Drive electric motor, powertrain and electric vehicle

Abstract

A drive electric motor, a powertrain and an electric vehicle. The drive electric motor comprises an electric motor stator and an electric motor rotor. A stator core of the electric motor stator comprises a central hole and winding slots, wherein the central hole accommodates the electric motor rotor; the winding slots are spaced apart from each other in the circumferential direction of the drive electric motor, and the winding slots penetrate two end faces of the stator core in the axial direction of the drive electric motor; the winding slots are used for cooling winding wires accommodated in said winding slots. At least one of the two end faces of the stator core comprises at least one recess, wherein the recess is filled with an injection-molded part; the injection-molded part comprises at least one axial through-hole. The winding wires pass through the axial through-hole, and the wall of the axial through-hole surrounds a plurality of winding wires. The circumferential width of the axial through-hole is less than that of the winding slots, or the radial length of the axial through-hole is less than that of the winding slots. End-face injection molding is used to fix one end of the winding wires and seal the ends of the winding slots, so that there is a smaller gap between the winding wires and the winding slots without being filled with any injection-molded part, enabling direct cooling of the winding wires by coolant in the gap, and thereby improving heat dissipation efficiency.

Description

A drive motor, powertrain, and electric vehicle

[0001] This application claims priority to Chinese Patent Application No. 202423169784.9, filed on December 19, 2024, entitled "A Drive 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 a drive motor, powertrain, and electric vehicle. Background Technology

[0003] With the continuous advancement of the new energy vehicle industry, powertrain systems are gradually moving towards a higher degree of integration, leading to an increase in the power density of drive motors and thus placing higher demands on their heat dissipation efficiency. During motor operation, stator core heat loss is a significant heat source. Cooling the stator core with oil or water can reduce the temperature of the winding conductors, thereby reducing heat loss and improving motor efficiency. A common solution is indirect cooling of the winding conductors, which suffers from insufficient contact between the conductors and the coolant, resulting in poor cooling performance. Summary of the Invention

[0004] This application provides a drive motor, which includes a motor stator and a motor rotor. The stator core of the motor stator includes a central hole and a plurality of winding slots. The central hole is used to accommodate the motor rotor. The plurality of winding slots are distributed circumferentially along the drive motor. Each winding slot extends through both end faces of the stator core along the axial direction of the drive motor. Each winding slot is used to receive coolant to directly cool the plurality of winding wires accommodated in each winding slot. At least one of the two end faces of the stator core includes at least one groove. Each groove is used to fill an injection molded part. Each injection molded part includes at least one axial through hole, wherein: the plurality of winding wires accommodated in each winding slot pass through an axial through hole. The hole wall of each axial through hole is used to surround the plurality of winding wires accommodated in a winding slot. The circumferential width of each axial through hole is less than the circumferential width of each winding slot, or the radial length of each axial through hole is less than the radial length of each winding slot.

[0005] The drive motor uses end face injection molding to fix one end of the winding wire and seal the end of the winding slot. There is no filling injection molding part between the winding wire and the winding slot for fixation. There is a smaller gap between the winding wire and the winding slot. The coolant can directly cool the winding wire in this gap, which improves the heat exchange efficiency between the coolant and the winding wire and improves the heat dissipation efficiency of the winding wire.

[0006] In one possible implementation, each groove on each end face of the stator core is used to fill an injection molded part, the slot opening of each winding slot is radially oriented towards and connected to the central hole of the stator core, and the slot opening of each winding slot is used to fill an injection molded strip, wherein: the two ends of each injection molded strip are distributed along the axial direction of the drive motor, and the two ends of each injection molded strip are used to fix the injection molded parts on the two end faces respectively.

[0007] The injection-molded strip penetrates multiple layers of the stator core and is fixedly connected to the injection-molded parts on both end faces, enhancing the overall stability of the drive motor structure and ensuring its reliability and durability during long-term operation. The injection-molded strip effectively separates the motor rotor housed in the center hole from the winding wires housed in the winding slots, preventing direct contact and potential electrical short circuits. Furthermore, the tight fit between the injection-molded strip and the end-face injection-molded parts creates a closed coolant passage within the winding slots. This closed passage ensures coolant circulation within the winding slots, effectively carrying away heat generated by the winding wires and improving the drive motor's heat dissipation performance. Simultaneously, the coolant passage does not contact the motor rotor, avoiding interference and influence on the rotor's movement caused by the coolant.

[0008] In one possible implementation, each injection molded part is used to protrude from the groove along the axial direction of the stator core and form an injection disc. The injection disc includes an annular groove with its opening facing away from the axial through hole. The axial through hole is used to penetrate the bottom wall of the annular groove along the axial direction of the stator core. The annular groove includes a first annular groove wall and a second annular groove wall. The first annular groove wall surrounds the second annular groove wall. The portions of multiple winding wires in each winding slot that pass through the axial through hole are arranged between the first annular groove wall and the second annular groove wall.

[0009] The first and second annular groove walls act as injection molding steps, extending the creepage distance and thus further reducing the height of the motor stator end. The stepped design, by creating different height levels on the surface of the insulating material, increases the distance the charge travels on the insulating surface, thereby reducing the risk of arcing. By incorporating the first annular groove wall, it is possible to reduce the height of the motor stator end while maintaining a sufficient creepage distance, resulting in a more compact and efficient drive motor.

[0010] In one possible implementation, an annular groove is used to enclose an injection-molded ring to form an annular liquid-cooled cavity. This annular liquid-cooled cavity accommodates the portions of multiple winding wires contained in each winding slot that pass through an axial through-hole. Coolant can be added to the annular liquid-cooled cavity to immerse and cool the ends of the winding wires. Immersion cooling has higher heat dissipation efficiency, as it more effectively transfers heat from the winding wires to the coolant, which then carries the heat away through coolant circulation.

[0011] In one possible implementation, an annular liquid cooling cavity is used to connect to multiple winding slots through multiple axial through holes. The coolant in the annular liquid cooling cavity can immerse and cool the ends of the winding wires, and can also directly cool the winding wires in the winding slots through the axial through holes.

[0012] In one possible implementation, the outer circumferential surface of an injection-molded ring includes multiple oil holes, each connecting the inner and outer sides of an annular liquid-cooled cavity. Coolant enters the stator core through these oil holes and directly cools the winding conductors in the winding slots. This direct contact between the coolant and the winding conductors significantly improves heat dissipation efficiency. This cooling method rapidly absorbs and removes the heat generated by the winding conductors, effectively reducing their operating temperature and thus enhancing the overall thermal efficiency of the drive motor.

[0013] In one possible implementation, along the axial direction of the drive motor, the lengths of a first annular groove wall and a second annular groove wall are less than the lengths of the portions of the winding slots through which multiple wires pass. The length of the first annular groove wall is less than the length of the second annular groove wall. Each first annular groove wall includes multiple oil holes, each connecting both sides of the first annular groove wall radially along the drive motor. The winding wires have a certain axial length within the annular liquid cooling cavity, increasing the volume ratio of the winding wires within the cavity. The annular liquid cooling cavity forms a suitable axial length to accommodate the winding wires. The shorter length of the first annular groove wall allows the injection ring to form a receiving groove capable of accommodating the outer surface of the first annular groove wall. This results in a larger connection area between the injection ring and the first annular groove wall, facilitating more stable fixing of the injection ring by the injection disc and contributing to the stability of the drive motor during operation.

