Rotor punching sheet for oil-cooled driving motor, oil-cooled driving motor and power assembly

Abstract

The utility model relates to the technical field of motors, in particular to a rotor punching sheet for an oil-cooled driving motor, the oil-cooled driving motor and a power assembly. The rotor punching sheet comprises a central hole, a plurality of cooling holes and a plurality of magnetic steel holes, the central hole is used for assembling a rotor shaft, each magnetic steel hole is used for assembling magnetic steel, each cooling hole is used for circulating cooling oil, one central hole penetrates through the rotor punching sheet along the axial direction of the rotor punching sheet, and each magnetic steel hole penetrates through the rotor punching sheet along the axial direction of the rotor punching sheet. The plurality of magnetic steel holes are arranged around a central hole, each cooling hole penetrates through the rotor punching sheet along the axial direction of the rotor punching sheet, the plurality of cooling holes are arranged around a central hole, the hole wall of at least one of the plurality of cooling holes comprises a plurality of heat dissipation bulges, and the plurality of heat dissipation bulges are arranged on the hole wall of the cooling hole at intervals. And the contact area between the cooling oil and the rotor punching sheet is larger, and the heat exchange effect is better, so that the oil cooling heat dissipation effect of the rotor can be improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electric machines, and in particular to a rotor lamination for an oil-cooled driving electric machine, an oil-cooled driving electric machine and a power assembly. BACKGROUND

[0002] With the development of new energy vehicles, the electric machine in the power assembly of an electric vehicle is developing towards high speed, high density and miniaturization.

[0003] At present, cooling oil is supplied to the rotor of an electric machine to cool the rotor by liquid cooling. Specifically, the cooling oil flowing through the oil passage in the rotor flows to both sides of the end of the rotor and is sprayed out with the rotation of the rotor, and the cooling oil exchanges heat with the rotor during the flow process to cool the rotor. The heat dissipation effect of the rotor affects the working efficiency of the electric machine. CONTENT OF THE INVENTION

[0004] The present application provides a rotor lamination for an oil-cooled driving electric machine, an oil-cooled driving electric machine and a power assembly, 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 electric machine.

[0005] In a first aspect, the present application provides a rotor lamination for an oil-cooled driving electric machine. The rotor lamination comprises 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, and 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 of cooling holes are arranged around the central hole, and the hole wall of at least one of the plurality of cooling holes comprises a plurality of heat dissipation protrusions, which are arranged at intervals on the hole wall of the cooling hole.

[0006] The above rotor lamination, the hole wall of at least one of the cooling holes comprises a plurality of heat dissipation protrusions, which can increase the surface area of the hole wall of the cooling hole. When 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, so that the oil cooling heat dissipation effect of the rotor can be improved.

[0007] In one 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 removed by heat exchange between the cooling oil and the rotor lamination. In this embodiment, the hole wall of each 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 at different positions of the rotor lamination.

[0008] In one embodiment, the third section is symmetrically arranged along the radial direction of the rotor, and the first section and the second section are symmetrically arranged along the radial direction of the rotor. One end of the first section is connected to the third section, and the other end of the first section is connected to one end of the second section. The other end of the second section is connected to 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 can 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.

[0009] In one 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 hole wall on the side of the cooling hole close to the center hole, and 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, and a part of the heat dissipation protrusions are distributed in the second section, which can further facilitate the heat dissipation of the magnetic steel in the magnetic steel hole by the cooling oil.

[0010] In one 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 less 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 hole wall on the side of the cooling hole away from the center hole, and 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 can further facilitate the heat dissipation of the magnetic steel in the magnetic steel hole by the cooling oil.

[0011] 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.

[0012] 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.

[0013] 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 1mm, and the length of each heat dissipation protrusion protruding from the hole wall of the cooling hole is 1-2mm.

[0014] 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.

