Rotor lamination for oil-cooled drive motor, oil-cooled drive motor, and powertrain

Abstract

The present application relates to the technical field of motors, and in particular, to a rotor lamination for an oil-cooled drive motor, an oil-cooled drive motor, and a powertrain. The rotor lamination comprises a central hole, a plurality of cooling holes and a plurality of magnet slots, wherein the central hole is configured for accommodating a rotor shaft, each magnet slot is configured for accommodating a magnet, each cooling hole is configured for circulating cooling oil, the central hole extends through the rotor lamination in an axial direction of the rotor lamination, each magnet slot extends through the rotor lamination in the axial direction of the rotor lamination, the plurality of magnet slots are arranged around the central hole, each cooling hole extends through the rotor lamination in the axial direction of the rotor lamination, the plurality of cooling holes are arranged around the central hole, a hole wall of at least one of the plurality of cooling holes comprises a plurality of heat-dissipating protrusions, and the plurality of heat-dissipating protrusions are arranged in a spaced apart manner on the hole wall of the cooling hole. The larger contact area between the cooling oil and the rotor lamination results in a better heat exchange effect, thereby improving oil-cooling heat dissipation performance in rotors.

Description

Rotor laminations for oil-cooled drive motors, oil-cooled drive motors and powertrains

[0001] Cross-reference to related applications

[0002] This application claims priority to Chinese patent application filed on November 30, 2024, with application number 202422969600.0 and entitled "Rotor laminations for oil-cooled drive motors, oil-cooled drive motors and powertrains", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of motor technology, and in particular to a rotor lamination for an oil-cooled drive motor, an oil-cooled drive motor, and a powertrain. Background Technology

[0004] With the development of new energy vehicles, the electric motors in the powertrain of electric vehicles are developing towards high speed, high density, and miniaturization.

[0005] Currently, liquid cooling is achieved by circulating cooling oil into the rotor of a motor. Specifically, the cooling oil enters the rotor's internal oil passages and flows to both sides of the rotor's ends as the rotor rotates, where it is sprayed out. During this flow, the cooling oil exchanges heat with the rotor, thus dissipating heat. The effectiveness of rotor cooling affects the motor's operating efficiency. Summary of the Invention

[0006] This application provides a rotor lamination for an oil-cooled drive motor, an oil-cooled drive motor, and a power assembly. The rotor lamination can improve the heat exchange between the cooling oil and the rotor, enhance the heat dissipation effect of the rotor, and optimize the motor performance.

[0007] In a first aspect, embodiments of this application provide a rotor lamination for an oil-cooled drive motor. The rotor lamination includes a central hole, multiple cooling holes, and multiple magnet holes. The central hole is used to assemble a rotor shaft, each magnet hole is used to assemble a magnet, and each cooling hole is used for the flow of cooling oil. The central hole extends through the rotor lamination along its axial direction, and each magnet hole extends through the rotor lamination along its axial direction. The multiple magnet holes are arranged around the central hole, and each cooling hole extends through the rotor lamination along its axial direction. At least one of the multiple cooling holes has a wall comprising multiple heat dissipation protrusions, which are spaced apart from each other on the wall of the cooling hole.

[0008] In the aforementioned rotor laminations, at least one of the cooling holes has multiple heat dissipation protrusions on its wall, which increase the surface area of ​​the cooling hole wall. When cooling oil flows through the cooling hole, the contact area between the cooling oil and the rotor laminations is larger, resulting in better heat exchange and thus improving the oil cooling performance of the rotor.

[0009] In one embodiment, each cooling hole is arranged circumferentially between two adjacent magnet holes along the rotor lamination. Heat generated by the magnets embedded in the magnet holes can be removed through heat exchange between the cooling oil and the rotor lamination. Each cooling hole in at least one cooling hole has a wall divided into multiple segments, including a first segment, a second segment, and a third segment. The first segment connects to the second segment via the third segment. The first and second segments are arranged symmetrically or oppositely along the radial direction of the rotor. Multiple heat dissipation protrusions are spaced apart at at least one of the first, second, and third segments. Different distribution positions of the heat dissipation protrusions can alter the heat dissipation effect at different locations on the rotor lamination.

[0010] In one embodiment, a third segment of the hole wall is radially symmetrical about the rotor, as are a first segment and a second segment of the hole wall. One end of the first segment of the hole wall connects to the third segment, and the other end connects to one end of the second segment, which in turn connects to the third segment. Multiple heat dissipation protrusions are radially symmetrically distributed at least one of the first, second, and third segment of the hole wall. The connection of the first, second, and third segment of the hole wall forms a triangle, which helps to enhance the structural strength of the rotor laminations. The radially symmetrical distribution of the multiple heat dissipation protrusions can balance the heat dissipation effect on both sides of the cooling holes.

[0011] In one embodiment, the distance between a third section of the hole wall and the outer peripheral surface of the rotor lamination along the radial direction is greater than the distance between a first section of the hole wall and a second section of the hole wall and the outer peripheral surface of the rotor lamination. The third section of the hole wall is the hole wall on the side of the cooling hole closer to the central hole. The first and second section of the hole wall are closer to the magnet hole than the third section of the hole wall. A portion of the multiple heat dissipation protrusions is spaced apart on a first section of the hole wall, and a portion of the multiple heat dissipation protrusions is spaced apart on a second section of the hole wall, which is more conducive to the cooling oil dissipating heat from the magnet inside the magnet hole.

[0012] In one embodiment, the distance between a third section hole wall and the outer peripheral surface of the rotor lamination along the radial direction is less than the distance between a first section hole wall and a second section hole wall and the outer peripheral surface of the rotor lamination. The third section hole wall is the hole wall on the side of the cooling hole away from the central hole. The third section hole wall is closer to the magnet hole than the first section hole wall and the second section hole wall. The multiple heat dissipation protrusions are spaced apart on the third section hole wall, which is more conducive to the cooling oil dissipating heat from the magnet inside the magnet hole.

