Motor, powertrain, and electric vehicle

Abstract

The present application provides a motor, a powertrain, and an electric vehicle. A stator of the motor comprises a plurality of stator cores, a plurality of winding slots of the stator extend through the plurality of stator cores, and each winding slot is used for accommodating a plurality of wires. The plurality of stator cores includes a first core and a second core. One end of the plurality of wires is exposed from one end surface of the second core. First flow channels of the first core extend through the first core in the axial direction of the motor. The end surface of the second core covers outlets of the first flow channels in the axial direction of the motor. Outlets of second flow channels extend through the end surface of the second core, and each second flow channel is used for making the outlet of a first flow channel in communication with the end surface of the second core. The outlet of the second flow channel is distributed on the outer peripheral side of one winding slot. The distance between the outlet of the second flow channel and the winding slot in the radial direction of the motor is greater than the distance between the first flow channel and the winding slot. By means of the cooperation of different flow channels in the stator, the present application can reduce the risk of insulating varnish blocking the flow channels while ensuring the cooling effect of the motor.

Description

Electric motors, powertrains and electric vehicles

[0001] This application claims priority to Chinese Patent Application No. 202510397110.4, filed on March 28, 2025, entitled "Electric Motor, Powertrain and Electric Vehicle", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of electric vehicle technology, and in particular to an electric motor, powertrain, and electric vehicle. Background Technology

[0003] An electric motor is an electromagnetic device that converts or transmits electrical energy based on the law of electromagnetic induction. In the powertrain of an electric vehicle, the electric motor is used to convert electrical energy into mechanical energy, and then transmit the mechanical energy to the reducer to drive the wheels of the electric vehicle.

[0004] During the operation of an electric motor, the energy lost in the stator and windings is gradually converted into heat, causing the temperature of the stator and windings to rise continuously. To control the temperature rise of the motor, cooling channels can be arranged in the stator, using the cooling medium in the cooling channels to remove the heat generated by the stator and windings.

[0005] In addition, to improve the insulation performance of motors, the stator and windings are usually impregnated with varnish, allowing the insulating varnish to penetrate into the windings and the gaps between the windings and the winding slots. However, during the varnish drying process, the insulating varnish overflowing from the winding slots can easily enter the cooling channels of the stator, causing blockage and negatively impacting the cooling effect of the stator and windings. Summary of the Invention

[0006] This application provides an electric motor, a powertrain, and an electric vehicle.

[0007] In a first aspect, embodiments of this application provide an electric motor. The stator of the motor includes multiple stator cores, and multiple winding slots of the stator extend through the multiple stator cores along the axial direction of the motor, with each winding slot used to accommodate multiple wires.

[0008] The stator cores include a first core and a second core. One end of each of the multiple conductors protrudes from one end face of the second core. A first flow channel penetrates the first core, and along the axial direction of the motor, one end face of the second core covers the outlet of the first flow channel. The outlet of a second flow channel penetrates one end face of the second core, connecting the outlet of the first flow channel to one end face of the second core. The outlet of the second flow channel is located on the outer periphery of a winding slot. Radially along the motor, the distance between the outlet of the second flow channel and a winding slot is greater than the distance between the first flow channel and a winding slot.

[0009] In this embodiment, when the motor is in operation, the introduction of alternating current into multiple wires within a winding slot leads to resistance losses. Furthermore, the alternating magnetic flux generated by the energized wires causes hysteresis and eddy current losses within the multiple stator cores, resulting in a continuous increase in heat generation in the wires and stator cores. In this embodiment, the first flow channel is relatively close to a winding slot, shortening the distance between the cooling medium in the first flow channel and the multiple wires. This facilitates the conduction of heat generated by the wires to the first flow channel, thereby improving heat dissipation efficiency.

[0010] In this embodiment, one end of each of the multiple conductors protrudes from one end face of the second iron core, indicating that one end face of the second iron core is also one end face of the stator, and the second iron core is distributed at the ends of the multiple stator iron cores. To improve the insulation and thermal conductivity of the stator and conductors, the stator and conductors are typically impregnated with varnish. During the varnish drying process, some of the varnish from one winding slot can easily overflow onto one end face of the second iron core. Since the first flow channel is not distributed within the second iron core, and its outlet is not located on one end face of the second iron core, even if the first flow channel is adjacent to a winding slot, the varnish overflowing onto one end face of the second iron core is unlikely to flow directly into the first flow channel.

[0011] However, if the second core has an axial flow channel, and the outlet of this axial flow channel is adjacent to a winding slot, and this axial flow channel is connected to the first flow channel, it is equivalent to extending the outlet of the first flow channel to one end face of the second core. This increases the possibility of insulating varnish flowing into the axial flow channel and causing blockage. In this embodiment, one end face of the second core covers the outlet of the first flow channel along the motor axis. This means that the projection area of ​​the outlet of the first flow channel along the motor axis on one end face of the second core corresponds to the solid structure of the second core. The solid structure corresponding to this projection area will prevent the cooling medium of the first flow channel from flowing directly out along the motor axis, which helps to reduce the risk of the flow channel being blocked.

[0012] The second flow channel in this embodiment guides the cooling medium from the first flow channel out from one end face of the second iron core. The outlet of the second flow channel is located on the outer periphery of a winding slot, and the radial distance between the outlet of the second flow channel and the winding slot is greater than the radial distance between the first flow channel and the winding slot. Guided by the second flow channel, the cooling medium flows out from one end face of the second iron core at a position relatively far from the winding slot compared to the first flow channel, extending the path of the insulating varnish from one winding slot to the outlet of the second flow channel. This effectively prevents blockage of the cooling medium at the outlet of the second flow channel, improving cooling efficiency. The smooth flow of the cooling medium from one end face of the second iron core facilitates its continued movement to one end of multiple conductors, reducing the risk of localized overheating of the conductors. It also eliminates the need for an oil spray ring, reducing the size of the motor. Furthermore, it facilitates the recovery and recycling of the cooling medium.

[0013] Understandably, to avoid clogging of the second flow channel, it is sufficient to ensure that the outlet of the second flow channel is far away from the winding slot, while the radial distance between the rest of the second flow channel, excluding the outlet, and the winding slot can be adjusted according to actual needs.

[0014] If only the issue of flow channel blockage is considered, a separate axial flow channel can be used in the stator, with this other axial flow channel extending radially away from one winding slot. In this case, although the insulating varnish from one winding slot is difficult to flow to the outlet of the other axial flow channel, the radial distance between the other axial flow channel and multiple conductors is also relatively large, which will negatively impact the cooling effect of the conductors. In the embodiments of this application, the distance between the first flow channel and one winding slot is relatively small, while the distance between the outlet of the second flow channel and one winding slot is relatively large. Through the cooperation of the first and second flow channels, compared to one or the other axial flow channel, the embodiments of this application can avoid the varnish overflowing from the winding slot from blocking the flow channel while ensuring the winding cooling effect.

[0015] In one embodiment, a radial slot wall of a winding slot faces away from the inner circumferential surface of the stator along the radial direction of the motor. At least a portion of the first flow channel and the outlet of the second flow channel are distributed on both sides of a radial slot wall of a winding slot along the radial direction of the motor.

[0016] In this embodiment, a radial slot wall of a winding slot refers to an inner wall of a winding slot along the radial direction of the motor. The outlet of the second flow channel is distributed on the outer periphery of a winding slot, indicating that the outlet of the second flow channel is distributed on the side of a radial slot wall of a winding slot away from the inner periphery of the stator.

[0017] In this embodiment, at least a portion of the first flow channel and the outlet of the second flow channel are distributed on both sides of a radial slot wall of a winding slot along the radial direction of the motor. This means that at least a portion of the first flow channel is closer to the inner circumferential surface of the stator than a radial slot wall of a winding slot, shortening the distance between the cooling medium of the first flow channel and the conductor, thus enhancing the cooling effect. Furthermore, the multiple winding slots of the stator are arranged at intervals along the circumference of the motor, and the distribution of at least a portion of the first flow channel and the second flow channel on different sides of a radial slot wall of a winding slot indicates that at least a portion of the first flow channel is located between one winding slot and another, allowing the cooling medium of the first flow channel to dissipate heat from the conductors in adjacent winding slots.

[0018] In one embodiment, the distance between the outlet of the second flow channel along the radial direction of the motor and a radial wall of a winding slot is greater than the distance between the first flow channel and a radial wall of a winding slot.

[0019] In this embodiment, the radial distance between the outlet of the second flow channel and a radial wall of a winding slot is relatively large, which helps to reduce the risk of the second flow channel being blocked by insulating varnish.

[0020] In one embodiment, the length of the first iron core along the axial direction of the motor is greater than the length of the second iron core. The length of the first flow channel is greater than the length of the second flow channel.

