Cooling structure for a rotor and motor including same

Abstract

Embodiments of the present application disclose a motor cooling structure and a motor. The motor cooling structure includes a motor rotor, and further includes: a cooling groove formed on the motor rotor; a cooling assembly configured to cool the motor rotor, a heat dissipation section of the cooling assembly being located outside the motor rotor; and an end plate, a cooling cavity being formed between the end plate and an end face of the motor rotor. By means of the embodiments of the present application, a heat absorption section of the cooling assembly can be used to conduct heat inside the motor rotor to the heat dissipation section outside the motor rotor, and then the heat absorption section can be cooled by a heat exchange action between the heat dissipation section and the heat absorption section of the cooling assembly. The cooling assembly can rotate together with the motor rotor, and even when the motor rotor rotates at high speed, it can be ensured that heat exchange between the motor rotor and cooling oil in the external cooling cavity by means of the cooling assembly is carried out efficiently, thereby continuously achieving efficient cooling of the motor rotor.

Description

[0001] COOLING STRUCTURE FOR A ROTOR AND MOTOR INCLUDING SAME

[0002] TECHNICAL FIELD

[0003] The present application relates to the technical field of motor cooling, and relates in particular to a motor cooling structure and a motor.

[0004] BACKGROUND ART

[0005] Faced with environmental pollution caused by exhaust gas of motor vehicles, the national requirements for emissions are increasingly stringent, especially in the automobile field. Therefore, new energy vehicles have emerged to replace traditional internal combustion engine vehicles. Drive motors are used as the core driving components of the new energy vehicles. Their operation efficiency and cost performance are of great concern, and the cooling mode of the motors is particularly important for the efficiency and cost performance of the motors.

[0006] At present, with the trend of all-in-one new energy driving systems, oil-cooled motors have gradually become mainstream. Most of the existing oil cooling technologies are developed around stator iron cores and end windings. However, with the trend of high speed of the drive motor, the temperature of the motor rotor has also become the focus of attention. With the increase of the temperature of the rotor iron core and the magnet, on the one hand, the performance of the magnet is reduced, and on the other hand, the risk of demagnetization of the magnet is increased. In the prior art, the cooling design for rotors do not provide adequate cooling effect for the rotors, and the pressure loss of the system oil circuit is also increased.

[0007] SUMMARY OF THE INVENTION

[0008] The present application is intended to solve at least one of the technical problems existing in the prior art. Therefore, the present application provides a motor cooling structure, to resolve the problem of poor cooling effect of the electronic rotor.

[0009] In a first aspect, the present application provides a motor cooling structure, comprising a motor rotor, and further comprising: a cooling groove formed on the motor rotor and provided with an opening on a surface of the motor rotor, the opening being located on an axial end face of the motor rotor; a cooling assembly, wherein a heat absorption section of the cooling assembly is inserted into the cooling groove from the opening and is configured to cool the motor rotor, and a heat dissipation section of the cooling assembly is located outside the motor rotor; and an end plate, wherein the end plate is disposed at an end face of the motor rotor, a cooling cavity is formed between the end plate and the end face of the motor rotor, the cooling cavity is in communication with a main oil passage inside a central shaft, and the heat dissipation section is located within the cooling cavity.

[0010] On the basis of the foregoing motor cooling structure, the heat absorption section of the cooling assembly can be inserted into the cooling groove formed on the motor rotor, and the heat dissipation section of the cooling assembly can be disposed within the cooling cavity formed between the end plate and the motor rotor, so that conduction of heat from inside the motor rotor to the heat dissipation section outside the motor rotor by using the heat absorption section of the cooling assembly is implemented, and then the heat absorption section can be cooled by a heat exchange action between the heat dissipation section and the heat absorption section of the cooling assembly. The cooling assembly is provided so that there is no need to provide the cooling groove as a circulating oil passage, that is, the cooling groove may be of a groove-type structure with an opening on one side, making the processing and arrangement of the entire cooling structure less restricted and more flexible. Also, the cooling assembly can rotate with the motor rotor, and even when the motor rotor rotates at high speed, it can be ensured that heat exchange between the motor rotor and cooling oil in the external cooling cavity by means of the cooling assembly is carried out efficiently, thereby continuously achieving efficient cooling of the motor rotor.