[0013] In one embodiment, the multi-segment hole wall further includes a fourth segment hole wall. A first segment hole wall and a second segment hole wall are arranged radially opposite to each other along the rotor. One end of the first segment hole wall is connected to one end of the second segment hole wall through a third segment hole wall, and the other end of the first segment hole wall is connected to the other end of the second segment hole wall through a fourth segment hole wall. Specifically, the distance between the first segment hole wall and the outer circumferential surface of the rotor lamination along the radial direction is greater than the distance between the second segment hole wall and the outer circumferential surface of the rotor lamination. Multiple heat dissipation protrusions are distributed on one of the second segment hole walls. The cooling hole has a trapezoidal shape. The second segment hole wall is closer to the magnet hole than the other segment hole walls, and the multiple heat dissipation protrusions spaced apart on the second segment hole wall are more conducive to the cooling oil dissipating heat from the magnet inside the magnet hole.

[0014] In one embodiment, the length of each heat dissipation protrusion protruding from the wall of the cooling hole is greater than the width of each heat dissipation protrusion, which can increase the surface area of ​​the heat dissipation protrusion, thereby increasing the surface area of ​​the inner wall of the cooling hole.

[0015] In one embodiment, at least one of the width of each heat dissipation protrusion and the spacing between two adjacent heat dissipation protrusions is greater than or equal to 1 mm, and the length of each heat dissipation protrusion protruding from the wall of the cooling hole is 1-2 mm.

[0016] In one embodiment, the multiple heat dissipation protrusions are divided into multiple heat dissipation protrusion segments, each segment including two or more heat dissipation protrusions. At least two segments of the multiple heat dissipation protrusions differ in at least one of the following: the number, shape, or spacing of the heat dissipation protrusions. The number, shape, or spacing of the heat dissipation protrusions in different segments within the cooling holes can be adjusted according to the specific structure of the rotor laminations to meet the heat dissipation requirements at different locations of the rotor laminations.

[0017] Secondly, embodiments of this application provide an oil-cooled drive motor for driving the wheels of an electric vehicle. The oil-cooled drive motor includes a stator and a rotor. The central hole of the stator accommodates the rotor. The rotor includes multiple rotor cores arranged sequentially adjacent to each other along the rotor's axial direction. Each rotor core includes multiple rotor laminations of any type provided in the first aspect. The multiple rotor laminations in each rotor core are arranged sequentially adjacent to each other along the drive motor's axial direction. Multiple cooling holes in one rotor lamination of each rotor core are connected to multiple cooling holes in the other rotor lamination, forming multiple axial flow channels. Cooling oil flows through these axial flow channels, achieving oil cooling of the rotor through heat exchange between the cooling oil and the rotor core. Since the wall of at least one cooling hole in the rotor lamination includes multiple heat dissipation protrusions, the oil cooling effect can be improved by increasing the heat exchange area, resulting in higher efficiency for the oil-cooled drive motor. In one embodiment, the wall of each cooling hole in the rotor lamination of at least one rotor core includes multiple heat dissipation protrusions, and the distribution of these protrusions is identical in the multiple rotor laminations of the same rotor core. The heat dissipation effect at different locations of the same rotor core can be kept relatively consistent, which can reduce the flow resistance of the cooling oil and enhance the oil cooling effect.

[0018] In one embodiment, the distribution of heat dissipation protrusions in the rotor laminations of one rotor core differs from that in the rotor laminations of the other rotor core, thereby altering the heat dissipation effect at different positions along the axial direction of the oil-cooled drive motor.

[0019] In one embodiment, multiple axial flow channels in one rotor core of two adjacent rotor cores receive cooling oil through multiple axial flow channels in the other rotor core. The number of heat dissipation protrusions in the rotor laminations of one rotor core is greater than the number of heat dissipation protrusions in the rotor laminations of the other rotor core. A greater number of heat dissipation protrusions results in a larger contact area between the cooling holes and the cooling oil, leading to higher heat exchange efficiency between the cooling oil and the rotor laminations. Consequently, the oil cooling effect of the rotor core formed by these rotor laminations is better.

[0020] Thirdly, embodiments of this application provide a powertrain that can be applied to an electric vehicle. The powertrain includes a reducer and any of the oil-cooled drive motors provided in the second aspect, the oil-cooled drive motors being used to drive the wheels of the electric vehicle via the reducer. Attached Figure Description

[0021] Figure 1 is a structural schematic diagram of an electric vehicle provided in an embodiment of this application;

[0022] Figure 2 is a structural schematic diagram of a powertrain provided in an embodiment of this application;

[0023] Figure 3 is a cross-sectional structural diagram of an oil-cooled drive motor provided in an embodiment of this application;

[0024] Figure 4a is a schematic diagram of the rotor structure of an oil-cooled drive motor provided in an embodiment of this application;

[0025] Figure 4b is an exploded view of the rotor of an oil-cooled drive motor provided in an embodiment of this application;

[0026] Figure 5 is a schematic diagram of the rotor lamination of an oil-cooled drive motor provided in an embodiment of this application;

[0027] Figure 6a is a schematic diagram of the cooling hole structure of the rotor lamination of an oil-cooled drive motor according to an embodiment of this application;

[0028] Figure 6b is a schematic diagram of the cooling hole structure of the rotor lamination of an oil-cooled drive motor according to an embodiment of this application;

[0029] Figure 6c is a schematic diagram of the cooling hole structure of the rotor lamination of an oil-cooled drive motor according to an embodiment of this application;

[0030] Figure 7a is a schematic diagram of the cooling hole structure of the rotor lamination of an oil-cooled drive motor according to an embodiment of this application;

[0031] Figure 7b is a schematic diagram of the cooling hole structure of the rotor lamination of an oil-cooled drive motor according to an embodiment of this application;

[0032] Figure 8a is a schematic diagram of the cooling hole structure of the rotor lamination of an oil-cooled drive motor according to an embodiment of this application;

[0033] Figure 8b is a schematic diagram of the cooling hole structure of the rotor lamination of an oil-cooled drive motor according to an embodiment of this application;

[0034] Figure 9 is a schematic diagram of the cooling hole structure of the rotor lamination of an oil-cooled drive motor according to an embodiment of this application;

[0035] Figure 10 is a partial structural diagram of the cooling holes of the rotor laminations of an oil-cooled drive motor provided in an embodiment of this application;

[0036] Figure 11a is a partial structural diagram of the cooling holes of the rotor laminations of an oil-cooled drive motor provided in an embodiment of this application;

[0037] Figure 11b is a partial structural diagram of the cooling holes of the rotor laminations of an oil-cooled drive motor provided in an embodiment of this application;

[0038] Figure 12 is a schematic diagram of the structure of a rotor core of an oil-cooled drive motor provided in an embodiment of this application;

[0039] Figure 13 is a schematic diagram of the structure of two rotor laminations of an oil-cooled drive motor provided in an embodiment of this application;

[0040] Figure 14 is a schematic diagram of the structure of two rotor cores of an oil-cooled drive motor provided in an embodiment of this application.