[0015] In a second aspect, the embodiments of the present application provide an oil-cooled driving motor. The oil-cooled driving motor is used to drive a wheel of an electric vehicle. The oil-cooled driving motor comprises a stator and a rotor. The stator has a central hole for accommodating the rotor. The rotor comprises a plurality of rotor cores. The plurality of rotor cores are arranged in sequence along an axial direction of the rotor. Each rotor core comprises a plurality of rotor laminations provided in the first aspect. The plurality of rotor laminations in each rotor core are arranged in sequence along the axial direction of the driving motor. A plurality of cooling holes in one of the adjacent rotor laminations in each rotor core are connected to a plurality of cooling holes in the other rotor lamination to form a plurality of axial flow channels. Cooling oil flows through the axial flow channels. The oil cooling of the rotor is achieved by heat exchange between the cooling oil and the rotor core. The efficiency of the oil-cooled driving motor is improved by increasing the heat exchange area due to the fact that the hole wall of at least one cooling hole of the rotor lamination comprises a plurality of heat dissipation protrusions. In an embodiment, the hole wall of each cooling hole of the rotor laminations of at least one rotor core comprises a plurality of heat dissipation protrusions. 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 at different positions of the same rotor core is relatively consistent. The flow resistance of the cooling oil is reduced. The oil cooling effect is enhanced.

[0016] In an embodiment, the distribution of the heat dissipation protrusions in the rotor laminations of one of the adjacent rotor cores is different from the distribution of the heat dissipation protrusions in the rotor laminations of the other rotor core. Thus, the heat dissipation effect of the rotor at different positions along the axial direction of the oil-cooled driving motor is changed.

[0017] In an embodiment, the plurality of axial flow channels of one of the adjacent rotor cores receives cooling oil through the plurality of axial flow channels of the other rotor core. The number of heat dissipation protrusions in the rotor laminations of one of the adjacent rotor cores is greater than the number of heat dissipation protrusions in the rotor laminations of the other rotor core. The number of 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 lamination is high. Thus, the oil cooling effect of the rotor core formed by the rotor lamination is better.

[0018] In a third aspect, the embodiments of the present application provide a powertrain. The powertrain can be applied to an electric vehicle. The powertrain comprises a reducer and an oil-cooled driving motor provided in the second aspect. The oil-cooled driving motor is used to drive a wheel of the electric vehicle through the reducer. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 A structural schematic diagram of an electric vehicle provided in the embodiments of the present application;

[0020] Figure 2 A structural schematic diagram of a powertrain provided in the embodiments of the present application;

[0021] Figure 3 A cross-sectional structure schematic diagram of an oil-cooled driving motor provided for an embodiment of the present application is shown in FIG. 1.

[0022] Figure 4a A structure schematic diagram of a rotor of an oil-cooled driving motor provided for an embodiment of the present application is shown in FIG. 2.

[0023] Figure 4b An exploded view of a rotor of an oil-cooled driving motor provided for an embodiment of the present application is shown in FIG. 3.

[0024] Figure 5 A structure schematic diagram of a rotor lamination of an oil-cooled driving motor provided for an embodiment of the present application is shown in FIG. 4.

[0025] Figure 6a A structure schematic diagram of a cooling hole of a rotor lamination of an oil-cooled driving motor provided for an embodiment of the present application is shown in FIG. 5.

[0026] Figure 6b A structure schematic diagram of a cooling hole of a rotor lamination of an oil-cooled driving motor provided for an embodiment of the present application is shown in FIG. 6.

[0027] Figure 6c A structure schematic diagram of a cooling hole of a rotor lamination of an oil-cooled driving motor provided for an embodiment of the present application is shown in FIG. 7.

[0028] Figure 7a A structure schematic diagram of a cooling hole of a rotor lamination of an oil-cooled driving motor provided for an embodiment of the present application is shown in FIG. 8.

[0029] Figure 7b A structure schematic diagram of a cooling hole of a rotor lamination of an oil-cooled driving motor provided for an embodiment of the present application is shown in FIG. 9.

