End plates, rotor assemblies, motors and vehicles

Abstract

This application relates to an end plate, a rotor assembly, a motor, and a vehicle. The end plate includes a plate body, a first oil passage, and a second oil passage. A shaft hole is provided in the middle of the plate body. The first oil passage extends radially along the plate body, and its cross-section gradually narrows outwards in a radial direction. The large-diameter end of the first oil passage penetrates the wall of the shaft hole. The axis of the second oil passage is angled to the radial direction of the plate body. One end of the second oil passage connects to the small-diameter end of the first oil passage, and the other end penetrates the outer circumferential surface of the plate body. Because the first oil passage is gradually narrowing, the cooling oil is accelerated within the first oil passage through the gradually decreasing cross-section. During the rotation of the end plate, the cooling oil inside the end plate is thrown out through the second oil passage. Since the axis of the second oil passage is angled to the radial direction of the plate body, the cooling oil can be thrown out in a direction inclined relative to the radial direction, avoiding excessive oil entering the air gap and helping to reduce the oil churning loss of the motor.

Description

Technical Field

[0001] This application relates to the field of new energy technology, specifically to an end plate, rotor assembly, motor, and vehicle. Background Technology

[0002] In new energy vehicles, the electric motor is the core component for energy conversion, and its efficiency directly affects the vehicle's range and performance. New energy vehicles typically employ a dual-motor or multi-motor design on both the front and rear axles. This design achieves better power distribution and handling performance, but it also introduces higher energy losses. Particularly in oil-cooled motors, the high-speed rotation of the rotor assembly forcibly agitates the cooling oil inside the motor housing. In this case, oil agitation losses account for a significant portion of the motor's energy loss, becoming a major factor limiting improvements in motor efficiency.

[0003] Please see Figure 1 In existing motors, oil channels are typically provided in the shaft 200 and end plate 100 to allow lubricating oil flowing inside the shaft 200 to flow into the end plate 100. When the rotor assembly rotates at high speed, centrifugal force throws the cooling oil radially out along the end plate 100, achieving direct cooling of the inner windings of the stator assembly 400. However, due to the air gap 500 between the rotor core 300 and the stator assembly 400, a low pressure is formed in the air gap 500 during the high-speed rotation of the rotor assembly. This pressure is lower than the atmospheric pressure inside the casing, causing the air gap 500 to adsorb the surrounding oil or oil mist (similar to a "pump effect"). Some of the cooling oil is drawn into the air gap 500 area of ​​the motor (the cooling oil flow direction is as follows). Figure 1 (As indicated by the arrow in the image), resulting in significant oil churning losses. Utility Model Content

[0004] One objective of this application is to provide an end plate to solve the technical problem of excessive oil churning loss in existing motors; another objective is to provide a rotor assembly; a third objective is to provide a motor; and a fourth objective is to provide a vehicle.

[0005] To achieve the above objectives, the technical solution adopted in this application is as follows: An end plate, comprising: The plate body has a shaft hole in the middle. The first oil passage extends radially along the plate and its cross-section gradually narrows outward in the radial direction. The large-diameter end of the first oil passage penetrates the wall of the shaft hole. The second oil passage has its axis set at an angle to the radial direction of the plate. One end of the second oil passage is connected to the small-diameter end of the first oil passage, and the other end of the second oil passage passes through the outer peripheral surface of the plate.

[0006] According to the above technical means, since the cross-section of the first oil passage gradually decreases radially outward (i.e., from the center of the plate to the outer periphery), when the flow rate is constant, the gradual reduction of the cross-section of the oil passage accelerates the cooling oil flowing inside the first oil passage, making the outlet velocity of the first oil passage greater than the inlet velocity. The axis of the second oil passage is set at an angle to the radial direction of the plate. One end of the second oil passage is connected to the small-diameter end of the first oil passage, and the other end of the second oil passage penetrates the outer periphery of the plate. During the rotation of the end plate, the cooling oil inside the end plate can be thrown out through the second oil passage. Since the axis of the second oil passage is set at an angle to the radial direction of the plate, the cooling oil can be thrown out in a direction inclined relative to the radial direction, which can avoid excessive oil entering the air gap and help reduce the oil churning loss of the motor.

[0007] Furthermore, the angle between the axis of the second oil passage and the radial direction of the plate is 20°~30°.