[0014] In one possible implementation, each winding slot accommodates multiple winding wires that are multiple flat wires, and the multiple flat wires in each winding slot are arranged radially along the drive motor, wherein: the wall of each axial through hole is used to fix at least one of the multiple flat wires in each winding slot along the circumferential or radial direction of the drive motor.

[0015] The flat wire structure of flat conductors significantly increases the contact area between conductors, thereby increasing the heat dissipation area and facilitating rapid heat dissipation. Compared to traditional round conductors, flat conductors have a higher slot fill factor. A higher slot fill factor means that more conductor can be filled within the same winding slot space, allowing for the carrying of larger currents. Simultaneously, the higher slot fill factor allows for a larger cross-sectional area of ​​the winding conductors, correspondingly reducing the DC resistance of the winding conductors, minimizing unnecessary copper losses, and improving the utilization efficiency of the copper wire, indirectly contributing to heat dissipation. The flat wire winding design makes the winding structure more compact, reducing the gaps between windings, thus improving heat conduction efficiency.

[0016] In one possible implementation, the length of each axial through-hole along the radial direction of the drive motor is greater than or equal to the thickness of multiple flat wires stacked sequentially. Sufficient length of the axial through-hole to accommodate multiple flat wires stacked sequentially significantly increases the fill rate of the flat wire winding, thereby increasing the motor's power output. When the axial through-hole length is sufficient, adequate heat dissipation channels are ensured between the multiple flat wires; the stacked flat wires can form tiny gaps that act as heat dissipation channels, aiding in heat dissipation. The length of the axial through-hole being greater than or equal to the thickness of the multiple flat wires stacked sequentially helps ensure the stability of the flat wire winding during motor operation. The stacked flat wires form a more robust structure, reducing loosening or damage caused by vibration and impact. The design of the axial through-holes also considers ease of manufacturing and maintenance. When the axial through-hole length is sufficient, it is easier to place multiple flat wires stacked sequentially into the slot, simplifying the winding process. During maintenance, if winding replacement or repair is required, the wires can be more easily removed and installed.

[0017] In one possible implementation, along the circumference of the drive motor, the width of each axial through-hole is greater than or equal to the width of each flat wire. When the width of the axial through-hole is sufficient to accommodate the width of the flat wire, it ensures that the flat wires are tightly packed within the axial through-hole, thereby increasing the slot fill factor. This allows more wires to be filled in the same space, thus increasing the motor's power output. When the width of the axial through-hole is greater than or equal to the width of the flat wire, a gap exists between the axial through-hole and the flat wire, which facilitates direct cooling of the flat wire by the coolant, increasing heat dissipation efficiency.

[0018] In one possible implementation, the multiple winding conductors accommodated in each winding slot are separated from the slot walls by insulating paper, and the wall of each axial through hole surrounds the insulating paper in each winding slot. The main function of the insulating paper in the stator core is isolation and protection. It covers the winding conductors, ensuring good isolation between the winding conductors and the stator core, preventing short circuits between the winding conductors and the stator core. The insulating paper also prevents short circuits between multiple sets of winding conductors, ensuring normal motor operation.

[0019] In one possible implementation, each injection molded part includes an annular groove wall surrounding an axial through hole. The annular groove wall of each injection molded part is used to enclose a cover plate to form a liquid cooling cavity. Each liquid cooling cavity is used to accommodate portions of multiple wires in each winding slot that pass through the axial through hole. Each liquid cooling cavity includes an oil hole for communicating between the inner and outer sides of the liquid cooling cavity.

[0020] The liquid cooling chamber immerses and cools the ends of the winding conductors. Immersion cooling quickly reduces the heat at the ends of the winding conductors, improving the heat dissipation efficiency of the drive motor. Coolant enters the liquid cooling chamber through an oil hole at one end of the stator core to immerse and cool the ends of the winding conductors. It then passes through axial through-holes to cool the winding conductors in the winding slots, and finally flows out through an oil hole at the other end of the stator core. Alternatively, coolant enters the winding slots through an internal flow channel from the oil holes of the stator laminations, directly cooling the winding conductors in the slots. It then diffuses axially from the winding slots along the stator core towards the liquid cooling chambers at both ends of the stator core, immersing and cooling the ends of the winding conductors within the liquid cooling chambers, before flowing out through oil holes at both ends of the stator core.

[0021] In one possible implementation, the drive motor housing is used to fix and house the drive motor stator. The inner circumferential surface of the drive motor housing includes an oil outlet. The gap between the outer circumferential surface of the motor stator and the drive motor housing is used to receive coolant output from the oil outlet and to deliver coolant to each winding slot through the internal flow channels of the motor stator. The housing has an oil outlet, through which coolant can enter the motor stator and flow to the winding slots through the internal flow channels, thereby dissipating heat from the winding wires and ensuring that the drive motor does not experience performance degradation or shortened lifespan due to overheating under high load operation.

[0022] This application also provides a powertrain including a reducer and a drive motor, the drive motor being used to drive an electric vehicle via the reducer. The powertrain also includes a motor controller. The motor controller is used to receive power from a power battery, convert direct current into alternating current and transmit it to the drive motor, which in turn converts electrical energy into mechanical energy, thereby driving the wheels to rotate via the reducer.

[0023] This application also provides an electric vehicle, which includes multiple wheels and a powertrain for driving the multiple wheels. A drive motor receives electrical energy from a power battery and converts it into mechanical energy, rotating the motor shaft and, through a reducer, driving the multiple wheels to rotate, thereby propelling the electric vehicle. Attached Figure Description

[0024] Figure 1 is a schematic diagram of an electric vehicle provided in an embodiment of this application;

[0025] Figure 2 is another schematic diagram of the electric vehicle provided in an embodiment of this application;

[0026] Figure 3 is a schematic diagram of a powertrain provided in an embodiment of this application;

[0027] Figure 4 is a schematic diagram of a drive motor provided in an embodiment of this application;

[0028] Figure 5 is a schematic diagram of a motor stator provided in an embodiment of this application;

[0029] Figure 6 is a schematic diagram of a stator core provided in an embodiment of this application;

[0030] Figure 7 is a schematic diagram of the assembly of the stator core and injection molded parts provided in an embodiment of this application;

[0031] Figure 8 is an exploded view of Figure 7;

[0032] Figure 9 is an assembly diagram of the stator core, injection molded part and winding conductor provided in the embodiment of this application;

[0033] Figure 10 is a schematic diagram of a motor stator provided in an embodiment of this application;

[0034] Figure 11 is a cross-sectional view of section AA in Figure 10;

[0035] Figure 12 is an enlarged view of section I in Figure 11;

[0036] Figure 13 is a cross-sectional view of section BB in Figure 10;

[0037] Figure 14 is an enlarged view of section II in Figure 13;

[0038] Figure 15 is a schematic diagram of injection molding at both ends of a motor stator provided in an embodiment of this application;

[0039] Figure 16 is a schematic diagram of the assembly of a stator core and an injection molded disc according to an embodiment of this application;

[0040] Figure 17 is an exploded view of Figure 16;

[0041] Figure 18 is a schematic diagram of an injection molding disc provided in an embodiment of this application;

[0042] Figure 19 is a schematic diagram of a motor stator provided in an embodiment of this application;

[0043] Figure 20 is a cross-sectional view at CC in Figure 19;

[0044] Figure 21 is an assembly diagram of the injection disc and injection ring provided in an embodiment of this application;

[0045] Figure 22 is a cross-sectional schematic diagram of the stator oil passage of an electric motor provided in an embodiment of this application;

[0046] Figure 23 is a schematic diagram of a motor stator provided in an embodiment of this application;

[0047] Figure 24 is an exploded view of Figure 23. Detailed Implementation

[0048] The technical solutions in 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.