[0030] Figure 8a A structure schematic diagram of a cooling hole of a rotor lamination of an oil-cooled driving motor provided for an embodiment of the present application is shown in FIG. 10.

[0031] Figure 8b A structure schematic diagram of a cooling hole of a rotor lamination of an oil-cooled driving motor provided for an embodiment of the present application is shown in FIG. 11.

[0032] Figure 9 A structure schematic diagram of a cooling hole of a rotor lamination of an oil-cooled driving motor provided for an embodiment of the present application is shown in FIG. 12.

[0033] Figure 10 A structure schematic diagram of a cooling hole of a rotor lamination of an oil-cooled driving motor provided for an embodiment of the present application is shown in FIG. 13.

[0034] Figure 11a A structure schematic diagram of a cooling hole of a rotor lamination of an oil-cooled driving motor provided for an embodiment of the present application is shown in FIG. 14.

[0035] Figure 11b A partial structural schematic diagram of a cooling hole of a rotor lamination of an oil-cooled driving motor is provided for an embodiment of the present application.

[0036] Figure 12 A structural schematic diagram of a rotor core of an oil-cooled driving motor is provided for an embodiment of the present application.

[0037] Figure 13 A structural schematic diagram of two rotor laminations of an oil-cooled driving motor is provided for an embodiment of the present application.

[0038] Figure 14 A structural schematic diagram of two rotor cores of an oil-cooled driving motor is provided for an embodiment of the present application.

[0039] Reference signs:

[0040] 1000 - power assembly; 2000 - transmission mechanism; 3000 - wheel;

[0041] 100 - motor; 200 - motor controller; 300 - speed reducer;

[0042] 10 - rotor; 20 - stator; 201 - stator core; 202 - stator winding; 30 - housing;

[0043] 1 - rotor shaft; 2 - rotor core; 21 - rotor lamination; 211 - central 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 - magnet hole; 3 - end plate; 31 - liquid outlet hole; 4 - fixing member; 4a - annular structure member; 4b - annular shoulder; 5 - magnet;

[0044] d1 - oil inlet channel; d2 - axial flow channel; t - radial protrusion; S - power output end; T, T1, T2 - heat dissipation protrusion. DETAILED DESCRIPTION

[0045] In the prior art, cooling oil is supplied to the rotor of the motor to cool the rotor, and the liquid cooling effect of the rotor affects the performance of the motor.

[0046] Based on this, the present application provides a rotor lamination for an oil-cooled driving motor, an oil-cooled driving motor and a power assembly, 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.

[0047] In order to make the purpose, technical scheme and advantages of the present application clearer, the present application will be described in further detail below with reference to the drawings.

[0048] Figure 1 This is a schematic diagram of the structure of an electric vehicle provided in an embodiment of this application, such as... Figure 1 As shown, the electric vehicle can specifically be a pure electric vehicle (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, transferring 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 from the vehicle's internal and external environment, and a battery to supply power to the powertrain 1000, which is not shown here.

[0049] Figure 2 This is a schematic diagram of the powertrain 1000 provided in an embodiment of this application. Figure 2 As shown, the powertrain 1000 includes an oil-cooled drive motor 100 and a motor controller 200. The motor controller 200 converts the direct current (DC) power supplied by the battery into alternating current (AC) power and supplies the AC power to the oil-cooled drive motor 100. In one embodiment, the powertrain 1000 further includes a reducer 300, through which the power output of the oil-cooled drive motor 100 is connected to the vehicle's wheels 3000. The reducer 300 can also be referred to as a transmission.

[0050] 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.

[0051] Figure 3 This is a schematic cross-sectional view of an oil-cooled drive motor 100. Figure 3As shown, the oil-cooled driving motor 100 comprises a rotor 10, a stator 20 and a housing 30, the stator 20 and part of 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 driving 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 driving motor to form a power output end S of the oil-cooled driving motor 100. The stator 20 comprises a stator core 201 and a stator winding 202 wound on the stator core 201. When the stator winding 202 is energized, a magnetic field can be formed in the central hole of the stator core 201, and the rotor 10 can rotate around the axis of the rotor 10 in the magnetic field.