[0008] Based on the aforementioned technical means, since the angle α between the axis of the second oil passage and the radial direction of the plate is 20°~30°, that is, the angle between the axis of the second oil passage and the axis of the plate is 60°~70°, the outlet velocity V of the second oil passage is vector decomposed, where the axial outlet velocity is Vsinα and the radial outlet velocity is Vcosα. Through CFD simulation verification, it was found that when the angle α between the axis of the second oil passage and the radial direction of the plate is 20°~30°, the radial impact component can be effectively reduced by up to 60%, the air gap oil film thickness can be controlled below 0.08mm, and the air gap oil inlet can be reduced by more than 50%.

[0009] Furthermore, the roughness of the inner wall surface of the first oil passage is less than a first preset value, the roughness of the inner wall surface of the second oil passage is less than a second preset value, and the second preset value is less than or equal to the first preset value.

[0010] Based on the aforementioned technical means, the smoothness of the inner walls of the first and second oil passages can be improved by limiting the surface roughness requirements. This reduces turbulence and eddies in the cooling oil as it flows within the first and second oil passages, thereby reducing energy loss due to friction between the cooling oil and the inner walls during high-speed flow and preventing the cooling oil from overheating due to friction. A second preset value ≤ the first preset value makes the inner wall of the second oil passage smoother than that of the first oil passage, reducing friction between the high-speed flowing cooling oil and the inner wall of the second oil passage, lowering the viscous resistance during the cooling oil ejection process, and improving flow efficiency.

[0011] Furthermore, the outer peripheral surface of the plate includes a chamfered surface, and the other end of the second oil passage is disposed through the chamfered surface.

[0012] According to the above technical means, since the outer peripheral surface of the plate includes a chamfered surface, it can have an inclined guiding surface, which prevents the cooling oil from accumulating on the outer peripheral surface of the end plate, thereby preventing excessive oil from entering the air gap. The other end of the second oil passage (i.e., the cooling oil outlet end) is set through the chamfered surface, which allows the cooling oil to be thrown out from the chamfered surface, so that the thrown-out cooling oil can flow along the chamfered surface to the side away from the air gap.

[0013] Furthermore, the first oil passage and the second oil passage are smoothly connected to form an oil-throwing channel, and there are multiple oil-throwing channels, which are evenly arranged along the circumference of the plate.

[0014] Based on the aforementioned technical means, a smooth transition connection can reduce the frictional resistance of the cooling oil when it turns between the first and second oil passages. Multiple oil-throwing channels are evenly distributed circumferentially along the plate. When the end plate rotates with the shaft, these channels utilize centrifugal force to throw the cooling oil out of the second oil passage, forming a uniform oil film covering the surface of the stator assembly. The evenly distributed circumferential oil-throwing channels ensure that the oil film covers the entire 360° range without any dead zones, preventing localized overheating.

[0015] A rotor assembly includes the aforementioned end plate and a rotating shaft, the rotating shaft being interference-fitted with the shaft hole; the rotating shaft has a third oil passage extending axially inside it, and the rotating shaft has an oil outlet hole penetrating the shaft wall, the oil outlet hole corresponding to the large-diameter end of the first oil passage.

[0016] Based on the aforementioned technical means, due to the interference fit between the shaft and the shaft hole, the end plate can be fixedly mounted on the shaft, allowing the shaft to drive the end plate to rotate synchronously. The oil outlet is positioned corresponding to the large-diameter end of the first oil passage, enabling communication between the third oil passage and the first oil passage. This allows the cooling oil inside the shaft to enter the first oil passage through centrifugal force during rotation, and then be ejected by the rotation of the end plate. This provides cooling and lubrication for the stator assembly and other components inside the housing (such as bearings).

[0017] Furthermore, the oil outlet hole is coaxially arranged with the first oil passage, and the diameter of the oil outlet hole is larger than the diameter of the large-diameter end of the first oil passage.

[0018] According to the aforementioned technical means, since the diameter of the oil outlet is larger than the diameter of the large-diameter end of the first oil passage, the oil outlet can fully cover the large-diameter end of the first oil passage, ensuring that the edge of the oil outlet completely covers the inlet of the first oil passage. This prevents the cooling oil from overflowing or dispersing due to diameter mismatch when flowing out of the oil outlet, thus increasing the total amount of cooling oil entering the end plate from the shaft. Furthermore, the flow of cooling oil from the oil outlet to the first oil passage is accelerated due to the reduced cross-sectional area, further improving cooling efficiency.

