Oil cooling structure of a motor

Abstract

The present invention proposes an oil cooling structure for a motor, which relates to the technical field of motor cooling. The oil cooling structure of the motor comprises: a rotating shaft, which is a hollow shaft and has an oil inlet at one end; a plurality of oil spray holes, which are spaced apart along the axial direction on the rotating shaft, and the oil spray holes penetrate the side wall of the rotating shaft in the radial direction of the rotating shaft; an oil regulating ring, which is arranged inside the rotating shaft, and the plurality of oil spray holes are located on both sides of the oil regulating ring. An inner hole is provided in the middle of the oil regulating ring, and a plurality of oil guide grooves are spaced apart on the outer circumference of the oil regulating ring. The present invention ensures that the oil on the left and right sides can be sprayed out synchronously by installing the oil regulating ring, and can adjust the oil rejection ratio on the left and right sides, which is close to the volume ratio of the stator coils on the left and right sides, has a good cooling effect, ensures the dynamic balance of the rotor during operation, and ensures that the convective heat transfer coefficient is appropriate. Compared with installing an oil pipe, the installation is simple and the cost is reduced. In addition, a split rotating shaft is adopted, and the split position is far away from the end of the spline portion where the oil inlet is provided, and the torque it withstands can be ignored, making its strength reliable.

Description

Technical Field

[0001] The invention belongs to the technical field of motor cooling, and particularly relates to an oil cooling structure of a motor. Background Art

[0002] The drive motor generates a large amount of heat during continuous operation. If the motor temperature is too high, it will affect the reliable operation and performance of the motor. In order to maintain the normal operation of the motor, it is generally necessary to design a special cooling structure on the motor to take away the heat generated during the operation of the motor. Common cooling methods include air cooling, liquid cooling and oil cooling, or increasing the motor volume to improve the heat dissipation effect of the motor.

[0003] At present, most of the common pure electric vehicle motors on the market are water-cooled, that is, flow channels are machined in the motor casing to allow cooling water to circulate in the casing flow channels to remove the heat generated by the motor stator and rotor. Since the cooling water does not directly contact the heat source (stator and rotor), the cooling effect is general. In addition, the flow channel structure must be reserved in the casing, which will cause the motor volume to increase and the manufacturing cost to increase. As the requirements for motor power, performance and cost become increasingly higher, traditional air cooling and water cooling methods can no longer meet the above requirements, and oil-cooled motors have gradually become a research hotspot.

[0004] However, the rotor cooling structure of existing oil-cooled motors generally has uneven axial flow and temperature distribution of the motor, with more oil thrown out on the oil-introducing side and less on the other side, which can easily cause unbalanced rotor rotation; it is impossible to lubricate the bearings on the other side; the parts have poor processability and are difficult to install; and there are also disadvantages such as poor heat dissipation effect, complex structural process, and high cost. Summary of the Invention

[0005] In order to solve the above technical problems, the present invention proposes an oil cooling structure for a motor to improve the problems of uneven axial flow and temperature distribution in the rotor cooling structure of the oil-cooled motor, which causes unbalanced rotor rotation, poor heat dissipation effect, complex structural process and high cost.

[0006] The present invention provides an oil cooling structure for a motor, comprising: a rotating shaft, the rotating shaft being a hollow shaft, one end of which is provided with an oil inlet;

[0007] a plurality of oil injection holes, spaced apart and distributed along the axial direction on the rotating shaft, and the oil injection holes penetrate the side wall of the rotating shaft in the radial direction of the rotating shaft;

[0008] The oil regulating ring is arranged inside the rotating shaft, and the multiple oil injection holes are located on both sides of the oil regulating ring. An inner hole is provided in the middle of the oil regulating ring, and multiple oil guide grooves are provided at intervals on the outer circumference of the oil regulating ring.

[0009] In one embodiment of the present invention, the other end of the rotating shaft is a closed structure, and a rotor module and a stator module are installed on the outside of the rotating shaft. The oil enters the interior of the rotating shaft from the oil inlet and is sprayed toward the rotor module and the stator module from the oil injection hole.

[0010] In one embodiment of the present invention, the rotating shaft is a split rotating shaft, and the split position is located close to one end of the rotating shaft away from the oil inlet.