[0021] In this embodiment, a first flow channel is distributed in the first iron core, and a second flow channel is distributed in the second iron core. The distance between the first flow channel and a winding slot is relatively small, making the cooling effect of the first flow channel on multiple wires within a winding slot better than that of the second flow channel. Therefore, the length of the first flow channel is greater than the length of the second flow channel, and the axial length of the first iron core is greater than the axial length of the second iron core, thus expanding the portion of the wire that can exchange heat with the first flow channel, which is beneficial to improving the overall cooling efficiency of the wire.

[0022] In one embodiment, the inlet of the second flow channel penetrates through the other end face of the second iron core, and the other end face of the second iron core is arranged adjacent to the first iron core along the axial direction of the motor. The inlet of the second flow channel is used to connect to the outlet of the first flow channel, and the opening direction of the inlet of the second flow channel faces the outlet of the first flow channel.

[0023] In this embodiment, the inlet of the second flow channel penetrates through the other end face of the second iron core. The radial distance between the outlet of the second flow channel and the conductor is relatively larger than the radial distance between the first flow channel and the conductor. To shorten the average distance between the second flow channel and the conductor along the radial direction of the motor, the inlet of the second flow channel can be used to directly connect to the outlet of the first flow channel. Specifically, the other end face of the second iron core is arranged adjacent to the first iron core, and the opening direction of the inlet of the second flow channel faces the outlet of the first flow channel, reducing the radial distance between the inlet of the second flow channel and the conductor, facilitating heat exchange between the portion of the conductor distributed in the second iron core and the second flow channel.

[0024] In one embodiment, the outlet of the second flow channel is oriented toward one end of a plurality of wires, and the inlet of the second flow channel is spaced apart from the outlet of the first flow channel along the radial direction of the motor.

[0025] The stator cores include a third core, which is located between the first and second cores. A third flow channel runs through the third core, connecting the first and second flow channels. The third flow channel extends radially from the outlet of the first flow channel towards the inlet of the second flow channel.

[0026] In this embodiment, after flowing through the second channel, the cooling medium can be used to further cool one end of multiple conductors. To prevent the second channel from being blocked by insulating varnish, and to facilitate the movement of the cooling medium to the end of the conductor, the opening direction of the outlet of the second channel can be directed towards the end of the conductor. Guided by the second channel, the cooling medium can be concentrated and sprayed onto the end of the conductor along the opening direction of the second channel.

[0027] In this embodiment, to reduce the flow resistance of the cooling medium in the second flow channel, the opening direction of the inlet of the second flow channel can be matched with the opening direction of the outlet of the second flow channel, such that the inlet of the second flow channel is spaced apart from the outlet of the first flow channel along the radial direction of the motor. In this case, a third flow channel of a third core is needed to connect the first and second flow channels. Specifically, the third core is distributed between the first and second cores along the axial direction of the motor, one end of the third flow channel is connected to the outlet of the first flow channel, and the other end of the third flow channel is connected to the inlet of the second flow channel. The third flow channel can be used to change the flow direction of the cooling medium in the first flow channel and compensate for the radial distance between the first and second flow channels.

[0028] In one embodiment, the second flow channel includes an axial section and an inclined section, which are arranged adjacent to each other and connected along the axial direction of the motor. The inlet and outlet of the second flow channel are respectively distributed in the axial section and the inclined section. The axial section extends parallel to the axial direction of the motor, and the inclined section extends toward one end of the plurality of wires.

[0029] In this embodiment, the cooling medium in the third flow channel flows sequentially through the axial section and the inclined section of the second flow channel, and the extension directions of the axial section and the inclined section intersect. The axial section acts as a buffer between the third flow channel and the inclined section. Compared to a scheme where the inclined section is directly connected to the third flow channel, the axial section in this embodiment can reduce the angle of change in the flow direction of the cooling medium when it enters the second flow channel from the third flow channel, which is beneficial to reducing the flow resistance of the cooling medium and improving the cooling efficiency.

[0030] In one embodiment, a first groove in a first core, a second groove in a second core, and a third groove in a third core are used to form a winding slot. A circumferential groove wall of the first groove includes a first cooling groove, which is recessed away from the plurality of wires along the circumference of the motor. The gap between the first cooling groove and the plurality of wires forms a first flow channel. The first flow channel extends axially along the motor. The cross-sectional area of ​​the third groove is larger than that of the first groove, and the gap between the third groove and the plurality of wires forms a third flow channel.

[0031] In the embodiments of this application, a circumferential groove wall of the first groove refers to an inner wall of the first groove along the circumference of the motor.

[0032] In this embodiment, the first groove, the third groove, and the second groove are arranged along the axial direction of the motor to form a winding slot. A first flow channel is formed in the first cooling groove of the first groove. Specifically, the first cooling groove is distributed on a circumferential groove wall of the first groove, and the first cooling groove is recessed along the circumference of the motor away from the conductor. The first flow channel communicates with the first groove, allowing the cooling medium in the first flow channel to directly contact the surface of the conductor, which enhances the cooling effect. Since the first flow channel is distributed within the first groove, in order to achieve the third flow channel communicating with the first flow channel along the axial direction of the motor, the cross-sectional area of ​​the third groove needs to be larger than the cross-sectional area of ​​the first groove, so that space can be left between the third groove and the conductor to form the third flow channel.

[0033] In one embodiment, a circumferential groove wall of the third groove along the axial direction of the motor is aligned with the bottom of the first cooling groove.

[0034] In this embodiment, since the third groove is connected to the first groove, one circumferential groove wall of the third groove and one circumferential groove wall of the first groove are distributed on the same side of multiple wires in a winding slot. One circumferential groove wall of the third groove is aligned with the bottom of the first cooling groove along the axial direction of the motor, which can prevent the third groove from obstructing the cooling medium of the first flow channel along the axial direction of the motor, and facilitate the connection between the third flow channel and the first flow channel.

[0035] In one embodiment, the cross-sectional area of ​​the second groove is smaller than that of the first groove, and a circumferential wall of the second groove along the axial direction of the motor is aligned with the opening of the first cooling groove.

[0036] In this embodiment, since the second groove is connected to the first groove, one circumferential groove wall of the second groove and one circumferential groove wall of the first groove are distributed on the same side of multiple conductors in a winding slot. The second groove penetrates one end face of the second iron core, and it is necessary to prevent the insulating varnish overflowing from the second groove from blocking the second flow channel. The cross-sectional area of ​​the second groove is smaller than the cross-sectional area of ​​the first groove and the cross-sectional area of ​​the third groove. One circumferential groove wall of the second groove is aligned with the opening of the first cooling groove along the axial direction of the motor, so that the cooling medium is blocked by the second iron core after flowing sequentially through the outlet of the first flow channel and the inlet of the third flow channel, guiding the cooling medium to continue flowing radially along the motor to the outlet of the third flow channel.

[0037] In one embodiment, the distance between a radial groove wall of a third groove along the radial direction of the motor and the plurality of wires is greater than or equal to the distance between the second flow channel and the plurality of wires.

[0038] In this embodiment, the cooling medium flows from the first flow channel to the second flow channel under the guidance of the third flow channel. To achieve radial flow of the cooling medium in the third flow channel along the motor, the radial distance between one radial groove wall in the third groove that faces away from the inner circumferential surface of the stator and the conductor needs to be adjusted. The radial distance between one radial groove wall of the third groove and the conductor is greater than or equal to the radial distance between the second flow channel and the conductor, which is equivalent to the radial length of the circumferential groove wall of the third groove being greater than or equal to the radial distance between the second flow channel and another radial groove wall of the third groove, so that there is a sufficiently large gap between the third groove and the conductor for the cooling medium to flow to the second flow channel.

[0039] In one embodiment, the plurality of stator cores includes two third cores, with a third groove in one third core and another third groove in the other third core respectively serving to connect two adjacent first grooves in the first core. A radial groove wall of each of the third grooves includes a second cooling groove, each second cooling groove being opposite to a plurality of conductor recesses along the radial direction of the motor. The length of each second cooling groove is greater than the length of each first groove along the circumferential direction of the motor, and the projection of the second cooling groove of one third groove partially overlaps with the projection of the second cooling groove of the other third groove along the axial direction of the motor.

[0040] In this embodiment, a third iron core and another third iron core are distributed along the axial direction of the motor between the first iron core and the second iron core. A first groove is used to form a winding slot with a third groove of a third iron core, and another first groove is used to form another winding slot with another third groove of another third iron core. The winding slots are arranged adjacent to each other.

[0041] In this embodiment, a radial groove wall of a third groove in one third core and a radial groove wall of another third groove in another third core both include a second cooling groove. Taking the second cooling groove of a third groove in one third core as an example: the second cooling groove of a third groove in one third core is recessed radially away from the conductor in a winding slot, and both ends of the second cooling groove of a third groove in one third core extend circumferentially away from the conductor, such that the circumferential length of the second cooling groove of a third groove in one third core is greater than the circumferential length of a first groove. The axial projection of the second cooling groove of a third groove in one third core partially overlaps with the axial projection of the second cooling groove of another third groove in another third core, such that the second cooling groove of a third groove in one third core and the second cooling groove of another third groove in another third core are connected axially along the motor. It can be understood that, in this embodiment, the projection of the second cooling groove refers to the projection of the area enclosed by the groove wall of the second cooling groove.