[0011] In an embodiment of the foregoing motor cooling structure, the motor cooling structure further comprises a first through hole, wherein the first through hole extends through a side wall of the central shaft along a radial direction of the motor, and is in communication with the main oil passage inside the central shaft and the cooling cavity; or the first through hole sequentially extends through the side wall of the central shaft and the end plate along the radial direction of the motor, and is in communication with the main oil passage inside the central shaft and the cooling cavity.

[0012] Further, on the basis of the foregoing motor cooling structure, the first through hole is provided so that oil can be actively supplied into the cooling cavity, thereby improving the cooling efficiency of the motor rotor.

[0013] In an embodiment of the foregoing motor cooling structure, the motor cooling structure further comprises a second through hole provided on the end plate, wherein the second through hole has a first end connected to an outer peripheral side of the cooling cavity, and a second end extending to the outside of the end plate in a direction away from an axis of the motor.

[0014] Further, on the basis of the foregoing motor cooling structure, the second through hole is provided so that cooling oil in the cooling cavity can be discharged, thereby enabling the cooling oil in the cooling cavity to form a circulation. The cooling oil with a relatively low temperature enters the cooling cavity through the first through hole and cools the motor rotor, and the cooling oil with an increased temperature caused by the motor rotor is discharged from the second through hole.

[0015] In an embodiment of the foregoing motor cooling structure, the first end of the second through hole is closer to the axis of the motor than the second end of the second through hole.

[0016] In an embodiment of the foregoing motor cooling structure, the first through hole and the second through hole are staggered in the radial direction of the motor.

[0017] In an embodiment of the foregoing motor cooling structure, at least one first through hole is arranged in a circumferential direction of the motor, and / or at least one second through hole is arranged in the circumferential direction of the motor.

[0018] In an embodiment of the foregoing motor cooling structure, open structures are formed at both ends of the first through hole, and / or open structures are formed at both ends of the second through hole. In an embodiment of the foregoing motor cooling structure, a sealing structure is provided at a joint between the end plate and the motor rotor.

[0019] In an embodiment of the foregoing motor cooling structure, a plurality of cooling grooves are arranged in the circumferential direction of the motor.

[0020] In an embodiment of the foregoing motor cooling structure, the cooling grooves are arranged in at least one layer in the radial direction of the motor.

[0021] In an embodiment of the foregoing motor cooling structure, the number of the cooling groove is at least one, and preferably matches the number of rotor poles of the motor rotor.

[0022] In an embodiment of the foregoing motor cooling structure, the motor rotor comprises a rotor iron core and at least one layer of permanent magnets that are coaxially disposed; and preferably, the cooling groove is located between the permanent magnets and the rotor iron core, and / or the cooling groove is located in two adjacent layers of the permanent magnets.

[0023] In an embodiment of the foregoing motor cooling structure, the cooling assembly comprises a heat pipe, the heat pipe has at least one evaporation section and at least one condensation section, the evaporation section forms the heat absorption section, and the condensation section forms the heat dissipation section.

[0024] In an embodiment of the foregoing motor cooling structure, at least part of the condensation section is bent towards a side close to the axis of the motor, with a bending angle a ranging from 0° to 180°, preferably from 45° to 90°, and a condensation end of the condensation section is located at a position close to the axis of the motor.

[0025] Further, on the basis of the foregoing motor cooling structure, with such an arrangement, the centrifugal force generated when the motor rotor is operating can be used to quickly throw the low-temperature liquid at the condensation end back to the evaporation section, and then the rotation of the motor rotor can be used to improve the liquid circulation efficiency in the heat pipe, thereby improving the cooling efficiency of the heat pipe on the motor rotor. In an embodiment of the foregoing motor cooling structure, the condensation section is bent from a position of the opening and extends in a radial direction of the motor.

[0026] In an embodiment of the foregoing motor cooling structure, the condensation section is spaced apart from the axial end face of the motor rotor.

[0027] In an embodiment of the foregoing motor cooling structure, the cooling groove extends along an axial direction of the motor rotor.

[0028] In an embodiment of the foregoing motor cooling structure, the cooling grooves extend through the motor rotor, openings are formed on two axial end faces of the motor rotor, and two heat pipes disposed opposite to each other in the axial direction of the motor are provided within each of the cooling grooves.

[0029] In an embodiment of the foregoing motor cooling structure, a reserved gap is provided between evaporation ends of two oppositely disposed evaporation sections.

[0030] In an embodiment of the foregoing motor cooling structure, the reserved gap is filled with a thermally conductive adhesive.