[0052] The inner part of the rotor 10 provided in the embodiments of the present application forms an oil-cooling circuit, and the cooling oil supplied to the oil-cooling circuit in the rotor 10 can be used to cool the rotor 10 by liquid cooling, and finally the cooling oil can be sprayed out from the two axial ends of the rotor 10. In the embodiments of 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 (axial) of the oil-cooled driving motor 100 is represented by the letter A, the radial direction (radial) of the oil-cooled driving motor 100 is represented by the letter R, and the circumferential direction (circumferential) of the oil-cooled driving motor 100 is represented by the letter C.

[0053] Figure 4a The structure of the rotor 10 provided in an embodiment of the present application, Figure 4b The structure of the rotor 10 can be combined with Figure 4a and Figure 4b understood.

[0054] In an embodiment, the rotor 10 comprises a plurality of rotor cores 2, and the plurality of rotor cores 2 are arranged in sequence and adjacent to each other along the axial direction of the oil-cooled driving motor. Each rotor core 2 comprises a plurality of cooling axial flow channels d2, and the plurality of axial flow channels d2 of each rotor core 2 can respectively communicate with the plurality of cooling channels d2 of the adjacent rotor core 2 along the axial direction of the oil-cooled driving motor to form a circuit for the cooling oil to flow in the inner part of the rotor 10.

[0055] In an embodiment, the rotor 10 further comprises 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.

[0056] In an embodiment, the rotor 10 comprises a rotor shaft 1, a plurality of rotor cores 2, two end plates 3 and a plurality of magnetic steels 5. As Figure 4bAs shown, along the axial direction of the motor, the two end plates 3 are arranged on both sides of the rotor core 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 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 multiple axial flow channels d2 formed by the multiple 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.

[0057] In some embodiments, the multiple rotor cores 2 and the two end plates 3 arranged on both sides of the multiple rotor cores 2 along the axial direction of the oil-cooled driving motor can be axially limited by two fixing members 4. One of the two fixing members 4 is arranged on the side of one of the end plates 3 away from the multiple 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 multiple rotor cores 2 along the axial direction of the oil-cooled driving motor.

[0058] In one embodiment, one of the fixing members 4 is an annular shoulder 4b of the rotor shaft 1, and the annular section shoulder 4a protrudes outwardly 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.

[0059] In one embodiment, the other fixing member 4 is an annular structure member 4a, which is used to be sleeved on the rotor shaft 1 to realize fixation through friction.

[0060] In one embodiment, each rotor core 2 of the rotor 10 provided by the embodiment of the present application includes multiple rotor laminations 21 as shown. Figure 5 As shown, the multiple rotor laminations 21 are arranged adjacent to each other along the axial direction of the oil-cooled driving motor to form a rotor core 2.

[0061] Please refer to Figure 5As shown, the rotor lamination 21 comprises a central hole 211 for assembling the rotor shaft 1, a plurality of cooling holes 212 for flowing cooling oil, and a plurality of magnetic steel holes 213 for assembling the magnetic steel 5. 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, so as to form a ring-shaped 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.

[0062] In an 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 limiting.

[0063] In an embodiment, each cooling hole 212 penetrates the rotor lamination 21 along the axial direction of the rotor lamination, and the plurality of cooling holes 212 are arranged at intervals along the circumferential direction of the rotor lamination, and each cooling hole 212 is arranged between two adjacent magnetic steel holes 213 along the circumferential direction of the rotor lamination. 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 through the cooling hole 212.

[0064] In an embodiment, the hole wall of at least one 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, and 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.

