling hole 291 of the third punch 2e through the connecting hole 24.

[0076] In the example of FIG10 b , the communicating holes 24 communicating with the grooves 26 and the communicating holes 24 not communicating with the grooves 26 are alternately arranged along the circumference of the stator 10. That is, of any two adjacent communicating holes 24 along the circumference of the stator 10, one communicating hole 24 can communicate with the grooves 26, while the other communicating hole 24 cannot communicate with the grooves 26.

[0077] Figure 10c shows the structure of the third punch 2e and the two stator punches 2b. Along the axial direction of the stator 10, the two stator punches 2b are arranged at both ends of the third punch 2e. Along the axial direction of the stator 10, the multiple grooves 26 of the two stator punches 2b correspond to each other. The orthographic projection of the multiple grooves 26 of one stator punch 2b on the other stator punch 2b coincides with the multiple grooves 26 on the other stator punch 2b. The cooling medium in the outer cooling hole 292 of the third punch 2e can flow along the axial direction of the stator 10 toward the two stator punches 2b at both ends of the third punch 2e, enter the connecting hole 24 through the grooves 26 on the stator punch 2b, and further enter the inner cooling hole 291 of the third punch 2e.

[0078] 10b and 10c , a portion of the communicating holes 24 can communicate with the outer cooling holes 292 of the third punch 2e through the grooves 26, while a portion of the communicating holes 24 cannot. When arranging the third punch 2e and the two stator punches 2b, the two stator punches 2b can be rotated relative to each other by a certain angle along the circumference of the stator 10, so that a portion of the inner cooling holes 291 of the third punch 2e communicate with a portion of the outer cooling holes 292 through the grooves 26 of one of the stator punches 2b, and another portion of the inner cooling holes 291 of the third punch 2e communicates with another portion of the outer cooling holes 292 through the grooves 26 of the other stator punch 2b.

[0079] Figure 10d illustrates a simplified example of at least two channels for cooling medium flow formed by staggering two stator punches 2b along the circumference of the stator 10. Specifically, along the circumference of the stator 10, of two adjacent inner cooling holes 291 in the same third punch 2e, one inner cooling hole 291 communicates with the outer cooling hole 292 via the groove 26 of one stator punch 2b, while the other inner cooling hole 291 does not communicate with the outer cooling hole 292 via the groove 26 of one stator punch 2b. Along the axial direction of the stator 10, one end of the same outer cooling hole 292 communicates with the inner cooling hole 291 via the groove 26 of one stator punch 2b, while the other end of the outer cooling hole 292 does not communicate with the inner cooling hole 291 of the other stator punch 2b, thereby forming a U-shaped flow channel as shown in Figure 10d. Along the circumference of the stator 10, the U-shaped flow channels corresponding to any two adjacent inner cooling holes 291 face opposite directions along the axial direction of the stator 10.

[0080] FIG11 a illustrates the structure of a third punch 2e, two stator punches 2b, and two first punches 2c. One stator punch 2b and one first punch 2c are arranged in sequence at the end of the third punch 2e along the axial direction of the stator 10, with the stator punch 2b arranged between the third punch 2e and the first punch 2c. The number of conducting holes 27 in the first punch 2c is less than the number of communicating holes 24 in the stator punch 2b. During arrangement, the angle of the first punch 2c relative to the stator punch 2b can be adjusted so that some conducting holes 27 in the first punch 2c communicate with communicating holes 24 that connect the stator punch 2b to the groove 26, while other conducting holes 27 in the first punch 2c communicate with communicating holes 24 in the stator punch 2b that are isolated from the groove 26.

[0081] Figure 11b illustrates the cross-sectional structure of the structure shown in Figure 11a. Along the radial direction of the stator 10, taking one of the outer cooling holes 292 and one of the inner cooling holes 291 of the third punch 2e as an example, Figure 11c illustrates an enlarged view of the details at C1 in Figure 11b, and Figure 11d illustrates an enlarged view of the details at C2 in Figure 11b.

