Oil-cooled electric motor, powertrain and electric vehicle

Abstract

The embodiment of the application provides an oil-cooled motor, a power assembly and an electric vehicle, and relates to the technical field of motors. In the oil-cooled motor, the rotor core comprises multiple groups of magnetic steel grooves, multiple first internal flow channels and multiple second internal flow channels. The multiple groups of magnetic steel grooves are arranged in a circumferential interval, and two layers of magnetic steel grooves in each group of magnetic steel grooves are arranged in a radial layer. Each first internal flow channel is distributed between two adjacent groups of magnetic steel grooves. Each second internal flow channel is distributed between two layers of magnetic steel grooves in one group of magnetic steel grooves. At least one of the shape, size or cross-sectional area of the first internal flow channel and the second internal flow channel is different. Each first recess in the end plate is used for directly connecting the internal flow channel of the rotor shaft and one first internal flow channel, and each second recess is used for directly connecting one first internal flow channel and one second internal flow channel which are circumferentially adjacent. By arranging different internal flow channels in different regions of the rotor core, the rotor heat dissipation efficiency, electromagnetic characteristics and structural strength are considered, and the overall performance of the motor is improved.

Description

Technical Field

[0001] This application relates to the field of motor technology, and more particularly to an oil-cooled motor, powertrain, and electric vehicle. Background Technology

[0002] In oil-cooled motors, the internal flow channels of the rotor core refer to dedicated channels formed inside the rotor core for the flow of cooling oil. These internal flow channels, together with the end plates at both ends, form the cooling oil circuit, enabling efficient heat dissipation during rotor operation. Therefore, the internal flow channels of the rotor core significantly affect the rotor's heat dissipation efficiency, electromagnetic characteristics, and structural strength. Current flow channel designs struggle to balance these performance characteristics, thus limiting the improvement of oil-cooled motor performance. Summary of the Invention

[0003] This application provides an oil-cooled motor, a powertrain, and an electric vehicle, which balances rotor heat dissipation efficiency, electromagnetic characteristics, and structural strength, thereby improving the overall performance of the oil-cooled motor.

[0004] To achieve the above objectives, this application adopts the following technical solution: A first aspect of this application provides an oil-cooled motor, the rotor of which includes a rotor shaft, a rotor core, and two end plates. The two end plates are respectively arranged at both axial ends of the rotor core. The rotor shaft passes through the central hole of the rotor core and the central holes of the two end plates.

[0005] The rotor core includes multiple sets of magnetic slots, multiple first internal flow channels, and multiple second internal flow channels. The multiple sets of magnetic slots are arranged at intervals along the circumference of the rotor. Each set of magnetic slots includes two layers of magnetic slots, arranged radially along the rotor. Each first internal flow channel is located between two adjacent sets of magnetic slots. Each second internal flow channel is located between the two layers of magnetic slots in one set of magnetic slots. At least one of the shapes, dimensions, or cross-sectional areas of the first and second internal flow channels differs. The end plate includes multiple first grooves and multiple second grooves, distributed on the side of the end plate facing the rotor core. Each first groove directly connects to an internal flow channel on the rotor shaft and a first internal flow channel. Each second groove directly connects to a circumferentially adjacent first internal flow channel and a second internal flow channel.

[0006] In the oil-cooled motor disclosed in this application, both the first and second internal flow channels are distributed between the magnet slots, close to the magnets embedded within the slots, thus improving the rotor's heat dissipation efficiency. Furthermore, given the significant differences in spatial layout, magnetic flux distribution, mechanical strength, and heat dissipation conditions within each set of magnet slots and between adjacent sets, internal flow channels of different shapes, sizes, or cross-sectional areas are configured. This allows the first and second internal flow channels to precisely adapt to the needs of their respective areas, maximizing the balance between rotor heat dissipation, electromagnetic characteristics, and structural strength, thereby enhancing the overall performance of the oil-cooled motor.

[0007] In one embodiment, the cross-sectional area of ​​the first internal flow channel is larger than the cross-sectional area of ​​the second internal flow channel. Furthermore, the radial dimension of the first internal flow channel is larger than the radial dimension of the second internal flow channel. The circumferential dimension of the first internal flow channel is larger than the circumferential dimension of the second internal flow channel.

[0008] In the oil-cooled motor disclosed in this application, a large-cross-sectional area first internal flow channel is arranged using the relatively large core space between two adjacent sets of magnet slots. This achieves efficient space utilization and provides sufficient margin for a smooth contour transition, effectively reducing stress concentration and ensuring the mechanical strength of the rotor under high-speed rotation. Furthermore, it has minimal impact on the relatively sparse magnetic circuit between the two sets of magnet slots, preventing significant magnetic flux leakage or performance degradation. The large-cross-sectional area first internal flow channel also provides heat exchange capacity matching the heat dissipation requirements, preventing localized overcooling or excessive flow resistance due to overly narrow flow channels.

[0009] By utilizing the limited core space within each set of magnet slots to arrange a small-cross-sectional area second internal flow channel, the mechanical strength of the rotor under high-speed rotation is ensured, avoiding the compression of the magnet slots by excessively large flow channels and minimizing the weakening of the core's mechanical strength. Simultaneously, the small-cross-sectional area of ​​the second internal flow channel not only reduces the impact on the dense magnetic circuit within each set of magnet slots, preventing significant magnetic flux leakage or performance degradation, but also achieves a higher local flow velocity within the limited space, thereby obtaining stronger heat transfer capacity and meeting large heat dissipation requirements.

[0010] The first internal flow channel has large radial and circumferential dimensions, which gives it a large cross-sectional area, thereby reducing the flow resistance of the cooling oil in the first internal flow channel and increasing its flow capacity.

[0011] The second internal flow channel has small radial and circumferential dimensions, resulting in a smaller cross-sectional area. This increases the flow rate of the cooling oil in the second internal flow channel, enhances the convective heat transfer coefficient of the cooling oil, and meets the larger heat dissipation requirements of each set of magnet slots.

[0012] In one embodiment, the maximum radial dimension of the first internal flow channel is smaller than the maximum circumferential dimension of the first internal flow channel. Specifically, the circumferential dimension of the end of the first internal flow channel opposite to the central hole of the rotor core is smaller than the circumferential dimension of the end of the first internal flow channel facing the central hole of the rotor core.

[0013] In the oil-cooled motor provided in this application, since the magnetic flux path is mainly in the radial direction, the maximum radial dimension of the first internal flow channel is small, which limits the radial space occupied by the first internal flow channel in the magnetic flux path, thereby reducing the cutting effect on the magnetic circuit and preventing magnetic flux leakage or distortion.

[0014] The larger maximum circumferential dimension of the first internal flow channel compensates for its radial dimension, resulting in a larger flow cross-sectional area. This ensures the flow capacity of the first internal flow channel and reduces flow resistance. The smaller maximum radial dimension of the first internal flow channel allows its shape to conform to the geometry of the gap between adjacent sets of magnet slots, maximizing the flow cross-sectional area within a limited space and improving space utilization.

[0015] The first internal flow channel has a variable cross-section shape that is wider on the inside and narrower on the outside in the radial direction. On the one hand, since the magnetic flux density is higher closer to the outer periphery, the first internal flow channel is narrower on the outer radial side to reduce the cutting effect on the magnetic circuit and prevent magnetic flux leakage or distortion. On the other hand, under the action of centrifugal force, the cooling oil in the first internal flow channel gathers radially outward. The narrow outer radial side of the first internal flow channel locally throttles the flow, reduces the outflow velocity of the cooling oil, prolongs the heat exchange time between the cooling oil and the rotor core, and thus improves the heat dissipation efficiency.

[0016] In one embodiment, the circumferential dimension of the second internal flow channel is larger than the radial dimension of the second internal flow channel. On the one hand, this does not increase the occupancy of radial space, prevents excessive weakening of the mechanical strength of the iron core due to the increase of the second internal flow channel, and reduces the cutting of the radial main magnetic circuit by the second internal flow channel. On the other hand, by making the circumferential dimension of the second internal flow channel larger, the flow cross-section of the second internal flow channel is increased, and the coverage of the cooling oil in the circumferential direction is wider, which is beneficial to improving the heat dissipation efficiency.

[0017] In one embodiment, the radial distance between the first internal flow channel and the outer peripheral surface of the rotor core is greater than the radial distance between the second internal flow channel and the outer peripheral surface of the rotor core. Specifically, the circumferential distance between the circumferentially adjacent first and second internal flow channels is greater than the radial distance.