[0042] In this embodiment, the second flow channel can not only connect to the first flow channel within one winding slot, but can also be shared by the first flow channels of two adjacent winding slots. Specifically, the cooling medium in one first groove and another first groove flows to the second cooling groove of one third groove of one third core and the second cooling groove of another third groove of another third core, respectively. The cooling medium in the second cooling groove of the other third groove of another third core can continue to flow to the second cooling groove of one third groove of one third core. In this case, simply connecting one second flow channel to the second cooling groove of one third groove of one third core allows two first flow channels to share one second flow channel. This embodiment helps reduce the number of second flow channels in the stator and reduces the risk of the second flow channel outlet being blocked by insulating varnish.

[0043] In one embodiment, a third core includes a fourth groove, with one circumferential wall of the fourth groove aligned with the bottom of the first cooling groove along the axial direction of the motor, and the distance between one radial wall of the fourth groove and the plurality of wires being less than the distance between the second flow channel and the plurality of wires. The fourth groove along the axial direction of the motor is used to connect to another third groove of another third core.

[0044] In this embodiment, the cross-sectional area of ​​the fourth groove is smaller than that of the third groove of a third iron core. This allows for control of the volume used for slotting within the third iron core, which is beneficial for improving the mechanical strength of the stator and reducing the negative impact on its electromagnetic performance. In this case, since the distance between one radial groove wall of the fourth groove and the multiple conductors is smaller than the distance between the second flow channel and the multiple conductors, the fourth groove cannot directly deliver the cooling medium to the second flow channel. Therefore, another third iron core can be used as the connecting structure between the fourth groove and the second flow channel. Specifically, the fourth groove, together with another first groove and another third groove of another third iron core, forms another winding slot. The fourth groove connects to another third groove of another third iron core along the axial direction of the motor, allowing the cooling medium of the other first groove to flow sequentially through the fourth groove and the other third groove of another third iron core before flowing into the second flow channel.

[0045] In one embodiment, a third core includes a fourth flow channel distributed radially along the motor between a radial groove wall of a fourth groove and the outer peripheral surface of a third core. The fourth flow channel along the motor's axial direction serves to connect to a second cooling groove of another third core.

[0046] In this embodiment, since the radial distance between one radial wall of the fourth groove and the conductor is less than the radial distance between the second flow channel and the conductor, there is space between one wall of the fourth groove and the outer surface of a third core that can be used to arrange the fourth flow channel. The fourth flow channel can be used to receive the cooling medium. The fourth flow channel is connected to the second cooling groove of another third groove of another third core, and the second cooling groove of another third groove of another third core is connected to the second cooling groove of a third groove of a third core, so that the cooling medium received by the fourth flow channel can flow to another first groove and a first groove respectively through the second cooling groove of another third groove of another third core and the second cooling groove of a third groove of a third core, which facilitates the rational distribution of the cooling medium.

[0047] Secondly, embodiments of this application provide a powertrain. The powertrain includes a motor controller, a reducer, and a motor as described in any embodiment of the first aspect. The motor controller supplies electrical power to the motor, and the motor is used to drive the reducer.

[0048] In the embodiments of this application, applying the motor described in any of the embodiments of the first aspect to the powertrain can reduce the risk of the flow channels of the motor stator being blocked by insulating varnish, thereby enhancing the cooling effect of the motor and improving the working efficiency of the motor and the powertrain.

[0049] Thirdly, embodiments of this application provide an electric vehicle. The electric vehicle includes a power battery and a powertrain as described in the second aspect. The powertrain is used to receive power from the power battery and to drive the wheels of the electric vehicle.

[0050] In the embodiments of this application, applying the powertrain described in the second aspect to electric vehicles is beneficial to improving the safety performance of electric vehicles. Attached Figure Description

[0051] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the embodiments of this application will be described below.

[0052] Figure 1 is a schematic diagram of an electric vehicle provided in an embodiment of this application;

[0053] Figure 2 is a schematic diagram of the powertrain provided in an embodiment of this application;

[0054] Figure 3 is a schematic diagram of the motor provided in an embodiment of this application;

[0055] Figure 4 is an exploded view of the stator provided in an embodiment of this application;

[0056] Figure 5 is a partial schematic diagram of the first iron core and the second iron core provided in the embodiments of this application;

[0057] Figure 6 is a schematic diagram of a motor provided by the prior art;

[0058] Figure 7 is a schematic diagram of a motor provided by the prior art;

[0059] Figure 8 is a schematic diagram of the motor provided in an embodiment of this application;

[0060] Figure 9 is a schematic diagram of the motor provided in an embodiment of this application;

[0061] Figure 10 is a schematic diagram of the motor provided in an embodiment of this application;

[0062] Figure 11 is an exploded view of the stator provided in an embodiment of this application;

[0063] Figure 12 is a partial schematic diagram of the first iron core and the third iron core provided in the embodiments of this application;

[0064] Figure 13 is a partial schematic diagram of the second and third iron cores provided in the embodiments of this application;

[0065] Figure 14 is a schematic diagram of the stator provided in an embodiment of this application;

[0066] Figure 15 is a partial enlarged view of part M in the stator shown in Figure 14;

[0067] Figure 16 is a partial schematic diagram of the third iron core provided in an embodiment of this application;

[0068] Figure 17 is a partial schematic diagram of the third iron core provided in an embodiment of this application;

[0069] Figure 18 is a partial schematic diagram of the third iron core provided in an embodiment of this application;

[0070] Figure 19 is a schematic diagram of the third iron core provided in an embodiment of this application;

[0071] Figure 20 is a schematic diagram of the motor provided in an embodiment of this application;

[0072] Figure 21 is a schematic diagram of the motor provided in an embodiment of this application;

[0073] Figure 22 is a schematic diagram of the motor provided in an embodiment of this application;

[0074] Figure 23 is a schematic diagram of the first iron core and the third iron core provided in the embodiments of this application;

[0075] Figure 24 is a schematic diagram of the second and third iron cores provided in the embodiments of this application;

[0076] Figure 25 is a schematic diagram of the third iron core provided in an embodiment of this application. Detailed Implementation

[0077] The technical solutions of the embodiments of this application will be described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0078] For ease of understanding, the relevant technical terms involved in the embodiments of this application will be explained and described below.

[0079] Parallelism: The parallelism defined in the embodiments of this application is not limited to absolute parallelism. This definition of parallelism can be understood as basic parallelism, allowing for situations where the parallelism is not absolute due to factors such as assembly tolerance, design tolerance, and structural flatness.

[0080] Currently, the cooling channels of motor stators are easily blocked by insulating varnish. This application provides a motor whose stator includes multiple stator cores arranged along the motor's axial direction. Multiple winding slots of the stator extend through the multiple stator cores along the motor's axial direction, and each winding slot is used to accommodate multiple winding wires.

[0081] The stator cores include a first core and a second core. One end of one of the multiple conductors protrudes from one end face of the second core. A first flow channel runs through the first core. Along the axial direction of the motor, one end face of the second core covers the outlet of the first flow channel; that is, the outlet of the first flow channel is spaced apart from one end face of the second core, preventing the cooling medium in the first flow channel from flowing directly to one end face of the second core. The outlet of the second flow channel runs through one end face of the second core, connecting the outlet of the first flow channel to one end face of the second core. The outlet of the second flow channel is located on the outer periphery of a winding slot. Radially along the motor, the distance between the outlet of the second flow channel and a winding slot is greater than the distance between the first flow channel and a winding slot.

[0082] This application embodiment, through the coordination of different flow channels in the stator, reduces the risk of insulating varnish clogging the flow channels while ensuring the cooling effect of the stator and windings. The motor provided in this application embodiment can be applied to a powertrain, and a powertrain including the motor provided in this application embodiment can be applied to electric vehicles.

[0083] Please refer to Figure 1, which is a schematic diagram of an electric vehicle 1 provided in an embodiment of this application. In one embodiment, the electric vehicle 1 includes a powertrain 10 and a power battery 20. In this embodiment, the electric vehicle 1 refers to a wheeled device driven or towed by a power unit. The power battery 20 is used to supply power to the powertrain 10; the power battery 20 can also be referred to as a battery pack. The powertrain 10 is the power source of the electric vehicle 1 and is used to drive the wheels 40 of the electric vehicle 1. In one embodiment, the electric vehicle 1 further includes a frame 30, which is used to mount the powertrain 10 and the power battery 20. The frame 30 is the structural skeleton of the electric vehicle 1 and can withstand the loads from the internal and external environment of the electric vehicle 1.

[0084] Please refer to Figure 2, which is a schematic diagram of the powertrain 10 provided in an embodiment of this application. In one embodiment, the powertrain 10 includes a motor 11, a motor controller 12, and a reducer 13. A power battery supplies power to the motor 11 through the motor controller 12. Specifically, the motor controller 12 converts the direct current supplied by the power battery into alternating current and delivers the alternating current to the motor 11. The motor 11 is driven by the reducer 13 to drive the wheels to rotate. In one embodiment, the motor controller 12 controls the motor 11 and the reducer 13.