[0049] Motors experience frequent changes in operating conditions and generate significant heat during operation, leading to elevated motor temperatures and impacting their lifespan and safety. Improving motor heat dissipation efficiency is currently a key issue in motor development. Currently, coolant is commonly used to exchange heat with the winding conductors and stator core to reduce motor temperature and improve cooling efficiency. However, due to the presence of insulating components such as plastic injection molding between the winding conductors and the coolant, indirect contact cooling occurs between the coolant and the winding conductors, resulting in low heat exchange efficiency and ineffective cooling.

[0050] To address the aforementioned issues, this application provides a drive motor with direct cooling within the winding slots. The drive motor includes a stator and a rotor. The stator core of the stator includes a central hole and multiple winding slots. The central hole accommodates the rotor. The multiple winding slots are spaced apart circumferentially along the drive motor. Each winding slot extends through both end faces of the stator core along the axial direction of the drive motor. Each winding slot receives coolant to directly cool the multiple winding wires contained in the slot. At least one end face of the stator core includes at least one groove. Each groove is used to fill an injection molded part. Each injection molded part includes at least one axial through hole. The multiple winding wires contained in each winding slot pass through the axial through hole. The wall of each axial through hole surrounds the multiple winding wires contained in a winding slot. The circumferential width of each axial through hole is less than the circumferential width of each winding slot, or the radial length of each axial through hole is less than the radial length of each winding slot. The drive motor provided in this application uses end-face injection molding to fix one end of the winding wire and seal the end of the winding slot. There is a smaller gap between the winding wire and the slot wall of the winding slot, and the coolant can directly cool the winding wire more efficiently within this gap, thereby improving the cooling effect.

[0051] This application provides an electric vehicle. Please refer to Figure 1, which is a schematic diagram of an electric vehicle provided in this application embodiment. In this application embodiment, the electric vehicle 2 includes a powertrain 3 and a plurality of wheels 4, the powertrain 3 being used to drive the plurality of wheels 4.

[0052] In one embodiment, the powertrain 3 is used to drive the two front wheels 41 of the electric vehicle 2, or to drive the two rear wheels 42 of the electric vehicle 2. In another embodiment, there are two powertrains 3, one powertrain 3 for driving the two front wheels 41 of the electric vehicle 2 and the other powertrain 3 for driving the two rear wheels 42 of the electric vehicle 2.

[0053] In this embodiment of the application, the electric vehicle 2 includes two-wheeled, three-wheeled, or four-wheeled vehicles. In this embodiment of the application, the electric vehicle 2 includes pure electric vehicles (BEV, Battery Electric Vehicle), hybrid electric vehicles (HEV, Hybrid Electric Vehicle), and range-extended battery vehicles (REEV, Range Extended Electric Vehicle).

[0054] In one embodiment, the electric vehicle 2 further includes a power battery 5, and the powertrain 3 receives electrical energy from the power battery 5 and converts the electrical energy into mechanical energy to drive multiple wheels 4 to rotate, thereby driving the electric vehicle 2 to move.

[0055] This application provides a powertrain. Please refer to Figures 2 and 3. Figure 2 is another schematic diagram of an electric vehicle provided in this application embodiment, and Figure 3 is a schematic diagram of a powertrain provided in this application embodiment. The powertrain 3 includes a drive motor 1 and a reducer 6. The drive motor 1 drives the electric vehicle 2 through the reducer 6. The drive motor 1 receives electrical energy from the power battery 5 and converts it into mechanical energy. The motor shaft 30 of the drive motor 1 rotates, driving multiple wheels 4 to rotate through the reducer 6, thereby propelling the electric vehicle 2.

[0056] In this embodiment, the powertrain 3 further includes a motor controller 7. The motor controller 7 is used to receive power from the power battery 5, convert direct current into alternating current and transmit it to the drive motor 1, and the drive motor 1 converts electrical energy into mechanical energy, thereby driving the wheel 4 to rotate via the reducer 6.

[0057] In this embodiment, the housing of the powertrain 3 includes a motor slot, the inner diameter of which is equal to the outer diameter of the drive motor 1. The drive motor 1 is installed inside the motor slot. The power battery 5 is electrically connected to the drive motor 1 inside the motor slot to rotate the motor shaft 30 of the drive motor 1. In one embodiment, the reducer 6 includes a single-speed reducer, a two-speed reducer, or a gearbox. In one embodiment, as shown in FIG3, the reducer 6 includes an input shaft 61, an intermediate shaft 62, and an output shaft 63. The motor shaft 30 of the drive motor 1 extends out of the motor slot and is connected to the input shaft 61 of the reducer 6 outside the motor slot, driving the input shaft 61 to rotate. The input shaft 61 is used to drive the drive motor 1 and the intermediate shaft 62, the intermediate shaft 62 is used to drive the output shaft 63, and the output shaft 63 is used to drive the wheels 4. In one embodiment, the reducer 6 drives two wheels 4 respectively through two half-shafts 43.

[0058] This application provides a drive motor. Please refer to Figures 4, 5, and 6. Figure 4 is a schematic diagram of a drive motor provided in this application embodiment, Figure 5 is a schematic diagram of a motor stator provided in this application embodiment, and Figure 6 is a schematic diagram of a stator core provided in this application embodiment. In one embodiment, the drive motor 1 includes a motor stator 10 and a motor rotor 20. The motor stator 10 includes a stator core 110, which is annular in shape. The stator core 110 includes a central hole 111 for the motor rotor 20 to pass through. The central axis of the motor rotor 20 coincides with the center line of the central hole 111, and the motor rotor 20 rotates relative to the motor stator 10 within the central hole 111.

[0059] The stator core 110 includes multiple winding slots 112, which are spaced apart circumferentially along the drive motor 1. Each winding slot 112 extends through both end faces of the stator core 110 along the axial direction of the drive motor 1. Each winding slot 112 receives coolant to directly cool the multiple winding wires 120 contained within it. The winding slot 112 also allows coolant to flow through to cool the winding wires 120, and supports and fixes them. The winding wires 120 are embedded within the stator core 110 to ensure that current can flow smoothly through them and generate a stable magnetic field. In one embodiment, as shown in FIG4, the two ends of the winding wires 120 are intertwined. By intertwining, a specific magnetic field structure can be formed, thereby realizing the conversion and transmission of electromagnetic energy. This application only shows the end winding structure of the winding in Figure 4. In this application, Figures 5 and 9 only illustrate the positional relationship and connection structure of the winding wire 120 and the injection molded part 115, and do not show the connection of multiple sets of winding wires 120 at the end.

[0060] In this embodiment, the stator core 110 is formed by stacking and fixing multiple layers of stator laminations 113. Each stator lamination 113 is annular, and the outer diameter and inner diameter of two adjacent layers of stator laminations 113 are equal. The multiple layers of stator laminations 113 are stacked to form an annular stator core 110 with a central hole 111. The motor stator 10 is fixed inside the housing of the power assembly 3. The motor rotor 20 passes through the central hole 111 of the stator core 110. Each winding slot 112 of the stator core 110 passes through multiple winding wires 120. The winding wires 120 exit from both ends of the stator core 110. The winding wires 120 receive electrical energy from the power battery and generate a magnetic field. The magnetic field generates magnetic force on the motor rotor 20, causing the motor rotor 20 to rotate. The motor rotor 20 drives the motor shaft to rotate.