[0018] In the oil-cooled motor provided in this application, the second internal flow channel is closer to the outer circumferential surface of the rotor core, while the first internal flow channel is farther away from the outer circumferential surface of the rotor core. The circumferentially adjacent first and second internal flow channels are radially misaligned, and their circumferential projections do not overlap.

[0019] The large circumferential spacing and small radial spacing between the circumferentially adjacent first and second internal flow channels result in a larger circumferential dimension of the core between them, improving the circumferential continuity of the rotor core and reducing adverse effects on the rotor's mechanical strength. Furthermore, it shortens the circumferential coverage of the rotor oil path, preventing radial cutting of the magnetic flux and affecting the rotor's electromagnetic characteristics. It also simplifies the connecting oil path between the first and second internal flow channels, ensuring smooth and rapid entry of cooling oil into the internal flow channels of the rotor core, thus improving heat dissipation efficiency.

[0020] In one embodiment, the two layers of magnet slots in the same group are symmetrically arranged about the radial symmetry line of the rotor. In at least a portion of the multiple groups of magnet slots, at least one second internal flow channel is distributed on each side of the circumferential direction of the radial symmetry line of the two layers of magnet slots in the same group. The offsetting of the second internal flow channels facilitates the normalization of the two end plates of the rotor, simplifies the rotor structure, and reduces the manufacturing cost of the rotor.

[0021] In one embodiment, the radial dimension of the first groove is greater than the circumferential dimension of the first groove. A portion of the first groove is used to directly connect to a first internal flow channel, and another portion of the first groove is used to directly connect to an internal flow channel of the rotor shaft. The radial dimension of a portion of the first groove is greater than the radial dimension of the other portion of the first groove.

[0022] In the oil-cooled motor disclosed in this application, the large radial dimension of the first groove facilitates a short radial flow path for the oil, minimizes oil loss, and ensures rapid flow of cooling oil to the portion where the first groove connects with the first internal flow channel. The small circumferential dimension of the first groove reduces the weakening of the circumferential continuity of the end plate, reduces stress concentration, ensures the electromagnetic characteristics and mechanical strength of the rotor, and also helps to reduce circumferential heat dissipation loss of the oil during flow.

[0023] The radial dimension of another part of the first groove is small to shorten the radial flow path of the oil and reduce flow losses. The radial dimension of a part of the first groove is large, which increases the flow area on the radial outer side of the first groove and reduces the flow velocity. This is beneficial for guiding the cooling oil to flow faster to the radial outer side of the first groove, thereby improving heat exchange efficiency.

[0024] In one embodiment, a portion of the second groove is used to directly connect to a first internal flow channel. Another portion of the second groove is used to directly connect to a second internal flow channel. A further portion of the second groove is used to directly connect to a portion of the second groove and the other portion of the second groove.

[0025] In this arrangement, a portion of the second groove is radially offset from another portion of the second groove along the rotor. The circumferential distance between the portion of the second groove and the other portion of the second groove is greater than the radial distance between the portion of the second groove and the other portion of the second groove, in order to accommodate the radially offset first and second internal flow channels.

[0026] The large circumferential distance and small radial distance between one part and the other part of the second groove reduce the impact on the mechanical strength of the end plate through the large circumferential distance, and shorten the radial flow path of the cooling oil through the small radial distance, thereby reducing flow resistance and radial flow loss of the oil.

[0027] In one embodiment, the circumferential dimension of a portion of the second groove is greater than the circumferential dimension of the other portion of the second groove and the circumferential distance between the portion of the second groove and the other portion of the second groove. The radial dimension of the other portion of the second groove is greater than the radial distance between the portion of the second groove and the other portion of the second groove, but less than the radial dimension of the portion of the second groove.

[0028] In the oil-cooled motor disclosed in this application, a portion of the second groove has a large circumferential dimension, while the other portion of the second groove has a small circumferential dimension, and the circumferential distance between the two portions of the second groove is small. This reduces the flow resistance of the oil from the first internal flow channel into the second groove, ensuring smooth entry of the cooling oil. Furthermore, it increases the flow velocity of the cooling oil entering the second internal flow channel, ensuring rapid entry and enhancing heat exchange efficiency. It also shortens the circumferential flow path of the oil and ensures the mechanical strength of the end plate, reducing stress concentration.

[0029] The radial dimension of one part of the second groove is large, the radial dimension of the other part of the second groove is smaller, and the radial distance between the two parts of the second groove is small. On the one hand, this is used to increase the flow rate of cooling oil entering the second internal flow channel, which is beneficial to enhancing heat exchange efficiency. On the other hand, it is used to shorten the radial flow path of cooling oil on the end plate, reducing oil flow resistance and radial flow loss.

[0030] In one embodiment, a portion of the first groove is used to directly connect to a first internal flow channel, and another portion of the first groove is used to directly connect to an internal flow channel of the rotor shaft. A portion of the second groove is used to directly connect to a first internal flow channel, and another portion of the second groove is used to directly connect to a second internal flow channel. At least a portion of each of the plurality of second grooves reuses a portion of a corresponding first groove. This serves two purposes: firstly, it enables different flow channel connection methods to meet the rotor heat dissipation requirements of different motors; secondly, by reusing the grooves, the connection between oil circuits is simplified, which helps reduce maintenance costs.

[0031] In one embodiment, the plurality of first grooves and the plurality of second grooves are each comprised of multiple groups. Each group of first grooves comprises two first grooves. Each group of second grooves comprises two second grooves. A portion of each second groove in one group reuses a portion of one first groove in one group of first grooves.

[0032] In this design, one portion of one of the two first grooves in the same group reuses another portion of the other first groove. Similarly, one portion of one of the two second grooves in the same group reuses another portion of the other second groove. This design serves two purposes: firstly, it allows for different flow channel connections to meet the rotor cooling requirements of different motors; secondly, by reusing the grooves, it simplifies the connection between oil circuits, thereby reducing maintenance costs.

[0033] In one embodiment, one portion of the first groove in each group of first grooves is used to directly connect to another portion of the second groove in a corresponding group of second grooves. Cooling oil flows directly from one portion of the first groove into another portion of each second groove in the group of second grooves, thereby achieving different flow channel connections to meet the rotor heat dissipation requirements of different motors. In one embodiment, the end plate includes multiple third grooves distributed on the side of the end plate facing the rotor core. Each third groove directly connects to a second internal flow channel, and an oil hole is distributed at the bottom of the groove, penetrating the end plate along the rotor's axial direction. Another portion of the second groove connects to a second internal flow channel. Each third groove reuses another portion of a corresponding second groove. This serves two purposes: firstly, it allows for different flow channel connection methods to meet the rotor heat dissipation requirements of different motors; secondly, by reusing the grooves, the connection between oil circuits is simplified, which helps reduce maintenance costs.

[0034] A second aspect of this application provides a powertrain including a reducer and the aforementioned oil-cooled motor, the oil-cooled motor being used to drive the wheels of an electric vehicle via the reducer.

[0035] The powertrain provided in this application includes the aforementioned oil-cooled motor. Therefore, the powertrain provided in this application solves the same technical problem and has the same technical effect as the oil-cooled motor in the aforementioned technical solution, and will not be repeated here.

[0036] A third aspect of this application provides an electric vehicle including wheels and the aforementioned powertrain for driving the wheels.