[0085] The motor 11 converts electrical energy into mechanical energy to generate driving torque. In one embodiment, the motor 11 includes a stator 100, windings 200, a rotor 300, and a motor shaft 400. Alternating current is applied to the multiple conductors 210 of the windings 200, generating alternating magnetic flux. The alternating magnetic flux generated by the windings 200 interacts with the permanent magnet flux generated by the rotor 300, causing the rotor 300 to rotate relative to the stator 100. The rotor 300 is fixedly connected to the motor shaft 400, allowing the motor shaft 400 to rotate with the rotor 300. The stator 100 is rotatably connected to the motor shaft 400, enabling the motor shaft 400 to rotate relative to the stator 100, converting electrical energy into mechanical energy. The output end of the motor shaft 400 is used to transmit mechanical energy to the reducer 13.

[0086] The stator and windings of an electric motor generate heat during operation, causing the motor temperature to rise. If heat is not dissipated in time, it will affect the efficiency of the motor and powertrain, and may even damage the motor due to overheating. To achieve heat dissipation, the stator is usually equipped with flow channels. Cooling medium flows through these channels, carrying away the heat generated by the stator and windings.

[0087] To improve the insulation and thermal conductivity of the stator and windings, they are usually impregnated with varnish. However, during the drying process of the insulating varnish, there is a risk that the insulating varnish in the winding slots may overflow onto the stator end face and flow into the flow channel, causing blockage.

[0088] This application embodiment improves the flow channel of the stator, avoiding the outlet of the flow channel near the winding slot from directly penetrating the end face of the stator. This increases the difficulty of the insulating varnish overflowing from the winding slot blocking the flow channel, allowing the cooling medium to flow smoothly out of the end face of the stator, which is beneficial to improving the working efficiency of the motor and extending the life of the motor.

[0089] The motor 11 provided in the embodiments of this application is described in detail below.

[0090] Please refer to Figures 3 to 5. Figure 3 is a schematic diagram of the motor 11 provided in an embodiment of this application. Figure 4 is an exploded view of the stator 100 provided in an embodiment of this application. Figure 5 is a partial schematic diagram of the first iron core 110 and the second iron core 120 provided in an embodiment of this application. In Figure 5, the second flow channel 121 refers to the outlet of the second flow channel 121.

[0091] In one embodiment, the stator 100 of the motor 11 includes a plurality of stator cores 101, and a plurality of winding slots 102 of the stator 100 pass through the plurality of stator cores 101 along the axial direction O of the motor 11, and each winding slot 102 is used to accommodate a plurality of wires 210.

[0092] Multiple stator cores 101 include a first core 110 and a second core 120. One end of a plurality of conductors 210 protrudes from one end face 122 of the second core 120. A first flow channel 111 of the first core 110 penetrates the first core 110, and along the axial direction O of the motor 11, one end face 122 of the second core 120 covers the outlet of the first flow channel 111. The outlet of the second flow channel 121 penetrates through one end face 122 of the second core 120, and the second flow channel 121 connects the outlet of the first flow channel 111 with one end face 122 of the second core 120. The outlet of the second flow channel 121 is distributed on the outer periphery of a winding slot 102. Along the radial direction R of the motor 11, the distance between the outlet of the second flow channel 121 and a winding slot 102 is greater than the distance between the first flow channel 111 and a winding slot 102.

[0093] In the embodiments of this application, for ease of description, one end face 122 of the second iron core 120 is referred to as the end face 122a of the second iron core 120, and one winding slot 102 is referred to as the winding slot 102a.

[0094] Taking winding slot 102a as an example among multiple winding slots 102, when the motor 11 is in operation, the alternating current flowing through the multiple wires 210 in winding slot 102a causes resistance loss. The alternating magnetic flux generated by the energized wires 210 also causes hysteresis loss and eddy current loss within the multiple stator cores 101, resulting in a continuous increase in heat generation in the wires 210 and stator cores 101. In this embodiment, the first flow channel 111 is relatively close to the winding slot 102a, shortening the distance between the cooling medium in the first flow channel 111 and the multiple wires 210, facilitating the conduction of heat generated by the wires 210 to the first flow channel 111, and improving heat dissipation efficiency.

[0095] In this embodiment, one end of each of the multiple conductors 210 protrudes from the end face 122a of the second core 120, indicating that the end face 122a of the second core 120 is one end face of the stator 100, and the second core 120 is distributed at the ends of the multiple stator cores 101. During the drying process of the insulating varnish, some of the insulating varnish in the winding slot 102a easily overflows to the end face 122a of the second core 120. Since the first flow channel 111 is not distributed in the second core 120, and the outlet of the first flow channel 111 is not distributed in the end face 122a of the second core 120, even if the first flow channel 111 is arranged adjacent to the winding slot 102a, the insulating varnish overflowing to the end face 122a of the second core 120 is difficult to flow directly into the first flow channel 111.

[0096] However, if the second core 120 has an axial flow channel 1201a as shown in FIG. 6, with its outlet adjacent to the winding slot 102a and connected to the first flow channel 111, it would be equivalent to extending the outlet of the first flow channel 111 to the end face 122a of the second core 120, increasing the possibility of insulating varnish flowing into the axial flow channel 1201a and causing blockage. In this embodiment, the end face 122a of the second core 120 covering the outlet of the first flow channel 111 along the axial direction O of the motor 11 means that the projection area of ​​the outlet of the first flow channel 111 along the axial direction O of the motor 11 corresponds to the solid structure of the second core 120. The solid structure corresponding to this projection area would block the cooling medium of the first flow channel 111 from flowing directly out along the axial direction O of the motor 11. Therefore, the second core 120 in this embodiment does not have the axial flow channel 1201a as shown in FIG. 6, which helps to reduce the risk of the flow channel being blocked.

[0097] In this embodiment, a second flow channel 121 of the second core 120 replaces the axial flow channel 1201a in FIG. 6. The second flow channel 121 guides the cooling medium of the first flow channel 111 to flow out from the end face 122a of the second core 120. Unlike the axial flow channel 1201a in FIG. 6, the outlet of the second flow channel 121 in this embodiment is distributed on the outer periphery of the winding slot 102a, and the radial distance between the outlet of the second flow channel 121 and the winding slot 102a is greater than the radial distance between the first flow channel 111 and the winding slot 102a. Under the guidance of the second flow channel 121, the cooling medium flows out from the end face 122a of the second core 120 at a position far away from the winding slot 102a relative to the first flow channel 111, extending the path of the insulating varnish from the winding slot 102a to the outlet of the second flow channel 121. This effectively avoids blockage of the cooling medium in the second flow channel 121 at the outlet of the second flow channel 121, improving cooling efficiency. The cooling medium can flow smoothly from the end face 122a of the second iron core 120, which helps the cooling medium to continue moving to one end of the multiple wires 210, reducing the risk of local overheating of the wires 210, and eliminating the need for an oil spray ring, thus reducing the size of the motor 11. In addition, it also facilitates the recovery and recycling of the cooling medium.

[0098] Understandably, to avoid the second flow channel 121 from being blocked, it is sufficient to ensure that the outlet of the second flow channel 121 is far away from the winding slot 102, and the radial distance between the remaining part of the second flow channel 121 other than the outlet and the winding slot 102 can be adjusted according to actual needs.

[0099] If only the issue of channel blockage is considered, the axial channel 1201b shown in Figure 7 can be used alone. That is, the axial channel 1201b is entirely radially R away from the winding slot 102a along the motor 11. In this case, although the insulating varnish of the winding slot 102a is difficult to flow to the outlet of the axial channel 1201b, the radial distance between the axial channel 1201b and the multiple wires 210 is also relatively large, which will negatively affect the cooling effect of the wires 210. In this embodiment, the distance between the first channel 111 and the winding slot 102a is relatively small, and the distance between the outlet of the second channel 121 and the winding slot 102a is relatively large. Through the cooperation of the first channel 111 and the second channel 121, this embodiment, compared to either the axial channel 1201a or the axial channel 1201b, can ensure the cooling effect of the winding 200 while preventing the insulating varnish overflowing from the winding slot 102 from blocking the channel.

[0100] In one embodiment, the cooling medium may be any one of ethylene glycol-based cooling oil, synthetic oil, or mineral oil.

[0101] Please refer to Figure 5. In one embodiment, a radial slot wall of the winding slot 102a along the radial direction R of the motor 11 faces away from the inner circumferential surface of the stator 100. At least a portion of the first flow channel 111 and the outlet of the second flow channel 121 along the radial direction R of the motor 11 are distributed on both sides of a radial slot wall of the winding slot 102a.

