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 lamination for oil-cooled driving motor, oil-cooled driving motor and power assembly

[0001] Cross-reference to related applications

[0002] This application claims priority to the Chinese patent application No. 202422969600.0, filed on November 30, 2024, and entitled "Rotor lamination for oil-cooled driving motor, oil-cooled driving motor and power assembly", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0003] The present application relates to the technical field of electric machines, and in particular to a rotor lamination for an oil-cooled driving motor, an oil-cooled driving motor and a power assembly. BACKGROUND

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

[0005] Currently, cooling oil is supplied to the rotor of the electric machine to cool the rotor by liquid cooling. Specifically, the cooling oil flows into the oil passage inside the rotor, and flows to both sides of the end of the rotor and is sprayed out with the rotation of the rotor. The cooling oil exchanges heat with the rotor during the flow process to cool the rotor. The cooling effect of the rotor affects the working efficiency of the electric machine. SUMMARY

[0006] The present application provides a rotor lamination for an oil-cooled driving motor, an oil-cooled driving motor and power assembly, which can improve the heat exchange between the cooling oil and the rotor, improve the cooling effect of the rotor, and optimize the performance of the electric machine.

[0007] In a first aspect, the present application provides a rotor lamination for an oil-cooled driving motor. The rotor lamination includes a central hole, a plurality of cooling holes and a plurality of magnetic steel holes. The central hole is used to assemble a rotor shaft. Each magnetic steel hole is used to assemble a magnetic steel. Each cooling hole is used to flow cooling oil. The central hole penetrates the rotor lamination along the axial direction of the rotor lamination. Each magnetic steel hole penetrates the rotor lamination along the axial direction of the rotor lamination. The plurality of magnetic steel holes are arranged around the central hole. Each cooling hole penetrates the rotor lamination along the axial direction of the rotor lamination. The plurality cooling holes are arranged around the central hole. The hole wall of at least one of the plurality of cooling holes includes a plurality of heat dissipation protrusions. The plurality of heat dissipation protrusions are arranged at intervals on the hole wall of the cooling hole.

[0008] The above rotor lamination, the hole wall of at least one of the plurality of cooling holes includes a plurality of heat dissipation projections. The heat dissipation projections can increase the surface area of the hole wall of the cooling hole. When the cooling oil flows through the cooling hole, the contact area between the cooling oil and the rotor lamination is larger, and the heat exchange effect is better, thereby improving the oil cooling effect of the rotor.

[0009] In an embodiment, each cooling hole is arranged between two adjacent magnetic steel holes along the circumferential direction of the rotor lamination, and the heat generated by the magnetic steel embedded in the magnetic steel hole can be taken away by heat exchange between the cooling oil and the rotor lamination. The wall of each of the at least one cooling hole is divided into multiple sections, including a first section, a second section, and a third section. The first section is connected to the second section through the third section. The first section and the second section are symmetrically or oppositely arranged along the radial direction of the rotor. The heat dissipation protrusions are distributed in at least one of the first section, the second section, and the third section. Different distribution positions of the heat dissipation protrusions can change the heat dissipation effect of different positions of the rotor lamination.

[0010] In an embodiment, the third section is symmetrically arranged along the radial direction of the rotor. The first section and the second section are symmetrically arranged along the radial direction of the rotor. One end of the first section is used to connect the third section. The other end of the first section is used to connect one end of the second section. The other end of the second section is used to connect the third section. The heat dissipation protrusions are symmetrically distributed in at least one of the first section, the second section, and the third section along the radial direction of the rotor. The first section, the second section, and the third section are connected to form a triangle, which is beneficial to enhance the structural strength of the rotor lamination. The symmetric distribution of the heat dissipation protrusions along the radial direction of the rotor can balance the heat dissipation effect on both sides of the cooling hole in the circumferential direction.

[0011] In an embodiment, the distance between the third section and the outer circumferential surface of the rotor lamination along the radial direction of the rotor lamination is greater than the distance between the first section and the second section and the outer circumferential surface of the rotor lamination. The third section is the wall of the cooling hole close to the center hole. The first section and the second section are closer to the magnetic steel hole than the third section. A part of the heat dissipation protrusions are distributed in the first section. A part of the heat dissipation protrusions are distributed in the second section, which is more beneficial to the heat dissipation of the magnetic steel in the magnetic steel hole by the cooling oil.

[0012] In an embodiment, the distance between the third section and the outer circumferential surface of a rotor lamination along the radial direction of the rotor lamination is less than the distance between the first section and the second section and the outer circumferential surface of a rotor lamination. The third section is the wall of the cooling hole away from the center hole. The third section is closer to the magnetic steel hole than the first section and the second section. The heat dissipation protrusions are distributed in the third section, which is more beneficial to the heat dissipation of the magnetic steel in the magnetic steel holes by the cooling oil.