[0031] In an embodiment of the foregoing motor cooling structure, the motor cooling structure further comprises a supporting block, wherein the supporting block comprises a fixed connecting portion configured to connect the end plate and / or the motor rotor, and a limiting section configured to limit and cooperate with the condensation section in a circumferential direction of the motor.

[0032] In an embodiment of the foregoing motor cooling structure, the end plate is a dynamic balance plate that rotates with the motor rotor, the fixed connecting portion is connected to the end plate, the limiting section extends along the axial direction of the motor, and an end of the limiting section facing the motor rotor is provided with a matching surface that matches a peripheral side surface of the condensation section.

[0033] In an embodiment of the foregoing motor cooling structure, an end of the limiting section is located within a projection range of the condensation section in a direction perpendicular to the axis of the motor. In a second aspect, the present application provides a motor, comprising the motor cooling structure as described above, and further comprising a central shaft, wherein the motor rotor is driven coaxially with the central shaft; the motor can achieve a significant improvement in the temperature of the rotor iron core and / or permanent magnets by means of the foregoing motor cooling mechanism.

[0034] One or more of the foregoing embodiments of the present application have at least one or more of the following beneficial effects.

[0035] In the present application, the cooling assembly is provided so that the heat absorption section of the cooling assembly can be inserted into the cooling groove formed on the motor rotor, and the heat dissipation section of the cooling assembly can be disposed within the cooling cavity formed between the end plate and the motor rotor. Therefore, conduction of heat from inside the motor rotor to the heat dissipation section outside the motor rotor by using the heat absorption section of the cooling assembly is implemented, and then the heat absorption section can be cooled by a heat exchange action between the heat dissipation section and the heat absorption section of the cooling assembly. The cooling assembly is provided so that there is no need to provide the cooling groove as a circulating oil passage, that is, the cooling groove may be of a groove-type structure with an opening on one side, making the processing and arrangement of the entire cooling structure less restricted and more flexible. Also, the cooling assembly can rotate with the motor rotor, and even when the motor rotor rotates at high speed, it can be ensured that heat exchange between the motor rotor and cooling oil in the external cooling cavity by means of the cooling assembly is carried out efficiently, thereby continuously achieving efficient cooling of the motor rotor.

[0036] Furthermore, the first through hole is provided so that oil can be actively supplied into the cooling cavity, thereby improving the cooling efficiency of the motor rotor.

[0037] Furthermore, the second through hole is provided so that cooling oil in the cooling cavity can be discharged, thereby enabling the cooling oil in the cooling cavity to form a circulation. The cooling oil with a relatively low temperature enters the cooling cavity through the first through hole and cools the motor rotor, and the cooling oil with an increased temperature caused by the motor rotor is discharged from the second through hole.

[0038] Furthermore, the condensation section of the heat pipe is bent towards one side of the axis of the motor, and with such an arrangement, the centrifugal force generated when the motor rotor is operating can be used to quickly throw the low-temperature liquid at the condensation end back to the evaporation section, and then the rotation of the motor rotor can be used to improve the liquid circulation efficiency in the heat pipe, thereby improving the cooling efficiency of the heat pipe on the motor rotor.

[0039] Additional aspects and advantages of the present application will be given in part in the following description, and will become apparent in part from the following description, or be learned from the practice of the present application.

[0040] DESCRIPTION OF THE DRAWINGS

[0041] The disclosure of the present application will become more readily understood with reference to the accompanying drawings. Those skilled in the art will readily appreciate that these drawings are for illustrative purposes only and are not intended to limit the scope of the present application. In addition, similar numerals are used to denote similar components throughout the drawings, in which:

[0042] FIG. 1 is a schematic structural diagram of a motor cooling structure according to an embodiment of the present application;

[0043] FIG. 2 is a schematic structural diagram of a heat pipe according to an embodiment of the present application;

[0044] FIG. 3 is a schematic structural diagram of another heat pipe according to an embodiment of the present application;

[0045] FIG. 4 is a cross-sectional view of a motor rotor according to an embodiment of the present application;

[0046] FIG. 5 is an axial end view of a motor rotor according to an embodiment of the present application; FIG. 6 is a schematic structural diagram of a motor rotor according to an embodiment of the present application;

[0047] FIG. 7 is a schematic structural diagram of an end plate according to an embodiment of the present application;

[0048] FIG. 8 is an axial end view of one side of an end plate according to an embodiment of the present application;

[0049] FIG. 9 is an axial end view of the other side of the end plate according to an embodiment of the present application;

[0050] FIG. 10 is a cross-sectional view of the end plate according to an embodiment of the present application;

[0051] FIG. 11 is a partial enlarged view of a position of a cooling cavity according to an embodiment of the present application;

[0052] FIG. 12 is a schematic structural diagram of a central shaft according to an embodiment of the present application; and

[0053] FIG. 13 is a schematic structural diagram of the interior of the central shaft according to an embodiment of the present application.