[0061] In this embodiment, the multiple winding slots 112 are distributed at intervals along the circumference of the drive motor 1, which ensures that the winding wires 120 can be embedded therein in a specific arrangement, helping to form a uniform magnetic field distribution and improve the efficiency and performance of the motor. In one embodiment, the multiple winding slots 112 are distributed at equal intervals along the circumference of the drive motor 1, and the multiple winding slots 112 are evenly arranged on the stator core 110, which helps to increase thermal uniformity, improve heat dissipation efficiency, ensure that the motor can operate stably for a long time, and improve the life and performance of the motor.

[0062] Please refer to Figures 7 and 8. Figure 7 is a schematic diagram of the stator core and injection molded part assembly provided in an embodiment of this application, and Figure 8 is an exploded view of Figure 7. In one embodiment, at least one of the two end faces of the stator core 110 includes at least one groove 114. Each groove 114 is used to fill an injection molded part 115, and each injection molded part 115 includes at least one axial through hole 1151. In one embodiment, the opening of the groove 114 is located on one of the end faces of the stator core 110. Each winding slot 112 penetrates the bottom wall of the groove 114 at least one end along the axial direction of the stator core 110, and the winding slot 112 and the slot cavity of the groove 114 are connected. The length of the groove 114 in both the radial and circumferential directions along the stator core is greater than the length of the winding slot 112 in both directions.

[0063] In this embodiment, please refer to Figure 9, which is a schematic diagram of the assembly of the stator core, injection molded part, and winding wire provided in this embodiment. A groove 114 is used to accommodate an injection molded part 115. The lengths of the groove 114 in both radial and circumferential directions along the stator core are the same as the lengths of the injection molded part 115 in both directions. The injection molded part 115 is fixed in the groove 114. In one embodiment, an axial through hole 1151 of the injection molded part 115 extends through the injection molded part 115 along the axial direction of the stator core 110. Each axial through hole 1151 and at least one winding slot 112 are connected along the axial direction of the stator core 110. The winding wire 120 is accommodated in the winding slot 112 and the axial through hole 1151 and exits from one end of the axial through hole 1151 away from the winding slot 112. The portions of the winding wires 120 accommodated in different winding slots 112 that exit at both ends of the stator core 110 are connected to form the entire winding of the drive motor 1.

[0064] In this embodiment, the wall of each axial through hole 1151 surrounds multiple winding wires 120 accommodated in a winding slot 112. The injection molded part 115 fixes and supports the winding wires 120 on the end face of the stator core 110, preventing displacement or deformation of the winding wires 120 during motor operation, thus helping to maintain the performance and stability of the motor. In one embodiment, the injection molded part 115 can be made of nylon, polyester, polycarbonate, or other special engineering plastics. The injection molded part 115 separates the winding wires 120 from the sidewalls of the groove 114, insulating and separating the winding wires 120 from the stator core 110.

[0065] Please refer to Figures 10, 11, 12, 13, and 14. Figure 10 is a schematic diagram of a motor stator provided in an embodiment of this application. Figure 11 is a cross-sectional view of section AA in Figure 10. Figure 12 is an enlarged view of section I in Figure 11. Figure 13 is a cross-sectional view of section BB in Figure 10. Figure 14 is an enlarged view of section II in Figure 13. In this embodiment of the application, the circumferential width of each axial through hole 1151 is less than the circumferential width of each winding slot 112, or the radial length of each axial through hole 1151 is less than the radial length of each winding slot 112.

[0066] In this embodiment, the radial length d2 of each axial through hole 1151 is less than the radial length d4 of each winding slot 112. The radial winding conductor 120 of the stator core 110 is fixed in the axial through hole 1151, and there is a gap 1121 between the winding conductor 120 and the sidewall of the winding slot 112. Referring to FIG14, the gap 1121 is located on the radial outer side of the winding conductor 120, and the gap 1121 is used for the flow of coolant to directly cool the winding conductor 120. Alternatively, the circumferential width d1 of each axial through hole 1151 is smaller than the circumferential width d3 of each winding slot 112. The circumferential winding conductor 120 along the stator core 110 is fixed within the axial through hole 1151, and a gap 1121 is provided between the winding conductor 120 and the circumferential sidewall of the winding slot 112. The gap 1121 can be located on one circumferential side of the winding conductor 120, and the gap 1121 is used for the flow of coolant to directly cool the winding conductor 120. In one embodiment, the radial length d2 of each axial through hole 1151 is smaller than the radial length d4 of each winding slot 112, and the circumferential width d1 of each axial through hole 1151 is smaller than the circumferential width d3 of each winding slot 112. A gap 1121 is provided on both the radial and circumferential sides of the winding conductor 120. The drive motor 1 provided in this application embodiment uses end face injection molding to fix one end of the winding wire 120 and seal the end of the winding slot 112. There is no filling injection molding part between the winding wire 120 and the winding slot 112 for fixation. There is a smaller gap 1121 between the winding wire 120 and the winding slot 112. The coolant can directly cool the winding wire 120 within the gap 1121, thereby improving the heat exchange efficiency between the coolant and the winding wire 120 and improving the heat dissipation efficiency of the winding wire 120.

[0067] Please refer to Figures 10, 13, and 14. In this embodiment, the stator lamination 113 has an oil port 1131 on its outer peripheral surface. The oil port 1131 is connected to the winding slot 112 by an internal flow channel 1132. Coolant can enter the winding slot 112 from the oil port 1131 through the internal flow channel 1132 to directly cool the winding wire 120 in the winding slot 112. Direct cooling is beneficial to improving the heat dissipation efficiency of the winding wire 120. In one embodiment, the stator core 110 includes two oil ports 1131, which are spaced apart along the axial direction of the stator core 110. The two stator laminations 113 at the two ends along the axial direction are provided with grooves 114 to accommodate the injection molded part 115. The outer peripheral surface of the second stator lamination 113 at both ends is provided with oil ports 1131. One oil port 1131 forms an oil inlet, and the other oil port 1131 forms an oil outlet. Coolant enters the winding slot 112 through one oil port 1131, directly cools the winding wire 120 in the winding slot 112, and then exits through the other oil port 1131.

[0068] Please refer to Figures 14 and 15. Figure 15 is a schematic diagram of injection molding at both ends of a motor stator provided in an embodiment of this application.

[0069] In one embodiment, each groove 114 on each end face of the stator core 110 is used to fill an injection molded part 115, the slot opening 1122 of each winding slot 112 is radially oriented towards and communicates with the center hole 111 of the stator core 110 along the drive motor 1, and the slot opening 1122 of each winding slot 112 is used to fill an injection molded strip 116, wherein: the two ends of each injection molded strip 116 are distributed along the axial direction of the drive motor 1, and the two ends of each injection molded strip 116 are respectively used to fix the injection molded parts 115 on the two end faces.

[0070] In this embodiment, grooves 114 are provided on both end faces of the stator core 110, and both grooves 114 are used to fill the injection molded parts 115. The injection molded parts 115 seal both ends of the stator core 110, effectively preventing leakage of oil or other liquids inside the drive motor 1. This improved sealing helps ensure the stable operation of the drive motor 1 and extends its service life. The injection molded parts 115 and the stator core 110 can form a structurally robust whole, which helps improve the overall rigidity and vibration performance of the motor. During the operation of the drive motor 1, the sealing effect of the injection molded parts 115 can reduce the vibration and displacement of the winding wires 120 inside the stator core 110, thereby ensuring the stability and reliability of the drive motor 1.