[0013] In one embodiment, the multi-section hole wall further comprises a fourth section hole wall, a first section hole wall and a second section hole wall are arranged opposite in the radial direction of the rotor, one end of the first section hole wall is connected to one end of the second section hole wall through the third section hole wall, and the other end of the first section hole wall is connected to the other end of the second section hole wall through the fourth section hole wall. Wherein: the distance between the first section hole wall and the outer circumferential surface of the rotor lamination in the radial direction of the rotor lamination is greater than the distance between the second section hole wall and the outer circumferential surface of the rotor lamination, and the plurality of heat dissipation protrusions are distributed on the second section hole wall. The cooling hole has a trapezoidal shape, the second section hole wall is closer to the magnet hole than the other section hole walls, and the plurality of heat dissipation protrusions distributed on the second section hole wall are more conducive to cooling the magnet in the magnet hole.

[0014] In one embodiment, the length of each heat dissipation protrusion protruding from the hole 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 and thus increase 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 distance 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 hole wall of the cooling hole is 1-2 mm.

[0016] In one embodiment, the plurality of heat dissipation protrusions are divided into a plurality of sections of heat dissipation protrusions, each section of heat dissipation protrusions comprises two or more heat dissipation protrusions, and at least two sections of heat dissipation protrusions in the plurality of sections of heat dissipation protrusions differ in at least one of the number, shape or distance of the heat dissipation protrusions. The number, shape or distance of the heat dissipation protrusions in different sections of the cooling hole can be adjusted according to the specific structure of the rotor lamination to meet the heat dissipation requirements of different positions of the rotor lamination.

[0017] In a second aspect, the embodiments of the present application provide an oil-cooled driving motor, which is used to drive a wheel of an electric vehicle. The oil-cooled driving motor comprises a stator and a rotor, a central hole of the stator is used to accommodate the rotor, and the rotor comprises a plurality of rotor cores which are arranged in sequence along an axial direction of the rotor. Each of the rotor cores comprises a plurality of rotor laminations provided in the first aspect, and the plurality of rotor laminations in each of the rotor cores are arranged in sequence along the axial direction of the driving motor. A plurality of cooling holes in one of the rotor laminations in each of the rotor cores are connected to a plurality of cooling holes in another of the rotor laminations to form a plurality of axial flow channels. Cooling oil flows through the axial flow channels, and the oil cooling of the rotor can be achieved by heat exchange between the cooling oil and the rotor cores. Since the hole wall of at least one of the cooling holes in the rotor laminations comprises a plurality of heat dissipation protrusions, the heat dissipation effect of the oil cooling can be improved by increasing the heat exchange area, and the efficiency of the oil-cooled driving motor is higher. In one embodiment, the hole wall of each of the cooling holes in the rotor laminations of at least one of the rotor cores comprises a plurality of heat dissipation protrusions, and the distribution of the heat dissipation protrusions in the plurality of rotor laminations of the same rotor core is the same. The heat dissipation effect of different positions of the same rotor core can be kept relatively consistent, the flow resistance of the cooling oil can be reduced, and the heat dissipation effect of the oil cooling can be enhanced.

[0018] In one embodiment, the distribution of the heat dissipation protrusions in the rotor laminations of one of the rotor cores of the adjacent two rotor cores is different from the distribution of the heat dissipation protrusions in the rotor laminations of the other of the rotor cores, so that the heat dissipation effect of different positions of the rotor along the axial direction of the oil-cooled driving motor is changed.

[0019] In one embodiment, the plurality of axial flow channels of one of the rotor cores of the adjacent two rotor cores receive cooling oil through the plurality of axial flow channels of the other of the rotor cores, and the number of the heat dissipation protrusions in the rotor laminations of one of the rotor cores is greater than the number of the heat dissipation protrusions in the rotor laminations of the other of the rotor cores. The number of the heat dissipation protrusions is large, the contact area between the cooling hole and the cooling oil is large, the heat exchange efficiency between the cooling oil and the rotor laminations is high, and the oil cooling heat dissipation effect of the rotor core formed by the rotor laminations is better.