[0019] Furthermore, the rotor core is sleeved on the rotating shaft, and two end plates are respectively provided at both ends of the rotor core, and the second oil passages of the end plates are inclined in the direction away from the rotor core.

[0020] Based on the aforementioned technical means, since two end plates are respectively provided at both ends of the rotor core, a rigid integral structure can be formed, preventing the silicon steel laminations inside the rotor core from axially shifting or radially loosening due to centrifugal force during high-speed rotation. The second oil passages of both end plates are inclined in the direction away from the rotor core, which can prevent cooling oil from entering the air gap between the rotor core and the stator assembly.

[0021] Furthermore, the outer diameter of the plate is smaller than the outer diameter of the rotor core.

[0022] According to the above-mentioned technical means, since the outer diameter of the plate is smaller than the outer diameter of the rotor core, compared with the end plate and rotor core being set to the same diameter in the traditional motor, the design of the end plate and rotor core being of the same diameter will lead to the air pump effect, which will increase the oil volume inside the air gap by 35% to 40%. However, by shortening the outer diameter of the plate (i.e. the outer diameter of the end plate), this application can increase the radial distance between the end plate and the stator assembly, forming a more open space between the end plate and the stator assembly, and connecting it with the atmospheric pressure environment inside the casing, which is beneficial to reducing the air pump effect caused by low pressure in the air gap.

[0023] Furthermore, the difference between the outer diameter of the plate and the outer diameter of the rotor core is 3mm to 7mm.

[0024] According to the above technical means, since the maximum outer diameter of the plate is 3mm to 7mm smaller than the outer diameter of the rotor core, it can not only ensure the fixing effect of the end plate on the rotor core, but also reduce the flow resistance and increase the flow rate of the cooling oil between the rotor assembly and the stator assembly by reducing the outer diameter of the end plate, which is conducive to improving the heat exchange effect and cooling efficiency.

[0025] An electric motor includes the aforementioned rotor assembly and a stator assembly disposed on the outer periphery of the rotor assembly. An air gap exists between the rotor assembly and the stator assembly, and a second oil passage is inclined in a direction away from the air gap.

[0026] According to the above technical means, since the second oil passage is inclined in the direction away from the air gap, the amount of oil entering the air gap can be reduced by changing the oil throwing path, thereby avoiding high oil churning loss caused by a large amount of cooling oil inside the air gap when the rotor assembly rotates at high speed relative to the stator assembly.

[0027] A vehicle comprising the aforementioned motor.

[0028] Based on the aforementioned technical means, the significantly reduced oil churning loss of the motor in this application improves motor efficiency, resulting in a more rapid power response during vehicle start-up and overtaking. When the motor of this application is applied to the motor system of new energy vehicles, it can effectively address the problems of a large proportion of low torque and significant oil churning loss under CLTC operating conditions.

[0029] The beneficial effects of this application are: (1) In this application, the second oil passage is radially inclined relative to the end plate, which can cause the cooling oil to be thrown out towards the side away from the air gap, changing the direction of oil flow and avoiding direct impact on the air gap area. The axial flow component of the oil flow increases and the radial flow component decreases, which can significantly reduce the amount of oil entering the air gap, thereby reducing the oil churning loss caused by excessive oil accumulation inside the air gap when the rotor assembly rotates at high speed.

[0030] (2) In this application, the cooling oil is accelerated in the first oil channel with a gradually narrowing structure. When it enters the second oil channel, it can be thrown out at a higher speed. The outlet flow rate of the second oil channel is also increased, which can make the cooling oil throw out to a farther distance. In addition, the oil jet is more concentrated during the throwing process, which can reduce the phenomenon of too much oil entering the air gap due to the dispersion of the oil jet. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the pumping effect generated when the end plate throws oil in the prior art; Figure 2 A cross-sectional view of a motor provided in an embodiment of this application, wherein the arrow indicates the direction of coolant flow; Figure 3 Cross-sectional view of the end plate provided in the embodiments of this application Figure 1 ; Figure 4 Enlarged detail view of a portion of the end plate provided in an embodiment of this application; Figure 5 Cross-sectional view of the end plate provided in the embodiments of this application Figure 2 ; Figure 6 This is a cross-sectional view of a rotor assembly provided in an embodiment of this application, wherein the arrow indicates the direction of coolant flow.