[0071] In this embodiment, the slot 1122 of the winding slot 112 is the radial opening of the winding slot 112, and the slot 1122 communicates with the center hole 111. Multiple slots 1122 are arranged at intervals along the circumference of the stator core 110, which makes the magnetic field generated by the winding conductor 120 inside the stator core 110 more uniform. When current passes through the winding conductor 120, a closed magnetic circuit is formed inside the stator core 110. The radial opening of the slot 1122 helps to make the magnetic circuit smoother, reduce magnetic resistance, and thus improve the strength and efficiency of the magnetic field. This design ensures that the drive motor 1 generates a stable rotating magnetic field during operation, thereby driving the motor rotor 20 to rotate.

[0072] In this embodiment, the slot 1122 is used to fill an injection molding strip 116. The injection molding strip 116 penetrates multiple stacked stator cores 110 and is fixedly connected to the injection molding parts 115 on both end faces. This fixation enhances the overall stability of the drive motor 1 structure, ensuring the reliability and durability of the drive motor 1 during long-term operation. The injection molding strip 116 effectively separates the motor rotor 20 housed in the center hole 111 from the winding wires 120 housed in the winding slot 112, preventing direct contact and potential electrical short circuits between them. The injection molding strip 116 and the end face injection molding parts 115 are tightly integrated, forming a closed coolant passage within the winding slot 112. This closed passage ensures that the coolant can circulate within the winding slot 112, effectively carrying away the heat generated by the winding wires 120, thereby improving the heat dissipation performance of the drive motor 1. At the same time, since the coolant passage does not contact the motor rotor 20, interference and influence caused by the coolant on the movement of the motor rotor 20 are avoided.

[0073] In this embodiment, the shape of the injection molding strip 116 is not limited. The injection molding strip 116 can be customized according to different requirements of the drive motor 1, such as adjusting its size, shape, and material, to adapt to different models and specifications of drive motors 1. This flexibility helps to meet the diverse needs of the market. In one embodiment, the injection molded part 115 and the injection molding strip 116 are integrally injection molded. The integral injection molding process is beneficial to improving production efficiency, and the structure of the integrally injection molded part 115 and the injection molding strip 116 is more stable.

[0074] Please refer to Figures 16, 17 and 18. Figure 16 is a schematic diagram of a stator core and injection molded disc assembly provided in an embodiment of this application. Figure 17 is an exploded view of Figure 16. Figure 18 is a schematic diagram of an injection molded disc provided in an embodiment of this application.

[0075] In one embodiment, each injection molded part 115 is used to protrude from the groove 114 along the axial direction of the stator core 110 and connect along the circumferential direction of the stator core 110 to form an injection molded disc 117. The injection molded disc 117 includes an annular groove 1171, and an axial through hole 1151 is used to penetrate the bottom wall of the annular groove 1171 along the axial direction of the stator core 110. The annular groove 1171 includes a first annular groove wall 1172 and a second annular groove wall 1173. The first annular groove wall 1172 surrounds the second annular groove wall 1173. In each winding slot 112, the portions of multiple winding wires 120 passing through the axial through hole 1151 are arranged between the first annular groove wall 1172 and the second annular groove wall 1173.

[0076] In this embodiment, multiple injection molded parts 115 are connected circumferentially along the stator core 110 to form an injection molded disk 117. The injection molded disk 117 has a circular ring structure, forming a more stable injection molded structure. In one embodiment, the injection molded disk 117 has a first annular groove wall 1172 and a second annular groove wall 1173 that protrude from the plane of the groove 114 along the axial direction of the stator core 110. The first annular groove wall 1172 and the second annular groove wall 1173, together with the plane where the axial through hole 1151 is located in the injection molded disk 117, form an annular groove 1171. The annular groove 1171 communicates with the axial through hole 1151, and the ends of multiple winding wires 120 are located between the first annular groove wall 1172 and the second annular groove wall 1173. In another embodiment, the ends of multiple winding wires 120 are located between the first annular groove wall 1172 and the second annular groove wall 1173, that is, multiple winding wires 120 are located within the annular groove 1171.

[0077] In this embodiment, the first annular groove wall 1172 and the second annular groove wall 1173 act as injection molding steps, which can extend the creepage distance and further shorten the end height of the motor stator 10. Creepage distance refers to the shortest path measured along the insulating surface between two conductive components or between a conductive component and the equipment's protective interface. Under the influence of an electric field, charges move on the insulating surface. If the creepage distance is too short, it may cause arcing between the two conductors through contaminants on the insulating material surface, thus threatening the safe operation of the equipment. The stepped design increases the distance that charges move on the insulating surface by forming different height levels on the insulating material surface, thereby reducing the risk of arcing. By setting the first annular groove wall, it is possible to reduce the end height of the motor stator 10 while maintaining a sufficient creepage distance, thus making the drive motor more compact and efficient.

[0078] Referring to Figures 16, 17, 18, 19 and 20, Figure 19 is a schematic diagram of a motor stator provided in an embodiment of this application, and Figure 20 is a cross-sectional view at CC in Figure 19.

[0079] In one embodiment, an annular groove 1171 is used to enclose an injection ring 118 to form an annular liquid cooling cavity 1174, and an annular liquid cooling cavity 1174 is used to accommodate the portion of the plurality of winding wires 120 contained in each winding slot 112 that passes through an axial through hole 1151.

[0080] In this embodiment, the central hole of the injection ring 118 is connected to the central hole of the stator core 110. The injection ring 118 and the groove of the annular groove 1171 enclose the annular liquid cooling cavity 1174. Coolant flows in the annular liquid cooling cavity 1174. The coolant immerses and cools the end of the winding wire 120 in the annular liquid cooling cavity 1174. Immersion cooling has higher heat dissipation efficiency and can more effectively transfer heat from the winding wire 120 to the coolant.

[0081] In this embodiment, please refer to Figures 19 and 14. Figure 14 is a schematic diagram of a motor stator provided in this embodiment. The first annular groove wall 1172 and the second annular groove wall 1173 can be used to apply sealant, forming a sealing cavity with the injection ring 118. The arrangement of the first annular groove wall 1172 and the second annular groove wall 1173 can increase the contact area between the sealant and the injection ring 118, ensuring the fixing and sealing effect of the injection ring 118. Furthermore, the first annular groove wall 1172 and the second annular groove wall 1173 can absorb excess sealant, preventing sealant from overflowing the inner and outer diameters of the motor stator 10 and affecting the assembly of the motor stator 10 and the motor rotor 20.

[0082] In one embodiment, each injection-molded part 115 includes an oil passage hole 1155, which penetrates the injection-molded part 115 along the axial direction of the stator core 110. The two ends of the oil passage hole 1155 are respectively connected to an annular liquid cooling cavity 1174 and a winding slot 112. The annular liquid cooling cavity 1174 is used to connect to the winding slot 112 through the oil passage hole 1155. In another embodiment, the annular liquid cooling cavity 1174 is connected to the corresponding winding slot 112 through the oil passage hole 1155 on each injection-molded part 115, allowing coolant in one annular liquid cooling cavity 1174 to enter each winding slot 112. The coolant in the annular liquid cooling cavity 1174 can immerse and cool the ends of the winding conductors 120. The annular liquid cooling cavity 1174 is connected to the winding slots 112 through the oil passage hole 1155, directly cooling the winding conductors 120 within the winding slots 112. The winding conductor 120 is submerged in coolant, which ensures that the conductor temperature drops evenly and avoids local overheating; the coolant is in direct contact with the surface of the winding conductor 120, which can quickly remove the heat generated by the winding conductor 120 and achieve efficient heat dissipation.