[0020] In a third aspect, the embodiments of the present application provide a power assembly, which can be applied to an electric vehicle. The power assembly comprises a reducer and an oil-cooled driving motor provided in the second aspect, and the oil-cooled driving motor is used to drive a wheel of the electric vehicle through the reducer. BRIEF DESCRIPTION OF DRAWINGS

[0021] FIG. 1 is a structural schematic diagram of an electric vehicle provided in the embodiments of the present application;

[0022] FIG. 2 is a structural schematic diagram of a power assembly provided in the embodiments of the present application;

[0023] Fig. 3 is a cross-sectional structure diagram of an oil-cooled driving motor according to an embodiment of the present application;

[0024] Fig. 4a is a structure diagram of a rotor of an oil-cooled driving motor according to an embodiment of the present application;

[0025] Fig. 4b is an exploded view of a rotor of an oil-cooled driving motor according to an embodiment of the present application;

[0026] Fig. 5 is a structure diagram of a rotor lamination of an oil-cooled driving motor according to an embodiment of the present application;

[0027] Fig. 6a is a structure diagram of a cooling hole of a rotor lamination of an oil-cooled driving motor according to an embodiment of the present application;

[0028] Fig. 6b is a structure diagram of a cooling hole of a rotor lamination of an oil-cooled driving motor according to an embodiment of the present application;

[0029] Fig. 6c is a structure diagram of a cooling hole of a rotor lamination of an oil-cooled driving motor according to an embodiment of the present application;

[0030] Fig. 7a is a structure diagram of a cooling hole of a rotor lamination of an oil-cooled driving motor according to an embodiment of the present application;

[0031] Fig. 7b is a structure diagram of a cooling hole of a rotor lamination of an oil-cooled driving motor according to an embodiment of the present application;

[0032] Fig. 8a is a structure diagram of a cooling hole of a rotor lamination of an oil-cooled driving motor according to an embodiment of the present application;

[0033] Fig. 8b is a structure diagram of a cooling hole of a rotor lamination of an oil-cooled driving motor according to an embodiment of the present application;

[0034] Fig. 9 is a structure diagram of a cooling hole of a rotor lamination of an oil-cooled driving motor according to an embodiment of the present application;

[0035] Fig. 10 is a structure diagram of a cooling hole of a rotor lamination of an oil-cooled driving motor according to an embodiment of the present application;

[0036] Fig. 11a is a structure diagram of a cooling hole of a rotor lamination of an oil-cooled driving motor according to an embodiment of the present application;

[0037] Fig. 11b is a structure diagram of a cooling hole of a rotor lamination of an oil-cooled

[0038] Fig. 12 is a structure diagram of a rotor core of an oil-cooled driving motor according to an embodiment of the present application;

[0039] FIG. 13 is a structural schematic diagram of two rotor laminations of an oil-cooled driving motor according to an embodiment of the present application;

[0040] FIG. 14 is a structural schematic diagram of two rotor cores of an oil-cooled driving motor according to an embodiment of the present application.

[0041] 1000, powertrain; 2000, transmission mechanism; 3000, wheel; 100, motor; 200, motor controller; 300, speed 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 section of hole wall; 2122, second section of hole wall; 2123, third section of hole wall; 2124, fourth section of hole wall; 213, magnetic steel hole; 3, end plate; 31, liquid outlet hole; 4, fixing member; 4a, annular structure member; 4b, annular shoulder; 5, magnetic steel; 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 DESCRIPTION

[0042] In the prior art, cooling oil is supplied to the rotor of the motor to cool the rotor by liquid cooling, and the liquid cooling effect of the rotor affects the performance of the motor.

[0043] Therefore, the present application provides a rotor lamination for an oil-cooled driving motor, an oil-cooled driving motor, and a powertrain, which can improve the heat exchange between the cooling oil and the rotor, improve the heat dissipation effect of the rotor, and optimize the performance of the motor.

[0044] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the drawings.

[0045] FIG. 1 is a structural schematic diagram of an electric vehicle provided by an embodiment of the present application. As shown in FIG. 1, the electric vehicle can 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 power assembly 1000, a transmission mechanism 2000, and wheels 3000. The power assembly 1000 is configured to convert electric energy into mechanical energy, the transmission mechanism 2000 is drivingly connected to the power assembly 1000 and the wheels 3000, and can transmit the mechanical energy output by the power assembly to the wheels 3000 to drive the wheels to rotate. Of course, the electric vehicle also includes a vehicle frame that bears the load of the internal and external environment of the vehicle and a battery that supplies power to the power assembly 1000, which is not shown here.

[0046] FIG. 2 is a structural schematic diagram of the power assembly 1000 provided by an embodiment of the present application. As shown in FIG. 2, the power assembly 1000 includes an oil-cooled drive motor 100 and a motor controller 200. The motor controller 200 is configured to convert the direct current provided by the battery into alternating current and deliver the alternating current to the oil-cooled drive motor 100. In an embodiment, the power assembly 1000 also includes a speed reducer 300, and the power output end of the oil-cooled drive motor 100 is drivingly connected to the wheels 3000 of the vehicle through the speed reducer 300. The speed reducer 300 can also be referred to as a transmission.

[0047] In an embodiment of the present application, the oil-cooled drive motor 100 of the electric vehicle is supplied with cooling oil to exchange heat with the oil-cooled drive motor 100, so that the oil-cooled drive motor 100 can be cooled to improve the performance of the motor.