[0082] Referring to Figures 11b and 11c, the third punch 2e, the stator punch 2b, and the first punch 2c at C1 in Figure 11b are arranged adjacent to each other along the axial direction of the stator 10. The first punch 2c and the third punch 2e are opposite each other along the axial direction of the stator 10. A space K connected to the outer cooling hole 292 is formed between the groove 26 of the stator punch 2b, the side of the first punch 2c facing the stator punch 2b, and the side of the third punch 2e facing the first punch 2c. This space K can be considered a circumferential liquid cooling channel. The connecting hole 24 of the stator punch 2b is connected to the inner cooling hole 291 of the third punch 2e along the axial direction of the stator 10. The radial flow channel J of the stator punch 2b can connect the above space K with the connecting hole 24 of the stator punch 2b, thereby connecting the outer cooling hole 292 of the third punch 2e to the inner cooling hole 291 through the stator punch 2b. The first punch 2c blocks the groove 26 and inner cooling hole 291 of the stator punch 2b shown in FIG11c , along the axial direction of the stator 10. As shown by the arrows in FIG11c , after the coolant is injected into the outer cooling hole 292, it flows along the axial direction of the stator 10 to the space K between the third punch 2e and the first punch 2c, and then flows circumferentially along the stator 10. The coolant in space K flows along the groove 26 and connecting hole 24 of the stator punch 2b into the inner cooling hole 291 of the third punch 2e, thereby connecting the outer cooling hole 292 of the third punch 2e with the inner cooling hole 291.

[0083] Referring to Figures 11b and 11d , the third punch 2e, the stator punch 2b, and the first punch 2c at C2 in Figure 11b are adjacently arranged along the axial direction of the stator 10. The first punch 2c and the third punch 2e are axially opposed to each other in the stator 10. A space K communicating with the outer cooling hole 292 is formed between the groove 26 of the stator punch 2b, the side of the first punch 2c facing the stator punch 2b, and the side of the third punch 2e facing the first punch 2c. This space K is also the space formed by the groove 26 of the stator punch 2b. The guide hole 27 of the first punch 2c, the connecting hole 24 of the stator punch 2b, and the inner cooling hole 291 of the third punch 2e are sequentially connected along the axial direction of the stator 10. As shown by the arrows in Figure 11d, after the coolant is injected into the outer cooling hole 292, the coolant flows along the axial direction of the stator 10 to the space K between the third punching plate 2e and the first punching plate 2c, and then flows along the circumferential direction of the stator 10. The coolant in the inner cooling hole 291 of the third punching plate 2e flows along the axial direction of the stator 10 to the communicating hole 24 of the stator punching plate 2b and the conducting hole 27 of the first punching plate 2c, and then flows out.

[0084] It should be understood that, along the axial direction of the stator 10, the cooling medium circulation mode shown in FIG11c is equivalent to the side of a U-shaped circulation channel in FIG10d having a groove 26, and the cooling medium circulation mode shown in FIG11d is equivalent to the side of a U-shaped circulation channel in FIG10d without a groove 26.

[0085] Figure 12a shows a cross-sectional structure of a stator 10 provided in an embodiment of the present application. As shown in Figure 12a, along the axial direction of the stator 10, adjacent to the third punch 2e are stator punches 2b, first punch 2c, two third punches 2e, and second punch 2d. The structure of each punch 2 can be seen with reference to Figures 7b to 11d. Along the radial direction of the stator 10, Figure 12b shows an enlarged view of point D1 in Figure 12a, and Figure 12c shows an enlarged view of point D2 in Figure 12a.

[0086] Referring to Figures 12a and 12b , after the coolant is injected through the liquid inlet 101, the circumferential channel 11 of the housing 1 transports the coolant to the multiple external cooling holes 292 on the outer circumferential surface of the third punch 2e. The coolant in the external cooling holes 292 flows along the axial direction of the stator 10 to the space K between the third punch 2e and the first punch 2c, and then flows circumferentially along the stator 10. The coolant in space K enters the internal cooling holes 291 of the third punch 2e along the groove 26 and connecting hole 24 of the stator punch 2b and flows along the axial direction of the stator 10 to the other end of the stator 10.