[0083] In this embodiment, referring to Figure 17, the oil passage 1155 and the axial through hole 1151 are connected along the radial direction of the stator core 110. The coolant flowing in the oil passage 1155 can directly immerse and cool the winding conductor 120 in the axial through hole 1151. During injection molding, the oil passage 1155 is simultaneously injection molded on the inner wall of the axial through hole 1151. The circumferential length of the oil passage 1155 is less than the circumferential length of the axial through hole 1151 to ensure the fixing strength of the axial through hole 1151 to the winding conductor 120. In one embodiment, the oil passage 1155 and the axial through hole 1151 can be spaced apart along the radial direction of the stator core 110. The oil passage 1155 is located radially outside the axial through hole 1151, and the coolant flows through the oil passage 1155 radially outside the axial through hole 1151.

[0084] In one embodiment, coolant enters the annular liquid cooling cavity 1174 from one end of the stator core 110, flows through the annular liquid cooling cavity 1174 and through multiple oil passages 1155 into multiple winding slots 112, directly cooling multiple sets of winding wires 120, and then enters the annular liquid cooling cavity 1174 at the other end, flowing out from the other end of the stator core 110.

[0085] In one embodiment, referring to Figure 20, specifically the dashed arrows in Figure 20, coolant enters the winding slot 112 from the oil port 1131 of the stator lamination 113 through the internal flow channel 1132. It flows through the winding slot 112 to directly cool the winding conductors 120 within the winding slot 112, and flows out from both axial ends of the winding slot 112, entering the annular liquid cooling cavity 1174 through the oil passage 1155. Within the annular liquid cooling cavity 1174, the ends of the winding conductors 120 are directly cooled. In one embodiment, referring to Figures 19 and 20, the oil port 1131 and the internal flow channel 1132 are located on the stator lamination 113 at the middle position of the entire stator core 110. After the coolant enters the winding slot 112 through the oil port 1131 at the middle position, it can flow to the annular liquid cooling cavities 1174 at both ends, which is conducive to the coolant being delivered to both ends of the stator core 110 more quickly, and to rapidly cool the entire winding conductor 120.

[0086] In this embodiment, referring to Figure 19, the outer peripheral surface of the injection ring 118 includes a plurality of oil holes 1181, each oil hole 1181 for connecting the inner and outer sides of the annular liquid cooling cavity 1174. In one embodiment, each oil hole 1181 penetrates the inner and outer walls of the injection ring 118. External coolant can enter the annular liquid cooling cavity 1174 at one end through the oil holes 1181, and the coolant flows through the winding groove 112 to the annular liquid cooling cavity 1174 at the other end, and flows out through the oil holes 1181 on the side wall of the annular liquid cooling cavity 1174 at the other end. In one embodiment, the multiple oil holes 1181 can be coolant outlets. The coolant enters the winding groove 112 through the oil port 1131 and the internal flow channel 1132, and flows into the two annular liquid cooling cavities 1174 at both ends of the winding groove 112. The coolant then flows out through the oil holes 1181 on the cavity walls of the two annular liquid cooling cavities 1174, forming a complete coolant passage.

[0087] In this embodiment, the coolant directly cools the winding wire 120 in the winding slot 112. The coolant is in direct contact with the winding wire 120, which can significantly improve the heat dissipation efficiency. This cooling method can quickly absorb and remove the heat generated by the winding wire 120, effectively reduce the operating temperature of the winding wire 120, and thus improve the overall thermal efficiency of the drive motor 1.

[0088] Please refer to Figures 16, 17, and 19. In one embodiment, along the axial direction of the drive motor 1, the length of a first annular groove wall 1172 and the length of a second annular groove wall 1173 are less than the length of the portion through which multiple winding wires 120 pass in each winding slot 112 through the axial through hole 1151. The length of a first annular groove wall 1172 is less than the length of the second annular groove wall 1173. A first annular groove wall 1172 includes a plurality of other oil holes 1175, each of which is used to connect the two sides of a first annular groove wall 1172 along the radial direction of the drive motor 1.

[0089] In this embodiment of the application, please refer to Figure 20. The length L1 of the first annular groove wall 1172 and the length L2 of the second annular groove wall 1173 are both less than the length L3 of the portion of the winding wire 120 passing through the axial through hole 1151. The winding wire 120 has a certain axial length in the annular liquid cooling cavity 1174, which increases the volume ratio of the winding wire 120 in the annular liquid cooling cavity 1174. The annular liquid cooling cavity 1174 forms a suitable axial length to accommodate the winding wire 120.

[0090] In this embodiment of the application, referring to Figure 21, which is a schematic diagram of an assembly of the injection molded disc and injection ring provided in this embodiment, the length L1 of the first annular groove wall 1172 along the axial direction of the drive motor is less than the length L2 of the second annular groove wall 1173. The inner wall of the second annular groove wall 1173 and one outer wall of the injection ring 118 are fitted together. The outer side of the second annular groove wall 1173 encloses a central hole, which is flush with the central hole of the stator core, facilitating the passage and accommodation of the motor rotor. Because the first annular groove wall 1172 is shorter, the injection ring 118 can form a receiving groove capable of accommodating the outer surface of the first annular groove wall 1172. The connection area between the injection ring 118 and the first annular groove wall 1172 is larger, which is beneficial for the injection molded disc 117 to more stably fix the injection ring 118, and for the drive motor 1 to maintain stability during operation. In one embodiment, referring to FIG21, the second annular groove wall 1173 includes a plurality of other oil holes 1175. The larger length of the second annular groove wall 1173 is conducive to forming other oil holes 1175. Coolant can be directly introduced into the annular liquid cooling cavity 1174 from the other oil holes 1175 to immerse and cool the ends of the winding wires 120 contained in the annular liquid cooling cavity 1174, which is conducive to quickly removing the heat from the ends of the winding wires 120.

[0091] In this embodiment of the application, please refer to FIG4. Each winding slot 112 accommodates multiple winding wires 120, which are multiple flat wires 121. The multiple flat wires 121 in each winding slot 112 are arranged radially along the drive motor 1. The wall of each axial through hole 1151 is used to fix at least one of the multiple flat wires 121 in each winding slot 112 along the circumference or radial direction of the drive motor 1.

[0092] In this embodiment, multiple flat wires 121 are arranged radially along the drive motor 1 to form a flat wire winding 122. The flat wire winding 122 has advantages in improving the performance, efficiency, and thermal management capabilities of the drive motor 1. The flat wire structure of the flat wires 121 significantly increases the contact area between the wires, thereby increasing the heat dissipation area and facilitating rapid heat dissipation. Secondly, the flat wires 121 have a higher slot fill factor than traditional round wires. The increased slot fill factor means that more wires can be filled in the same winding slot 112 space, allowing for the carrying of larger currents. At the same time, the higher slot fill factor increases the cross-sectional area of ​​the winding wires 120, correspondingly reducing the DC resistance of the winding wires 120, reducing unnecessary copper losses, and also improving the utilization efficiency of the copper wire, indirectly benefiting heat dissipation. Furthermore, the design of the flat wire winding 122 makes the winding structure more compact, reducing the gaps between windings, thereby improving heat conduction efficiency.