[0065] In an embodiment, as shown in a rotor lamination 21, Figure 5 the hole wall of each cooling hole 212 comprises a plurality of heat dissipation protrusions T to increase the contact area between the rotor lamination 21 and the cooling oil and enhance the liquid cooling effect.

[0066] The distribution position and shape of the heat dissipation protrusions T comprised by 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.

[0067] Figure 6a to Figure 6cFig. 1 is a sectional view of a part of a rotor lamination 21, which part includes a cooling hole 212. The hole wall of the cooling hole 212 is divided into a plurality of hole walls, which include a first hole wall 2121, a second hole wall 2122, and a third hole wall 2123. The first hole wall 2121 connects the second hole wall 2122 through the third hole wall 2123, and as a specific shape example, the first hole wall 2121, the second hole wall 2122, and the third hole wall 2123 are sequentially connected to form a triangular structure.

[0068] In an embodiment, the plurality of heat dissipation protrusions T are arranged in at least one of the first hole wall 2121, the second hole wall 2122, and the third hole wall 2123. Figure 6a An example is shown in which the plurality of heat dissipation protrusions T are arranged in one of the hole walls of the cooling hole 212, Figure 6b An example is shown in which the plurality of heat dissipation protrusions T are arranged in two of the hole walls of the cooling hole 212, Figure 6c An example is shown in which the plurality of heat dissipation protrusions T are arranged in three of the hole walls of the cooling hole 212.

[0069] In an embodiment, the hole wall of the first hole wall 2121, the second hole wall 2122, and the third hole wall 2123 that is closer to the magnetic steel hole 213 is provided with the plurality of heat dissipation protrusions T, which can increase the contact area of the hole wall with the cooling oil and improve the heat dissipation efficiency.

[0070] In an embodiment, in combination with Figure 6a to Figure 6b As shown in the figure, the first hole wall 2121, the second hole wall 2122, and the third hole wall 2123 are arranged in an equilateral triangle, which can strengthen the structural strength of the cooling hole 212.

[0071] In an embodiment, as shown in Figure 7a and Figure 7b The third hole wall 2123 is radially symmetrical to the oil-cooled driving motor, and the first hole wall 2121 and the second hole wall 2122 are radially symmetrical to the oil-cooled driving motor. One end of the first hole wall 2121 is used to connect the third hole wall 2123, the other end of the first hole wall 2121 is used to connect one end of the second hole wall 2122, and the other end of the second hole wall 2122 is used to connect the third hole wall 2123. The plurality of heat dissipation protrusions T are arranged in at least one of the first hole wall 2121, the second hole wall 2122, and the third hole wall 2123 in a radial direction of the oil-cooled driving motor, which can balance the heat dissipation effect in a circumferential direction of the oil-cooled driving motor. When the cooling hole is arranged between the two magnetic steel holes 213, the cooling hole can balance the heat dissipation effect on the magnets 5 in the two magnetic steel holes 213.

[0072] Referring to the structure of rotor lamination 21, in one embodiment, such as Figure 7a As shown, a first section of hole wall 2121 and a second section of hole wall 2122 are radially symmetrical about the rotor, and a third section of 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 of hole wall 2121 and the second section of hole wall 2122. When the cooling holes 212 are arranged circumferentially between the two magnet holes 213 along the oil-cooled drive motor, and the first section of hole wall 2121 and the second section of hole wall 2122 are close to the two magnet holes 213, the multiple heat dissipation protrusions T included in the first section of hole wall 2121 and the second section of hole wall 2122 can increase the contact area between the cooling oil and the first section of hole wall 2121 and the second section of 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.

[0073] Referring to the structure of rotor lamination 21, in one embodiment, such as Figure 7b As shown, the first section of the hole wall 2121 and the second section of the hole wall 2122 are radially symmetrical about the rotor, and the third section of the hole wall 2123 is radially symmetrical along the oil-cooled drive motor. Multiple 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 drive motor between the two magnet holes 213, the contact area between the cooling oil and the first section of the hole wall 2121 and the second section of the hole wall 2122 is similar. Therefore, 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 provide relatively uniform heat dissipation and cooling to the magnets 5 on both sides of the cooling holes 212.