[0087] 12c and 12d, the cooling medium in the inner cooling hole 291 of the third punch 2e flows out along the axial direction of the stator 10 through the connecting hole 24 of the stator punch 2b, the conducting hole 27 of the first punch 2c, the through hole 25 of one stator punch 2a, the connecting hole 24 of another stator punch 2a, and the liquid outlet 28 of the second punch 2d to the liquid outlet 102. The cooling medium flowing out from the liquid outlet 102 can be sprayed onto the end winding of the stator winding 20 to cool the end winding.

[0088] With reference to Figures 12a to 12c, Figure 12d illustrates a simulated physical structure of the channel formed by the stator 10 for the circulation of the cooling medium. As shown in Figure 12d, channel c1 is formed by the liquid inlet pipe 13 on the housing 1 and is used to connect the liquid inlet 101 with the circumferential channel 11. Channel c2 is formed by the circumferential channel 11 of the housing 1 and is annular and is used to connect the liquid inlet pipe 13 with multiple external cooling holes 292 on the outer peripheral surface of the third punch 2e. Channel c3 is formed by the external cooling holes 292, and there are multiple external cooling holes 292, which are arranged at intervals along the circumference of the stator 10. Channel c4 is formed by the third punch 2e, the first punch 2c, and the stator punch 2b, that is, the space K between the third punch 2e and the first punch 2c. Each channel c4 is connected to multiple channels c3. Channel c6 is formed by the liquid outlet 28 of the second punch 2d. The through-holes 25 of the two stator punchings 2a intersect to form a channel c5, which is used to connect multiple channels c6 with multiple channels c4. In the embodiment of the present application, the through-holes 25 of the two stator punchings 2a intersect to form channel c5, allowing the cooling medium to flow along the circumference of the stator 10 to be supplied to the multiple liquid outlets 102. In the specific design, the number, shape, and distribution of the liquid outlets 102 can be adjusted according to product requirements to meet the liquid cooling requirements of end windings at different angles and directions.

[0089] 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 windings at the axial ends of the stator 10 through the cooling channels of the stator 10 itself. The two stator punchings 2a are arranged to be deflected along the circumference of the stator 10, so that the multiple through holes 25 of the two stator punchings 2a can be connected in sequence to form a circumferentially continuous channel, so that the cooling medium can flow along the circumference of the stator 10 and be sprayed from at least two adjacent liquid outlets 102. By placing the two stator punchings 2a close to the axial ends of the stator 10 and setting the distribution of the liquid outlets 102, non-uniform oil spraying can be achieved at the ends of the stator 10, thereby achieving efficient cooling of the end windings and achieving good liquid cooling and heat dissipation effects. In some embodiments, compared with traditional oil cooling and heat dissipation, the stator 10 of the motor 100 provided in the embodiment of the present application has a lower temperature and 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.

[0090] 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 a circumferential flow channel, characterized in that: The stator punching sheet includes a plurality of communicating holes and a plurality of circumferential flow channels; Along the circumference of the stator punching sheet, each of the communicating holes and each of the circumferential flow channels penetrates the stator punching sheet; Along the circumference of the stator sheet, the plurality of communication holes are arranged at intervals, the plurality of circumferential flow channels are arranged at intervals, and each of the circumferential flow channels is connected to at least two of the communication holes; Along the radial direction of the stator punching sheet, the distance between the center of the circumferential flow channel and the center of the stator punching sheet is greater than the distance between the center of the connecting hole and the center of the stator punching sheet.

2. The stator sheet according to claim 1, characterized in that: The stator punching sheet comprises a groove penetrating the stator punching sheet along the circumferential direction of the stator punching sheet, and the outer peripheral surface of the stator punching sheet comprises a notch of the groove; Along the radial direction of the stator punching sheet, the groove bottom of the groove is connected with at least two of the connecting holes, and the groove is the circumferential flow channel.