[0037] The electric vehicle provided in this application includes the aforementioned powertrain. Therefore, the electric vehicle provided in this application solves the same technical problem and has the same technical effect as the powertrain of the aforementioned technical solution, and will not be repeated here. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the structure of an electric vehicle provided in an embodiment of this application; Figure 2 This is a schematic diagram of the structure of a powertrain provided in an embodiment of this application; Figure 3 This is a schematic diagram of the structure of an oil-cooled motor provided in an embodiment of this application; Figure 4 A schematic diagram of a rotor provided in an embodiment of this application; Figure 5 for Figure 4 Exploded view of the central rotor; Figure 6 for Figure 4 Cross-sectional view of the central rotor; Figure 7 A partial structural schematic diagram of the rotor provided in an embodiment of this application; Figure 8 for Figure 7 Schematic diagram of the rotor core structure; Figure 9 A partial exploded view of the rotor provided in an embodiment of this application; Figure 10 for Figure 9 A schematic diagram of the structure of the first end plate in the middle; Figure 11 for Figure 9 Schematic diagram of the structure of the second end plate; Figure 12 This is one of the rotor cooling oil circuit structure diagrams provided in the embodiments of this application; Figure 13 This is the second diagram of the rotor cooling oil circuit structure provided in the embodiments of this application; Figure 14 This is one of the schematic diagrams of the rotor core provided in the embodiments of this application; Figure 15 This is one of the structural schematic diagrams of the end plate provided in the embodiments of this application; Figure 16 for Figure 14 The rotor core and Figure 15 A schematic diagram of the end plate in the assembled state; Figure 17 This is a schematic diagram of the structure of the first end plate provided in an embodiment of this application; Figure 18 for Figure 17 The first end plate and Figure 8 A schematic diagram of the rotor core in the assembled state; Figure 19 This is a schematic diagram of the structure of the second end plate provided in an embodiment of this application; Figure 20 for Figure 19 The second end plate and Figure 8 A schematic diagram of the rotor core in the assembled state; Figure 21 This is the second schematic diagram of the rotor core structure provided in the embodiments of this application; Figure 22 This is a second schematic diagram of the end plate structure provided in the embodiments of this application; Figure 23 for Figure 21 The rotor core and Figure 22 A schematic diagram of the end plate in the assembled state; Figure 24 This is the third schematic diagram of the end plate structure provided in the embodiments of this application; Figure 25 for Figure 24 Mid-end plate and Figure 8 A schematic diagram of the rotor core in the assembled state; Figure 26 Fourth schematic diagram of the end plate provided in the embodiments of this application; Figure 27 for Figure 26 Mid-end plate and Figure 8 A schematic diagram of the rotor core in the assembled state; Figure 28 Fifth schematic diagram of the end plate provided in the embodiments of this application; Figure 29 for Figure 28 Mid-end plate and Figure 8 A schematic diagram of the rotor core in the assembly state.

[0039] Figure label: 1000 - Electric vehicles; 100 - Powertrain; 200 - Wheels; 10 - Oil-cooled motor; 20 - Reducer; 01-Rotor; 02-Stator; 021-Stator winding; 1-Rotor core; 11-Magnetic slot; 12-First internal flow channel; 13-Second internal flow channel; 2-End plate; 2a-First end plate; 2b-Second end plate; 21-First groove; 22-Second groove; 23-Third groove; 24-Oil hole; 3-Rotor shaft; 31-Protrusion; 32-Axial flow channel; 33-Radial oil hole; 4-Pressure plate; 5-Magnet. Detailed Implementation

[0040] In oil-cooled motors, the internal flow channels of the rotor core refer to dedicated channels formed inside the rotor core for the flow of cooling oil. These internal flow channels, together with the end plates at both ends, form the cooling oil circuit, enabling efficient heat dissipation during rotor operation. Therefore, the internal flow channels of the rotor core significantly affect the rotor's heat dissipation efficiency, electromagnetic characteristics, and structural strength. Current flow channel designs struggle to balance these performance characteristics, thus hindering performance improvements in oil-cooled motors.

[0041] This application provides an oil-cooled motor, a powertrain, and an electric vehicle. By arranging different internal flow channels in different regions of the rotor core, the overall performance of the oil-cooled motor can be improved by taking into account the rotor heat dissipation efficiency, electromagnetic characteristics, and structural strength.

[0042] The electric vehicle provided in this application is a wheeled device driven or towed by a power unit. In some embodiments, the electric vehicle includes pure electric vehicles, hybrid electric vehicles, range-extended electric vehicles, or plug-in hybrid electric vehicles, etc.

[0043] Among them, pure electric vehicles are called battery electric vehicles, abbreviated as BEV. Hybrid electric vehicles are called hybrid electric vehicles, abbreviated as HEV. Range-extended electric vehicles are called range-extended electric vehicles, abbreviated as REEV. Plug-in hybrid electric vehicles are called plug-in hybrid electric vehicles. In hybrid electric vehicles, abbreviated as PHEV.

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

[0045] Figure 1 This is a schematic diagram of an electric vehicle provided as an embodiment of this application. (Refer to...) Figure 1 The electric vehicle 1000 includes a powertrain 100 and wheels 200, with the powertrain 100 driving the wheels 200. The interaction between the wheels 200 and the road surface drives the electric vehicle 1000 to move.

[0046] Figure 2 This is a schematic diagram of a powertrain provided in an embodiment of this application. (Refer to...) Figure 2 The portion shown in the dashed box is the powertrain 100. The powertrain 100 includes an oil-cooled motor 10 and a reducer 20. The oil-cooled motor 10 is used to drive the wheels 200 through the reducer 20.

[0047] The oil-cooled motor 10 is used to convert electrical energy into mechanical energy. The reducer 20 converts the mechanical energy output by the oil-cooled motor 10 into a greater torque output to drive the wheel 200 to rotate.

[0048] Figure 3 This is a schematic diagram of the structure of an oil-cooled motor provided in an embodiment of this application. (Refer to...) Figure 3 The oil-cooled motor 10 includes a rotor 01 and a stator 02. The rotor 01 passes through the central hole of the stator 02 along direction A, where A indicates the axial direction of the oil-cooled motor 10, and the central hole of the stator 02 is indicated by the letter a. The rotor 01 and the stator 02 work together to achieve the conversion of electrical energy into mechanical energy.

[0049] When the stator winding 021 of stator 02 is energized, it generates a rotating magnetic field. This rotating magnetic field interacts with the inherent magnetic field of the magnets in rotor 01, producing an electromagnetic force. The electromagnetic force acting on rotor 01 generates an electromagnetic torque relative to its rotation axis. This electromagnetic torque directly drives rotor 01 to rotate, thus converting electrical energy into mechanical energy. The rotor shaft 3 of rotor 01 is used to transmit the rotational torque generated by rotor 01 outwards, ultimately achieving the output of mechanical energy. The magnets... Figure 3 Not shown in the image.

[0050] In the embodiments of this application, the axial direction of the oil-cooled motor 10, the axial direction of the rotor 01, and the axial direction of the stator 02 refer to the same direction. The radial direction of the oil-cooled motor 10, the radial direction of the rotor 01, and the radial direction of the stator 02 refer to the same direction. The circumferential direction of the oil-cooled motor 10, the circumferential direction of the rotor 01, and the circumferential direction of the stator 02 refer to the same direction.

[0051] For ease of understanding, in the following text and in the accompanying drawings of the embodiments of this application, the axial direction of rotor 01 is referred to by the letter A, the radial direction of rotor 01 is referred to by the letter B, and the circumferential direction of rotor 01 is referred to by the letter C.

[0052] As the motor speed and power density continue to increase, the heat generated by the rotor 01 increases. Based on this, the embodiments of this application use oil cooling to cool the rotor 01 in order to improve the cooling efficiency of the rotor 01.

[0053] The rotor 01 of the oil-cooled motor 10 of this application will now be described in further detail with reference to the accompanying drawings.

[0054] Figure 4 This is a schematic diagram of a rotor provided as an embodiment of this application. (Refer to...) Figure 4 The rotor 01 includes a rotor shaft 3, a rotor core 1, and two end plates 2. The two end plates 2 are arranged at both ends of the rotor core 1 along the axial direction. The two end plates 2 include a first end plate 2a and a second end plate 2b. The first end plate 2a is arranged at one end of the rotor core 1 along the A direction, and the second end plate 2b is arranged at the other end of the rotor core 1 along the A direction.

[0055] Figure 5 for Figure 4 A partially exploded view of the central rotor. (Refer to...) Figure 5 The rotor shaft 3 passes through the center hole of the rotor core 1 and the center holes of the two end plates 2. The center hole of the rotor core is as follows: Figure 5 The letter b indicates the center hole of the first end plate 2a. Figure 5 The center hole of the second end plate 2b, as indicated by the letter c1 in the middle, is as follows: Figure 5 The letter c2 in the middle refers to.

[0056] Reference Figure 4 and Figure 5 The rotor shaft 3 includes a protrusion 31 that protrudes along direction B from the outer circumferential surface of the rotor shaft 3 and is located on the side of the first end plate 2a away from the rotor core 1 along direction A. The rotor 01 also includes a pressure plate 4, which is located on the side of the second end plate 2b away from the rotor core 1 along direction A.

[0057] During installation, the rotor shaft 3 passes sequentially through the center hole of the first end plate 2a, the center hole of the rotor core 1, the center hole of the second end plate 2b, and the center hole of the pressure plate 4, such that the first end plate 2a abuts against the protrusion 31, and the pressure plate 4 abuts against the second end plate 2b. The center hole of the pressure plate 4 is as follows: Figure 5 The letter d indicates that the rotor core 1 and the two end plates 2 are axially fixed to the rotor shaft 3 by the protrusion 31 and the pressure plate 4, so as to limit the displacement of the rotor core 1 and the two end plates 2 along the A direction.