[0048] FIG. 3 is a cross-sectional structural schematic diagram of an oil-cooled drive motor 100. As shown in FIG. 3, the oil-cooled drive motor 100 includes a rotor 10, a stator 20, and a housing 30, and a part of the stator 20 and the rotor 10 are accommodated in the housing 30. In an embodiment, the stator 20 is fixed in the housing 30 along the circumferential direction of the oil-cooled drive motor, the rotor 10 is rotatably assembled in the central hole of the stator 20, and one end of the rotor 10 extends out of the housing 30 along the axial direction of the oil-cooled drive motor to form a power output end S of the oil-cooled drive motor 100. The stator 20 includes a stator core 201 and a stator winding 202 wound on the stator core 201. When the stator winding 202 is supplied with electricity, a magnetic field can be formed in the central hole of the stator core 201, and the rotor 10 can rotate around the axial line of the rotor 10 in the magnetic field.

[0049] The oil cooling circuit is formed inside the rotor 10. The cooling oil is supplied into the oil cooling circuit inside the rotor 10 to cool the rotor 10 by liquid cooling. The cooling oil is finally sprayed out from the two axial ends of the rotor 10. In the present application, the axial direction of the rotor and the axial direction of the oil-cooled driving motor refer to the same direction, the circumferential direction of the rotor and the circumferential direction of the oil-cooled driving motor refer to the same direction, and the radial direction of the rotor and the radial direction of the oil-cooled driving motor refer to the same direction. For the convenience of understanding, the axial direction of the oil-cooled driving motor 100 is referred to as letter A, the radial direction of the oil-cooled driving motor 100 is referred to as letter R, and the circumferential direction of the oil-cooled driving motor 100 is referred to as letter C.

[0050] FIG. 4a is a structure of the rotor 10 in an embodiment provided by the present application, and FIG. 4b is an exploded view of the rotor. The structure of the rotor 10 can be understood in combination with FIG. 4a and FIG. 4b.

[0051] In an embodiment, the rotor 10 includes a plurality of rotor cores 2 arranged in sequence along the axial direction of the oil-cooled driving motor. Each rotor core 2 includes a plurality of axial flow channels d2. The plurality of axial flow channels d2 of each rotor core 2 and the plurality of axial flow channels d2 of the adjacent rotor core 2 can respectively communicate along the axial direction of the oil-cooled driving motor to form a circuit for the cooling oil to flow inside the rotor 10.

[0052] In an embodiment, the rotor 10 further includes a plurality of magnetic steels 5, and each rotor core 2 is embedded with a plurality of magnetic steels 5. The magnetic steels 5 can form a magnetic field of the rotor 10, which is used to couple with the magnetic field of the stator 20 to drive the rotor 10 to rotate around the axis.

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

[0054] In some embodiments, the plurality of rotor cores 2 and the two end plates 3 arranged on both sides of the plurality of rotor cores 2 along the axial direction of the oil-cooled driving motor can be axially positioned by two fixing members 4. One of the two fixing members 4 is arranged on the side of one of the two end plates 3 away from the plurality of rotor cores 2 along the axial direction of the oil-cooled driving motor, and the other fixing member 4 is arranged on the side of the other end plate 3 away from the plurality of rotor cores 2 along the axial direction of the oil-cooled driving motor.

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

[0056] In one embodiment, the other fixing member 4 is an annular structure member 4a which is used to be fixed on the rotor shaft 1 by friction.

[0057] In one embodiment, each rotor core 2 of the rotor 10 provided by the embodiments of the present application comprises a plurality of rotor laminations 21 as shown in FIG. 5, and the plurality of rotor laminations 21 arranged adjacent to each other along the axial direction of the oil-cooled driving motor can form one rotor core 2.

[0058] Please refer to FIG. 5, the rotor lamination 21 comprises a central hole 211, a plurality of cooling holes 212 and a plurality of magnetic steel holes 213, the central hole 211 is used to assemble the rotor shaft 1, each magnetic steel hole 213 is used to assemble the magnetic steel 5, and each cooling hole 212 is used to flow the cooling oil. The central hole 211 penetrates the rotor lamination 21 along the axial direction of the rotor lamination, and each magnetic steel hole 213 penetrates the rotor lamination 21 along the axial direction of the rotor lamination. The plurality of magnetic steel holes 213 are arranged at intervals around the central hole 211, and when each magnetic steel hole 213 is assembled with the magnetic steel 5, the plurality of magnetic steels 5 are arranged at intervals around the central hole 211 to form an annular rotor magnetic field for coupling with the stator magnetic field of the stator 20. The plurality of magnetic steel holes 213 arranged at intervals around the central hole 211 can also be considered as the plurality of magnetic steel holes 213 arranged at intervals along the circumferential direction of the oil-cooled driving motor.