3. The stator sheet according to claim 2, characterized in that: Along the circumferential direction of the stator punching sheet, one of the communicating holes is communicated with the groove bottom of the groove, and another communicating hole adjacent to the one communicating hole is isolated from the groove.

4. The stator sheet according to claim 3, characterized in that: Along the radial direction of the stator punching sheet, the distance between the communicating hole and the groove bottom of the groove is greater than the size of the communicating hole.

5. The stator lamination according to any one of claims 1 to 4, characterized in that: Along the circumference of the stator punching sheet, the size of the circumferential flow channel is larger than the size of the connecting hole.

6. The stator lamination according to any one of claims 1 to 5, characterized in that: Along the radial direction of the stator punching sheet, the size of the circumferential flow channel is larger than the size of the connecting hole.

7. A motor, characterized in that: The stator of the motor comprises a first punching sheet and at least one stator punching sheet according to any one of claims 1 to 6; The first punching sheet comprises a plurality of conducting holes, each of the conducting holes penetrates the first punching sheet along the circumferential direction of the stator punching sheet, and the plurality of conducting holes are arranged at intervals along the circumferential direction of the stator; Along the axial direction of the stator, the first punching sheet is arranged adjacent to the stator punching sheet, and the conducting hole is communicated with the circumferential flow channel or the communicating hole.

8. The motor according to claim 7, characterized in that Along the axial direction of the stator, the first punching sheet is arranged between two first punching sheets; A circumferential flow channel of the stator punching sheet is a groove, and the outer peripheral surface of the stator punching sheet includes a notch of the groove; Another circumferential flow channel of the stator punching sheet is a through hole, and along the circumference of the stator, the size of the through hole is larger than the size of the connecting hole.

9. The motor according to claim 7 or 8, characterized in that The number of the stator punching sheets is two, and the two stator punching sheets are arranged adjacent to each other along the axial direction of the stator; Along the axial direction of the stator, the circumferential flow channel of one stator punching sheet is connected to the circumferential flow channel of another adjacent stator punching sheet, and the communicating hole of one stator punching sheet is connected to the circumferential flow channel of another adjacent stator punching sheet; Along the circumference of the stator, a structure portion between two adjacent circumferential flow channels of one stator punching sheet blocks the circumferential flow channel of another adjacent stator punching sheet.

10. The motor according to claim 8 or 9, characterized in that The stator comprises at least one second punching plate, the second punching plate comprises a plurality of liquid outlet holes, each of the liquid outlet holes penetrates the second punching plate along the axial direction of the stator, and the plurality of liquid outlet holes are arranged at intervals along the circumferential direction of the stator; Along the axial direction of the stator, the second punching sheet is arranged on a side of the other stator punching sheet away from the first punching sheet, and the circumferential flow channel is connected to at least two adjacent liquid outlet holes along the circumference of the stator.

11. The motor according to any one of claims 8 to 10, characterized in that: The stator comprises at least one third punching plate, wherein the third punching plate comprises a plurality of inner cooling holes and a plurality of outer cooling holes; Along the circumferential direction of the stator, a plurality of the inner cooling holes are arranged at intervals, and a plurality of the outer cooling holes are arranged at intervals; Along the radial direction of the stator, the distance between the inner cooling hole and the center of the stator is smaller than the distance between the outer cooling hole and the center of the third punching plate; Along the axial direction of the stator, the third punching sheet is arranged on a side of the stator punching sheet away from the first punching sheet, the outer cooling hole is communicated with the circumferential flow channel, and the inner cooling hole is communicated with the connecting hole.

12. The motor according to claim 11, characterized in that The number of the external cooling holes is greater than the number of the circumferential flow channels.

13. The motor according to claim 11 or 12, characterized in that The outer cooling hole is communicated with the outer peripheral surface of the third punching plate along the radial direction of the stator.

14. A powertrain, characterized in that: A motor comprising a reducer or a transmission and any one of claims 7 to 13; The motor comprises an output shaft, a rotor and a stator, wherein the stator is sleeved outside the rotor, the output shaft is coaxially connected to the rotor, and the output shaft is drivingly connected to the input shaft of the reducer or 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.

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