[0032] Among them, 1. End plate; 1a. First end plate; 1b. Second end plate; 11. Plate body; 12. Shaft hole; 13. First oil passage; 14. Second oil passage; 15. Chamfered surface; 2. Rotating shaft; 21. Third oil passage; 22. Oil outlet; 23. Oil inlet; 3. Rotor core; 4. Stator assembly; 5. Air gap; 6. Casing.

[0033] 100, End plate; 200, Shaft; 300, Rotor core; 400, Stator assembly; 500, Air gap. Detailed Implementation

[0034] The embodiments of this application will be described below with reference to the accompanying drawings and preferred embodiments. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. This application can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. It should be understood that the preferred embodiments are only for illustrating this application and are not intended to limit the scope of protection of this application.

[0035] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this application. Therefore, the drawings only show the components related to this application and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0036] Please see Figures 2 to 6 The first aspect of this application proposes an end plate 1, including a plate body 11, a first oil passage 13, and a second oil passage 14. A shaft hole 12 is provided in the middle of the plate body 11 for cooperating with a rotating shaft 2 in a rotor assembly, thereby achieving synchronous rotation of the end plate 1 and the rotating shaft 2. Figure 2 and Figure 3 As shown.

[0037] Please see Figure 3 and Figure 4 The first oil passage 13 extends radially along the plate 11 to realize the flow of cooling oil inside the end plate 1. The cross section of the first oil passage 13 is gradually reduced in the radial outward direction (i.e. from the center of the plate 11 to the outer periphery). When the flow rate is constant, the cooling oil is accelerated when flowing inside the first oil passage 13 by gradually reducing the cross section of the oil passage, so that the outlet flow velocity of the first oil passage 13 is greater than the inlet flow velocity of the first oil passage 13.

[0038] The large-diameter end of the first oil passage 13 penetrates the wall of the shaft hole 12 to align with the oil outlet 22 on the rotating shaft 2, allowing the oil flowing inside the rotating shaft 2 to enter the end plate 1 through the large-diameter end of the first oil passage 13. Figure 6 As shown.

[0039] The axis of the second oil passage 14 is set at an angle to the radial direction of the plate 11. One end of the second oil passage 14 is connected to the small-diameter end of the first oil passage 13, and the other end of the second oil passage 14 penetrates the outer circumferential surface of the plate 11. During the rotation of the end plate 1, the cooling oil inside the end plate 1 can be thrown out through the second oil passage 14. Because the axis of the second oil passage 14 is set at an angle to the radial direction of the plate 11, the cooling oil can be thrown out in a direction inclined relative to the radial direction. Figure 2 and Figure 6 As shown, this can prevent excessive oil from entering the air gap 5, which helps reduce the oil churning loss of the motor.

[0040] It should be noted that in the prior art, the cooling oil is thrown out radially, and the radial oil flow directly impacts the air gap 5 area, forming a continuous oil film with a thickness of up to 0.3 mm. When the motor speed n>8000 rpm, since the power P of shear loss is proportional to the square of the fluid movement speed n, significant viscous shear loss will occur. However, in this application, the second oil passage 14 is set radially inclined relative to the end plate 1, which allows the cooling oil to be thrown out towards the side away from the air gap 5, changing the direction of oil flow and avoiding direct impact on the air gap 5 area. The axial flow component of the oil flow increases and the radial flow component decreases, which can significantly reduce the amount of oil entering the air gap 5, thereby reducing the oil churning loss caused by excessive oil accumulation inside the air gap 5 when the rotor assembly rotates at high speed.

[0041] At the same time, as the cooling oil is accelerated in the first oil passage 13, it can be thrown out at a higher speed after entering the second oil passage 14. The outlet flow rate of the second oil passage 14 is also increased, which can make the cooling oil throw out to a greater distance. Moreover, the oil jet is more concentrated during the throwing process, which can reduce the phenomenon of too much oil entering the air gap 5 due to the dispersion of the oil jet.

[0042] As a specific embodiment of this application, the diameter of the large-diameter end of the first oil passage 13 is 3mm, the diameter of the small-diameter end of the first oil passage 13 is 2mm, and the diameter of the second oil passage 14 is the same as the diameter of the small-diameter end of the first oil passage 13.