[0074] In one embodiment, such as Figure 8a As shown, when the first segment hole wall 2121 and the second segment hole wall 2122 are radially symmetrical about the rotor, the 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 distributed at intervals in 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.

[0075] In one embodiment, such as Figure 8bAs shown, when a first section of the hole wall 2121 and a second section of the hole wall 2122 are radially symmetrical about the rotor, the third section of the hole wall 2123 can be the hole wall of the cooling hole 212 close to one side of the central hole 211. In 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 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. The third section of the hole wall 2123 is closer to the magnet steel hole 213 than the first section of the hole wall 2121 and the second section of the hole wall 2122. At this time, part of the plurality of heat dissipation protrusions T are distributed at the first section of the hole wall 2121, and part of the plurality of heat dissipation protrusions T are distributed at the second section of the hole wall 2122, which is more conducive to cooling the magnet steel 5 in the magnet steel hole 213 by the cooling oil.

[0076] In one embodiment, in combination with Figure 8a As shown, when the third section of the hole wall 2123 is the hole wall of the cooling hole 212 close to one side of the central hole 211. The third section of the hole wall 2123 is arc-shaped, and the specific curvature is matched with the central hole 211 of the rotor lamination 21, so that the shape of the third section of the hole wall 2123 can be matched with the shape of the central hole 211. In the radial direction of the oil-cooled driving motor, the distance between the third section of the hole wall 2123 and the central hole 211 is substantially consistent, which can enhance the strength of the rotor lamination 21.

[0077] Figure 9 Another cross-sectional view of a part of the structure of the rotor lamination 21 is shown, which includes a cooling hole 212. As shown, Figure 9 As shown, 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 in 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 plurality of heat dissipation protrusions T are distributed at 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 is not shown here.

[0078] In an embodiment, along the radial direction of the oil-cooled driving motor, the distance between a first section of the hole wall 2121 and the outer circumferential surface of the rotor lamination 21 is greater than the distance between a second section of the hole wall 2122 and the outer circumferential surface of the rotor lamination 21, that is, the second section of the hole wall 2122 is closer to the outer circumferential surface of the rotor lamination 21 and is closer to the magnetic steel hole 213 of the rotor lamination 21. The plurality of heat dissipation protrusions T are distributed on 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 lamination 21 due to the centripetal force, the contact area between the cooling oil and the second section of the hole wall 2122 is increased, and the heat dissipation effect can be enhanced.

[0079] In an embodiment, as shown in Figure 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 lamination 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 lamination 21.

[0080] In an embodiment, as shown in Figure 9 , the first section of the hole wall 2121 and the second section of the hole wall 2122 are opposite along the radial direction of the oil-cooled driving motor, the included angle β between the first section of the hole wall 2121 and the third section of the hole wall 2123 is substantially 60°, and the included angle β between the first section of the hole wall 2121 and the fourth section of the hole wall 2124 is substantially 60°, which can strengthen the structural strength of the cooling hole 212.

[0081] In an embodiment, as shown in Figure 10 , the partial structure of the cooling hole 212, 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.

[0082] In an embodiment, as shown in Figure 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, thereby increasing the surface area of the inner wall of the cooling hole 212.

[0083] In an embodiment, as shown in , the width w1 of each heat dissipation protrusion T is greater than the distance w2 between adjacent two heat dissipation protrusions T, which increases the surface of the inner wall of the cooling hole 212 and also ensures the structural strength of the rotor lamination 21.

[0084] 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.

[0085] 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.

[0086] by Figure 11a Taking a cooling hole 212 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.

[0087] by Figure 11b Taking a cooling hole 212 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 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 protruding from the hole wall is different from the height of heat dissipation protrusions T2 protruding 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.