[0093] In this embodiment, multiple flat wires 121 pass through the winding slot 112, and the ends of the multiple flat wires 121 are fixed by the axial through hole 1151. This can effectively prevent the flat wires 121 from loosening or being damaged due to vibration or friction during the operation of the drive motor 1. This fixing method improves the structural stability and reliability of the flat wires 121 and extends the service life of the drive motor 1.

[0094] In the embodiments of this application, the flat wires 121 are fixedly arranged along at least one of the circumferential or radial directions of the drive motor 1, which is beneficial to forming a uniform magnetic field within the drive motor 1.

[0095] In one embodiment, the winding method of the flat conductor 121 includes, but is not limited to, hairpin flat wire and I-pin flat wire. Hairpin winding can reduce the assembly space and conductor gap required for winding installation, and its slot fill factor can reach approximately 70%. I-pin winding does not require pre-forming and is assembled in a single slot, which can further reduce the assembly space required for winding, and its slot fill factor can reach approximately 74%, resulting in superior power. In this embodiment, referring to Figure 12, along the radial direction of the drive motor 1, the length of each axial through hole 1151 is greater than or equal to the thickness of the multiple flat conductors 121 stacked sequentially.

[0096] In this embodiment, the radial length of the axial through-hole 1151 is sufficient to accommodate multiple flat wires 121 stacked sequentially, which can significantly improve the fill rate of the flat wire winding 122, thereby increasing the power output of the motor. Secondly, when the length of the axial through-hole 1151 is sufficient, it can ensure that there are enough heat dissipation channels between the multiple flat wires 121. The stacked flat wires 121 can form tiny gaps, which can serve as heat dissipation channels and help dissipate heat. In addition, the contact area between the flat wires 121 and the axial through-hole 1151 is larger, resulting in higher heat conduction efficiency and further improving the heat dissipation performance of the drive motor 1. Furthermore, the length of the axial through-hole 1151 is greater than or equal to the thickness of the multiple flat wires 121 stacked sequentially, which helps to ensure the stability of the flat wire winding 122 during motor operation. The stacked flat wires 121 can form a more robust structure, reducing loosening or damage caused by vibration and impact. It is worth noting that the design of the axial through hole 1151 also takes into account the convenience of manufacturing and maintenance. When the length of the axial through hole 1151 is sufficient, it is easier to stack multiple flat wires 121 sequentially into the slot, simplifying the winding process. During maintenance, if it is necessary to replace or repair the winding, the wires can be removed and installed more easily.

[0097] In this embodiment, referring to Figure 12, along the circumference of the drive motor 1, the width of each axial through-hole 1151 is greater than or equal to the width of each flat wire 121. In one embodiment, when the width of the axial through-hole 1151 is sufficient to accommodate the width of the flat wire 121, it can be ensured that the flat wire 121 is tightly arranged within the axial through-hole 1151, thereby increasing the slot fill factor. More wires can be filled in the same space, thus increasing the power output of the motor. Due to the increased slot fill factor, the drive motor 1 can output greater power with the same volume or weight, i.e., the power density increases. Secondly, when the width of the axial through-hole 1151 is greater than or equal to the width of the flat wire 121, there is a gap between the axial through-hole 1151 and the flat wire 121, which facilitates the direct cooling of the flat wire 121 by the coolant, increasing the heat dissipation efficiency.

[0098] In this embodiment of the application, please refer to FIG14, which is a schematic diagram of a motor stator provided in this embodiment of the application. The multiple winding wires 120 contained in each winding slot 112 are spaced apart from the slot wall of the winding slot 112 by insulating paper 130, and the hole wall of each axial through hole 1151 is used to surround the insulating paper 130 in each winding slot 112.

[0099] In one embodiment, a certain insulation distance is required between the winding conductor 120 and the stator core 110; otherwise, problems such as electrical breakdown, short circuits between windings, and reduced contact spacing will occur. The main function of the insulating paper 130 in the stator core 110 is isolation and protection. It covers the winding conductor 120 to ensure good isolation between the winding conductor 120 and the stator core 110, preventing short circuits between the winding conductor 120 and the stator core 110. The insulating paper 130 can also prevent short circuits between multiple sets of winding conductors 120, ensuring normal motor operation.

[0100] In one embodiment, using insulating paper 130 thinner than the injection molded part to wrap the winding wire 120 helps to leave more space in the winding slot 112 to accommodate the winding wire and improve the slot fill factor of the winding slot 112.

[0101] In one embodiment, when the drive motor 1 is operating, the winding conductors 120 are exposed to high temperature, high voltage, and high frequency, which can easily lead to electrical insulation failure. The insulating paper 130, with its excellent high temperature and voltage resistance, effectively prevents electrical insulation failure when wrapped around the winding conductors 120. Furthermore, the insulating paper 130 also has good corrosion resistance, protecting the stator core 110 from external factors such as moisture and dust.

[0102] In one embodiment, the type of insulating paper 130 includes, but is not limited to, at least one of polyester film insulating paper, polyimide film insulating paper, aromatic polyamide insulating paper, blue shell insulating paper, and polyetheretherketone film (PEEK film). Polyester film insulating paper has good electrical and mechanical properties, and it has high heat resistance and voltage resistance, making it suitable for the insulation of winding conductors 120 of various drive motors 1; polyimide film insulating paper has excellent high temperature resistance and electrical properties, and it can maintain stable insulation performance in high temperature environments, making it suitable for the insulation of winding conductors 120 of high-temperature drive motors 1; aromatic polyamide insulating paper has extremely high heat resistance and electrical properties, and it can maintain stable insulation performance in extremely harsh environments, making it suitable for drive motors 1 with extremely high insulation performance requirements; blue shell insulating paper has specific physical and chemical properties, and it is usually used in drive motors 1 with certain insulation performance requirements; PEEK film has good processing and forming properties, and can be made to the 0.1mm level, improving the slot fill factor of winding slots 112.

[0103] In this application, please refer to Figures 23 and 24. Figure 23 is a schematic diagram of a motor stator provided in an embodiment of this application, and Figure 24 is an exploded view of Figure 23. Each injection molded part 115 includes an annular groove wall 1152, each annular groove wall 1152 surrounds an axial through hole 1151, and the annular groove wall 1152 of each injection molded part 115 is used to enclose a cover plate 119 to form a liquid cooling cavity 1153. Each liquid cooling cavity 1153 is used to accommodate the portion of multiple winding wires 120 in each winding slot 112 that pass through the axial through hole 1151. Each liquid cooling cavity 1153 includes a third oil hole 1154, and each third oil hole 1154 is used to connect the inner side and the outer side of the liquid cooling cavity 1153.

[0104] In one embodiment, each injection-molded part 115 protrudes from the groove 114 along the axial direction of the drive motor. Each injection-molded part 115 forms another groove at its protruding portion. The sidewall of the groove is an annular groove wall 1152, which surrounds the periphery of the axial through hole 1151. The annular groove wall 1152 and the cover plate 119 together form a liquid cooling cavity 1153, which allows the end of the winding wire 120 passing through the axial through hole 1151 to be immersed and cooled by the coolant in the liquid cooling cavity 1153. Immersion cooling can quickly reduce the heat at the end of the winding wire 120 and improve the heat dissipation efficiency of the drive motor 1.