[0059] In one embodiment, the inner wall of the central hole 211 of the rotor lamination 21 comprises one or more radial protrusions t. When the central hole 211 of the rotor lamination 21 is assembled with the rotor shaft 1, the radial protrusions t can be matched with the key grooves 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 21, and a plurality of cooling holes 212 are arranged at intervals along the circumferential direction of the rotor lamination 21, and each cooling hole 212 is arranged between two adjacent magnetic steel holes 213 along the circumferential direction of the rotor lamination 21. The heat generated by the magnetic steel 5 assembled in the magnetic steel hole 213 can be taken away through heat exchange with the cooling oil in the cooling hole 212.

[0061] In one embodiment, the hole wall of at least one cooling hole 212 of the plurality of cooling holes 212 comprises a plurality of heat dissipation protrusions T arranged at intervals 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 in 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 lamination 21 and the cooling oil, thereby improving the heat dissipation effect of the rotor 10.

[0062] In one embodiment, as shown in FIG. 5, the hole wall of each cooling hole 212 comprises a plurality of heat dissipation protrusions T, which increases the contact area between the rotor lamination 21 and the cooling oil and enhances the liquid cooling effect.

[0063] The distribution position and shape of the heat dissipation protrusions T included in the rotor lamination 21 provided in the embodiments of the present application can have various implementation manners. Next, the distribution of the plurality of heat dissipation protrusions T will be exemplarily introduced through specific embodiments.

[0064] FIGS. 6a to 6c are cross-sectional schematic views of a partial structure of a rotor lamination 21, which includes one cooling hole 212. The hole wall of the one cooling hole 212 is divided into a plurality of hole walls, which include a first section hole wall 2121, a second section hole wall 2122, and a third section hole wall 2123. The first section hole wall 2121 is connected to the second section hole wall 2122 through the third section hole wall 2123, and as a specific shape example, the first section hole wall 2121, the second section hole wall 2122, and the third section hole wall 2123 are sequentially connected to form a triangular structure.

[0065] In one embodiment, the plurality of heat dissipation protrusions T are arranged at intervals in at least one of the first section hole wall 2121, the second section hole wall 2122, and the third section hole wall 2123. FIG. 6a exemplifies a structure in which the plurality of heat dissipation protrusions T are arranged at intervals on one hole wall of the cooling hole 212, FIG. 6b exemplifies a structure in which the plurality of heat dissipation protrusions T are arranged at intervals in two hole walls of the cooling hole 212, and FIG. 6c exemplifies a structure in which the plurality of heat dissipation protrusions T are arranged at intervals among the three hole walls of the cooling hole 212.

[0066] In one embodiment, the first section of the hole wall 2121, the second section of the hole wall 2122 and the third section of the hole wall 2123 are provided with a plurality of heat dissipation protrusions T closer to the hole wall of the magnetic steel hole 213, which can increase the contact area of the hole wall with the cooling oil and improve the heat dissipation efficiency.

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

[0068] In one embodiment, as shown in FIGS. 7a and 7b, the third section of the hole wall 2123 is radially symmetrical to the oil-cooled driving motor, and the first section of the hole wall 2121 and the second section of the hole wall 2122 are radially symmetrical to the oil-cooled driving motor. One end of the first section of the hole wall 2121 is connected to the third section of the hole wall 2123, and the other end of the first section of the hole wall 2121 is connected to one end of the second section of the hole wall 2122, and the other end of the second section of the hole wall 2122 is connected to the third section of the hole wall 2123. A plurality of heat dissipation protrusions T are distributed in at least one of the first section of the hole wall 2121, the second section of the hole wall 2122 and the third section of the hole wall 2123, which can balance the heat dissipation effect along the circumferential direction of the oil-cooled driving motor. When the cooling hole is arranged between the two magnetic steel holes 213, the cooling hole has a balanced heat dissipation effect on the magnetic steel 5 in the two magnetic steel holes 213.

[0069] Referring to the structure of the rotor lamination 21, in one embodiment, as shown in FIG. 7a, the first section of the hole wall 2121 and the second section of the hole wall 2122 are radially symmetrical to the rotor, and the third section of the hole wall 2123 is radially symmetrical to the oil-cooled driving motor. A plurality of heat dissipation protrusions T are respectively and evenly distributed in the first section of the hole wall 2121 and the second section of the hole wall 2122. When the cooling hole 212 is arranged between the two magnetic steel holes 213 along the circumferential direction of the oil-cooled driving motor, the first section of the hole wall 2121 and the second section of the hole wall 2122 are respectively close to the two magnetic steel holes 213, and the plurality of heat dissipation protrusions T included in the first section of the hole wall 2121 and the second section of the hole wall 2122 can increase the contact area of the cooling oil with the first section of the hole wall 2121 and the second section of the hole wall 2122, thereby improving the heat exchange efficiency. Of course, when the contact area of the cooling oil with the first section of the hole wall 2121 and second section of the hole wall 2122 is similar, the heat exchange efficiency of the cooling oil through the first section of the hole wall 2121 and the second section of the hole wall 2132 with the rotor lamination 21 is similar, which can uniformly cool the magnetic steel 5 on both sides of the cooling hole 212.