[0011] In one embodiment of the present invention, the split rotating shaft includes a spline portion and a tail portion, the spline portion and the tail portion are fixedly connected, and the rotor module is mounted on the spline portion.

[0012] In one embodiment of the present invention, the spline portion is a hollow structure, the tail portion is a solid structure, the oil inlet is arranged at one end, and the tail portion is fixed to the other end of the spline portion to close the end of the spline portion away from the oil inlet.

[0013] In one embodiment of the present invention, the oil injection hole is located on the spline portion, and the oil regulating ring is arranged inside the spline portion.

[0014] In one embodiment of the present invention, the groove wall of the oil guide groove is a smooth structure or is provided with a spiral structure.

[0015] In one embodiment of the present invention, the diameter of the oil inlet hole is set between 0.7 times and 1.3 times the diameter of the inner hole of the oil regulating ring.

[0016] In one embodiment of the present invention, the oil injection hole on the oil regulating ring close to the oil inlet is the first oil injection hole, and the oil injection hole on the side away from the oil inlet is the second oil injection hole. The diameter of the first oil injection hole is set between 0.85 times and 1.15 times the diameter of the second oil injection hole.

[0017] In one embodiment of the present invention, all the oil guide grooves on the oil regulating ring occupy between 70% and 90% of the cylindrical surface of the oil regulating ring, and the diameter of the circumference of the bottom surface of the oil guide groove is set between 0.5 times and 0.7 times the diameter of the oil regulating ring.

[0018] The present invention proposes an oil cooling structure for a motor, in which an oil spray hole is opened on the rotating shaft, and cooling oil enters the cavity of the rotating shaft from the oil inlet at one end of the rotating shaft. When the rotating shaft rotates, the oil flows along the inner wall under the action of centrifugal force, so that the oil is thrown out from the oil spray hole. An oil regulating ring is installed inside the oil spray hole to realize liquid cooling of the rotor. The ratio of the oil thrown out on the left and right sides is close to the volume ratio of the stator coils on the left and right sides, and the cooling effect is good.

[0019] The present invention proposes an oil cooling structure for a motor. By installing an oil regulating ring, it is ensured that the oil on the left and right sides can be sprayed out synchronously, and the oil rejection ratio on the left and right sides can be adjusted to ensure the dynamic balance of the rotor during operation and the appropriate convection heat transfer coefficient. Compared with installing an oil pipe, the installation is simple and the cost is reduced.

[0020] The present invention proposes an oil cooling structure for a motor, wherein the rotating shaft adopts a split type rotating shaft, the spline part and the tail part are interference fit, the process is simple, the split position is away from the spline part and the oil inlet is provided at one end, the torque it bears can be ignored, and its strength is reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0022] Figure 1 FIG. 1 is a schematic structural diagram of a motor in one embodiment of the present invention.

[0023] Figure 2 FIG. 1 is a schematic cross-sectional structural diagram of a motor in one embodiment of the present invention.

[0024] Figure 3 FIG. 1 is a schematic structural diagram of a rotating shaft in a motor according to an embodiment of the present invention.

[0025] Figure 4 FIG. 1 is a schematic cross-sectional structural diagram of a rotating shaft in a motor according to an embodiment of the present invention.

[0026] Figure 5 Schematic diagram of the structure of the oil regulating ring in the motor in one embodiment of the present invention.

[0027] Figure 6 This is a front view of an oil regulating ring in a motor according to one embodiment of the present invention.

[0028] Description of labels:

[0029] Rotating shaft 10; oil regulating ring 20; aluminum conductor 111; stator core 121; copper wire 122; oil inlet 101; oil injection hole 102; spline portion 103; tail portion 104; inner hole 201; oil guide groove 202. DETAILED DESCRIPTION

[0030] The following describes the embodiments of the present invention through specific examples. Those skilled in the art will readily understand the other advantages and benefits of the present invention from the disclosure herein. The present invention may also be implemented or applied through various other specific embodiments, and the details in this specification may be modified or altered based on different viewpoints and applications without departing from the spirit of the present invention.