[0088] Figure 12 An example illustrates the structure of a rotor core 2, which includes a plurality of rotor laminations 21 as described above. The plurality of rotor laminations 21 are arranged adjacent to each other along the axial direction of the oil-cooled drive motor. Figure 10One rotor core 2 is shown. In the rotor core 2, a plurality of cooling holes 212 in one of the two adjacent rotor laminations 21 are respectively connected to a plurality of cooling holes 212 in the other of the two adjacent rotor laminations 21 to form a plurality of 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 walls of the cooling holes 212 to take away the heat of the rotor core 2, thereby achieving liquid cooling of the rotor core 2.

[0089] In one embodiment, the hole walls of each cooling hole 212 in the rotor laminations 21 of one rotor core 2 include a plurality of heat dissipation protrusions T, and the heat dissipation protrusions T in the plurality of rotor laminations 21 of the same rotor core 2 have the same distribution. When 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, the axial flow channels d2 formed by the connection of each cooling hole 212 in one of the rotor laminations 21 and one cooling hole 212 in the adjacent rotor lamination 21 along the axial direction of the oil-cooled drive motor can have a consistent shape, which reduces the resistance of the cooling oil flowing in the axial flow channels d2, facilitates heat exchange, and improves the cooling effect.

[0090] Figure 13 The structure of two adjacent rotor laminations 21 in one rotor core 2 is shown. Along the axial direction of the oil-cooled drive motor, the two rotor laminations 21 are arranged adjacent to each other, the central hole 211 of one of the rotor laminations 21 is coaxial with the central hole 211 of the other of the rotor laminations 21, and the inner walls of the two central holes 211 correspond to the radial protrusions t for keying with the key grooves of the rotor shaft 1. Each cooling hole 212 in one of the rotor laminations 21 corresponds to one cooling hole 212 in the other of the rotor laminations 21 along the axial direction of the oil-cooled drive motor, and the projection of each cooling hole 212 in the one of the rotor laminations 21 on the other of the rotor laminations 21 along the circumferential direction of the oil-cooled drive motor can intersect with one cooling hole 212. In one embodiment, the projection of each cooling hole 212 in the one of the rotor laminations 21 on the other of the rotor laminations 21 along the circumferential direction of the oil-cooled drive motor coincides with one cooling hole 212.

[0091] In one embodiment, the heat dissipation protrusions T in the rotor laminations 21 of one of the two adjacent rotor cores 2 have a different distribution than the heat dissipation protrusions T in the rotor laminations 21 of the other of the two adjacent rotor cores 2. The distribution of the heat dissipation protrusions T includes but is not limited to the distribution position, the number of distribution, the structure shape, and the like.

[0092] As Figure 14The illustrated rotor 10 includes two rotor cores 2, which are arranged adjacent to each other along the axial direction of the oil-cooled drive motor. Each rotor core 2 has a rotor lamination 21 comprising a plurality of cooling holes 212, including a plurality of first cooling holes 212a and a plurality of 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 a plurality of 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.

[0093] In one embodiment, such as Figure 14 The distribution of multiple heat dissipation protrusions T on the rotor laminations 21 of the two rotor cores 2 shown is 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. Similarly, 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, the different distribution of the heat dissipation protrusions T on the rotor laminations 21 of the two rotor cores 2 results in different contact areas between the cooling oil and the cooling holes 212 of the two rotor cores 2. This changes the heat exchange efficiency between the cooling oil and the two rotor cores 2, thereby altering the heat dissipation effect of the rotor 10 at different locations.

[0094] 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 greater 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 between the cooling oil and the rotor lamination 21, and a better oil-cooling heat dissipation effect of the rotor core 2 formed by the rotor lamination 21.

[0095] 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 at different positions of the rotor 10, and the adjustment can be achieved by changing the contact area between the cooling oil and the rotor core 2.