[0054] Description of reference numerals

[0055] 11. Cooling groove; 111. opening; 12. heat pipe; 121. evaporation section; 1211. evaporation end; 122. condensation section; 1221. condensation end; 13. cooling cavity; 141. first through hole; 142. second through hole; 15. thermally conductive adhesive; 16. supporting block; 17. sealing structure; 2. motor rotor; 21. rotor iron core; 22. permanent magnet; 3. central shaft; 4. end plate.

[0056] DETAILED DESCRIPTION

[0057] Some embodiments of the present application will be described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are only used to explain the technical principles of the present application, and are not intended to limit the scope of protection of the present application.

[0058] Faced with environmental pollution caused by exhaust gas of motor vehicles, the national requirements for emissions are increasingly stringent, especially in the automobile field. Therefore, new energy vehicles have emerged to replace traditional internal combustion engine vehicles. Drive motors are used as the core driving components of the new energy vehicles. Their operation efficiency and cost performance are of great concern, and the cooling mode of the motors is particularly important for the efficiency and cost performance of the motors.

[0059] At present, with the trend of all-in-one new energy driving systems, oil-cooled motors have gradually become mainstream. Most of the existing oil cooling technologies are developed around stator iron cores and end windings. However, with the trend of high speed of the drive motor, the temperature of the motor rotor has also become the focus of attention. With the increase of the temperature of the rotor iron core and the magnet, on the one hand, the performance of the magnet is reduced, and on the other hand, the risk of demagnetization of the magnet is increased. In the prior art, the cooling design for rotors do not provide adequate cooling effect for the rotors, and the pressure loss of the system oil circuit is also increased.

[0060] On this basis, the present embodiment provides a motor cooling structure, wherein a heat absorption section of a cooling assembly can be inserted into a cooling groove formed on a motor rotor, and a heat dissipation section of the cooling assembly can be disposed in a cooling cavity formed between an end plate and the motor rotor, so that conduction of heat from inside the motor rotor to the heat dissipation section outside the motor rotor by using the heat absorption section of the cooling assembly is implemented, and then the heat absorption section can be cooled by a heat exchange action between the heat dissipation section and the heat absorption section of the cooling assembly. The cooling assembly is provided so that there is no need to provide the cooling groove as a circulating oil passage, that is, the cooling groove may be of a groove-type structure with an opening on one side, making the processing and arrangement of the entire cooling structure less restricted and more flexible. Also, the cooling assembly can rotate with the motor rotor, and even when the motor rotor rotates at high speed, it can be ensured that heat exchange between the motor rotor and cooling oil in the external cooling cavity by means of the cooling assembly is carried out efficiently, thereby continuously achieving efficient cooling of the motor rotor.

[0061] The present application will be specifically described below by means of specific embodiments.

[0062] With reference to FIGS. 1 to 13, in a first aspect, the present embodiment provides a motor cooling structure. The motor cooling structure includes a motor rotor 2, and further includes: a cooling groove 11 formed on the motor rotor 2 and provided with an opening 111 on a surface of the motor rotor 2, wherein the opening 111 may specifically be located on an axial end face of the motor rotor 2, thereby cooperating with an end plate 4 disposed at an axial end face position of the motor rotor 2 to form a cooling cavity 13 capable of simultaneously cooling the axial end face of the motor rotor 2 and a heat dissipation section; a cooling assembly, wherein a heat absorption section of the cooling assembly is inserted into the cooling groove 11 from the opening 111 and configured to cool the motor rotor 2, and the heat dissipation section of the cooling assembly is located outside the motor rotor 2; and an end plate 4, wherein the end plate 4 is disposed at an end face of the motor rotor 2, the cooling cavity 13 is formed between the end plate 4 and the end face of the motor rotor 2, the cooling cavity 13 is in communication with a main oil passage inside a central shaft 3, and the heat dissipation section is located within the cooling cavity 13.