[0070] With reference to the structure of the rotor lamination 21, in one embodiment, as shown in FIG. 7b, a first section of the hole wall 2121 and a second section of the hole wall 2122 are radially symmetrical about the rotor, and a third section of the hole wall 2123 is radially symmetrical along the oil-cooled driving motor. The plurality of heat dissipation protrusions T are distributed at intervals on the third section of the hole wall 2123. When the cooling holes 212 are arranged at intervals along the circumference of the oil-cooled driving motor between the two magnetic steel holes 213, the cooling oil has similar contact areas with the first section of the hole wall 2121 and the second section of the hole wall 2122, and the heat exchange efficiency of the cooling oil through the first section of the hole wall 2121 and the second section of the hole wall 2122 with the rotor lamination 21 is similar, which can uniformly cool the magnetic steel 5 on both sides of the cooling hole 212.

[0071] In one embodiment, as shown in FIG. 8a, when a first section of the hole wall 2121 and a second section of the hole wall 2122 are radially symmetrical about the rotor, a third section of the hole wall 2123 is the hole wall on the side of the cooling hole 212 close to the outer circumferential surface of the rotor lamination 21. Along the radial direction of the oil-cooled driving motor, the distance between the third section of the hole wall 2123 and the outer circumferential surface of the rotor lamination 21 is smaller than the distance between the first section of the hole wall 2121 and the outer circumferential surface of the rotor lamination 21 and the distance between the second section of the hole wall 2122 and the outer circumferential surface of the rotor lamination 21, and the third section of the hole wall 2123 is closer to the magnetic steel hole 213 than the first section of the hole wall 2121 and the second section of the hole wall 2122. At this time, the plurality of heat dissipation protrusions T are distributed at intervals on the third section of the hole wall 2123, which is more conducive to heat dissipation of the magnetic steel 5 in the magnetic steel hole 213 by the cooling oil.

[0072] In one embodiment, as shown in FIG. 8b, when a first section of the hole wall 2121 and a second section of the hole wall 2122 are radially symmetrical about the rotor, a third section of the hole wall 2123 can be the hole wall on the side of the cooling hole 212 close to the central hole 211. Along the radial direction of the oil-cooled driving motor, the distance between the third section of the hole wall 2123 and the outer circumferential surface of the rotor lamination 21 is greater than the distance between the first section of the hole wall 2121 and the outer circumferential surface of the

[0073] In one embodiment, as shown in FIG. 8a, the third section of the hole wall 2123 is the hole wall of the cooling hole 212 close to the side of the center hole 211 of the rotor punching sheet 21. The third section of the hole wall 2123 is arc-shaped, and the specific curvature is matched with the center hole 211 of the rotor punching sheet 21, so that the shape of the third section of the hole wall 2123 can be matched with the shape of the center hole 211. Along the radial direction of the oil-cooled driving motor, the distance between the third section of the hole wall 2123 and the center hole 211 is substantially consistent, which can enhance the strength of the rotor punching sheet 21.

[0074] FIG. 9 shows a cross-sectional view of another partial structure of the rotor punching sheet 21, which includes a cooling hole 212. As shown in FIG. 9, the hole wall of the cooling hole 212 is divided into multiple sections of hole walls, which include a first section of the hole wall 2121, a second section of the hole wall 2122, a third section of the hole wall 2123, and a fourth section of the hole wall 2124. The first section of the hole wall 2121 and the second section of the hole wall 2122 are arranged opposite to each other along the radial direction of the oil-cooled driving motor. One end of the first section of the hole wall 2121 is connected to the second section of the hole wall 2122 through the third section of the hole wall 2123, and the other end of the first section of the hole wall 2121 is connected to the other end of the second section of the hole wall 2122 through the fourth section of the hole wall 2124, and the shape of the cooling hole 212 is similar to a trapezoid. The heat dissipation protrusions T are distributed in at least one of the first section of the hole wall 2121, the second section of the hole wall 2122, the third section of the hole wall 2123, and the fourth section of the hole wall 2124, which are not shown in the figure.

[0075] In one embodiment, along the radial direction of the oil-cooled driving motor, the distance between the first section of the hole wall 2121 and the outer circumferential surface of the rotor punching sheet 21 is greater than the distance between the second section of the hole wall 2122 and the outer circumferential surface of the rotor punching sheet 21, that is, the second section of the hole wall 2122 is closer to the outer circumferential surface of the rotor punching sheet 21 than the first section of the hole wall 2121, and is closer to the magnetic steel hole 213 of the rotor punching sheet 21. The heat dissipation protrusions T are distributed in the second section of the hole wall 2122. When the rotor 10 rotates, the cooling oil in the cooling hole 212 is concentrated to the side of the cooling hole 212 close to the outer circumferential surface of the rotor punching sheet 21 due to the centripetal force, and the contact area between the cooling oil and the second section of the hole wall 2122 is increased, which can enhance the heat dissipation effect.