[0043] Please refer to some preferred embodiments of this application. Figure 4An angle α exists between the axis of the second oil passage 14 and the radial direction of the plate 11, and the angle α between the axis of the second oil passage 14 and the radial direction of the plate 11 is 20°~30°, that is, the angle between the axis of the second oil passage 14 and the axis of the plate 11 is 60°~70°. The outlet velocity V of the second oil passage 14 is vector decomposed, where the axial outlet velocity is Vsinα and the radial outlet velocity is Vcosα. Through CFD simulation verification, it was found that when the angle α between the axis of the second oil passage 14 and the radial direction of the plate 11 is 20°~30°, the radial impact component can be effectively reduced by up to 60%, the oil film thickness in the air gap 5 can be controlled below 0.08mm, and the oil inlet volume inside the air gap 5 can be reduced by more than 50%.

[0044] In some embodiments of this application, please refer to Figure 4 The roughness of the inner wall surface of the first oil passage 13 is less than the first preset value, and the roughness of the inner wall surface of the second oil passage 14 is less than the second preset value. By limiting the roughness processing requirements, the smoothness of the inner wall surfaces of the first oil passage 13 and the second oil passage 14 can be improved, reducing the turbulence and eddies generated when the cooling oil flows inside the first oil passage 13 and the second oil passage 14. This can reduce the energy loss caused by friction between the cooling oil and the inner wall surface during high-speed flow, and prevent the temperature of the cooling oil from rising due to friction during the flow inside the first oil passage 13 and the second oil passage 14.

[0045] In some preferred embodiments of this application, the second preset value is less than or equal to the first preset value, making the inner wall surface of the second oil passage 14 smoother than the inner wall surface of the first oil passage 13. This is because the cooling oil in the second oil passage 14 has already been accelerated when it flows out of the outlet of the first oil passage 13, and its speed will be further increased by the centrifugal force of the rotating end plate 1. Setting the roughness of the inner wall surface of the second oil passage 14 to a lower level can reduce the friction between the high-speed flowing cooling oil and the inner wall surface of the second oil passage 14, reduce the viscous resistance of the cooling oil during the ejection process, and improve the flow efficiency.

[0046] As a specific embodiment of this application, the second preset value is ≤0.8μm. When the cooling oil flows in the non-linear oil passage (i.e. complex oil passage) formed by the connection of the first oil passage 13 and the second oil passage 14, the roughness of the inner wall surface of the second oil passage 14 is less than 0.8μm. This can prevent the cooling oil from generating turbulence or eddies when it turns inside the second oil passage 14, and can avoid energy loss and oil temperature rise.

[0047] In some embodiments of this application, please refer to Figure 3 and Figure 4The outer peripheral surface of plate 11 includes a chamfered surface 15, which provides an inclined guide surface to prevent coolant from accumulating on the outer peripheral surface of end plate 1, thereby preventing excessive oil from entering the air gap 5. The other end of the second oil passage 14 (i.e., the coolant outlet end) extends through the chamfered surface 15, allowing coolant to be thrown out from the chamfered surface 15 so that the thrown-out coolant flows along the chamfered surface 15 to the side away from the air gap 5.

[0048] In some embodiments of this application, please refer to Figure 5 An angle β exists between the chamfered surface 15 and the axial direction of the plate 11, causing the outer peripheral surface of the end plate 1 to be inclined, thus preventing the coolant from accumulating on the outer periphery of the end plate 1 and preventing the accumulated coolant from entering the air gap 5. Preferably, the angle β is 15°~20°, which facilitates the processing of the chamfered surface 15.

[0049] In some embodiments of this application, please refer to Figure 5 The chamfered surface 15 is connected to one end face of the plate 11 via a rounded corner, with a rounded corner size of Rx. When manufacturing the end plate 1 using a mold, the chamfered surface 15 and the rounded corner facilitate demolding of the end plate 1, reducing frictional resistance during demolding and preventing demolding difficulties, thus extending the mold's service life. Furthermore, the chamfered surface 15 and rounded corner design reduce burrs and sharp edges on the end plate 1, preventing scratches to operators or damage to other components, and improving the assembly safety of the end plate 1. Preferably, the value of x is 1.2mm to 1.5mm, which facilitates mold preparation.