[0058] Figure 6 for Figure 4 Cross-sectional view of the central rotor. (Refer to...) Figure 6 The internal flow channels of the rotor shaft 3 include an axial flow channel 32 and multiple radial oil holes 33. The axial flow channel 32 extends along direction A, and each radial oil hole 33 penetrates the sidewall of the axial flow channel 32 along direction B. The axial flow channel 32 is used to receive cooling oil, and each radial oil hole 33 is used to receive the cooling oil delivered by the axial flow channel 32 and to deliver cooling oil to the internal flow channels of the rotor core 1 through the two end plates 2. The internal flow channels of the rotor core 1 are as follows: Figure 6 The letter 'e' in the middle refers to.

[0059] The cooling oil entering the rotor core 1 exchanges heat with the rotor core 1 to remove the heat from the rotor core 1 and the magnets 5 embedded inside it. The cooling oil after heat exchange is thrown out from the ends of the two end plates 2 along direction A to cool the stator winding 021 or lubricate the bearings of the rotor shaft 3.

[0060] Since the internal flow channels of rotor core 1 are formed inside rotor core 1, and the internal flow channels of rotor core 1, together with its two end plates 2, constitute the cooling oil circuit of rotor 01, the internal flow channels of rotor core 1 will significantly affect the heat dissipation efficiency, electromagnetic characteristics and structural strength of rotor 01.

[0061] Of the two current flow channel design schemes, one scheme places the flow channel in the inner peripheral region away from the magnets. While this reduces the impact on electromagnetic characteristics and structural strength, the greater distance between the flow channel and the magnets results in insufficient heat dissipation for the rotor 01. The other scheme places the flow channel in the outer peripheral region closer to the magnets. This closer proximity improves heat dissipation efficiency to some extent, but exacerbates leakage flux and eddy current losses and weakens the core strength. Neither of these flow channel design schemes can simultaneously achieve optimal heat dissipation efficiency, electromagnetic characteristics, and structural strength for the rotor 01, thus limiting the performance improvement of the oil-cooled motor 10.

[0062] To address this issue, this application utilizes different internal flow channels in different regions of the rotor core 1 to maximize the balance between heat dissipation efficiency, electromagnetic characteristics, and structural strength of the rotor 01, thereby improving the overall performance of the oil-cooled motor 10.

[0063] The embodiments of this application will now be described in further detail with reference to the accompanying drawings.

[0064] Figure 7 This is a partial structural diagram of the rotor provided in an embodiment of this application. Figure 8 for Figure 7 A schematic diagram of the structure of the rotor core.

[0065] Reference Figure 7 and Figure 8 The rotor core 1 includes multiple sets of magnetic slots 11, which are arranged at intervals along the circumference of the rotor 01. Each set of magnetic slots 11 includes two layers of magnetic slots 11, which are arranged in layers along the radial direction of the rotor 01. A set of magnetic slots 11 is as follows: Figure 8 The dashed box f indicates the two layers of magnetic steel channels 11, as shown below. Figure 8 The dashed boxes g1 and g2 point to.

[0066] A set of magnetic slots 11 refers to a collection of multiple magnetic slots 11 used to embed the same magnetic pole. A magnetic pole is generated by multiple magnets within this set, with each magnet providing a portion of the magnetic flux to that pole. The magnets embedded in the same set of magnetic slots 11 exhibit the same magnetic polarity on the air gap side, either all being N poles or all being S poles, to ensure that the polarity of the magnetic pole is singular and that the magnetic field is superimposed and enhanced. Two circumferentially adjacent sets of magnetic slots 11 are used to embed magnetic poles with opposite polarities.

[0067] In some embodiments, the two layers of magnetic slots 11 in the same group of magnetic slots 11 are symmetrically arranged about the radial symmetry line of the rotor 01, as shown in the figure. Figure 8 The letter h indicates that each layer of magnetic steel grooves 11 in the same group is V-shaped, and the two layers of magnetic steel grooves 11 in the same group are arranged radially in a double V shape.

[0068] In other embodiments of this application, one layer of the same set of magnetic grooves 11 is in the shape of an "I" and the other layer is in the shape of a "V". The two layers of magnetic grooves 11 in the same set are arranged radially in a "V+I" shape. Those skilled in the art can selectively design according to actual needs.

[0069] The embodiments of this application will be described in further detail below, taking the example of two layers of magnetic steel grooves 11 in the same group of magnetic steel grooves 11 forming a double "V" shape.

[0070] Reference Figure 6 , Figure 7 and Figure 8 The rotor core 1 includes multiple first internal flow channels 12 and multiple second internal flow channels 13. Each first internal flow channel 12 is distributed between two adjacent sets of magnet slots 11, and each second internal flow channel 13 is distributed between two layers of magnet slots 11 in a set of magnet slots 11.

[0071] Figure 9 This is a partial exploded view of the rotor provided in an embodiment of this application. (Refer to...) Figure 9 Each end plate 2 includes multiple first grooves 21 and multiple second grooves 22, which are distributed on the side of the end plate 2 facing the rotor core 1. Each first groove 21 is used to directly connect the internal flow channel of the rotor shaft 3 and a first internal flow channel 12, and each second groove 22 is used to directly connect a circumferentially adjacent first internal flow channel 12 and a second internal flow channel 13.

[0072] Through multiple first grooves 21 and multiple second grooves 22 on the two end plates 2, cooling oil passages are formed between the rotor shaft 3 and the first internal flow channel 12 of the rotor core 1, as well as between the first internal flow channel 12 and the second internal flow channel 13, to achieve efficient heat dissipation during the operation of the rotor 01. The multiple first internal flow channels 12 and multiple second internal flow channels 13 of the rotor core 1 are distributed between the magnet slots 11 and are close to the magnets embedded in the magnet slots 11, thereby improving the heat dissipation efficiency of the rotor 01.

[0073] Within the same group of magnet slots 11, the magnetic flux density is higher, the heat dissipation requirement is greater, the usable core space is limited, and the structural strength requirement is lower. Conversely, between two adjacent groups of magnet slots 11 in the circumferential direction, the magnetic flux density is lower, the heat dissipation requirement is smaller, the usable core space is larger, and the structural strength requirement is higher. Therefore, the differences in spatial layout, magnetic flux distribution, mechanical strength, and heat dissipation conditions within and between groups are significant. If the same slotting scheme is used, it is difficult to simultaneously achieve optimal heat dissipation, electromagnetic characteristics, and mechanical strength, severely impacting the motor's operational reliability and overall performance.

[0074] In this application, reference is made to Figure 7 and Figure 8 Each first internal flow channel 12 is distributed between two adjacent sets of magnetic steel grooves 11. Each second internal flow channel 13 is distributed between two layers of magnetic steel grooves 11 in one set of magnetic steel grooves 11. The shape, size, or cross-sectional area of ​​the first internal flow channel 12 and the second internal flow channel 13 are different.

[0075] Given the significant differences in spatial layout, magnetic flux distribution, mechanical strength, and heat dissipation conditions within each set of magnet slots 11 and between adjacent sets of magnet slots 11, internal flow channels of different shapes, sizes, or cross-sectional areas are configured. This allows the first internal flow channel 12 to precisely adapt to the needs of each set of magnet slots 11, which have higher magnetic flux density, greater heat dissipation requirements, limited available core space, and lower structural strength requirements. Conversely, the second internal flow channel 13 can precisely adapt to the needs of adjacent sets of magnet slots 11, which have lower magnetic flux density, smaller heat dissipation requirements, greater available core space, and higher structural strength requirements. This effectively avoids the shortcomings of a single flow channel layout, which cannot simultaneously address heat dissipation, electromagnetic characteristics, and mechanical strength. It maximizes the balance between rotor 01's heat dissipation efficiency, electromagnetic characteristics, and structural strength, thereby improving the overall performance of the oil-cooled motor 10.

[0076] In some embodiments, refer to Figure 8 The cross-sectional area of ​​the first internal flow channel 12 is larger than the cross-sectional area of ​​the second internal flow channel 13. The cross-sectional area of ​​the first internal flow channel 12 refers to the flow area of ​​the first internal flow channel 12 perpendicular to direction A. The cross-sectional area of ​​the second internal flow channel 13 refers to the flow area of ​​the second internal flow channel 13 perpendicular to direction A.