[0031] It should be noted that the illustrations provided in this embodiment are only used to schematically illustrate the basic concept of the present invention. Therefore, the illustrations only show components related to the present invention and are not drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component can be changed at will, and the component layout type may also be more complicated.

[0032] like Figures 1 to 6 As shown, the present invention proposes an oil cooling structure for a motor to improve the problems of uneven axial flow and temperature distribution of the motor in the rotor cooling structure of the oil-cooled motor, which cause unbalanced rotor rotation, poor heat dissipation effect, complex structure and process, and high cost. Specifically, the structure includes a rotating shaft 10 and an oil regulating ring 20. The oil regulating ring 20 is installed inside the rotating shaft 10, and a rotor module and a stator module are provided on the outside of the rotating shaft 10. The rotor module includes an aluminum conductor 111 and a rotor core. The aluminum conductor 111 is die-cast and fixed on the rotor core. The stator module includes a stator core 121 and a copper wire 122. The copper wire 122 is wound on the stator core 121. A wire package is formed at the end of the copper wire 122, the right side is the wire package at the outgoing end, and the left side is the wire package at the non-outgoing end. Generally, the height of the wire package at the outgoing end is greater than the height of the wire package at the non-outgoing end. When the motor is working, the copper wire 122 generates heat, so more oil splashing is required on the right side to increase the cooling capacity.

[0033] like Figures 1 to 4As shown, in the embodiment, the rotating shaft 10 is a hollow shaft, that is, a hollow cavity is formed therein, the oil regulating ring 20 is arranged in the hollow cavity, and an oil inlet 101 is provided at one end of the rotating shaft 10, and the other end is a closed end, and the oil inlet 101 is arranged along the axial direction of the rotating shaft 10, the oil inlet 101 is communicated with the hollow cavity, and a plurality of oil injection holes 102 are provided on the rotating shaft 10, the oil injection holes 102 are distributed at intervals along the axial direction of the rotating shaft 10, and are located on both sides of the oil regulating ring 20, and the oil injection holes 102 pass through the side wall of the rotating shaft 10 along the radial direction of the rotating shaft 10, that is, the oil injection holes 102 are communicated with the hollow cavity. The rotating shaft 10 of the motor is a hollow shaft, and an oil injection hole 102 is opened on the rotating shaft 10. The cooling oil enters the hollow cavity of the rotating shaft from the oil inlet 101, cools the end of the rotor core through the oil injection hole 102 on the rotating shaft 10, and then relies on centrifugal force to throw the oil to the stator coil through the end of the rotor core, thereby cooling the copper wire and reducing copper loss.

[0034] like Figures 1 to 4 As shown, in this embodiment, the rotating shaft 10 is a split rotating shaft, and its split position is located near the rotating shaft 10 away from the end where the oil inlet 101 is provided. The rotating shaft 10 adopts a split rotating shaft, and an interference fit is adopted between the split parts. The process is simple, and the split position is close to the rotating shaft 10 away from the end where the oil inlet 101 is provided. The torque it withstands can be ignored, and the strength is reliable. Specifically, the split rotating shaft includes a spline portion 103 and a tail portion 104, and the spline portion 103 and the tail portion 104 are fixedly connected together, for example, fixedly connected together by an interference fit, and the connection between the spline portion 103 and the tail portion 104 is the split position of the split rotating shaft.

[0035] like Figures 1 to 6 As shown, in this embodiment, the spline portion 103 is a hollow structure, and the tail portion 104 is a solid structure. The oil inlet 101 is provided at one end of the spline portion 103, and the tail portion 104 is provided at the other end of the spline portion 103, thereby sealing the end of the spline portion 103 away from the oil inlet 101, thereby forming a rotating shaft 10 with the oil inlet 101 provided at one end and the other end sealed. The rotor module is mounted on the spline portion 103, and the oil injection hole 102 is also located on the spline portion 103. The oil regulating ring 20 is disposed inside the spline portion 103.