[0041] Reference numerals: 1000, Powertrain; 2000, Transmission Mechanism; 3000, Wheel; 100, Motor; 200, Motor Controller; 300, Reducer; 10, Rotor; 20, Stator; 201, Stator Core; 202, Stator Winding; 30, Housing; 1, Rotor Shaft; 2, Rotor Core; 21, Rotor Lamination; 211, Center Hole; 212, Cooling Hole; 212a, First Cooling Hole; 212b, Second Cooling Hole; 2121, First Hole Wall; 2122, Second Hole Wall; 2123, Third Hole Wall; 2124, Fourth Hole Wall; 213, Magnet Hole; 3, End Plate; 31, Liquid Outlet; 4, Fixing Component; 4a, Annular Structural Component; 4b, Annular Shoulder; 5, Magnet; d1, oil inlet channel; d2, axial flow channel; t, radial protrusion; S, power output end; T, heat dissipation protrusion; T1, heat dissipation protrusion; T2, heat dissipation protrusion. Detailed Implementation

[0042] In the prior art, cooling oil is introduced into the rotor of the motor to perform liquid cooling, and the liquid cooling effect of the rotor will affect the performance of the motor.

[0043] Based on this, embodiments of this application provide a rotor lamination for an oil-cooled drive motor, an oil-cooled drive motor, and a powertrain. The rotor lamination can improve the heat exchange between the cooling oil and the rotor, enhance the heat dissipation effect of the rotor, and optimize the motor performance.

[0044] To make the objectives, technical solutions, and advantages of this application clearer, the application will now be described in further detail with reference to the accompanying drawings.

[0045] Figure 1 is a structural schematic diagram of an electric vehicle provided in an embodiment of this application. As shown in Figure 1, the electric vehicle can specifically be a pure electric vehicle (pure EV / battery EV), a hybrid electric vehicle (HEV), a range-extended electric vehicle (REEV), or a plug-in hybrid electric vehicle (PHEV), etc. The electric vehicle includes a powertrain 1000, a transmission mechanism 2000, and wheels 3000. The powertrain 1000 converts electrical energy into mechanical energy, and the transmission mechanism 2000 is connected to the powertrain 1000 and the wheels 3000, transmitting the kinetic energy output from the powertrain to the wheels 3000 to drive their rotation. Of course, the electric vehicle also includes a frame to withstand the loads of the vehicle's internal and external environment, and a battery for supplying power to the powertrain 1000, which is not illustrated here.

[0046] Figure 2 is a schematic diagram of the powertrain 1000 provided in an embodiment of this application. As shown in Figure 2, the powertrain 1000 includes an oil-cooled drive motor 100 and a motor controller 200. The motor controller 200 is used to convert the DC power supplied by the battery into AC power and deliver the AC power to the oil-cooled drive motor 100. In one embodiment, the powertrain 1000 also includes a reducer 300, and the power output end of the oil-cooled drive motor 100 is connected to the vehicle wheels 3000 through the reducer 300. The reducer 300 can also be referred to as a transmission.

[0047] In this embodiment of the application, cooling oil is introduced into the oil-cooled drive motor 100 of the electric vehicle to exchange heat with the oil-cooled drive motor 100, which can cool the oil-cooled drive motor 100 and improve the motor performance.

[0048] Figure 3 is a schematic cross-sectional view of an oil-cooled drive motor 100. As shown in Figure 3, the oil-cooled drive motor 100 includes a rotor 10, a stator 20, and a housing 30, with the stator 20 and a portion of the rotor 10 housed within the housing 30. In one embodiment, the stator 20 is fixed circumferentially within the housing 30, and the rotor 10 is rotatably mounted within the central hole of the stator 20. One end of the rotor 10 extends axially from the housing 30, forming the power output terminal S of the oil-cooled drive motor 100. The stator 20 includes a stator core 201 and a stator winding 202 wound around the stator core 201. When energized, a magnetic field is generated in the central hole of the stator core 201, allowing the rotor 10 to rotate around its axis within the magnetic field.

[0049] The rotor 10 provided in this embodiment has an internal oil-cooling circuit. Cooling oil is introduced into the oil-cooling circuit within the rotor 10 to perform liquid cooling heat dissipation. Finally, the cooling oil can be sprayed out from the two axial ends of the rotor 10. In this embodiment, the axial direction of the rotor and the axial direction of the oil-cooled drive motor refer to the same direction; the circumferential direction of the rotor and the circumferential direction of the oil-cooled drive motor refer to the same direction; and the radial direction of the rotor and the radial direction of the oil-cooled drive motor refer to the same direction. For ease of understanding, the axial direction of the oil-cooled drive motor 100 is represented by the letter A, the radial direction by the letter R, and the circumferential direction by the letter C.

[0050] Figure 4a shows the structure of the rotor 10 in one embodiment of this application, and Figure 4b is an exploded view of the rotor. The structure of the rotor 10 can be understood by referring to Figures 4a and 4b.

[0051] In one embodiment, the rotor 10 includes a plurality of rotor cores 2, which are arranged adjacent to each other along the axial direction of the oil-cooled drive motor. Each rotor core 2 includes a plurality of axial flow channels d2, which can be connected to the plurality of axial channels d2 of adjacent rotor cores 2 along the axial direction of the oil-cooled drive motor to form a circuit for the flow of cooling oil inside the rotor 10.