[0077] The large cross-sectional area of ​​the first internal flow channel 12 is arranged in the larger core space between two adjacent sets of magnet slots 11. This achieves efficient space utilization and provides sufficient margin for a smooth contour transition, effectively reducing stress concentration and ensuring the mechanical strength of the rotor 01 under high-speed rotation. Furthermore, it has minimal impact on the relatively sparse magnetic circuit between the two sets of magnet slots 11, preventing significant magnetic flux leakage or performance degradation. The large cross-sectional area of ​​the first internal flow channel 12 also provides heat exchange capacity matching the heat dissipation requirements, preventing localized overcooling or excessive flow resistance due to overly narrow channels.

[0078] A second internal flow channel 13 with a small cross-sectional area is arranged within the limited iron core space of each set of magnet slots 11. This avoids the magnet slots 11 being squeezed due to excessively large flow channels, and reduces the weakening of the iron core's mechanical strength, ensuring the mechanical strength of the rotor 01 under high-speed rotation. Simultaneously, the second internal flow channel 13 with a small cross-sectional area not only reduces the impact on the dense magnetic circuit within each set of magnet slots 11, preventing significant magnetic flux leakage or performance degradation, but also achieves a higher local flow velocity within the limited space, thereby obtaining stronger heat transfer capacity and meeting large heat dissipation requirements.

[0079] Reference Figure 8 The radial dimension of the first internal flow channel 12 is greater than the radial dimension of the second internal flow channel 13. The circumferential dimension of the first internal flow channel 12 is greater than the circumferential dimension of the second internal flow channel 13. The radial dimension of the first internal flow channel 12 refers to its maximum dimension along direction B. The circumferential dimension of the first internal flow channel 12 refers to its maximum dimension along direction C. The radial dimension of the second internal flow channel 13 refers to its maximum dimension along direction B. The second internal flow channel 13 refers to its maximum dimension along direction C.

[0080] The first internal flow channel 12 has a large radial and circumferential dimension, which gives it a large cross-sectional area, thereby reducing the flow resistance of the cooling oil in the first internal flow channel 12 and increasing its flow capacity.

[0081] The second internal flow channel 13 has small radial and circumferential dimensions, which gives it a small cross-sectional area. This increases the flow rate of the cooling oil in the second internal flow channel 13, enhances the convective heat transfer coefficient of the cooling oil in the second internal flow channel 13, and meets the large heat dissipation requirements of each set of magnetic steel slots 11.

[0082] In some embodiments, refer to Figure 8 The maximum radial dimension of the first internal flow channel 12 is smaller than the maximum circumferential dimension of the first internal flow channel 12.

[0083] Since the magnetic flux path is mainly in the radial direction, the maximum radial dimension of the first internal flow channel 12 is small, which limits the radial space occupied by the first internal flow channel 12 in the magnetic flux path, thereby reducing the cutting effect on the magnetic circuit and preventing magnetic flux leakage or distortion.

[0084] The first internal flow channel 12 has a larger maximum circumferential dimension to compensate for its radial dimension, resulting in a larger flow cross-sectional area. This ensures the flow capacity of the first internal flow channel 12 and reduces flow resistance. The maximum radial dimension of the first internal flow channel 12 is smaller than its maximum circumferential dimension, allowing its shape to fit the geometry of the gap between adjacent sets of magnetic slots 11. This maximizes the flow cross-sectional area within a limited space, improving space utilization.

[0085] In some embodiments, refer to Figure 8 The circumferential dimension of the end of the first internal flow channel 12 away from the center hole of the rotor core 1 is smaller than the circumferential dimension of the end of the first internal flow channel 12 facing the center hole of the rotor core 1.

[0086] The first internal flow channel 12 has a variable cross-section shape that is wider on the inside and narrower on the outside in the radial direction. On the one hand, because the gap between two adjacent sets of magnet slots 11 gradually decreases radially outward, the magnetic flux density is higher closer to the outer periphery. The narrow radial outer side of the first internal flow channel 12 reduces the cutting effect on the magnetic circuit and prevents magnetic flux leakage or distortion. On the other hand, under the action of centrifugal force, the cooling oil in the first internal flow channel 12 gathers radially outward. The narrow radial outer side of the first internal flow channel 12 locally throttles the flow, reduces the outflow velocity of the cooling oil, prolongs the heat exchange time between the cooling oil and the rotor core 1, and thus improves the heat dissipation efficiency.

[0087] Reference Figure 8 The first internal flow channel 12 is △-shaped, and the sidewalls of the first internal flow channel 12 have a smooth transition to reduce local stress concentration.

[0088] In some embodiments, refer to Figure 8 The circumferential dimension of the second internal flow channel 13 is larger than the radial dimension of the second internal flow channel 13. On the one hand, it does not increase the occupancy of radial space, prevents excessive weakening of the mechanical strength of the iron core due to the increase of the second internal flow channel 13, and reduces the cutting of the radial main magnetic circuit by the second internal flow channel 13. On the other hand, by making the circumferential dimension of the second internal flow channel 13 larger, the flow cross-section of the second internal flow channel 13 is increased, and the coverage of the cooling oil in the circumferential direction is wider, which is beneficial to improving the heat dissipation efficiency.

[0089] In some embodiments, refer to Figure 8 The radial distance between the first internal flow channel 12 and the outer peripheral surface of the rotor core 1 is greater than the radial distance between the second internal flow channel 13 and the outer peripheral surface of the rotor core 1. The second internal flow channel 13 is closer to the outer peripheral surface of the rotor core 1, while the first internal flow channel 12 is farther away from the outer peripheral surface of the rotor core 1.

[0090] The circumferential spacing between the first internal flow channel 12 and the second internal flow channel 13 that are circumferentially adjacent is greater than the radial spacing.

[0091] The circumferentially adjacent first internal flow channel 12 and second internal flow channel 13 are radially offset, and their circumferential projections do not overlap. The circumferential spacing between the circumferentially adjacent first internal flow channel 12 and second internal flow channel 13 is large, while the radial spacing is small. On the one hand, this results in a larger circumferential dimension of the core between the first internal flow channel 12 and the second internal flow channel 13, thereby improving the circumferential continuity of the rotor core 1 and reducing the adverse effects on the mechanical strength of the rotor 01. On the other hand, it shortens the directional coverage of the oil path of the rotor 01, preventing radial cutting of the magnetic flux and affecting the electromagnetic characteristics of the rotor 01. It also simplifies the connecting oil path between the first internal flow channel 12 and the second internal flow channel 13, ensuring that the cooling oil enters the internal flow channel of the rotor core 1 smoothly and quickly, which is beneficial to improving heat dissipation efficiency.

[0092] exist Figure 8 In the given embodiment, the second internal flow channel 13 is distributed along the radial symmetry line of the rotor 01. Below, we will use... Figure 8 The embodiments of this application will be further described in detail using the rotor core 1 as an example.

[0093] Figure 10 for Figure 9 A schematic diagram of the structure of the first end plate 2a. Figure 11 for Figure 9 A schematic diagram of the structure of the second end plate 2b. (Refer to...) Figure 9 , Figure 10 and Figure 11 Both the first end plate 2a and the second end plate 2b include: a plurality of first grooves 21, a plurality of second grooves 22, and a plurality of third grooves 23, distributed on the side of the end plate 2 facing the rotor core 1. The third groove 23 is used to directly connect to a second internal flow channel 13. An oil hole 24 is distributed at the bottom of the third groove 23, penetrating the end plate 2 along the axial direction of the rotor 01 to discharge oil from the third groove 23. Figure 9 Taking the oil passage indicated by the dashed arrow as an example, a first groove 21 of the second end plate 2b, a first internal flow channel 12 of the rotor core 1, a second groove 22 of the first end plate 2a, a second internal flow channel 13 of the rotor core 1, and a third groove 23 of the second end plate 2b are sequentially connected to form a cooling oil passage. In this cooling oil passage, a first internal flow channel 12 and a second internal flow channel 13 of the rotor core 1 are connected in series.

[0094] Cooling oil sequentially enters a first groove 21 in the second end plate 2b, a first internal flow channel 12 in the rotor core 1, a second groove 22 in the first end plate 2a, a second internal flow channel 13 in the rotor core 1, and a third groove 23 in the second end plate 2b, and exits from an oil hole 24 in the third groove 23 of the second end plate 2b onto the rotor 01. The two layers of internal flow channels extend the oil flow path and improve the heat dissipation capacity of the rotor 01.

[0095] Figure 12 This is one of the cooling oil circuit structure diagrams of the rotor provided in the embodiments of this application. Figure 13 This is the second diagram of the rotor cooling oil circuit structure provided in the embodiments of this application. Figure 12 and Figure 13 The rotor cooling oil circuit shown is a series cooling oil circuit.