[0076] In one embodiment, as shown in FIG. 9, the first section of the hole wall 2121 is arc-shaped, and the specific curvature is matched with the center hole 211 of the rotor punching sheet 21, so that the shape of the cooling hole 212 can be matched with the shape of the center hole 211. Along the radial direction of the oil-cooled driving motor, the distance between the first section of the hole wall 2121 and the center hole 211 is substantially consistent, which can enhance the strength of the rotor punching sheet 21.

[0077] In one embodiment, as shown in FIG. 9, a first section of hole wall 2121 and a second section of hole wall 2122 are opposite along the radial direction of the oil-cooled driving motor, the angle β between the first section of hole wall 2121 and the third section of hole wall 2123 is approximately 60°, and the angle β between the first section of hole wall 2121 and the fourth section of hole wall 2124 is approximately 60°, which can strengthen the structural strength of the cooling hole 212.

[0078] In one embodiment, as shown in FIG. 10, the shape of each heat dissipation protrusion T perpendicular to the cross section of the axial direction of the oil-cooled driving motor is similar to a quadrilateral. On the basis of ensuring the strength of the rotor lamination 21, the heat dissipation protrusion T of this shape can greatly increase the surface area of the hole wall of the cooling hole 212 and improve the heat exchange efficiency of the rotor lamination 21 through the cooling hole 212.

[0079] In one embodiment, as shown in FIG. 10, the length h1 of each heat dissipation protrusion T protruding from the hole 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 and thus increase the surface area of the inner wall of the cooling hole 212.

[0080] In one embodiment, as shown in FIG. 10, the width w1 of each heat dissipation protrusion T is greater than the spacing w2 between adjacent two heat dissipation protrusions T, which can increase the surface area of the cooling hole 212 and 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 adjacent two heat dissipation protrusions T is greater than or equal to 1 mm, and the length of each heat dissipation protrusion T protruding from the hole wall of the cooling hole 212 is 1-2 mm. It should be understood that the dimensions in this embodiment are only one implementation, and in specific implementation, adaptive adjustment needs to be made according to the specific structure of the oil-cooled driving motor 100.

[0082] In some embodiments, the plurality of heat dissipation protrusions T included in the cooling hole 212 are divided into a plurality of sections of heat dissipation protrusions T, each section of heat dissipation protrusions T includes two or more heat dissipation protrusions T, and at least two sections of heat dissipation protrusions T are different in at least one of the number, shape or spacing of the heat dissipation protrusions T. When at least one of the number, shape or spacing of the heat dissipation protrusions T in two sections of heat dissipation protrusions T is different, the surface areas of the two sections of heat dissipation protrusions T can be different, so that the contact area of the cooling hole 212 at the two sections of heat dissipation protrusions T with the cooling oil is different, and thus the heat exchange efficiency of the cooling hole 212 at different positions is different. The number, shape or spacing of the heat dissipation protrusions T in different sections of the cooling hole 212 can be adjusted according to the specific structure of the rotor lamination 21 to meet the heat dissipation requirements of different positions of the rotor lamination 21.

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

[0084] For example, one cooling hole 212 shown in FIG. 11b includes multiple heat dissipation protrusions T, one heat dissipation protrusion T includes multiple heat dissipation protrusions T1, and one heat dissipation protrusion T includes multiple heat dissipation protrusions T2. For example, the number of heat dissipation protrusions T1 is the same as that of heat dissipation protrusions T2, the shapes are similar, the height of the heat dissipation protrusions T1 protruding from the hole wall is different from that of the heat dissipation protrusions T2, and the spacing between two heat dissipation protrusions T1 is also different from that between two heat dissipation protrusions T2.

[0085] FIG. 12 shows a structure of a rotor core 2 including multiple rotor laminations 21 described above, and the multiple rotor laminations 21 are sequentially and adjacently arranged along the axial direction of the oil-cooled driving motor to obtain one rotor core 2 shown in FIG. 10. Among them, the multiple cooling holes 212 of one of the two adjacent rotor laminations 21 are respectively communicated with the multiple cooling holes 212 of the other rotor lamination 21 to form multiple axial flow channels d2. When cooling oil flows in the axial flow channels d2, the cooling oil can exchange heat with the rotor core 2 through the inner wall of the cooling hole 212, and take away the heat of the rotor core 2 to achieve liquid cooling heat dissipation of the rotor core 2.