[0050] In some embodiments of this application, please refer to Figure 4 The first oil passage 13 and the second oil passage 14 are smoothly connected to form an oil-throwing channel. This smooth connection reduces the frictional resistance of the cooling oil when turning between the first oil passage 13 and the second oil passage 14. Multiple oil-throwing channels (two or more) are evenly distributed circumferentially along the plate 11. When the end plate 1 rotates with the shaft 2, the multiple oil-throwing channels use centrifugal force to throw the cooling oil out of the second oil passage 14, forming a uniform oil film covering the surface of the stator assembly 4. The circumferentially evenly distributed multiple oil-throwing channels ensure that the oil film covers the entire 360° range without dead zones, avoiding localized overheating.

[0051] As a specific embodiment of this application, the number of oil-slinging channels is 6, which is suitable for uniformly cooling a motor with three sets of symmetrically distributed magnetic poles.

[0052] Please see Figures 2 to 6The second aspect of this application proposes a rotor assembly, including the end plate 1 described in the above embodiments, and a rotating shaft 2. The rotating shaft 2 is interference-fitted with a shaft hole 12, which allows the end plate 1 to be fixedly mounted on the rotating shaft 2, so that the rotating shaft 2 drives the end plate 1 to rotate synchronously. The rotating shaft 2 has a third oil passage 21 extending axially inside it, and an oil outlet 22 penetrating the shaft wall. The oil outlet 22 corresponds to the large-diameter end of the first oil passage 13, enabling communication between the third oil passage 21 and the first oil passage 13. Figure 2 and Figure 6 As shown, the cooling oil inside the rotating shaft 2 enters the first oil passage 13 through centrifugal force during rotation, and is then thrown out by the rotation of the end plate 1, which can cool and lubricate the stator assembly 4 and other components (such as bearings) inside the housing 6.

[0053] In some embodiments of this application, please refer to Figure 2 and Figure 6 The oil outlet 22 is coaxially arranged with the first oil passage 13, which improves the accuracy of the cooling oil entering the first oil passage 13 from inside the shaft 2. This allows the cooling oil to directly enter the first oil passage 13 radially along the end plate 1, avoiding oil impact on the oil passage wall, eddy currents, or backflow caused by eccentricity or angular deviation. Furthermore, the diameter of the oil outlet 22 is larger than the diameter of the large-diameter end of the first oil passage 13, ensuring that the oil outlet 22 completely covers the large-diameter end of the first oil passage 13. This ensures that the edge of the oil outlet 22 completely covers the inlet of the first oil passage 13, preventing the cooling oil from overflowing or dispersing due to diameter mismatch when flowing out of the oil outlet 22. This helps increase the total amount of cooling oil entering the end plate 1 from the shaft 2. Additionally, the flow of cooling oil from the oil outlet 22 to the first oil passage 13 is accelerated due to the reduced cross-sectional area, further improving cooling efficiency.

[0054] In some embodiments of this application, please refer to Figure 6 The shaft 2 is also provided with an oil inlet 23 that communicates with the third oil passage 21, which is used to input cooling oil into the third oil passage 21 inside the shaft 2.

[0055] In some embodiments of this application, please refer to Figure 2 and Figure 6 The rotor assembly also includes a rotor core 3, which is sleeved on the rotating shaft 2. Two end plates 1, designated as the first end plate 1a and the second end plate 1b, are respectively provided at both ends of the rotor core 3. These end plates form a rigid integral structure, preventing the silicon steel laminations inside the rotor core 3 from axially shifting or radially loosening due to centrifugal force during high-speed rotation. Furthermore, the second oil passages 14 of both end plates 1 are inclined away from the rotor core 3, preventing cooling oil from entering the air gap 5 between the rotor core 3 and the stator assembly 4.

[0056] In some embodiments of this application, please refer to Figure 2 and Figure 6 The outer diameter of plate 11 is smaller than the outer diameter of rotor core 3. Compared with the traditional motor where the end plate and rotor core are of equal diameter, the design of the end plate and rotor core with equal diameter will cause an air pumping effect, which will increase the amount of oil in the air gap by 35% to 40%. However, by shortening the outer diameter of plate 11 (i.e. the outer diameter of end plate 1), this application can increase the radial distance between end plate 1 and stator assembly 4, forming a more open space between end plate 1 and stator assembly 4, and connecting it with the atmospheric pressure environment inside the housing 6, which is beneficial to reducing the air pumping effect caused by low pressure in air gap 5.