[0096] Reference Figure 12 and Figure 13 A portion of the first groove 21 is indicated by 21a, and another portion of the first groove 21 is indicated by 21b. A portion of the first groove 21 is used to directly connect to a first internal flow channel 12, and the other portion of the first groove 21 is used to directly connect to the internal flow channel of the rotor shaft 3.

[0097] The oil flowing out of the internal flow channel of the rotor shaft 3 enters radially into a part of the first groove 21 of an end plate 2. The oil that enters a part of the first groove 21 flows to another part of the first groove 21 and then flows into the corresponding first internal flow channel 12.

[0098] Reference Figure 12 and Figure 13 A portion of the second groove 22 is indicated by 22a, another portion of the second groove 22 is indicated by 22b, and yet another portion of the second groove 22 is indicated by 22c. A portion of the second groove 22 is used to directly connect to a first internal flow channel 12, another portion of the second groove 22 is used to directly connect to a second internal flow channel 13, and yet another portion of the second groove 22 is used to directly connect to a portion of the second groove 22 and the other portion of the second groove 22.

[0099] The cooling oil flowing out of the first internal flow channel 12 sequentially enters a portion of the second groove 22 of the other end plate 2, then flows to another portion of the second groove 22, and the oil entering the other portion of the second groove 22 flows into the corresponding second internal flow channel 13. The oil flowing out of the second internal flow channel 13 enters the third groove 23 of one end plate 2 and is discharged from the rotor 01 through the oil hole 24 at the bottom of the third groove 23.

[0100] In some embodiments, refer to Figure 10 and Figure 12The radial dimension of the first groove 21 is larger than its circumferential dimension. The first groove 21 is used to receive oil from the rotor shaft 3 and to transport the oil to the first internal flow channel 12. The large radial dimension of the first groove 21 helps to shorten the radial flow path of the oil, reduce oil loss, and ensure that the cooling oil flows quickly to the part where the first groove 21 meets the first internal flow channel 12. The small circumferential dimension of the first groove 21 reduces the weakening of the circumferential continuity of the end plate 2, reduces stress concentration, ensures the electromagnetic characteristics and mechanical strength of the rotor 01, and also helps to reduce circumferential heat loss of the oil during flow.

[0101] In some embodiments, refer to Figure 10 and Figure 12 The radial dimension of a portion of the first groove 21 is greater than the radial dimension of the other portion of the first groove 21.

[0102] The radial dimension of another part of the first groove 21 is small to shorten the radial flow path of the oil and reduce flow loss. The radial dimension of a part of the first groove 21 is large, which increases the flow area on the radial outer side of the first groove 21 and reduces the flow velocity. This is beneficial for guiding the cooling oil to flow faster to the radial outer side of the first groove 21, thereby improving heat exchange efficiency.

[0103] The shape of a portion of the first groove 21 is adapted to the shape of the first internal flow channel 12 to ensure a smooth transition of the oil path when the two are connected, thereby reducing flow loss.

[0104] In some embodiments, refer to Figure 10 and Figure 12 A portion of the second groove 22 and another portion of the second groove 22 are arranged radially offset along the rotor 01. The circumferential distance between the portion of the second groove 22 and the other portion of the second groove 22 is greater than the radial distance between the portion of the second groove 22 and the other portion of the second groove 22, so as to adapt to the radially offset layout of the first internal flow channel 12 and the second internal flow channel 13.

[0105] The large circumferential distance and small radial distance between one part and the other part of the second groove 22 reduce the impact on the mechanical strength of the end plate 2 through the large circumferential distance. At the same time, the small radial distance shortens the radial flow path of the cooling oil, reducing flow resistance and reducing radial flow loss of the oil.

[0106] In some embodiments, refer to Figure 10 and Figure 12 The circumferential dimension of a portion of the second groove 22 is greater than the circumferential dimension of the other portion of the second groove 22 and the circumferential distance between the portion of the second groove 22 and the other portion of the second groove 22, so as to form a second groove 22 with a wide inlet, a narrow outlet and a large circumferential span, to ensure the docking of a portion of the second groove 22 with the first internal flow channel 12.

[0107] A portion of the second groove 22 has a large circumferential dimension, which reduces the flow resistance of the oil in the first internal flow channel 12 into the second groove 22, ensuring that the cooling oil enters the second groove 22 smoothly. The other portion of the second groove 22 has a small circumferential dimension, which increases the flow rate of the cooling oil entering the second internal flow channel 13, ensuring that the oil enters the second internal flow channel 13 quickly, which is beneficial to enhancing heat exchange efficiency.

[0108] The small circumferential distance between one part and the other part of the second groove 22 shortens the circumferential flow path of the oil and ensures the mechanical strength of the end plate 2 while reducing stress concentration. Furthermore, since the first internal flow channel 12 is located between two adjacent sets of magnet slots 11, and the second internal flow channel 13 is located within one set of magnet slots 11, the other part of the second groove 22 spans at least one magnet slot 11. During oil flow, the oil in the second groove 22 carries away some of the heat from the magnets, thus improving the heat dissipation efficiency of the rotor 01.

[0109] In some embodiments, refer to Figure 10 and Figure 12 The radial dimension of the other part of the second groove 22 is greater than the radial distance between the part of the second groove 22 and the other part of the second groove 22, and less than the radial dimension of the part of the second groove 22.

[0110] The radial dimension of another part of the second groove 22 is smaller than that of a part of the second groove 22. As the cooling oil flows from the part with the larger radial dimension to the other part with the smaller radial dimension, the flow rate of the cooling oil increases, ensuring that the oil quickly enters the second internal flow channel 13, which is beneficial to enhancing the heat exchange efficiency.

[0111] The radial dimension of the other part of the second groove 22 is greater than the radial distance between one part of the second groove 22 and the other part of the second groove 22, so as to shorten the radial flow path of the cooling oil in the end plate 2 and reduce the oil flow resistance and radial flow loss.

[0112] In some embodiments, refer to Figure 10 and Figure 12 The circumferential dimension of the third groove 23 is larger than its radial dimension to accommodate the shape of the second internal flow channel 13. The elongated shape of the third groove 23 helps to increase the circumferential coverage of the cooling oil and improve the uniformity of heat dissipation.

[0113] exist Figures 8 to 13 In the embodiment shown, the first end plate 2a and the second end plate 2b have different structures, making it impossible to normalize the end plate 2, which results in a complex rotor 01 structure and high manufacturing cost.

[0114] To address this issue, in some embodiments, at least one second internal flow channel 13 is distributed on both sides of the radial symmetry line of the two layers of magnetic steel grooves 11 in the same group of magnetic steel grooves 11 in at least a portion of the multiple groups of magnetic steel grooves 11.

[0115] Figure 14 This is one of the structural schematic diagrams of the rotor core 1 provided in an embodiment of this application. Figure 8 The difference between the given embodiments is that, Figure 14 In the given embodiment, in a portion of the multiple sets of magnetic slots 11, a second internal flow channel 13 is distributed on each side of the radial symmetry line of the two layers of magnetic slots 11 in the same set of magnetic slots 11. By offsetting the second internal flow channel 13 to one side of the radial symmetry line, it is beneficial to normalize the two end plates 2 of the rotor 01, simplify the structure of the rotor 01, and reduce the manufacturing cost of the rotor 01.

[0116] Figure 15 This is one of the structural schematic diagrams of the end plate 2 provided in the embodiments of this application. Figure 16 for Figure 14 Rotor core 1 and Figure 15 A schematic diagram of end plate 2 in its assembled state. (Refer to...) Figure 14 , Figure 15 , Figure 16 In the two second internal flow channels 13 located on both sides of the radial symmetry line of the two layers of magnetic steel grooves 11, one second internal flow channel 13 is used to connect a third groove 23, and the other second groove 22 is used to connect another part of a second groove 22. The other part of the second groove 22 is indicated by 22b.

[0117] Another end plate 2 and Figure 15 The end plates 2 are given the same structure. Since the two end plates 2 of the rotor core 1 have the same structure, during installation, the two end plates 2 are installed at different angles. On the basis of ensuring that the first internal flow channel 12 and the second internal flow channel 13 are connected in series, the end plates 2 are normalized, which helps to simplify the structure of the rotor 01 and reduce the manufacturing cost of the rotor 01.

[0118] Figures 14 to 16 In the given embodiment, the communication method between the multiple grooves of the end plate 2 and the internal flow channel of the rotor core 1, as well as the design principles of the first groove 21, the second groove 22, and the third groove 23, are all the same as those in the embodiment. Figures 8 to 13 The embodiments shown are the same, and will not be described again here.