[0052] In one embodiment, the rotor 10 further includes a plurality of magnets 5, each rotor core 2 having a plurality of magnets 5 embedded therein. The magnets 5 are capable of forming a magnetic field of the rotor 10, which is coupled with the magnetic field of the stator 20 to drive the rotor 10 to rotate about an axis.

[0053] In one embodiment, the rotor 10 includes a rotor shaft 1, multiple rotor cores 2, two end plates 3, and multiple magnets 5. As shown in Figure 4b, along the axial direction of the motor, the two end plates 3 are arranged on both sides of the rotor cores 2, and the rotor shaft 1 can pass through one end plate 3, multiple rotor cores 2, and another end plate 3 in sequence. The multiple rotor cores 2 and the two end plates 3 can be fixed to the rotor shaft 1 by keyway engagement. One end of the rotor shaft 1 is a power output end S, which is used to drive and connect to a reducer. The rotor shaft 1 includes an oil inlet channel d1, which can supply liquid to multiple axial flow channels d2 formed by the multiple rotor cores 2. Each end plate 3 has an outlet hole 31 that communicates with the axial flow channel d2 in the adjacent rotor core 2. The outlet hole 31 can spray the cooling oil in the axial flow channel d2 out of the end plate 3 on the side away from the rotor core 2, thereby realizing oil spraying at both ends of the rotor 10.

[0054] In some embodiments, a plurality of rotor cores 2 and two end plates 3 arranged along the axial direction of the oil-cooled drive motor on both sides of the plurality of rotor cores 2 can be axially limited by two fasteners 4. One fastener 4 is arranged along the axial direction of the oil-cooled drive motor on one end plate 3 on the side opposite to the plurality of rotor cores 2, and the other fastener 4 is arranged along the axial direction of the oil-cooled drive motor on the other end plate 3 on the side opposite to the plurality of rotor cores 2.

[0055] In one embodiment, one of the fixing members 4 is an annular shoulder 4b of the rotor shaft 1, the annular shoulder 4a protruding radially from the outer circumferential surface of the rotor shaft 1. The annular shoulder 4b is part of the rotor shaft 1 and has an integral structure with the rotor shaft 1. The annular shoulder 4b is exemplarily arranged along the axial direction of the oil-cooled drive motor on the side of the rotor shaft 1 with the power output end S.

[0056] In one embodiment, another fixing member 4 is an annular structural member 4a, which is used to fix the rotor shaft 1 by frictional force.

[0057] In one embodiment, each rotor core 2 of the rotor 10 provided in this application includes a plurality of rotor laminations 21 as shown in FIG5. The plurality of rotor laminations 21 are arranged adjacent to each other along the axial direction of the oil-cooled drive motor to form a rotor core 2.

[0058] Referring to Figure 5, the rotor lamination 21 includes a central hole 211, multiple cooling holes 212, and multiple magnet holes 213. The central hole 211 is used to assemble the rotor shaft 1, each magnet hole 213 is used to assemble a magnet 5, and each cooling hole 212 is used for the flow of cooling oil. The central hole 211 penetrates the rotor lamination 21 along the axial direction of the rotor lamination, and each magnet hole 213 penetrates the rotor lamination 21 along the axial direction of the rotor lamination. The multiple magnet holes 213 are arranged at intervals around the central hole 211. When each magnet hole 213 is equipped with a magnet 5, the multiple magnets 5 arranged at intervals around the central hole 211 can form a ring-shaped rotor magnetic field for coupling with the stator magnetic field of the stator 20. The multiple magnet holes 213 arranged at intervals around the central hole 211 can also be considered as multiple magnet holes 213 arranged at intervals along the circumference of the oil-cooled drive motor.

[0059] In one embodiment, the inner wall of the center hole 211 of the rotor lamination 21 includes one or more radial protrusions t. When the center hole 211 of the rotor lamination 21 is assembled with the rotor shaft 1, the radial protrusions t can cooperate with the keyway of the rotor shaft 1 to achieve circumferential positioning.

[0060] In one embodiment, each cooling hole 212 extends through the rotor lamination 21 along the axial direction of the rotor lamination, and multiple cooling holes 212 are arranged at intervals along the circumference of the rotor lamination. Each cooling hole 212 is arranged between two adjacent magnet holes 213 along the circumference of the rotor lamination. The heat generated by the magnet 5 assembled in the magnet hole 213 can be carried away through heat exchange between the cooling hole 212 and the cooling oil.

[0061] In one embodiment, at least one of the plurality of cooling holes 212 has a hole wall comprising a plurality of heat dissipation protrusions T, which are spaced apart on the hole wall of the cooling hole 212. The plurality of heat dissipation protrusions T can increase the surface area of ​​the inner wall of the cooling hole 212. When cooling oil flows through the cooling hole 212, the contact area between the cooling oil and the hole wall of the cooling hole 212 is larger, which can improve the heat exchange efficiency between the rotor laminations 21 and the cooling oil, thereby improving the heat dissipation effect of the rotor 10.

[0062] In one embodiment, as shown in FIG5, a rotor lamination 21 has multiple heat dissipation protrusions T on the wall of each cooling hole 212, which increases the contact area between the rotor lamination 21 and the cooling oil and enhances the liquid cooling effect.

[0063] The distribution and shape of the heat dissipation protrusions T included in the rotor lamination 21 provided in this application embodiment may be implemented in various ways. Next, the distribution of multiple heat dissipation protrusions T will be exemplarily described through specific embodiments.

[0064] Figures 6a and 6c are cross-sectional schematic diagrams of a partial structure of a rotor lamination 21, which includes a cooling hole 212. The wall of the cooling hole 212 is divided into multiple segments, including a first segment 2121, a second segment 2122, and a third segment 2123. The first segment 2121 is connected to the second segment 2122 via the third segment 2123. As a specific shape example, the first segment 2121, the second segment 2122, and the third segment 2123 are sequentially connected to form a triangular structure.