[0036] like Figures 1 to 6As shown, in this embodiment, the oil regulating ring 20 is disposed within the hollow cavity of the rotating shaft 10 to divide the hollow cavity within the rotating shaft 10 into a left chamber and a right chamber. An inner hole 201 is provided in the center of the oil regulating ring 20. The diameter of the oil inlet 101 is set between 0.7 and 1.3 times the diameter of the inner hole 201 in the oil regulating ring 20. A plurality of oil guide grooves 202 are spaced apart on the outer circumference of the oil regulating ring 20, connecting the left and right chambers through the inner holes 201 and the oil guide grooves 202. It should be noted that the total number of oil guide grooves 202 on the oil regulating ring 20 occupies between 70% and 90% of the cylindrical surface of the oil regulating ring 20, and the diameter D4 of the circumference of the bottom surface of the oil guide grooves 20 is set between 0.5 and 0.7 times the diameter D5 of the oil regulating ring 20. In this embodiment, the groove wall of the oil guide groove is a smooth structure or is provided with a spiral structure.

[0037] like Figures 1 to 6 As shown, in this embodiment, the oil injection holes 102 are provided on the rotating shaft 10 on both sides of the oil regulating ring 20 to communicate with the left chamber and the right chamber respectively. The oil injection hole on the oil regulating ring 20 close to the oil inlet 101 (i.e., the oil injection hole communicated with the left chamber) is the first oil injection hole, and the oil injection hole on the side away from the oil inlet 101 (i.e., the oil injection hole communicated with the right chamber) is the second oil injection hole. The diameter of the first oil injection hole is set between 0.85 times and 1.15 times the diameter of the second oil injection hole.

[0038] like Figures 1 to 6As shown, it should be noted that the main components of the motor are the rotating shaft 10, the rotor module and the stator module. The stator module is, for example, installed on the housing of the motor. The stator module includes a stator core 121 and a copper wire 122. The copper wire 122 is wound on the stator core 121. The copper wire 122 will form a wire package at the end. The right side is the wire package at the outgoing end, and the left side is the wire package at the non-outgoing end. Generally, the height of the wire package at the outgoing end is greater than the height of the wire package at the non-outgoing end. When the motor is working, the copper wire will generate heat, so more oil splashing is required on the right side to increase the cooling capacity. If there is no oil regulating ring 20, the oil pressure at the left oil inlet is relatively large. In the initial oil injection stage, it will be sprayed directly to the right side, resulting in faster oil injection on the right and delayed oil injection on the left, which will affect the heat dissipation effect when the motor starts and affect the motor performance. In the present embodiment, due to the provision of the oil regulating ring 20, the oil enters the hollow cavity of the rotating shaft 10 from the oil inlet 101, and a larger portion of the oil is sprayed into the right chamber of the rotating shaft 10 from the inner hole 201 in the middle of the oil regulating ring 20, and a smaller portion rebounds into the left chamber, thereby ensuring that the left and right injection holes 102 can spray oil synchronously, and since the oil guide groove 202 is present on the outer circumference of the oil regulating ring 20, it is ensured that the oil in the left chamber and the right chamber can communicate with each other in time, and the oil regulating ring 20 can make the left injection amount slightly smaller than the right injection amount, and the injection ratio of the left and right sides is close to the volume ratio of the left and right coils, so that the cooling effect is optimal.

[0039] The present invention proposes an oil cooling structure for a motor, in which an oil spray hole is opened on the rotating shaft. Cooling oil enters the cavity of the rotating shaft from the oil inlet at one end of the rotating shaft. When the rotating shaft rotates, the oil will flow along the inner wall under the action of centrifugal force, so that the oil is thrown out from the oil spray hole to achieve liquid cooling of the rotor.

[0040] The present invention proposes an oil cooling structure for a motor. By installing an oil regulating ring, it is ensured that the oil on the left and right sides can be sprayed out synchronously, and the oil rejection ratio on the left and right sides can be adjusted to ensure the dynamic balance of the rotor during operation and the appropriate convection heat transfer coefficient. Compared with installing an oil pipe, the installation is simple and the cost is reduced.

[0041] The present invention proposes an oil cooling structure for a motor, wherein the rotating shaft adopts a split type rotating shaft, the spline part and the tail part are interference fit, the process is simple, the split position is away from the spline part and the oil inlet is provided at one end, the torque it bears can be ignored, and its strength is reliable.