[0102] In this embodiment, a radial groove wall of the winding groove 102a refers to an inner wall of the winding groove 102a along the radial direction R of the motor 11. The outlet of the second flow channel 121 is distributed on the outer peripheral side of the winding groove 102a, indicating that the outlet of the second flow channel 121 is distributed on the side of a radial groove wall of the winding groove 102a away from the inner peripheral surface of the stator 100.

[0103] In this embodiment, at least a portion of the first flow channel 111 and the outlet of the second flow channel 121 are distributed on both sides of a radial groove wall of the winding slot 102a along the radial direction R of the motor 11. This means that at least a portion of the first flow channel 111 is closer to the inner circumferential surface of the stator 100 relative to a radial groove wall of the winding slot 102a, shortening the distance between the cooling medium of the first flow channel 111 and the wire 210, which helps to enhance the cooling effect. In addition, the multiple winding slots 102 of the stator 100 are arranged at intervals along the circumferential direction C of the motor 11. The fact that at least a portion of the first flow channel 111 and the second flow channel 121 are distributed on different sides of a radial groove wall of the winding slot 102a also indicates that at least a portion of the first flow channel 111 is located between the winding slot 102a and another winding slot 102, so that the cooling medium of the first flow channel 111 can dissipate heat from the wires 210 in the two adjacent winding slots 102.

[0104] Please refer to Figure 5. In one embodiment, the outlets of the first flow channel 111 and the second flow channel 121 along the radial direction R of the motor 11 are distributed on both sides of a radial groove wall of the winding slot 102a. In another embodiment, the outlets of the first flow channel 111 and the second flow channel 121 along the radial direction R of the motor 11 are distributed on the same side of a radial groove wall of the winding slot 102a, and the radial groove wall of the winding slot 102a, the outlet of the second flow channel 121, and the first flow channel 111 are arranged alternately along the radial direction R of the motor 11.

[0105] Please refer to Figure 5. In one embodiment, the distance between the outlet of the second flow channel 121 along the radial direction R of the motor 11 and a radial wall of the winding slot 102a is greater than the distance between the first flow channel 111 and a radial wall of the winding slot 102a.

[0106] In this embodiment, the radial distance between the outlet of the second flow channel 121 and a radial wall of the winding slot 102a is relatively large, which helps to reduce the risk of the second flow channel 121 being blocked by insulating varnish.

[0107] Please refer to Figures 4 and 8, where Figure 8 is a schematic diagram of the motor 11 provided in an embodiment of this application. In one embodiment, the length of the first iron core 110 along the axial direction O of the motor 11 is greater than the length of the second iron core 120. The length of the first flow channel 111 is greater than the length of the second flow channel 121.

[0108] In this embodiment, the first flow channel 111 is distributed in the first iron core 110, and the second flow channel 121 is distributed in the second iron core 120. The distance between the first flow channel 111 and the winding slot 102a is relatively small, making the cooling effect of the first flow channel 111 on the multiple wires 210 in the winding slot 102a better than that of the second flow channel 121. Therefore, the length of the first flow channel 111 is greater than the length of the second flow channel 121, and the axial length of the first iron core 110 is greater than the axial length of the second iron core 120, which expands the portion of the wires 210 that can exchange heat with the first flow channel 111, thus improving the overall cooling efficiency of the wires 210.

[0109] Please refer to Figure 8. In one embodiment, the inlet of the second flow channel 121 penetrates through the other end face of the second iron core 120, and the other end face 122 of the second iron core 120 is arranged adjacent to the first iron core 110 along the axial direction of the motor 11. The inlet of the second flow channel 121 is used to connect to the outlet of the first flow channel 111, and the opening direction of the inlet of the second flow channel 121 faces the outlet of the first flow channel 111.

[0110] In this embodiment of the application, for ease of description, the other end face 122 of the second iron core 120 is referred to as the end face 122b of the second iron core 120. The inlet of the second flow channel 121 passes through the end face 122b of the second iron core 120.

[0111] In this embodiment, the radial distance between the outlet of the second flow channel 121 and the wire 210 is relatively larger than the radial distance between the first flow channel 111 and the wire 210. To shorten the average distance between the second flow channel 121 and the wire 210 along the radial direction R of the motor 11, the inlet of the second flow channel 121 can be used to directly connect to the outlet of the first flow channel 111. Specifically, the end face 122b of the second iron core 120 is arranged adjacent to the first iron core 110, and the opening direction of the inlet of the second flow channel 121 faces the outlet of the first flow channel 111, thereby reducing the radial distance between the inlet of the second flow channel 121 and the wire 210, which facilitates heat exchange between the portion of the wire 210 distributed in the second iron core 120 and the second flow channel 121.

[0112] Please refer to Figure 9, which is a schematic diagram of the motor 11 provided in an embodiment of this application. In one embodiment, the opening direction of the outlet of the second flow channel 121 faces one end of the plurality of wires 210, and the inlet of the second flow channel 121 is spaced apart from the outlet of the first flow channel 111 along the radial direction R of the motor 11. The plurality of stator cores 101 further include a third core 130, which is distributed between the first core 110 and the second core 120. A third flow channel 131 of the third core 130 penetrates the third core 130 and connects the first flow channel 111 and the second flow channel 121. Along the radial direction R of the motor 11, the third flow channel 131 extends from the outlet of the first flow channel 111 toward the inlet of the second flow channel 121.

[0113] In this embodiment, after the cooling medium flows through the second channel 121, it can be used to continue cooling one end of a plurality of wires 210. To prevent the second channel 121 from being blocked by insulating varnish, and to facilitate the movement of the cooling medium in the second channel 121 to the end of the wires 210, the opening direction of the outlet of the second channel 121 can be directed towards the end of the wires 210. Guided by the second channel 121, the cooling medium can be concentrated and sprayed onto the end of the wires 210 along the opening direction of the second channel 121.

[0114] In this embodiment, to reduce the flow resistance of the cooling medium in the second flow channel 121, the opening direction of the inlet of the second flow channel 121 can be matched with the opening direction of the outlet of the second flow channel 121, such that the inlet of the second flow channel 121 is spaced apart from the outlet of the first flow channel 111 along the radial direction R of the motor 11. In this case, the third flow channel 131 of the third core 130 is needed to connect the first flow channel 111 and the second flow channel 121. Specifically, the third core 130 is distributed between the first core 110 and the second core 120 along the axial direction O of the motor 11. One end of the third flow channel 131 is connected to the outlet of the first flow channel 111, and the other end of the third flow channel 131 is connected to the inlet of the second flow channel 121. The third flow channel 131 can be used to change the flow direction of the cooling medium in the first flow channel 111 to compensate for the radial distance between the first flow channel 111 and the second flow channel 121.

[0115] Please refer to Figure 10, which is a schematic diagram of the motor 11 provided in an embodiment of this application. In one embodiment, the second flow channel 121 includes an axial section 1211 and an inclined section 1212. The axial section 1211 and the inclined section 1212 are arranged adjacently and connected along the axial direction O of the motor 11. The inlet and outlet of the second flow channel 121 are respectively distributed in the axial section 1211 and the inclined section 1212. The axial section 1211 extends parallel to the axial direction O of the motor 11, and the inclined section 1212 extends toward one end of the plurality of wires 210.

[0116] In this embodiment, the cooling medium in the third flow channel 131 flows sequentially through the axial section 1211 and the inclined section 1212 of the second flow channel 121, with the extending directions of the axial section 1211 and the inclined section 1212 intersecting. The axial section 1211 acts as a buffer between the third flow channel 131 and the inclined section 1212. Compared to the scheme where the inclined section 1212 is directly connected to the third flow channel 131, the axial section 1211 in this embodiment can reduce the angle of change in the flow direction of the cooling medium when it enters the second flow channel 121 from the third flow channel 131, which is beneficial to reducing the flow resistance of the cooling medium and improving the cooling efficiency.

[0117] Please refer to Figures 4 and 10. In one embodiment, the second core 120 includes a plurality of stator laminations 123, which are stacked along the axial direction O of the motor 11. By employing different stacking methods on the plurality of stator laminations 123, axial sections 1211 and inclined sections 1212 of the second flow channel 121 can be formed respectively. Specifically, each stator lamination 123 includes a plurality of through holes, each through hole penetrating the stator lamination 123 along the axial direction O of the motor 11. The distance between the plurality of through holes of each stator lamination 123 and the axis of each stator lamination 123 decreases sequentially along the circumferential direction C of the motor 11. Exemplarily, the plurality of through holes of each stator lamination 123 are arranged along an involute curve. By stacking a portion of the stator laminations 123 along the axial direction O of the motor 11, the through holes of a portion of the stator laminations 123 can form the axial section 1211. Each of the other part of the stator laminations 123 is rotated by a specific angle and stacked in sequence. The through holes of the other part of the stator laminations 123 can form an inclined section 1212, which is connected to the axial section 1211.