[0119] In some embodiments, at least a portion of each of the plurality of second grooves 22 reuses a portion of a corresponding first groove 21 to achieve different connection methods of the internal flow channels of the rotor core 1, so as to meet the heat dissipation requirements of the rotor 01 of different motors.

[0120] exist Figures 17 to 20 In the given embodiment, a portion of the first groove 21 is indicated by 21a, and another portion of the first groove 21 is indicated by 21b. A portion of the second groove 22 is indicated by 22a, another portion of the second groove 22 is indicated by 22b, and yet another portion of the second groove 22 is indicated by 22c. Each portion of one of the multiple second grooves 22 reuses a corresponding portion of the first groove 21. The remaining portions of each second groove 22 reuse a third groove 23. Therefore, an oil hole 24 is distributed at the bottom of the other portion of the second groove 22, and the oil hole 24 penetrates the end plate 2 along the axial direction of the rotor 01 to discharge oil from the other portion of the second groove 22.

[0121] exist Figures 17 to 20 In one embodiment, a portion of the second groove 22 reuses a portion of a corresponding first groove 21, and the third groove 23 reuses another portion of a corresponding second groove 22. This serves two purposes: firstly, it enables different flow channel connections to meet the heat dissipation requirements of different motor rotors 01; secondly, by reusing the grooves, the connection between oil circuits is simplified, which helps reduce maintenance costs.

[0122] Taking the oil inlet of the first end plate 2a as an example, the cooling oil flows from another part of the first groove 21 in the first end plate 2a into a part of the first groove 21, and then the cooling oil in the part of the first groove 21 has two parallel flow paths.

[0123] The first path is: a portion of the cooling oil flows sequentially through a first internal flow channel 12, a part of the second groove 22 of the second end plate 2b, another part of the second groove 22 of the second end plate 2b, and another part of the second groove 22 of the second end plate 2b, and finally exits the rotor 01 through the oil hole 24 at the bottom of the groove of the other part of the second groove 22 of the second end plate 2b.

[0124] The second path is: another part of the cooling oil flows sequentially through a part of the second groove 22 of the first end plate 2a, another part of the second groove 22, another part of the second groove 22, the second internal flow channel 13, and another part of the second groove 22 of the second end plate 2b, and finally is discharged from the rotor 01 through the oil hole 24 at the bottom of the groove of the other part of the second groove 22 of the second end plate 2b.

[0125] The parallel connection of these two paths facilitates the addition of an internal oil flow path for rotor core 1, thereby improving the heat dissipation efficiency of rotor 01.

[0126] exist Figures 17 to 20In the embodiment shown, the first end plate 2a and the second end plate 2b have different structures, making it impossible to normalize the end plate 2, which results in a complex rotor 01 structure and high manufacturing cost.

[0127] To solve this problem, refer to Figure 21 In the multiple sets of magnetic steel slots 11, at least one second internal flow channel 13 is distributed on both sides of the radial symmetry line of the two layers of magnetic steel slots 11 in each set of magnetic steel slots 11. This is beneficial to normalize the two end plates 2 of the rotor 01, simplify the structure of the rotor 01, and reduce the manufacturing cost of the rotor 01.

[0128] exist Figures 21 to 23 In the illustrated embodiment, the two end plates 2 have identical structures. A portion of the first groove 21 is indicated by 21a, and another portion of the first groove 21 is indicated by 21b. A portion of the second groove 22 is indicated by 22a, another portion of the second groove 22 is indicated by 22b, and yet another portion of the second groove 22 is indicated by 22c. Each portion of the second groove 22 reuses a corresponding portion of the first groove 21.

[0129] Cooling oil flows into a portion of a first groove 21 from one end plate 2, and then the cooling oil in the portion of the first groove 21 has two parallel flow paths.

[0130] The first path is: a portion of the cooling oil flows sequentially through a first internal flow channel 12, a part of a second groove 22 of another end plate 2, another part of a second groove 22, another part of a second groove 22 and the second internal flow channel 13, and finally exits the rotor 01 through the oil hole 24 at the bottom of the third groove 23 of an end plate 2.

[0131] The second path is: another part of the cooling oil flows sequentially through a part of a second groove 22 of an end plate 2, another part of a second groove 22, another part of a second groove 22, a second internal flow channel 13, and finally exits the rotor 01 through the oil hole 24 at the bottom of the third groove 23 of another end plate 2.

[0132] exist Figures 24 to 25 In the illustrated embodiment, the two end plates 2 have identical structures. Each end plate 2 includes multiple first grooves 21, multiple second grooves 22, and multiple third grooves 23. The multiple first grooves 21 and multiple second grooves 22 on each end plate 2 are respectively divided into multiple groups, with each group of first grooves 21 including two first grooves 21 and each group of second grooves 22 including two second grooves 22. A group of first grooves 21 is as follows... Figure 24 The letter i points to a second groove 22, as shown in the image. Figure 24 The letter j in the middle refers to.

[0133] A portion of the first groove 21 is indicated by 21a, and another portion of the first groove 21 is indicated by 21b. A portion of the second groove 22 is indicated by 22a, another portion of the second groove 22 is indicated by 22b, and yet another portion of the second groove 22 is indicated by 22c.

[0134] Reference Figure 24 A portion of each of the two second grooves 22 in a set reuses a portion of one of the first grooves 21 in a set of first grooves 21. Another portion of one of the two first grooves 21 in the same set reuses another portion of the other first groove 21. Similarly, another portion of one of the two second grooves 22 in the same set reuses another portion of the other second groove 22.

[0135] Cooling oil flows from one end plate 2 into another part of a first groove 21 in the same group of first grooves 21, and then the cooling oil in each part of the first groove 21 has two parallel flow paths.

[0136] The first path is: a portion of the cooling oil flows sequentially through a first internal flow channel 12, a part of a second groove 22 of another end plate 2, another part of a second groove 22, another part of a second groove 22 and the second internal flow channel 13, and is discharged from the rotor 01 through the oil hole 24 at the bottom of the third groove 23 of an end plate 2.

[0137] The second path is: another part of the cooling oil flows sequentially through a part of a second groove 22 of an end plate 2, another part of a second groove 22, another part of a second groove 22, a second internal flow channel 13, and is discharged from the rotor 01 through the oil hole 24 at the bottom of the third groove 23 of another end plate 2.

[0138] exist Figures 26 to 27 In the illustrated embodiment, a portion of each second groove 22 in a set of second grooves 22 reuses a portion of one first groove 21 in a set of first grooves 21. Another portion of one first groove 21 in the same set of first grooves 21 reuses another portion of the other first groove 21. Similarly, another portion of one second groove 22 in the same set of second grooves 22 reuses another portion of the other second groove 22. The other portion of the first groove 21 in each set of first grooves 21 is used to directly connect to the other portion of the second groove 22 in the corresponding set of second grooves 22.

[0139] Cooling oil flows from one portion of a first groove 21 in an end plate 2 into a portion of each of the same group of first grooves 21 and another portion of each of the same group of second grooves 22. The cooling oil within each portion of a first groove 21 has two flow paths. The other portion of each of the same group of second grooves 22 has one flow path.

[0140] Within a portion of each first groove 21: a portion of cooling oil flows sequentially through a first internal flow channel 12, a portion of a second groove 22 of another end plate 2, another portion of a second groove 22, another portion of a second groove 22, and a second internal flow channel 13, and is discharged from the rotor 01 through the oil hole 24 at the bottom of the third groove 23 of an end plate 2.

[0141] Another portion of the cooling oil flows sequentially through a part of a second groove 22 of an end plate 2, another part of a second groove 22, another part of a second groove 22, a second internal flow channel 13, and is discharged from the rotor 01 through the oil hole 24 at the bottom of the third groove 23 of the other end plate 2.

[0142] The oil in another part of each second groove 22 in the same group flows through a second internal flow channel 13 and is discharged from the rotor 01 through the oil hole 24 at the bottom of the third groove 23 of the other end plate 2.

[0143] exist Figures 28 to 29 In the illustrated embodiment, a portion of each second groove 22 reuses a portion of a corresponding first groove 21. Each third groove 23 reuses another portion of a corresponding second groove 22.

[0144] Cooling oil flows into a portion of a first groove 21 in one end plate 2, and into another portion of the first groove 21. The cooling oil in each portion of the first groove 21 has two oil flow paths.