[0057] In some embodiments of this application, please refer to Figure 2 and Figure 6 The difference between the outer diameter of the plate 11 and the outer diameter of the rotor core 3 is 3mm to 7mm, meaning the maximum outer diameter of the plate 11 is 3mm to 7mm smaller than the outer diameter of the rotor core 3. This ensures the fixation of the end plate 1 on the rotor core 3 while also reducing the flow resistance and increasing the flow velocity of the cooling oil between the rotor assembly and the stator assembly 4 due to the smaller outer diameter of the end plate 1, thus improving heat exchange and cooling efficiency. Preferably, the difference between the outer diameter of the plate 11 and the outer diameter of the rotor core 3 is 5mm.

[0058] It should be noted that this application first uses the tapering configuration of the first oil passage 13 to provide high-speed flowing cooling oil to the second oil passage 14, which can increase the kinetic energy and coverage of the cooling oil during ejection. Then, by tilting the second oil passage 14 relative to the radial direction, the direction of the cooling oil ejection is changed, causing the cooling oil to be ejected away from the air gap 5, thus preventing excessive cooling oil from entering the air gap 5 and increasing oil churning losses. Finally, since the outer diameter of the end plate 1 is smaller than the outer diameter of the rotor core 3, the distance between the end plate 1 and the stator assembly 4 is increased, providing a buffer space for the oblique oil flow formed by the tilted oil ejection, reducing oil rebound and secondary oil churning. Through the synergistic effect of these three factors, precise oil ejection and efficient flow can be achieved, which is beneficial for achieving the optimal balance between cooling effect and oil churning losses.

[0059] Please see Figures 2 to 6 The third aspect of this application proposes an electric motor, including the rotor assembly described in the above embodiments, and a stator assembly 4 disposed on the outer periphery of the rotor assembly. An air gap 5 is provided between the rotor assembly and the stator assembly 4. The second oil passage 14 is inclined in the direction away from the air gap 5. The amount of oil entering the air gap 5 can be reduced by changing the oil throwing path, thereby avoiding high oil churning loss caused by a large amount of cooling oil inside the air gap 5 when the rotor assembly rotates at high speed relative to the stator assembly 4.

[0060] In some embodiments of this application, the motor is a high-speed oil-cooled permanent magnet synchronous motor. By setting the first oil passage 13, the second oil passage 14 and the outer diameter of the end plate 1, the efficiency performance of the motor during high-speed operation can be effectively improved.

[0061] Please see Figures 2 to 6 The fourth aspect of this application provides a vehicle including the motor described in the above embodiments, used to provide power to the vehicle. Since the oil-cooled motor supports high-speed operation, it can meet the power requirements of high-performance vehicles. Because the oil churning loss of the motor in this application is significantly reduced, the motor efficiency can be improved, resulting in a more rapid power response when the vehicle starts and overtakes.

[0062] At the same time, under continuous high-load conditions (such as climbing and towing), reducing the oil churning loss of the motor can reduce the motor temperature rise, avoid power attenuation due to overheating, and ensure the stability of power output.

[0063] In some embodiments of this application, the vehicle is a new energy vehicle. By configuring the first oil passage 13, the second oil passage 14, and the outer diameter of the end plate 1, this application effectively suppresses oil entry into the air gap 5 while maintaining excellent cooling performance. This significantly reduces oil churning losses in the rotor assembly during high-speed rotation and improves the overall efficiency of the motor, especially under the CLTC (China Light-duty Vehicle Test Cycle) condition when operating at low torque. In new energy vehicles, the improvement in motor efficiency directly translates into an increase in driving range, resulting in significant economic and environmental benefits.

[0064] When the motor described in this application is applied to the motor system of new energy vehicles, it can effectively address the problems of a large proportion of low torque and significant oil churning loss under CLTC operating conditions.

[0065] This application, by changing the oil-throwing direction of end plate 1, can precisely control the radial component of the cooling oil, reducing the total amount of cooling oil entering the air gap 5. Simultaneously, by gradually narrowing the first oil passage 13, the flow velocity of the cooling oil can be increased before it is thrown out, enhancing the kinetic energy and jetting effect of the cooling oil and preventing it from diffusing into the air gap 5 region. By shortening the outer diameter of end plate 1, this application can reduce the pumping effect of the air gap 5, which is beneficial for further reducing the oil churning loss of the motor. Through the above structural improvements, a balance can be achieved between cooling effect and oil churning loss, solving the technical problem of excessive oil consumption due to oil churning in traditional oil-cooled motors.