[0063] In the motor cooling structure provided in the present embodiment, the heat absorption section of the cooling assembly can be inserted into the cooling groove 11 formed on the motor rotor 2, and the heat dissipation section of the cooling assembly can be disposed within the cooling cavity 13 formed between the end plate 4 and the motor rotor 2, so that conduction of heat from inside the motor rotor 2 to the heat dissipation section outside the motor rotor 2 by using the heat absorption section of the cooling assembly is implemented, and then the heat absorption section can be cooled by a heat exchange action between the heat dissipation section and the heat absorption section of the cooling assembly. The cooling assembly is provided so that there is no need to provide the cooling groove 11 as a circulating oil passage, that is, the cooling groove 11 may be of a groove-type structure with an opening 111 on one side, making the processing and arrangement of the entire cooling structure less restricted and more flexible. Also, the cooling assembly can rotate with the motor rotor 2, and even when the motor rotor 2 rotates at high speed, it can be ensured that heat exchange between the motor rotor 2 and cooling oil in the external cooling cavity 13 by means of the cooling assembly is carried out efficiently, thereby continuously achieving efficient cooling of the motor rotor 2.

[0064] With continued reference to FIGS. 1, 7 and 10 to 13, in some embodiments, the motor cooling structure further includes a first through hole 141. The first through hole 141 extends through a side wall of the central shaft 3 along a radial direction of the motor and is in communication with the main oil passage inside the central shaft 3 and the cooling cavity 13; or the first through hole 141 sequentially extends through the side wall of the central shaft 3 and the end plate 4 along the radial direction of the motor and is in communication with the main oil passage inside the central shaft 3 and the cooling cavity 13. When the end plate 4 and the end face of the motor rotor 2 enclose the cooling cavity 13, the first through hole 141 needs to sequentially extend through the side wall of the central shaft 3 and the end plate 4 to be in communication with the main oil passage and the cooling cavity 13. When the end plate 4, the side wall of the central shaft 3, and the end face of the motor rotor 2 jointly enclose the cooling cavity 13, the first through hole 141 only needs to extend through the side wall of the central shaft 3 corresponding to the cooling cavity 13. The first through hole 141 is provided so that oil can be actively supplied into the cooling cavity 13, thereby improving the cooling efficiency of the motor rotor 2.

[0065] In a further embodiment, the motor cooling structure further includes a second through hole 142 provided on the end plate 4. A first end of the second through hole 142 is connected to an outer peripheral side of the cooling cavity 13, and a second end of the second through hole 142 extends to the outside of the end plate 4 in a direction away from the axis of the motor. The second through hole 142 is provided so that cooling oil in the cooling cavity 13 can be discharged, and the cooling oil in the cooling cavity 13 can thus form a circulation. The cooling oil with a lower temperature enters the cooling cavity 13 from the first through hole 141 and cools the motor rotor 2, and the cooling oil with an increased temperature caused by the motor rotor 2 is discharged from the second through hole 142. Specifically, since the first through hole 141 is provided on the inner peripheral side of the cooling cavity 13 (at a position close to the central shaft 3) and the second through hole 142 is close to the outer peripheral side of the cooling cavity 13, the cooling oil with a low temperature can be quickly introduced into the cooling cavity 13 from the first through hole

[0066] 141 by using a centrifugal force when the motor rotor 2 is working, and the cooling oil with a high temperature can be quickly introduced out of the cooling cavity 13 from the second through hole

[0067] 142 by using the centrifugal force.

[0068] With continued reference to FIGS. 1 and 10, in some embodiments, the first end of the second through hole 142 is closer to the axis of the motor than the second end of the second through hole 142, and such an arrangement can further improve the efficiency of the cooling oil in the cooling cavity 13 flowing out of the second through hole 142, and further accelerate the circulation efficiency of the cooling oil in the cooling cavity 13, thereby improving the cooling efficiency. Specifically, the extending direction of the second through hole 142 may form an angle of 30° to 80° with the axis of the motor, and further, the extending direction of the second through hole 142 may form an angle of 60° with the axis of the motor.

[0069] In a further embodiment, the first through hole 141 and the second through hole 142 are staggered in the radial direction of the motor, that is, under the action of the centrifugal force, the cooling oil with a lower temperature that has just flowed into the cooling cavity 13 from the first through hole 141 will not be directly thrown out of the cooling cavity 13 from the second through hole 142, ensuring that all the cooling oil that has entered the cooling cavity 13 can fully perform its function, thereby improving the cooling efficiency.

[0070] In some embodiments, a plurality of first through holes 141 are arranged in a circumferential direction of the motor, and / or a plurality of second through holes 142 are arranged in the circumferential direction of the motor.