[0042] The present invention proposes an oil cooling structure for a motor, so that oil enters the rotating shaft from one side, a larger portion of the oil is sprayed into the middle inner hole of the oil regulating ring, and a smaller portion rebounds to the left side, ensuring that the oil injection holes on the left and right sides can spray oil synchronously, ensuring that the oil injection holes on the left and right sides can spray oil synchronously, ensuring that the left and right side coils of the stator can be cooled at the same time, ensuring that the left and right side oils can communicate with each other for convection in time, and making the oil injection amount on the right side slightly smaller than the oil injection amount on the left side, thereby preventing excessive oil on one side from increasing oil stirring loss, ensuring that the left and right side coils of the stator can be cooled at the same time, ensuring the dynamic balance of the rotor during operation, and making the ratio of the convective heat transfer coefficients on the left and right side coils close to the volume ratio of the left and right side coils, so that the cooling effect is optimal.

[0043] The above description is only a preferred embodiment of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope involved in the present application is not limited to the technical solutions formed by a specific combination of the above-mentioned technical features, but should also cover other technical solutions formed by any combination of the above-mentioned technical features or their equivalent features without departing from the inventive concept, such as the technical solutions formed by replacing the above-mentioned features with (but not limited to) technical features with similar functions disclosed in this application.

[0044] Except for the technical features described in the specification, the remaining technical features are known technologies to those skilled in the art. In order to highlight the innovative features of the present invention, the remaining technical features will not be described here in detail.

Claims

1. An oil cooling structure for a motor, characterized in that: include: A rotating shaft, wherein the rotating shaft is a hollow shaft and an oil inlet is provided at one end thereof; a plurality of oil injection holes, spaced apart and distributed along the axial direction on the rotating shaft, and the oil injection holes penetrate the side wall of the rotating shaft in the radial direction of the rotating shaft; The oil regulating ring is arranged inside the rotating shaft, and the multiple oil injection holes are located on both sides of the oil regulating ring. An inner hole is provided in the middle of the oil regulating ring, and multiple oil guide grooves are provided at intervals on the outer circumference of the oil regulating ring.

2. The oil cooling structure of the motor according to claim 1, characterized in that: The other end of the rotating shaft is a closed structure, and a rotor module and a stator module are installed on the outside of the rotating shaft. Oil enters the interior of the rotating shaft from the oil inlet and is sprayed toward the rotor module and the stator module from the oil injection hole.

3. The oil cooling structure of the motor according to claim 2, characterized in that: The rotating shaft is a split type rotating shaft, and the split position is located close to the end of the rotating shaft away from the oil inlet.

4. The oil cooling structure of the motor according to claim 3, characterized in that: The split rotating shaft includes a spline portion and a tail portion, the spline portion and the tail portion are fixedly connected, and the rotor module is mounted on the spline portion.

5. The oil cooling structure of the motor according to claim 4, characterized in that: The spline portion is a hollow structure, the tail portion is a solid structure, the oil inlet is arranged at one end of the spline portion, and the tail portion is fixed to the other end of the spline portion to close the end of the spline portion away from the oil inlet.

6. The oil cooling structure of the motor according to claim 4, characterized in that: The oil injection hole is located on the spline portion, and the oil regulating ring is arranged inside the spline portion.

7. The oil cooling structure of the motor according to claim 1, characterized in that: The groove wall of the oil guide groove is a smooth structure or is provided with a spiral structure.

8. The oil cooling structure of the motor according to claim 2, characterized in that: The diameter of the oil inlet is set between 0.7 times and 1.3 times the diameter of the inner hole of the oil regulating ring.

9. The oil cooling structure of the motor according to claim 1, characterized in that: The oil injection hole on the oil regulating ring close to the oil inlet is the first oil injection hole, and the oil injection hole on the side away from the oil inlet is the second oil injection hole. The diameter of the first oil injection hole is set between 0.85 times and 1.15 times the diameter of the second oil injection hole.

10. The oil cooling structure of the motor according to claim 1, characterized in that: All the oil guide grooves on the oil regulating ring occupy between 70% and 90% of the cylindrical surface of the oil regulating ring, and the diameter of the circumference of the bottom surface of the oil guide groove is set between 0.5 times and 0.7 times the diameter of the oil regulating ring.

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