[0065] In one embodiment, a plurality of heat dissipation protrusions T are spaced apart on at least one of a first hole wall 2121, a second hole wall 2122, and a third hole wall 2123. Figure 6a illustrates a structure in which a plurality of heat dissipation protrusions T are spaced apart on one of the holes of a cooling hole 212, Figure 6b illustrates a structure in which a plurality of heat dissipation protrusions T are spaced apart on two of the holes of a cooling hole 212, and Figure 6c illustrates a structure in which a plurality of heat dissipation protrusions T are spaced apart on three of the holes of a cooling hole 212.

[0066] In one embodiment, the hole wall closer to the magnet hole 213 in a first hole wall 2121, a second hole wall 2122, and a third hole wall 2123 has multiple heat dissipation protrusions T, which can increase the contact area between the hole wall and the cooling oil and improve the heat dissipation efficiency.

[0067] In one embodiment, as shown in Figures 6a to 6b, a first section of hole wall 2121, a second section of hole wall 2122, and a third section of hole wall 2123 are arranged in an equilateral triangle, which can enhance the structural strength of the cooling hole 212.

[0068] In one embodiment, as shown in Figures 7a and 7b, a third segment hole wall 2123 is radially symmetrical about the oil-cooled drive motor, and a first segment hole wall 2121 and a second segment hole wall 2122 are also radially symmetrical about the oil-cooled drive motor. One end of the first segment hole wall 2121 is used to connect to the third segment hole wall 2123, the other end of the first segment hole wall 2121 is used to connect to one end of the second segment hole wall 2122, and the other end of the second segment hole wall 2122 is used to connect to the third segment hole wall 2123. Multiple heat dissipation protrusions T are radially symmetrically distributed in at least one of the first segment hole wall 2121, the second segment hole wall 2122, and the third segment hole wall 2123, which can balance the heat dissipation effect along the circumference of the oil-cooled drive motor. When the cooling holes are arranged between the two magnet holes 213, the heat dissipation effect of the cooling holes on the magnets 5 within the two magnet holes 213 is relatively balanced.

[0069] Referring to the structure of the rotor lamination 21, in one embodiment, as shown in Figure 7a, a first section hole wall 2121 and a second section hole wall 2122 are radially symmetrical about the rotor, and a third section hole wall 2123 is radially symmetrical along the oil-cooled drive motor. Multiple heat dissipation protrusions T are distributed at intervals on the first section hole wall 2121 and the second section hole wall 2122. When the cooling holes 212 are arranged at intervals along the circumference of the oil-cooled drive motor between the two magnet holes 213, and the first section hole wall 2121 and the second section hole wall 2122 are close to the two magnet holes 213, the multiple heat dissipation protrusions T included in the first section hole wall 2121 and the second section hole wall 2122 can increase the contact area between the cooling oil and the first section hole wall 2121 and the second section hole wall 2122, thereby improving heat exchange efficiency. Of course, since the contact area between the cooling oil and the first section hole wall 2121 and the second section hole wall 2122 is similar, the heat exchange efficiency of the cooling oil through the first section hole wall 2121 and the second section hole wall 2122 with the rotor lamination 21 is similar, and the magnets 5 on both sides of the cooling hole 212 can be cooled more evenly.

[0070] Referring to the structure of the rotor lamination 21, in one embodiment, as shown in Figure 7b, a first section wall 2121 and a second section wall 2122 are radially symmetrical about the rotor, and a third section wall 2123 is radially symmetrical along the oil-cooled drive motor. Multiple heat dissipation protrusions T are spaced apart on the third section wall 2123. When the cooling holes 212 are arranged circumferentially between the two magnet holes 213 along the oil-cooled drive motor, and the contact area between the cooling oil and the first section wall 2121 and the second section wall 2122 is similar, the heat exchange efficiency between the cooling oil and the rotor lamination 21 through the first section wall 2121 and the second section wall 2122 is similar, allowing for relatively uniform heat dissipation and cooling of the magnets 5 on both sides of the cooling holes 212.

[0071] In one embodiment, as shown in FIG8a, a first segment hole wall 2121 and a second segment hole wall 2122 are radially symmetrical about the rotor, and a third segment hole wall 2123 is the hole wall of the cooling hole 212 near the outer peripheral surface of the rotor lamination 21. Along the radial direction of the oil-cooled drive motor, the distance between the third segment hole wall 2123 and the outer peripheral surface of the rotor lamination 21 is smaller than the distance between the first segment hole wall 2121 and the second segment hole wall 2122 and the outer peripheral surface of the rotor lamination 21. The third segment hole wall 2123 is closer to the magnet hole 213 than the first segment hole wall 2121 and the second segment hole wall 2122. At this time, the multiple heat dissipation protrusions T are spaced apart on the third segment hole wall 2123, which is more conducive to the cooling oil dissipating heat from the magnet 5 in the magnet hole 213.

[0072] In one embodiment, as shown in FIG8b, when a first segment hole wall 2121 and a second segment hole wall 2122 are radially symmetrical about the rotor, the third segment hole wall 2123 can be the hole wall on the side of the cooling hole 212 closer to the central hole 211. Along the radial direction of the oil-cooled drive motor, the distance between the third segment hole wall 2123 and the outer peripheral surface of the rotor lamination 21 is greater than the distance between the first segment hole wall 2121 and the outer peripheral surface of the rotor lamination 21, and the distance between the second segment hole wall 2122 and the outer peripheral surface of the rotor lamination 21. The third segment hole wall 2123 is closer to the magnet hole 213 than the first segment hole wall 2121 and the second segment hole wall 2122. At this time, a portion of the multiple heat dissipation protrusions T are spaced apart on the first segment hole wall 2121, and a portion of the multiple heat dissipation protrusions T are spaced apart on the second segment hole wall 2122, which is more conducive to the cooling oil dissipating heat from the magnet 5 in the magnet hole 213.