[0118] In one embodiment, when multiple stator cores are fixed by welding, the outer surface of each stator core includes a welding groove. The welding grooves of each stator core and the flow channels of that stator core are arranged radially spaced along the motor, and the welding grooves of the multiple stator cores are adjacent and connected along the axial direction of the motor. The welding grooves in this embodiment facilitate the fixing of multiple stator cores through welding operations. It is understood that when multiple stator cores are fixed by other methods, such as bonding or riveting, each stator core may not include a welding groove.

[0119] Please refer to Figures 11 and 12. Figure 11 is an exploded view of the stator 100 provided in the embodiment of this application, and Figure 12 is a partial schematic diagram of the first iron core 110 and the third iron core 130 provided in the embodiment of this application.

[0120] In one embodiment, a first groove 112 of a first core 110, a second groove 124 of a second core 120, and a third groove 132 of a third core 130 are used to form a winding slot 102a. A circumferential groove wall of the first groove 112 includes a first cooling groove 1121. Along the circumferential direction C of the motor 11, the first cooling groove 1121 is recessed away from the plurality of wires 210, and the gap between the first cooling groove 1121 and the plurality of wires 210 is used to form a first flow channel 111. The first flow channel 111 extends along the axial direction O of the motor 11. The cross-sectional area of ​​the third groove 132 is larger than the cross-sectional area of ​​the first groove 112, and the gap between the third groove 132 and the plurality of wires 210 is used to form the third flow channel 131.

[0121] In this embodiment of the application, a circumferential groove wall of the first groove 112 refers to an inner wall of the first groove 112 along the circumferential C of the motor 11.

[0122] In this embodiment, the first groove 112, the third groove 132, and the second groove 124 are arranged along the axial direction O of the motor 11 to form a winding slot 102a. A first flow channel 111 is formed in the first cooling groove 1121 of the first groove 112. Specifically, the first cooling groove 1121 is distributed on one circumferential groove wall of the first groove 112, and is recessed along the circumferential direction C of the motor 11 away from the conductor 210. The first flow channel 111 communicates with the first groove 112, allowing the cooling medium in the first flow channel 111 to directly contact the surface of the conductor 210, which enhances the cooling effect. Since the first flow channel 111 is distributed within the first groove 112, in order for the third flow channel 131 to communicate with the first flow channel 111 along the axial direction O of the motor 11, the cross-sectional area of ​​the third groove 132 needs to be larger than the cross-sectional area of ​​the first groove 112, so that space can be left between the third groove 132 and the conductor 210 to form the third flow channel 131.

[0123] Please refer to Figure 12. In one embodiment, a circumferential groove wall of the third groove 132 along the axial direction O of the motor 11 is aligned with the bottom of the first cooling groove 1121.

[0124] In this embodiment, since the third groove 132 is connected to the first groove 112, one circumferential groove wall of the third groove 132 and one circumferential groove wall of the first groove 112 are distributed on the same side of the plurality of wires 210 in the winding slot 102a. One circumferential groove wall of the third groove 132 is aligned with the bottom of the first cooling groove 1121 along the axial direction O of the motor 11, which can prevent the third groove 132 from blocking the cooling medium of the first flow channel 111 along the axial direction O of the motor 11, and facilitate the connection between the third flow channel 131 and the first flow channel 111.

[0125] Please refer to Figures 12 and 13. Figure 13 is a partial schematic diagram of the second iron core 120 and the third iron core 130 provided in an embodiment of this application. In one embodiment, the cross-sectional area of ​​the second groove 124 is smaller than the cross-sectional area of ​​the first groove 112, and one circumferential groove wall of the second groove 124 is aligned with the opening of the first cooling groove 1121 along the axial direction O of the motor 11.

[0126] In this embodiment, since the second groove 124 is connected to the first groove 112, one circumferential groove wall of the second groove 124 and one circumferential groove wall of the first groove 112 are distributed on the same side of the multiple conductors 210 in the winding slot 102a. The second groove 124 penetrates the end face 122a of the second iron core 120, and it is necessary to prevent the insulating varnish overflowing from the second groove 124 from blocking the second flow channel 121. The cross-sectional area of ​​the second groove 124 is smaller than the cross-sectional area of ​​the first groove 112 and the cross-sectional area of ​​the third groove 132. One circumferential groove wall of the second groove 124 is aligned with the opening of the first cooling groove 1121 along the axial direction O of the motor 11, so that the cooling medium is blocked by the second iron core 120 after flowing through the outlet of the first flow channel 111 and the inlet of the third flow channel 131 in sequence, and the cooling medium is guided to continue flowing along the radial direction R of the motor 11 to the outlet of the third flow channel 131.

[0127] It should be noted that, in order to clearly show the structure presented by the stacked arrangement of the second iron core 120 and the first iron core 110 and the stacked arrangement of the second iron core 120 and the third iron core 130, Figures 12 and 13 are equivalent to observing multiple stator iron cores from two opposite perspectives. In fact, the winding slot 102a in Figure 12 and the winding slot 102a in Figure 13 are the same winding slot.

[0128] Please refer to Figure 13. In one embodiment, the distance between a radial groove wall of the third groove 132 along the radial direction R of the motor 11 and the plurality of wires 210 is greater than or equal to the distance between the second flow channel 121 and the plurality of wires 210.

[0129] In this embodiment, the cooling medium flows from the first flow channel 111 to the second flow channel 121 under the guidance of the third flow channel 131. To achieve the flow of the cooling medium along the radial direction R of the motor 11 in the third flow channel 131, it is necessary to adjust the radial distance between one radial groove wall of the third groove 132 facing away from the inner circumferential surface of the stator 100 and the conductor 210. The radial distance between one radial groove wall of the third groove 132 and the conductor 210 is greater than or equal to the radial distance between the second flow channel 121 and the conductor 210, which is equivalent to the radial length of the circumferential groove wall of the third groove 132 being greater than or equal to the radial distance between the second flow channel 121 and the other radial groove wall of the third groove 132, so that there is a sufficiently large gap between the third groove 132 and the conductor 210 for the cooling medium to flow to the second flow channel 121.

[0130] Please refer to Figures 14 and 15. Figure 14 is a schematic diagram of the stator 100 provided in the embodiment of this application, and Figure 15 is a partial enlarged view of the M part in the stator 100 shown in Figure 14.

[0131] In one embodiment, the plurality of stator cores 101 include two third cores 130. A third groove 132 of one third core 130 and another third groove 132 of the other third core 130 are respectively used to connect two adjacent first grooves 112 in the first core 110. A radial groove wall of each of the third grooves 132 and the other third groove 132 includes a second cooling groove 1321. Each second cooling groove 1321 is recessed away from the plurality of conductors 210 along the radial direction R of the motor 11. The length of each second cooling groove 1321 is greater than the length of each first groove 112 along the circumferential direction C of the motor 11. The projection of the second cooling groove 1321 of one third groove 132 partially overlaps with the projection of the second cooling groove 1321 of the other third groove 132 along the axial direction O of the motor 11.

[0132] In this embodiment of the application, for ease of description, one third iron core 130 is referred to as third iron core 130a, and the other third iron core 130 is referred to as third iron core 130b. One third groove 132 of the third iron core 130a is referred to as third groove 132a, and the other third groove 132 of the third iron core 130b is referred to as third groove 132b. The second cooling groove 1321 of the third groove 132a is referred to as second cooling groove 1321a, and the second cooling groove 1321 of the third groove 132b is referred to as second cooling groove 1321b. One of two adjacent first grooves 112 is referred to as first groove 112a, and the other first groove 112 of two adjacent first grooves 112 is referred to as first groove 112b.

[0133] In this embodiment, the third iron core 130a and the third iron core 130b are distributed along the axial direction O of the motor 11 between the first iron core 110 and the second iron core 120. The first groove 112a is used to form a winding slot 102a with the third groove 132a, and the first groove 112b is used to form a winding slot 102b with the third groove 132b. The winding slots 102a and 102b are arranged adjacent to each other.

[0134] In this embodiment, both a radial groove wall of the third groove 132a and a radial groove wall of the third groove 132b include a second cooling groove 1321. Taking the second cooling groove 1321a of the third groove 132a as an example: the second cooling groove 1321a is recessed along the radial direction R of the motor 11 away from the wire 210 in the winding groove 102a, and both ends of the second cooling groove 1321a extend along the circumferential direction C of the motor 11 away from the wire 210, so that the circumferential length of the second cooling groove 1321a is greater than the circumferential length of the first groove 112a. The axial projection of the second cooling groove 1321a and the axial projection of the second cooling groove 1321b partially overlap, so that the second cooling groove 1321a and the second cooling groove 1321b are connected along the axial direction O of the motor 11. It can be understood that, in this embodiment, the projection of the second cooling groove 1321 refers to the projection of the area enclosed by the groove wall of the second cooling groove 1321.