[0086] In one embodiment, the hole wall of each cooling hole 212 of the rotor lamination 21 of one rotor core 2 includes multiple heat dissipation protrusions T, and the distribution of the heat dissipation protrusions T in the multiple rotor laminations 21 of the same rotor core 2 is the same. When the multiple rotor laminations 21 are adjacently arranged along the axial direction of the oil-cooled driving motor to form one rotor core 2, the axial flow channel d2 formed after each cooling hole 212 of one rotor lamination 21 is communicated with one cooling hole 212 of the adjacent rotor lamination 21 can keep consistent in shape along the axial direction of the oil-cooled driving motor, which reduces the resistance of the cooling oil flowing in the axial flow channel d2, and is beneficial to accelerate heat exchange and improve 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 driving motor, the two rotor laminations 21 are arranged adjacently, the central hole 211 of one rotor lamination 21 is coaxial with the central hole 211 of the other rotor lamination 21, and the inner walls of the two central holes 211 correspond to the radial protrusions t for engaging with the keyway of the rotor shaft 1. Each cooling hole 212 of one rotor lamination 21 corresponds to one cooling hole 212 of the other rotor lamination 21 along the axial direction of the oil-cooled driving motor, and the projection of each cooling hole 212 of the one rotor lamination 21 on the other rotor lamination 21 along the circumferential direction of the oil-cooled driving motor can intersect with one cooling hole 212. In one embodiment, the projection of each cooling hole 212 of the one rotor lamination 21 on the other rotor lamination 21 along the circumferential direction of the oil-cooled driving motor coincides with one cooling hole 212.

[0088] In one embodiment, the distribution of the heat dissipation protrusions T in the rotor laminations 21 of one of the two adjacent rotor cores 2 is different from the distribution of the heat dissipation protrusions T 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 the distribution position, the distribution number, the structural shape, etc.

[0089] As shown in Figure 14, two rotor cores 2 included in one rotor 10 are arranged adjacently along the axial direction of the oil-cooled driving motor. The rotor laminations 21 of each rotor core 2 include a plurality of cooling holes 212, which include a plurality of first cooling holes 212a and a plurality of second cooling holes 212b, and the plurality of first cooling holes 212a and the plurality of second cooling holes 212b are arranged alternately and spaced apart along the circumferential direction of the oil-cooled driving motor. Along the circumferential direction of the oil-cooled driving motor, each first cooling hole 212a is arranged spaced apart between two second cooling holes 212b, and each second cooling hole 212b is arranged spaced apart between two first cooling holes 212a. The hole wall of each first cooling hole 212a is provided with a plurality of heat dissipation protrusions T. In any one rotor core 2, one first cooling hole 212a of each rotor lamination 21 can be in communication with one first cooling hole 212a of the adjacent rotor lamination 21 to form an axial flow channel d2 of the rotor core 2, and one second cooling hole 212b of each rotor lamination 21 can be in communication with one second cooling hole 212b of the adjacent rotor lamination 21 to form an axial flow channel d2 of the rotor core 2.

[0090] In one embodiment, the distribution of the plurality of heat dissipation protrusions T of the rotor lamination 21 of the two rotor cores 2 shown in FIG. 14 is different. Specifically, between the two rotor cores 2, one axial flow channel d2 formed by each first cooling hole 212a of one rotor core 2 is used to communicate with one axial flow channel d2 formed by each second cooling hole 212b of the other rotor core 2 along the axial direction of the oil-cooled driving motor, and one axial flow channel d2 formed by each second cooling hole 212b of one rotor core 2 is used to communicate with one axial flow channel d2 formed by each first cooling hole 212a of the other rotor core 2 along the axial direction of the oil-cooled driving motor. When the cooling oil passes through the channel formed by the communication of the two rotor cores 2, due to the different distribution of the heat dissipation protrusions T of the rotor laminations 21 of the two rotor cores 2, the contact area of the cooling oil with the cooling holes 212 of the two rotor cores 2 is different, which can change the heat exchange efficiency of the cooling oil with the two rotor cores 2, thereby changing the heat dissipation effect of the rotor 10 at different positions.

[0091] In one embodiment, the plurality of axial flow channels d2 of one of the two adjacent rotor cores 2 receives cooling oil through the plurality of axial flow channels d2 of the other rotor core 2, and 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 of the two rotor cores 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 a larger number of heat dissipation protrusions T has a larger surface area of the hole wall of the cooling hole 212, a larger contact area with the cooling oil, a higher heat exchange efficiency of the cooling oil with the rotor lamination 21, and a better oil-cooling heat dissipation effect of the rotor core 2 formed by the rotor lamination 21.

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

[0093] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can easily think of changes or replacements within the technical scope disclosed in the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A rotor lamination for an oil-cooled drive motor, characterized in that, 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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