[0073] In one embodiment, as shown in Figure 8a, the third section of the hole wall 2123 is the hole wall on the side of the cooling hole 212 closest to the central hole 211. The third section of the hole wall 2123 is arc-shaped, and the specific curvature is adapted to the central hole 211 of the rotor lamination 21, so that the shape of the third section of the hole wall 2123 can be adapted to the shape of the central hole 211. Along the radial direction of the oil-cooled drive motor, the distance between the third section of the hole wall 2123 and the central hole 211 is approximately consistent, which can enhance the strength of the rotor lamination 21.

[0074] Figure 9 illustrates a cross-sectional schematic diagram of a partial structure of another rotor lamination 21, which includes a cooling hole 212. As shown in Figure 9, the wall of the cooling hole 212 is divided into multiple segments, including a first segment 2121, a second segment 2122, a third segment 2123, and a fourth segment 2124. The first segment 2121 and the second segment 2122 are arranged radially opposite to each other along the oil-cooled drive motor. One end of the first segment 2121 is connected to the second segment 2122 via the third segment 2123, and the other end of the first segment 2121 is connected to the other end of the second segment 2122 via the fourth segment 2124. The cooling hole 212 has a trapezoidal shape. Multiple heat dissipation protrusions T are spaced apart and distributed at least one of a first section hole wall 2121, a second section hole wall 2122, a third section hole wall 2123, and a fourth section hole wall 2124, which are not shown in the figure here.

[0075] In one embodiment, along the radial direction of the oil-cooled drive motor, the distance between a first section of hole wall 2121 and the outer peripheral surface of the rotor lamination 21 is greater than the distance between a second section of hole wall 2122 and the outer peripheral surface of the rotor lamination 21. That is, the second section of hole wall 2122 is closer to the outer peripheral surface of the rotor lamination 21 than the first section of hole wall 2121, and thus closer to the magnet hole 213 of the rotor lamination 21. Multiple heat dissipation protrusions T are distributed on one of the second section of hole wall 2122. When the rotor 10 rotates, the cooling oil in the cooling hole 212 concentrates towards the side of the cooling hole 212 closer to the outer peripheral surface of the rotor lamination 21 due to centripetal force. This increases the contact area between the cooling oil and the second section of hole wall 2122, enhancing the heat dissipation effect.

[0076] In one embodiment, as shown in Figure 9, the first section of the hole wall 2121 is arc-shaped, and the specific curvature is adapted to the central hole 211 of the rotor lamination 21, so that the shape of the cooling hole 212 can be adapted to the shape of the central hole 211. Along the radial direction of the oil-cooled drive motor, the distance between the first section of the hole wall 2121 and the central hole 211 is approximately the same, which can enhance the strength of the rotor lamination 21.

[0077] In one embodiment, as shown in FIG9, a first section hole wall 2121 and a second section hole wall 2122 are opposite each other along the radial direction of the oil-cooled drive motor. The included angle β between the first section hole wall 2121 and the third section hole wall 2123 is approximately 60°, and the included angle β between the first section hole wall 2121 and the fourth section hole wall 2124 is approximately 60°, which can enhance the structural strength of the cooling hole 212.

[0078] In one embodiment, as shown in FIG10, a partial structure of a cooling hole 212 is provided, wherein the cross-sectional shape of each heat dissipation protrusion T perpendicular to the axial direction of the oil-cooled drive motor is similar to a quadrilateral. While ensuring the strength of the rotor laminations 21, this shape of the heat dissipation protrusions T can significantly increase the surface area of ​​the hole wall of the cooling hole 212, thereby improving the heat exchange efficiency of the rotor laminations 21 through the cooling hole 212.

[0079] In one embodiment, as shown in FIG10, the length h1 of each heat dissipation protrusion T protruding from the wall of the cooling hole 212 is greater than the width w1 of each heat dissipation protrusion T, which can increase the surface area of ​​the heat dissipation protrusion T, thereby increasing the surface area of ​​the inner wall of the cooling hole 212.

[0080] The width w1 of each heat dissipation protrusion T is greater than the distance w2 between two adjacent heat dissipation protrusions T, which increases the surface area of ​​the inner wall of the cooling hole 212 and can also ensure the structural strength of the rotor lamination 21.

[0081] In one specific embodiment, at least one of the width w1 of each heat dissipation protrusion T and the spacing w2 between two adjacent heat dissipation protrusions T is greater than or equal to 1 mm, and the length of each heat dissipation protrusion T protruding from the wall of the cooling hole 212 is 1-2 mm. It should be understood that the dimensions in this embodiment are only one implementation scheme, and in specific implementations, adaptive adjustments need to be made according to the specific structure of the oil-cooled drive motor 100.

[0082] In some embodiments, the cooling hole 212 includes multiple heat dissipation protrusions T divided into multiple heat dissipation protrusions T segments, each segment including two or more heat dissipation protrusions T. At least two segments of the multiple heat dissipation protrusions T differ in at least one of the following: number, shape, or spacing. When the number, shape, or spacing of the heat dissipation protrusions T in two segments differs, the surface areas of the two segments may differ, resulting in different contact areas between the cooling hole 212 and the cooling oil at the locations of the two heat dissipation protrusions T, thus leading to different heat exchange efficiencies at different locations of the cooling hole 212. The number, shape, or spacing of the heat dissipation protrusions T in different segments within the cooling hole 212 can be adjusted according to the specific structure of the rotor lamination 21 to meet the heat dissipation requirements at different locations of the rotor lamination 21.

[0083] Taking a cooling hole 212 as shown in Figure 11a as an example, the cooling hole 212 includes multiple heat dissipation protrusions T. Each heat dissipation protrusion T includes multiple heat dissipation protrusions T1 and multiple heat dissipation protrusions T2. For example, the number of heat dissipation protrusions T1 and T2 is the same, their shapes are similar but their sizes are different, and the spacing between two heat dissipation protrusions T1 is also different from the spacing between two heat dissipation protrusions T2.

[0084] Taking a cooling hole 212 as shown in Figure 11b as an example, the cooling hole 212 includes multiple heat dissipation protrusions T. Each heat dissipation protrusion T includes multiple heat dissipation protrusions T1 and multiple heat dissipation protrusions T2. For example, the number of heat dissipation protrusions T1 and T2 is the same, and their shapes are similar. The height of heat dissipation protrusions T1 from the hole wall is different from the height of heat dissipation protrusions T2 from the hole wall, and the distance between two heat dissipation protrusions T1 is also different from the distance between two heat dissipation protrusions T2.