[0096] The above merely describes specific embodiments 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 by The rotor lamination comprises a central hole for assembling a rotor shaft, a plurality of cooling holes for flowing cooling oil, and a plurality of magnet holes for assembling magnets, the central hole penetrates the rotor lamination along an axial direction of the rotor lamination, each of the magnet holes penetrates the rotor lamination along the axial direction of the rotor lamination, the plurality of magnet holes are arranged around the central hole, each of the cooling holes penetrates the rotor lamination along the axial direction of the rotor lamination, the plurality of cooling holes are arranged around the central hole, and a wall of at least one of the cooling holes comprises a plurality of heat dissipation protrusions arranged on the wall of the cooling hole.

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

3. The rotor lamination of claim 2, wherein, the third wall segment is symmetric along the radial direction of the rotor, the first wall segment and the second wall segment are symmetric along the radial direction of the rotor, one end of the first wall segment is connected to the third wall segment, the other end of the first wall segment is connected to one end of the second wall segment, and the other end of the second wall segment is connected to the third wall segment, wherein: the plurality of heat dissipation protrusions are symmetrically distributed in at least one of the first wall segment, the second wall segment, and the third wall segment along the radial direction of the rotor.

4. The rotor lamination of claim 3, wherein, a distance between the third wall segment and an outer circumferential surface of the rotor lamination along a radial direction of the rotor lamination is smaller than a distance between the first wall segment and the second wall segment and the outer circumferential surface of the rotor lamination, a part of the plurality of heat dissipation protrusions are distributed in the first wall segment, and a part of the plurality of heat dissipation protrusions are distributed in the second wall segment.

5. The rotor lamination of claim 3, wherein, a distance between the third wall segment and an outer circumferential surface of the rotor lamination along a radial direction of the rotor lamination is smaller than a distance between the first wall segment and the second wall segment and the outer circumferential surface of the rotor lamination, and the plurality of heat dissipation protrusions are distributed in the third wall segment.

6. The rotor lamination of claim 2, wherein, the plurality of wall segments further comprises a fourth wall segment, the first wall segment and the second wall segment are oppositely arranged along the radial direction of the rotor, one end of the first wall segment is connected to one end of the second wall segment through the third wall segment, the other end of the first wall segment is connected to the other end of the second wall segment through the fourth wall segment, and wherein: The distance between the first segment of the hole wall and the outer circumferential surface of the rotor lamination is greater than the distance between the second segment of the hole wall and the outer circumferential surface of the rotor lamination, and the plurality of heat dissipation protrusions are distributed on the second segment of the hole wall.

7. The rotor lamination of any of claims 1-6, wherein, 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.

8. The rotor lamination of claim 7, wherein, 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.

9. The rotor lamination of any of claims 1-8, wherein, The plurality of heat dissipation protrusions are divided into multiple segments of heat dissipation protrusions, each segment of heat dissipation protrusions includes two or more heat dissipation protrusions, and at least two segments of heat dissipation protrusions are different in at least one of the number, shape, or distance of the heat dissipation protrusions.

10. An oil-cooled drive motor for driving a wheel of an electric vehicle, characterized by The oil-cooled driving motor includes a stator and a rotor, a central hole of the stator is used to accommodate the rotor, the rotor includes a plurality of rotor cores, and the plurality of rotor cores are arranged in sequence along the axial direction of the rotor. Each rotor core includes a plurality of rotor laminations according to any one of claims 1-9, the plurality of rotor laminations in each rotor core are arranged in sequence along the axial direction of the driving motor, and the plurality of cooling holes in one of the two adjacent rotor laminations in each rotor core are respectively connected to the plurality of cooling holes in the other rotor lamination to form a plurality of axial flow channels.

11. An oil-cooled drive motor as claimed in claim 10, characterized in that The hole 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 in the plurality of rotor laminations of the same rotor core is the same.

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

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

14. A powertrain, characterized by, The power assembly includes a reducer and an oil-cooled driving motor according to any one of claims 10-13, and the oil-cooled driving motor is used to drive the wheels of an electric vehicle through the reducer.

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