[0135] In this embodiment, the second flow channel 121, besides connecting to the first flow channel 111 within the winding slot 102a, can also be shared by the first flow channels 111 of two adjacent winding slots 102. Specifically, as shown by the two bold dashed lines in FIG15, the cooling medium in the first groove 112a and the first groove 112b flows to the second cooling groove 1321a and the second cooling groove 1321b, respectively, wherein the cooling medium in the second cooling groove 1321b can continue to flow to the second cooling groove 1321a. In this case, by simply connecting one second flow channel 121 to the second cooling groove 1321a, two first flow channels 111 can share one second flow channel 121. This embodiment of the application is beneficial in reducing the number of second flow channels 121 in the stator 100 and can reduce the risk of the outlet of the second flow channel 121 being blocked by insulating varnish. It is understood that the bold dashed lines in FIG15 are only used to schematically show the movement trend of the cooling medium in different first flow channels 111 and do not mean that the cooling medium can only flow along the bold dashed lines.

[0136] In one embodiment, the third core 130a and the third core 130b have the same structure and both belong to the same type of stator core 101. The staggered arrangement of the third grooves 132a and 132b can be achieved by rotating and stacking the third cores 130a and 130b.

[0137] As shown in Figure 15, the cross-sectional shapes of the third groove 132a and the third groove 132b both exhibit a T-shaped structure. Please refer to Figures 16 to 18. Figure 16 is a partial schematic diagram of the third iron core 130 provided in an embodiment of this application; Figure 17 is a partial schematic diagram of the third iron core 130 provided in an embodiment of this application; and Figure 18 is a partial schematic diagram of the third iron core 130 provided in an embodiment of this application. Exemplarily, the cross-sections of the third groove 132a and the third groove 132b in this embodiment of the application can also be other shapes as shown in Figures 16 to 18. The cross-sections of the third groove 132a and the third groove 132b can also adopt different shapes, as long as the following conditions are met: the third groove 132a can transmit the cooling medium to one radial groove wall of the third groove 132a; the third groove 132b can transmit the cooling medium to one radial groove wall of the third groove 132b; and the second cooling groove 1321a of the third groove 132a is connected to the second cooling groove 1321b of the third groove 132b.

[0138] Please refer to Figure 15. In one embodiment, the third core 130a includes a fourth groove 133. Along the axial direction of the motor 11, one circumferential wall of the fourth groove 133 is aligned with the bottom of the first cooling groove 1121. Along the radial direction of the motor 11, the distance between one radial wall of the fourth groove 133 and the plurality of wires 210 is less than the distance between the second flow channel 121 and the plurality of wires 210. Along the axial direction of the motor 11, the fourth groove 133 is used to connect to the third groove 132b of the third core 130b.

[0139] In the embodiments of this application, for ease of description, the fourth groove 133 of the third iron core 130a is referred to as the fourth groove 133a.

[0140] In this embodiment, both the fourth groove 133a and the third groove 132a are distributed in the third iron core 130a. The cross-sectional area of ​​the fourth groove 133a is smaller than that of the third groove 132a, which allows control over the volume used for slotting in the third iron core 130a. This is beneficial for improving the mechanical strength of the stator 100 and reducing the negative impact on the electromagnetic performance of the stator 100. In this case, since the distance between one radial groove wall of the fourth groove 133a and the multiple wires 210 is smaller than the distance between the second flow channel 121 and the multiple wires 210, meaning that the fourth groove 133a cannot directly deliver the cooling medium to the second flow channel 121, the third iron core 130b can be used as a connecting structure between the fourth groove 133a and the second flow channel 121. Specifically, the fourth groove 133a is used to form a winding groove 102b with the first groove 112b and the third groove 132b. The fourth groove 133a is connected to the third groove 132b along the axial direction O of the motor 11, so that the cooling medium of the first groove 112b can flow through the fourth groove 133a and the third groove 132b in sequence and then flow into the second flow channel 121.

[0141] In one embodiment, the third iron core 130a includes a plurality of third grooves 132a and a plurality of fourth grooves 133a, which are arranged alternately along the circumferential direction C of the motor 11.

[0142] In one embodiment, the third core 130b includes a plurality of third grooves 132b and a plurality of fourth grooves 133b, which are arranged alternately along the circumferential direction C of the motor 11. Along the axial direction O of the motor 11, each third groove 132a of the third core 130a is opposite to one of the fourth grooves 133b of the third core 130b, and each fourth groove 133a of the third core 130a is opposite to one of the third grooves 132b of the third core 130b.

[0143] Please refer to Figures 12, 13, and 15. In one embodiment, the third core 130a includes a fourth flow channel 134, which is distributed along the radial direction R of the motor 11 between a radial groove wall of the fourth groove 133a and the outer peripheral surface of the third core 130a. Along the axial direction O of the motor 11, the fourth flow channel 134 connects to the second cooling groove 1321b of the third core 130b.

[0144] In this embodiment, since the radial distance between one radial wall of the fourth groove 133a and the wire 210 is less than the radial distance between the second flow channel 121 and the wire 210, there is space between one wall of the fourth groove 133a and the outer surface of the third iron core 130a that can be used to arrange the fourth flow channel 134. The fourth flow channel 134 can be used to receive the cooling medium.

[0145] In this embodiment, the fourth flow channel 134 is connected to the second cooling tank 1321b of the third iron core 130b, and the second cooling tank 1321b is connected to the second cooling tank 1321a, so that the cooling medium received by the fourth flow channel 134 can flow to the first groove 112b and the first groove 112a through the second cooling tank 1321b and the second cooling tank 1321a respectively, which facilitates the rational distribution of the cooling medium.

[0146] Please refer to Figures 12, 14, and 19, where Figure 19 is a schematic diagram of the third core 130 provided in an embodiment of this application. In one embodiment, the first core 110 further includes a fifth flow channel 113, which is distributed on the outer surface of the first core 110. The projection of the fourth flow channel 134 along the axial direction of the motor 11 partially overlaps with the projection of the fifth flow channel 113, and the fourth flow channel 134 is used to receive the cooling medium of the fifth flow channel 113. In this case, the fourth flow channel 134 may be spaced apart from the outer surface of the third core 130a.

[0147] Please refer to Figures 3 and 20, where Figure 20 is a schematic diagram of the motor 11 provided in an embodiment of this application. In one embodiment, the plurality of stator cores 101 further includes a third core 130c, which, along the axial direction of the motor 11, is distributed on both sides of the first core 110. The motor 11 also includes a motor housing 500 for accommodating the stator 100. The motor housing 500 includes a liquid inlet 510, and a fourth flow channel 134 of the third core 130c is used to receive the cooling medium delivered by the liquid inlet 510 and to deliver the cooling medium to the first flow channel 111. In this case, the fourth flow channel 134 needs to communicate with the outer surface of the third core 130a.

[0148] Please refer to Figure 21, which is a schematic diagram of the motor 11 provided in an embodiment of this application. In one embodiment, a plurality of stator cores 101 include two core groups 103, a third core 130c, and a third core 130d. Each core group 103 includes a first core 110, a third core 130a, a third core 130b, and a second core 120. The third cores 130c and 130d are distributed between the two core groups 103. The two core groups 103 are axially symmetrical about the third cores 130c and 130d. The third flow channel 131 of the third core 130c is used to transport the received cooling medium to the first flow channel 111 of one of the core groups 103, and the third flow channel 131 of the third core 130d is used to transport the received cooling medium to the first flow channel 111 of the other core group 103. The second flow channel 121 of the two core assemblies 103 is used to deliver the cooling medium to both ends of the multiple conductors 210 respectively.

[0149] In this embodiment, the cooperation of two core groups 103 and third cores 130c and 130d can reduce the risk of insulating varnish overflowing to the two end faces of the stator 100 and clogging the flow channels, and keep the flow of the cooling medium unobstructed, which helps to improve the working efficiency of the motor 11 and extend the service life of the motor 11.

[0150] Please refer to Figure 22, which is a schematic diagram of the motor 11 provided in an embodiment of this application. In one embodiment, a plurality of stator cores 101 include two core groups 103, which are arranged adjacent to each other along the axial direction O of the motor 11. The motor housing includes two liquid inlets, each for supplying cooling medium to a fourth flow channel 134 of at least one of the third cores 130a or 130b of one core group 103. Each liquid inlet is opposite to at least one of the third cores 130a or 130b of one core group 103 along the radial direction R of the motor 11. In this case, two adjacent first cores 110 in the two core groups 103 can be regarded as one first core 110.

[0151] In this embodiment, the two liquid inlets can increase the input of cooling medium. Since the third core 130 has a larger slot volume than the first core 110 and the second core 120, this embodiment omits the third core 130c and the third core 130d between the two core groups 103, which is beneficial to improving the overall structural strength and electromagnetic performance of the stator 100.

[0152] In one embodiment, each core group 103 may contain only one third core 130, that is, each core group 103 includes a first core 110, a third core 130a and a second core 120, or each core group 103 includes a first core 110, a third core 130b and a second core 120, as long as it is ensured that the cooling medium in each first flow channel 111 can flow out from the end face of the stator 100.