[0085] Figure 12 illustrates the structure of a rotor core 2, which includes multiple rotor laminations 21 as described above. These laminations are arranged adjacent to each other along the axial direction of the oil-cooled drive motor to form the rotor core 2 shown in Figure 10. Multiple cooling holes 212 of one rotor lamination 21 in adjacent rotor laminations 21 are connected to multiple cooling holes 212 of the other rotor lamination 21, forming multiple axial flow channels d2. When cooling oil flows through the axial flow channels d2, the cooling oil can exchange heat with the rotor core 2 through the inner wall of the cooling holes 212, carrying away the heat from the rotor core 2 and achieving liquid cooling of the rotor core 2.

[0086] In one embodiment, the wall of each cooling hole 212 in the rotor laminations 21 of a rotor core 2 includes multiple heat dissipation protrusions T, and the distribution of heat dissipation protrusions T in multiple rotor laminations 21 of the same rotor core 2 is the same. When multiple rotor laminations 21 are arranged adjacently along the axial direction of the oil-cooled drive motor to form a rotor core 2, the shape of the axial flow channel d2 formed by each cooling hole 212 of a rotor lamination 21 communicating with a cooling hole 212 of an adjacent rotor lamination 21 can be kept consistent along the axial direction of the oil-cooled drive motor, reducing the resistance of the cooling oil flowing in the axial flow channel d2, which is beneficial to accelerating heat exchange and improving the cooling effect.

[0087] Figure 13 illustrates the structure of two adjacent rotor laminations 21 in a rotor core 2. Along the axial direction of the oil-cooled drive motor, the two rotor laminations 21 are arranged adjacently, with the center holes 211 of one rotor lamination 21 and the center holes 211 of the other rotor lamination 21 coaxial, and the radial protrusions t on the inner walls of the two center holes 211 corresponding to the keyway of the rotor shaft 1. Each cooling hole 212 of one rotor lamination 21 and one cooling hole 212 of the other rotor lamination 21 correspond along the axial direction of the oil-cooled drive motor, and the projection of each cooling hole 212 of one rotor lamination 21 onto the other rotor lamination 21 along the circumferential direction of the oil-cooled drive motor can overlap with a cooling hole 212. In one embodiment, the projection of each cooling hole 212 of one rotor lamination 21 onto the other rotor lamination 21 along the circumferential direction of the oil-cooled drive motor coincides with a cooling hole 212.

[0088] In one embodiment, the distribution of heat dissipation protrusions T in the rotor laminations 21 of one of two adjacent rotor cores 2 differs from that in the rotor laminations 21 of the other rotor core 2. The distribution of the heat dissipation protrusions T includes, but is not limited to, characteristics such as their location, number, and structural shape.

[0089] Figure 14 illustrates a rotor 10 comprising two rotor cores 2, which are arranged adjacent to each other along the axial direction of an oil-cooled drive motor. Each rotor core 2 has a rotor lamination 21 comprising multiple cooling holes 212, including multiple first cooling holes 212a and multiple second cooling holes 212b, which are arranged alternately along the circumference of the oil-cooled drive motor. Along the circumference of the oil-cooled drive motor, each first cooling hole 212a is spaced between two second cooling holes 212b, and each second cooling hole 212b is spaced between two first cooling holes 212a. Each first cooling hole 212a has multiple heat dissipation protrusions T distributed on its wall. In any rotor core 2, a first cooling hole 212a of each rotor lamination 21 can be connected with a first cooling hole 212a of an adjacent rotor lamination 21 to form an axial flow channel d2 of the rotor core 2, and a second cooling hole 212b of each rotor lamination 21 can be connected with a second cooling hole 212b of an adjacent rotor lamination 21 to form an axial flow channel d2 of the rotor core 2.

[0090] In one embodiment, as shown in FIG14, the distribution positions of the multiple heat dissipation protrusions T on the rotor laminations 21 of the two rotor cores 2 are different. Specifically, between the two rotor cores 2, an axial flow channel d2 formed by each first cooling hole 212a of one rotor core 2 is used to communicate with an axial flow channel d2 formed by a second cooling hole 212b of the other rotor core 2 along the axial direction of the oil-cooled drive motor, and an axial flow channel d2 formed by each second cooling hole 212b of one rotor core 2 is used to communicate with an axial flow channel d2 formed by a first cooling hole 212a of the other rotor core 2 along the axial direction of the oil-cooled drive motor. When the cooling oil passes through the channel formed by the connection between the two rotor cores 2, due to the different distribution of the heat dissipation protrusions T on the rotor laminations 21 of the two rotor cores 2, the contact area between the cooling oil and the cooling holes 212 of the two rotor cores 2 is different, which can change the heat exchange efficiency between the cooling oil and the two rotor cores 2, thereby changing the heat dissipation effect of the rotor 10 at different positions.

[0091] In one embodiment, multiple axial flow channels d2 of one rotor core 2 receive cooling oil through multiple axial flow channels d2 of the other rotor core 2. The number of heat dissipation protrusions T in the rotor laminations 21 of the two rotor cores 2 is different. Specifically, the number of heat dissipation protrusions T in the rotor laminations 21 of one rotor core 2 is greater than the number of heat dissipation protrusions T in the rotor laminations 21 of the other rotor core 2. The rotor lamination 21 with more heat dissipation protrusions T has a larger surface area of ​​the cooling hole wall 212, a larger contact area between the rotor lamination 21 and the cooling oil, and a higher heat exchange efficiency between the cooling oil and the rotor lamination 21. Therefore, the oil cooling heat dissipation effect of the rotor core 2 formed by the rotor lamination 21 is better.

[0092] It should be understood that in the structural design of rotor 10, the distribution of heat dissipation protrusions T in the rotor laminations 21 of the multiple rotor cores 2 included in rotor 10 can be adjusted according to the heat dissipation requirements of different positions of rotor 10, which can be achieved by changing the contact area between cooling oil and rotor core 2.