[0066] It should be understood that the terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “described” as used herein may also include the plural forms. The terms “comprising,” “including,” “containing,” and “having” are inclusive and therefore indicate the presence of the stated features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein are not construed as requiring them to be performed in a particular order described or illustrated unless the order of performance is explicitly indicated. It should also be understood that additional or alternative steps may be used.

[0067] Although terms such as first, second, third, etc., may be used in this document to describe multiple elements, components, regions, layers, and / or segments, these elements, components, regions, layers, and / or segments should not be limited by these terms. These terms may be used only to distinguish one element, component, region, layer, or segment from another. Unless the context clearly indicates otherwise, terms such as "first," "second," and other numerical terms used herein do not imply order or sequence. Therefore, the first element, component, region, layer, or segment discussed below may be referred to as the second element, component, region, layer, or segment without departing from the teachings of the exemplary embodiments.

[0068] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. An end plate (1), characterized in that, include: Plate (11), the middle part of which is provided with shaft hole (12); The first oil passage (13) extends radially along the plate (11), and the cross section of the first oil passage (13) gradually narrows in the radial outward direction. The large-diameter end of the first oil passage (13) penetrates the hole wall of the shaft hole (12). The second oil passage (14) has its axis set at an angle to the radial direction of the plate (11). One end of the second oil passage (14) is connected to the small diameter end of the first oil passage (13), and the other end of the second oil passage (14) passes through the outer peripheral surface of the plate (11).

2. The end plate (1) according to claim 1, characterized in that, The angle between the axis of the second oil passage (14) and the radial direction of the plate (11) is 20°~30°.

3. The end plate (1) according to claim 1, characterized in that, The roughness of the inner wall surface of the first oil passage (13) is less than the first preset value, and the roughness of the inner wall surface of the second oil passage (14) is less than the second preset value, and the second preset value is less than the first preset value.

4. The end plate (1) according to claim 1, characterized in that, The outer peripheral surface of the plate (11) includes a chamfered surface (15), and the other end of the second oil passage (14) is provided through the chamfered surface (15).

5. The end plate (1) according to any one of claims 1 to 4, characterized in that, The first oil passage (13) and the second oil passage (14) are smoothly connected to form an oil-throwing channel. There are multiple oil-throwing channels, and the multiple oil-throwing channels are evenly arranged along the circumference of the plate (11).

6. A rotor assembly, characterized in that, The device includes an end plate (1) as described in any one of claims 1 to 5, and a rotating shaft (2) that is press-fitted with the shaft hole (12). The rotating shaft (2) has a third oil passage (21) extending along its axial direction inside, and the rotating shaft (2) has an oil outlet hole (22) that penetrates the shaft wall. The oil outlet hole (22) is corresponding to the large-diameter end of the first oil passage (13).

7. The rotor assembly according to claim 6, characterized in that, The oil outlet (22) is coaxially arranged with the first oil passage (13), and the diameter of the oil outlet (22) is greater than the diameter of the large diameter end of the first oil passage (13).

8. The rotor assembly according to claim 6, characterized in that, It also includes a rotor core (3), which is sleeved on the rotating shaft (2). Two end plates (1) are respectively provided at both ends of the rotor core (3), and the second oil passages (14) of the end plates (1) are inclined in the direction away from the rotor core (3).

9. The rotor assembly according to claim 8, characterized in that, The outer diameter of the plate (11) is smaller than the outer diameter of the rotor core (3).

10. The rotor assembly according to claim 9, characterized in that, The difference between the outer diameter of the plate (11) and the outer diameter of the rotor core (3) is 3mm to 7mm.

11. An electric motor, characterized in that, The rotor assembly includes the rotor assembly as described in any one of claims 6 to 10, and further includes a stator assembly (4) disposed on the outer periphery of the rotor assembly, wherein the rotor assembly and the stator assembly (4) have an air gap (5), and the second oil passage (14) is inclined in a direction away from the air gap (5).

12. A vehicle, characterized in that, Including the motor as described in claim 11.

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