[0105] In one embodiment, the liquid cooling cavity 1153 has a third oil hole 1154, which connects the inner and outer sides of the liquid cooling cavity 1153. In another embodiment, coolant enters the liquid cooling cavity 1153 from the third oil hole 1154 at one end of the stator core 110 to immerse and cool the end of the winding conductor 120, and then cools the winding conductor 120 in the winding slot 112 through the axial through hole 1151, before flowing out through the third oil hole 1154 at the other end of the stator core 110. In one embodiment, coolant enters the winding slot 112 from the oil port 1131 of the stator lamination 113 through the internal flow channel 1132, directly cooling the winding wire 120 in the winding slot 112, and then diffuses from the winding slot 112 along the axial direction of the stator core 110 towards the liquid cooling cavities 1153 at both ends of the stator core 110, immersing and cooling the ends of the winding wire 120 in the liquid cooling cavities 1153, and then flows out through the third oil hole 1154 at both ends of the stator core 110.

[0106] In this embodiment, please refer to Figure 22, which is a cross-sectional schematic diagram of the stator oil passage provided in this embodiment. The drive motor 1 also includes a housing 9, which is used to fix and accommodate the stator 10 of the drive motor 1. The inner circumferential surface of the housing 9 includes an oil outlet 91. The gap 92 between the outer circumferential surface of the stator 10 and the housing 9 is used to receive the coolant output from the oil outlet 91 and to deliver the coolant to each winding slot 112 through the internal flow channel 1132 of the stator 10.

[0107] In one embodiment, the housing 9 of the drive motor 1 can be connected to transmission components such as transmission gears and transmission shafts to transmit the rotational power of the drive motor 1 to other equipment or systems. The housing 9 can fix, house, and protect key components such as the motor stator 10 and motor rotor 20 in the drive motor 1, preventing them from being subjected to external mechanical impacts such as collisions and compression, thereby ensuring the integrity and stability of the internal components of the drive motor 1.

[0108] In one embodiment, the housing 9 has a high protection rating, such as IP67, which can prevent dust, moisture and other contaminants from entering the drive motor 1 and ensure that the drive motor 1 can operate stably in harsh environments.

[0109] The drive motor 1 generates a large amount of heat during operation. If the heat cannot be dissipated in time, it will cause the motor to overheat and be damaged. In this embodiment, the housing 9 is provided with an oil outlet 91. Coolant can enter the motor stator 10 through the oil outlet 91 and flow to the winding slot 112 through the internal flow channel 1132, thereby dissipating heat from the winding wires 120 and ensuring that the drive motor 1 will not reduce its performance or shorten its lifespan due to overheating when working under high load.

[0110] In one embodiment, the housing 9 may also be equipped with other heat dissipation structures, such as heat sinks, vents, cooling pipe interfaces, etc., to help dissipate heat from the internal components of the drive motor 1.

[0111] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

A drive motor, characterized in that, The drive motor includes a stator and a rotor. The stator core includes a central hole and multiple winding slots. The central hole accommodates the rotor. The winding slots are spaced circumferentially along the drive motor. Each winding slot extends through both end faces of the stator core along the axial direction of the drive motor. Each winding slot receives coolant to directly cool multiple winding wires contained within it. At least one of the two end faces of the stator core includes at least one groove. Each groove is used to fill an injection molded part. Each injection molded part includes at least one axial through hole, wherein: Each winding slot accommodates multiple winding wires that pass through one of the axial through holes. The wall of each axial through hole is used to surround the multiple winding wires accommodated in one of the winding slots. The circumferential width of each axial through hole is less than the circumferential width of each winding slot, or the radial length of each axial through hole is less than the radial length of each winding slot. The drive motor according to claim 1 is characterized in that, Each groove on each end face of the stator core is used to fill one of the injection molded parts, the slot opening of each winding slot is radially oriented towards and communicates with the center hole of the stator core, and the slot opening of each winding slot is used to fill one injection molded strip, wherein: Each injection strip has two ends distributed along the axial direction of the drive motor, and is used to fix the injection molded parts at the two end faces respectively. The drive motor according to claim 1 or 2 is characterized in that, Each of the injection molded parts is used to protrude from the groove along the axial direction of the stator core and connect circumferentially along the stator core to form an injection molded disc. The injection molded disc includes an annular groove. The axial through hole is used to penetrate the bottom wall of the annular groove along the axial direction of the stator core. The annular groove includes a first annular groove wall and a second annular groove wall. The first annular groove wall surrounds the second annular groove wall. The portions of the plurality of winding wires in each winding slot that pass through the axial through hole are arranged between the first annular groove wall and the second annular groove wall. The drive motor according to claim 3 is characterized in that, The annular groove is used to enclose an injection ring to form an annular liquid cooling cavity, and the annular liquid cooling cavity is used to accommodate the portion of the plurality of winding wires contained in each winding slot that passes through an axial through hole. The drive motor according to claim 4 is characterized in that, Each of the injection molded parts includes an oil passage hole for penetrating the bottom wall of the annular groove and one end face of the injection molded part along the axial direction of the stator core, and an annular liquid cooling cavity for connecting the winding slot through the oil passage hole. The drive motor according to claim 4 is characterized in that, The outer circumferential surface of the injection ring includes a plurality of oil holes, each of which is used to connect the inner and outer sides of the annular liquid cooling cavity. The drive motor according to claim 3 is characterized in that, Along the axial direction of the drive motor, the length of the first annular groove wall and the length of the second annular groove wall are less than the length of the portion of the plurality of winding wires passing through the axial through hole in each winding slot. The length of the first annular groove wall is less than the length of the second annular groove wall. The second annular groove wall includes a plurality of additional oil holes, each of which is used to connect the two sides of the second annular groove wall along the radial direction of the drive motor. The drive motor according to any one of claims 1-7 is characterized in that, Each winding slot accommodates multiple flat wires, which are arranged radially along the drive motor. The wall of each of the axial through holes is used to fix at least one of the plurality of flat wires in each of the winding slots along the circumferential or radial direction of the drive motor. The drive motor according to claim 8 is characterized in that, Along the radial direction of the drive motor, the length of each of the axial through holes is greater than or equal to the thickness of the plurality of flat wires stacked sequentially. The drive motor according to claim 8 or 9 is characterized in that, Along the circumference of the drive motor, the width of each of the axial through holes is greater than or equal to the width of each of the flat wires. The drive motor according to any one of claims 1-10 is characterized in that, The multiple winding wires contained in each winding slot are spaced apart from the slot wall by insulating paper, and the wall of each axial through hole is used to surround the insulating paper in each winding slot. The drive motor according to claim 1 or 2 is characterized in that, Each of the injection molded parts includes an annular groove wall surrounding an axial through hole. The annular groove wall of each injection molded part is used to enclose a cover plate to form a liquid cooling cavity. Each liquid cooling cavity is used to receive portions of the plurality of wires in each winding slot that pass through the axial through hole. Each liquid cooling cavity includes an oil hole for communicating between the inner and outer sides of the liquid cooling cavity. The drive motor according to any one of claims 1-12 is characterized in that, The housing of the drive motor is used to fix and accommodate the stator of the drive motor. The inner circumferential surface of the drive motor housing includes an oil outlet hole. The gap between the outer circumferential surface of the motor stator and the housing of the drive motor is used to receive the coolant output from the oil outlet hole and to deliver coolant to each winding slot through the internal flow channel of the motor stator. A powertrain, characterized in that, The powertrain includes a speed reducer and a drive motor as described in any one of claims 1-13, the drive motor being used to drive an electric vehicle via the speed reducer. An electric vehicle, characterized in that, It includes a plurality of wheels and a powertrain as described in claim 14, the powertrain being used to drive the plurality of wheels.

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