[0093] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A rotor lamination for an oil-cooled drive motor, characterized by The rotor lamination includes a central hole, multiple cooling holes, and multiple magnet holes. The central hole is used to assemble the rotor shaft, each magnet hole is used to assemble a magnet, and each cooling hole is used to circulate cooling oil. The central hole extends through the rotor lamination along its axial direction, and each magnet hole extends through the rotor lamination along its axial direction. The multiple magnet holes are arranged around the central hole, and each cooling hole extends through the rotor lamination along its axial direction. The multiple cooling holes are arranged around the central hole, and at least one of the cooling holes has a wall with multiple heat dissipation protrusions, which are spaced apart from each other on the wall of the cooling hole.

2. The rotor lamination as described in claim 1, characterized in that, Each of the cooling holes is arranged circumferentially along the rotor lamination between two adjacent magnet holes. The wall of each cooling hole in the at least one cooling hole is divided into multiple segments, including a first segment, a second segment, and a third segment, wherein: The first section of the hole wall is connected to the second section of the hole wall through the third section of the hole wall. The first section of the hole wall and the second section of the hole wall are arranged symmetrically or oppositely along the radial direction of the rotor. The plurality of heat dissipation protrusions are distributed at intervals in at least one of the first section of the hole wall, the second section of the hole wall and the third section of the hole wall.

3. The rotor lamination as described in claim 2, characterized in that, The third segment of the bore wall is radially symmetrical about the rotor, the first segment of the bore wall and the second segment of the bore wall are radially symmetrical about the rotor, one end of the first segment of the bore wall is used to connect to the third segment of the bore wall, the other end of the first segment of the bore wall is used to connect to one end of the second segment of the bore wall, and the other end of the second segment of the bore wall is used to connect to the third segment of the bore wall, wherein: The plurality of heat dissipation protrusions are symmetrically distributed radially along the rotor on at least one of the first section hole wall, the second section hole wall, and the third section hole wall.

4. The rotor lamination as described in claim 3, characterized in that, The distance between the third section hole wall and the outer peripheral surface of the rotor lamination along the radial direction is less than the distance between the first section hole wall, the second section hole wall and the outer peripheral surface of the rotor lamination. A portion of the plurality of heat dissipation protrusions are spaced apart on the first section hole wall, and a portion of the plurality of heat dissipation protrusions are spaced apart on the second section hole wall.

5. The rotor lamination as described in claim 3, characterized in that, The distance between the third section hole wall and the outer peripheral surface of the rotor lamination along the radial direction is less than the distance between the first section hole wall, the second section hole wall and the outer peripheral surface of the rotor lamination, and the plurality of heat dissipation protrusions are spaced apart on the third section hole wall.

6. The rotor lamination as described in claim 2, characterized in that, The multi-segment hole wall further includes a fourth segment hole wall. The first segment hole wall and the second segment hole wall are arranged radially opposite to each other along the rotor. One end of the first segment hole wall is connected to one end of the second segment hole wall through the third segment hole wall, and the other end of the first segment hole wall is connected to the other end of the second segment hole wall through the fourth segment hole wall, wherein: The distance between the first section of the hole wall and the outer peripheral surface of the rotor lamination along the radial direction is greater than the distance between the second section of the hole wall and the outer peripheral surface of the rotor lamination, and the plurality of heat dissipation protrusions are distributed on the second section of the hole wall.

7. The rotor lamination as described in any one of claims 1-6, characterized in that, The length of each heat dissipation protrusion protruding from the wall of the cooling hole is greater than the width of each heat dissipation protrusion.

8. The rotor lamination as described in claim 7, characterized in that, The width of each heat dissipation protrusion and the spacing between two adjacent heat dissipation protrusions are at least 1 mm or greater, and the length of each heat dissipation protrusion protruding from the wall of the cooling hole is 1-2 mm.

9. The rotor lamination as described in any one of claims 1-8, characterized in that, The plurality of heat dissipation protrusions are divided into multiple heat dissipation protrusion segments, each of which includes two or more heat dissipation protrusions. At least two of the multiple heat dissipation protrusion segments are different in at least one of the following: number, shape, or spacing of the heat dissipation protrusions.

10. An oil-cooled drive motor, said oil-cooled drive motor being used to drive the wheels of an electric vehicle, characterized in that, The oil-cooled drive motor includes a stator and a rotor. The central hole of the stator is used to accommodate the rotor. The rotor includes multiple rotor cores, which are arranged adjacent to each other along the axial direction of the rotor. Each rotor core includes a plurality of rotor laminations as described in any one of claims 1-9. The plurality of rotor laminations in each rotor core are arranged sequentially adjacent to each other along the axial direction of the drive motor. In each rotor core, a plurality of cooling holes of one rotor lamination in two adjacent rotor laminations are respectively connected to a plurality of cooling holes of the other rotor lamination to form a plurality of axial flow channels.

11. The oil-cooled drive motor as described in claim 10, characterized in that, The wall of each cooling hole in the rotor lamination of at least one rotor core includes a plurality of heat dissipation protrusions, and the distribution of the heat dissipation protrusions is the same in the plurality of rotor laminations of the same rotor core.

12. The oil-cooled drive motor as described in claim 11, characterized in that, The distribution of heat dissipation protrusions in the rotor laminations of one of the two adjacent rotor cores is different from the distribution of heat dissipation protrusions in the rotor laminations of the other rotor core.

13. The oil-cooled drive motor as described in claim 12, characterized in that, In two adjacent rotor cores, a plurality of axial flow channels in one rotor core receive oil through a plurality of axial flow channels in the other rotor core, wherein the number of heat dissipation protrusions in the rotor laminations of the one rotor core is greater than the number of heat dissipation protrusions in the rotor laminations of the other rotor core.

14. A powertrain, characterized in that, The powertrain includes a reduction gear and an oil-cooled drive motor as described in any one of claims 10-13, the oil-cooled drive motor being used to drive the wheels of the electric vehicle via the reduction gear.

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