[0153] Please refer to Figures 23 and 24. Figure 23 is a schematic diagram of the first iron core 110 and the third iron core 130 provided in the embodiment of this application, and Figure 24 is a schematic diagram of the second iron core 120 and the third iron core 130 provided in the embodiment of this application.

[0154] In one embodiment, the first flow channel 111 may also be distributed between the winding slots 102a and 102b, with the winding slots 102a, the first flow channel 111, and the winding slots 102b arranged sequentially and at intervals along the circumferential direction C of the motor 11. The third core 130 includes a third cooling groove 135, which penetrates the third core 130 along the axial direction O of the motor 11. The third cooling groove 135 is recessed toward the inner circumferential surface of the stator 100 along the radial direction R of the motor 11, and the bottom of the third cooling groove 135 is distributed between the winding slots 102a and 102b. The projection of the third cooling groove 135 along the axial direction O of the motor 11 at least partially overlaps with the projection of the first flow channel 111 and the projection of the second flow channel 121.

[0155] In this embodiment, the first flow channel 111 is distributed between the winding slots 102a and 102b, so that the cooling medium of the first flow channel 111 can cool the wires in both the winding slots 102a and 102b, thus improving cooling efficiency. Since the first flow channel 111 is spaced from the winding slot 102a, the third core 130 can connect to the first flow channel 111 without the aid of the third groove 132. Therefore, the cross-sectional areas of the first groove, second groove, and third groove can be equal, which helps reduce processing difficulty and cost. The third cooling groove 135 of the third core 130 is used to form the third flow channel 131. The bottom of the third cooling groove 135 and the first flow channel 111 are both distributed between the winding slots 102a and 102b. The axial projection of the third cooling groove 135 at least partially overlaps with the axial projection of the first flow channel 111 and the axial projection of the second flow channel 121, facilitating the connection of the third flow channel 131 to the first flow channel 111 and the second flow channel 121.

[0156] Please refer to Figures 23 and 24. In one embodiment, the minimum width of the third cooling groove 135 along the circumferential direction C of the motor 11 is greater than or equal to the inner diameter of the first flow channel 111 and the inner diameter of the second flow channel 121. This embodiment allows the axial projection of the third cooling groove 135 to cover the axial projections of the first flow channel 111 and the second flow channel 121, which helps to increase the volume of cooling medium that the third cooling groove 135 can transport and reduce the flow resistance of the cooling medium between the first flow channel 111 and the third flow channel 131, and between the second flow channel 121 and the third flow channel 131.

[0157] In one embodiment, the second groove 124a and the second groove 124b of the second core 120 are used to form winding slots 102a and 102b, respectively. The portion between two adjacent circumferential groove walls of the second groove 124a and the second groove 124b is used to cover the first flow channel 111. This embodiment effectively avoids the insulating varnish of the second groove 124a and the second groove 124b from clogging the flow channel by controlling the second core 120 to have no flow channel for the cooling medium of the first flow channel 111 to flow directly along the axial direction O of the motor 11 from between the second groove 124a and the second groove 124b.

[0158] Please refer to Figure 25, which is a schematic diagram of the third iron core 130 provided in an embodiment of this application. In one embodiment, when the fifth flow channel of the first iron core is used to transport the cooling medium conveyed by the motor housing to the third cooling tank 135, the third cooling tank 135 may be spaced apart from the outer surface of the third iron core 130.

[0159] It is understandable that the third iron core 130 shown in Figures 23 to 25 can also be applied to the structures shown in Figures 9, 10, 20, 21 and 22.

[0160] The foregoing has provided a detailed description of the motor, powertrain, and electric vehicle provided in the embodiments of this application. Specific examples have been used to illustrate the principles and embodiments of this application. The descriptions of the embodiments above are merely for the purpose of helping to understand the methods and core ideas of this application. Furthermore, those skilled in the art will recognize that, based on the ideas of this application, there will be changes in specific embodiments and application scope. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. An electric motor, characterized in that, The stator of the motor includes multiple stator cores, and multiple winding slots of the stator extend through the multiple stator cores along the axial direction of the motor. Each winding slot is used to accommodate multiple wires. The multiple stator cores include a first core and a second core, wherein: One end of each of the plurality of conductors is exposed on one end face of the second iron core. A first flow channel of the first iron core passes through the first iron core. Along the axial direction of the motor, the outlet of the first flow channel is covered by the one end face of the second iron core. The outlet of the second flow channel passes through the one end face of the second iron core. The second flow channel is used to connect the outlet of the first flow channel with the one end face of the second iron core. The outlet of the second flow channel is distributed on the outer periphery of one of the winding slots. Along the radial direction of the motor, the distance between the outlet of the second flow channel and the winding slot is greater than the distance between the first flow channel and the winding slot.

2. The motor according to claim 1, characterized in that, A radial slot wall of one winding slot is away from the inner circumferential surface of the stator along the radial direction of the motor, and at least a portion of the first flow channel and the outlet of the second flow channel are distributed on both sides of the radial slot wall of the one winding slot along the radial direction of the motor.

3. The motor according to claim 2, characterized in that, The distance between the outlet of the second flow channel along the radial direction of the motor and the radial wall of the winding slot is greater than the distance between the first flow channel and the radial wall of the winding slot.

4. The motor according to any one of claims 1-3, characterized in that, Along the axial direction of the motor, the length of the first iron core is greater than the length of the second iron core, and the length of the first flow channel is greater than the length of the second flow channel.

5. The motor according to any one of claims 1-4, characterized in that, The inlet of the second flow channel penetrates through the other end face of the second iron core. Along the axial direction of the motor, the other end face of the second iron core is arranged adjacent to the first iron core. The inlet of the second flow channel is used to connect to the outlet of the first flow channel, and the opening direction of the inlet of the second flow channel faces the outlet of the first flow channel.

6. The motor according to any one of claims 1-4, characterized in that, The opening direction of the outlet of the second flow channel faces one end of the plurality of wires, and the inlet of the second flow channel is spaced apart from the outlet of the first flow channel along the radial direction of the motor, wherein: The plurality of stator cores also includes a third core, which is distributed between the first core and the second core. A third flow channel of the third core passes through the third core and is used to connect the first flow channel and the second flow channel. Along the radial direction of the motor, the third flow channel extends from the outlet of the first flow channel toward the inlet of the second flow channel.

7. The motor according to claim 6, characterized in that, The first groove of the first iron core, the second groove of the second iron core, and the third groove of the third iron core are used to form the winding slot. A circumferential groove wall of the first groove includes a first cooling groove. The first cooling groove is recessed away from the plurality of wires along the circumference of the motor. The gap between the first cooling groove and the plurality of wires is used to form the first flow channel. The first flow channel extends along the axial direction of the motor. The cross-sectional area of ​​the third groove is larger than the cross-sectional area of ​​the first groove. The gap between the third groove and the plurality of wires is used to form the third flow channel.

8. The motor according to claim 7, characterized in that, Along the axial direction of the motor, one circumferential groove wall of the third groove is aligned with the bottom of the first cooling groove.

9. The motor according to claim 7, characterized in that, The cross-sectional area of ​​the second groove is smaller than that of the first groove, and one circumferential wall of the second groove along the axial direction of the motor is aligned with the opening of the first cooling groove.

10. The motor according to any one of claims 7-9, characterized in that, The distance between a radial wall of the third groove along the radial direction of the motor and the plurality of wires is greater than or equal to the distance between the second flow channel and the plurality of wires.

11. The motor according to claim 10, characterized in that, The plurality of stator cores includes two third cores. One third groove of one third core and another third groove of the other third core are respectively used to connect two adjacent first grooves in the first core. The radial groove wall of each of the first and second third grooves includes a second cooling groove. Each second cooling groove is recessed away from the plurality of conductors along the radial direction of the motor. The length of each second cooling groove is greater than the length of each first groove along the circumferential direction of the motor. The projection of the second cooling groove of one third groove partially overlaps with the projection of the second cooling groove of the other third groove along the axial direction of the motor.

12. The motor according to claim 11, characterized in that, The third iron core includes a fourth groove, with one circumferential groove wall of the fourth groove aligned with the bottom of the first cooling groove along the axial direction of the motor, and the distance between one radial groove wall of the fourth groove and the plurality of wires along the radial direction of the motor is less than the distance between the second flow channel and the plurality of wires. The fourth groove along the axial direction of the motor is used to connect to the other third groove of the other third iron core.

13. The motor according to claim 12, characterized in that, The third iron core includes a fourth flow channel, which is distributed radially between the radial groove wall of the fourth groove and the outer peripheral surface of the third iron core. The fourth flow channel is used to connect the second cooling groove of the other third iron core along the axial direction of the motor.

14. A powertrain, characterized in that, The powertrain includes a motor controller, a reducer, and a motor as described in any one of claims 1-13, wherein the motor controller is used to provide electrical power to the motor, and the motor is used to drive the reducer.

15. An electric vehicle, characterized in that, The electric vehicle includes a power battery and a powertrain as described in claim 14, the powertrain being used to receive power from the power battery and to drive the wheels of the electric vehicle.

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