[0145] The first path is: a portion of the cooling oil flows sequentially through a first internal flow channel 12, a part of a second groove 22 of another end plate 2, another part of a second groove 22, and another part of a second groove 22, and is discharged from the rotor 01 through the oil hole 24 at the bottom of the second groove 22 of the other end plate 2.

[0146] The second path is: another part of the cooling oil flows sequentially through a part of a second groove 22 of an end plate 2, another part of a second groove 22, another part of a second groove 22, a second internal flow channel 13, and is discharged from the rotor 01 through the oil hole 24 at the bottom of the third groove 23 of another end plate 2.

[0147] Within a portion of each first groove 21: a portion of cooling oil flows sequentially through a first internal flow channel 12, a portion of a second groove 22 of another end plate 2, another portion of a second groove 22, another portion of a second groove 22, and a second internal flow channel 13, and is discharged from the rotor 01 through the oil hole 24 at the bottom of the third groove 23 of an end plate 2.

[0148] Another portion of the cooling oil flows sequentially through a part of a second groove 22 of an end plate 2, another part of a second groove 22, and another part of a second groove 22, and is discharged from the rotor 01 through the oil hole 24 at the bottom of the groove of the other part of the second groove 22 of the end plate 2.

[0149] Figures 21 to 23 The illustrated embodiments Figures 24 to 25 The illustrated embodiments Figures 26 to 27 The illustrated embodiments and Figures 28 to 29 The embodiments shown are all hybrid schemes, including both parallel and series oil circuits. The oil circuit design is simple, and the two end plates 2 are normalized, which improves the heat dissipation efficiency of rotor 01, simplifies the structure of rotor 01, and reduces the manufacturing cost of rotor 01.

[0150] In this application, the first internal flow channel 12 and the second internal flow channel 13 of the rotor core 1, along with the grooves of the two end plates 2, enable the series, parallel, or mixed connection of the two oil channels, thereby lengthening the oil flow path and improving the heat dissipation efficiency of the rotor 01. Furthermore, the two-layer cooling oil circuit structure provided in this application is simple and has low maintenance costs.

[0151] Figures 21 to 23 The illustrated embodiments Figures 24 to 25 The illustrated embodiments Figures 26 to 27 The illustrated embodiments and Figures 28 to 29 In the illustrated embodiment, each first internal flow channel 12 receives cooling oil flowing in opposite directions from both axial ends simultaneously, doubling the oil supply flow rate and halving the flow resistance without increasing the flow channel size, while also achieving a more balanced pressure distribution. The second internal flow channel 13 provides more uniform oil supply, and even if the oil supply at one end fails, the other end can still maintain cooling, which helps improve the reliability of the oil-cooled motor 10.

[0152] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An oil-cooled motor, characterized in that, The rotor of the oil-cooled motor includes a rotor shaft, a rotor core, and two end plates. The two end plates are respectively arranged at both ends of the rotor core along its axial direction. The rotor shaft passes through the central hole of the rotor core and the central holes of the two end plates, wherein: The rotor core includes multiple sets of magnetic slots, multiple first internal flow channels, and multiple second internal flow channels. The multiple sets of magnetic slots are arranged at intervals along the circumference of the rotor. Each set of magnetic slots includes two layers of magnetic slots. The two layers of magnetic slots are arranged in layers along the radial direction of the rotor. Each first internal flow channel is distributed between two adjacent sets of magnetic slots. Each second internal flow channel is distributed between the two layers of magnetic slots in one set of magnetic slots. The shape, size, or cross-sectional area of ​​the first internal flow channel and the second internal flow channel are different. The end plate includes a plurality of first grooves and a plurality of second grooves, which are distributed on the side of the end plate facing the rotor core. Each first groove is used to directly connect the internal flow channel of the rotor shaft and a first internal flow channel, and each second groove is used to directly connect a circumferentially adjacent first internal flow channel and a second internal flow channel.

2. The oil-cooled motor according to claim 1, characterized in that, The cross-sectional area of ​​the first internal flow channel is larger than the cross-sectional area of ​​the second internal flow channel, wherein: The radial dimension of the first internal flow channel is greater than the radial dimension of the second internal flow channel, and the circumferential dimension of the first internal flow channel is greater than the circumferential dimension of the second internal flow channel.

3. The oil-cooled motor according to claim 1 or 2, characterized in that, The maximum radial dimension of the first internal flow channel is smaller than the maximum circumferential dimension of the first internal flow channel, wherein: The circumferential dimension of the end of the first internal flow channel away from the central hole of the rotor core is smaller than the circumferential dimension of the end of the first internal flow channel facing the central hole of the rotor core.

4. The oil-cooled motor according to any one of claims 1-3, characterized in that, The circumferential dimension of the second internal flow channel is greater than the radial dimension of the second internal flow channel.

5. The oil-cooled motor according to any one of claims 1-4, characterized in that, The radial distance between the first internal flow channel and the outer peripheral surface of the rotor core is greater than the radial distance between the second internal flow channel and the outer peripheral surface of the rotor core, wherein: The circumferential spacing between the first and second internal flow channels that are circumferentially adjacent is greater than the radial spacing.

6. The oil-cooled motor according to any one of claims 1-5, characterized in that, The two layers of magnetic slots in the same group are symmetrically arranged about the radial symmetry line of the rotor, wherein: In at least a portion of the multiple sets of magnetic steel grooves, at least one second internal flow channel is distributed on each side of the radial symmetry line of the two layers of magnetic steel grooves in the same set.

7. The oil-cooled motor according to any one of claims 1-6, characterized in that, The radial dimension of the first groove is larger than the circumferential dimension of the first groove; A portion of the first groove is used to directly connect to a first internal flow channel, and another portion of the first groove is used to directly connect to an internal flow channel of the rotor shaft. The radial dimension of the portion of the first groove is greater than the radial dimension of the other portion of the first groove.

8. The oil-cooled motor according to any one of claims 1-7, characterized in that, A portion of the second groove is used to directly connect to one of the first internal flow channels, another portion of the second groove is used to directly connect to one of the second internal flow channels, and yet another portion of the second groove is used to directly connect the aforementioned portion of the second groove and the aforementioned other portion of the second groove, wherein: The portion of the second groove and the other portion of the second groove are arranged radially offset from each other along the rotor, and the circumferential distance between the portion of the second groove and the other portion of the second groove is greater than the radial distance between the portion of the second groove and the other portion of the second groove.

9. The oil-cooled motor according to claim 8, characterized in that, The circumferential dimension of said portion of the second groove is greater than the circumferential dimension of said other portion of the second groove, and the circumferential distance between said portion of the second groove and said other portion of the second groove; The radial dimension of the other portion of the second groove is greater than the radial distance between the first portion of the second groove and the other portion of the second groove, and less than the radial dimension of the first portion of the second groove.

10. The oil-cooled motor according to any one of claims 1-9, characterized in that, A portion of the first groove is used to directly connect to a first internal flow channel, and another portion of the first groove is used to directly connect to an internal flow channel of the rotor shaft. A portion of the second groove is used to directly connect to a first internal flow channel, and another portion of the second groove is used to directly connect to a second internal flow channel, wherein: At least a portion of each of the plurality of second grooves reuses a portion of a corresponding first groove.

11. The oil-cooled motor according to claim 10, characterized in that, The plurality of first grooves and the plurality of second grooves are respectively comprised of multiple groups, each group of first grooves comprising two first grooves, each group of second grooves comprising two second grooves, and a portion of each second groove in one group of second grooves reuses a portion of one first groove in one group of first grooves, wherein: In the same group of first grooves, one portion of one first groove reuses another portion of the other first groove; In the same group of second grooves, one portion of the second groove reuses the other portion of the second groove.

12. The oil-cooled motor according to claim 11, characterized in that, The other portion of the first groove in each group of the first grooves is used to directly connect the other portion of the second groove in the corresponding group of the second grooves.

13. The oil-cooled motor according to any one of claims 1-12, characterized in that, The end plate includes a plurality of third grooves distributed on the side of the end plate facing the rotor core. Each third groove is used to directly connect to a second internal flow channel. An oil hole is distributed at the bottom of each third groove, penetrating the end plate along the axial direction of the rotor. Another portion of the second groove is used to connect to a second internal flow channel, and each of the third grooves reuses the other portion of a corresponding second groove.

14. A powertrain, characterized in that, The powertrain includes a reduction gear and an oil-cooled motor according to any one of claims 1-13, the oil-cooled motor being used to drive the wheels of the electric vehicle via the reduction gear.

15. An electric vehicle, characterized in that, The electric vehicle includes wheels and the powertrain of claim 14, the powertrain being used to drive the wheels.

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