[0071] In some embodiments, open structures are formed at both ends of the first through hole 141, and / or open structures are formed at both ends of the second through hole 142. Since the cooling cavity 13 on both sides of the first through hole 141 is in communication with the internal space of the central shaft 3 by means of the narrower first through hole 141, such an arrangement can enable the first through hole 141 itself to form a Laval nozzle structure. When the cooling oil flows from the central shaft 3 to the cooling cavity 13, the flow rate of the cooling oil can be significantly increased, and similarly, the flow rate of the cooling oil flowing from the second through hole 142 to the outside of the cooling cavity 13 can also be increased.

[0072] In some embodiments, the cooling grooves 11 are arranged in multiple layers in a radial direction of the motor. Specifically, the cooling grooves 11 may be arranged between every two adjacent layers of permanent magnets 22, and the cooling grooves 11 may also be arranged between the permanent magnets 22 and the rotor iron core 21.

[0073] In some embodiments, a sealing structure 17 is provided at a joint between the end plate 4 and the motor rotor 2. The sealing performance of the cooling cavity 13 can be improved by providing the sealing structure 17, thereby ensuring that the cooling oil flows along a set route (from the central shaft 3 to the cooling cavity 13 through the first through hole 141, and then from the cooling cavity 13 to the outside through the second through hole 142). Specifically, an annular groove may be provided on an end face(s) of the end plate 4 and / or the rotor iron core 21 of the motor rotor 2, and a sealing ring is provided within the annular groove, so as to form the sealing structure 17. The sealing structure 17 may be arranged in multiple layers along the radial direction of the motor rotor 2.

[0074] In some embodiments, a plurality of cooling grooves 11 are arranged in a circumferential direction of the motor.

[0075] Specifically, the number of the cooling grooves 11 matches the number of rotor poles of the motor rotor 2, and the cooling grooves 11 may be arranged at gaps between every two adjacent groups of permanent magnets 22 in the circumferential direction, thereby uniformly cooling each group of permanent magnets 22.

[0076] Further, the motor rotor 2 includes a rotor iron core 21 and at least one layer of permanent magnets 22 that are coaxially disposed; and the cooling groove 11 is located between the permanent magnets 22 and the rotor iron core 21, and / or the cooling groove 11 is located between two adjacent layers of permanent magnets 22.

[0077] In some embodiments, the end plate 4 may be a dynamic balance plate, which can not only provide the function of making the motor rotor 2 more stable during rotation, but also form the cooling cavity 13 as a part of the cooling cavity 13 of the motor rotor 2, thereby simplifying the overall cooling structure.

[0078] With continued reference to FIGS. 1 to 3, in some embodiments, the cooling assembly includes a heat pipe 12. The heat pipe has at least one evaporation section 121 and at least one condensation section 122. The evaporation section 121 of the heat pipe 12 forms the heat absorption section, and the condensation section 122 of the heat pipe 12 forms the heat dissipation section. An evaporation section may be understood as a heat pipe that is inserted into a groove, with two ends extending out of the stator iron core. The heat dissipation section may be formed with or without bending.

[0079] With continued reference to FIG. 3, in a further embodiment, at least part of the condensation section 122 is bent towards the side close to the axis of the motor, with a bending angle a ranging from 0° to 180°, preferably 45° to 90°, as shown in FIG. 2. A condensation end 1221 of the condensation section 122 is located at a position close to the axis of the motor. With such an arrangement, a centrifugal force generated when the motor rotor 2 is operating can be used to quickly throw low-temperature liquid at the condensation end 1221 back to the evaporation section 121, and then the rotation of the motor rotor 2 can be used to improve the liquid circulation efficiency in the heat pipe 12, thereby improving the cooling efficiency of the heat pipe 12 on the motor rotor 2.

[0080] With continued reference to FIGS. 1 and 2, specifically, the condensation section 122 is bent from the position of the opening 111 and extends along the radial direction of the motor. With such an arrangement, it can not only quickly throw the low-temperature liquid at the condensation end 1221 back to the evaporation section 121 by using the centrifugal force generated when the motor rotor 2 is operating, thereby improving the liquid circulation efficiency in the heat pipe 12 by using the rotation of the motor rotor 2, and further improving the cooling efficiency of the heat pipe 12 on the motor rotor 2; but also reduce the influence of the heat pipe 12 on the axial size of the entire motor. The end plate 4 can be closer to the motor rotor 2 by using the bending of the condensation section 122, thereby improving the rotational stability of the motor rotor 2. In a further embodiment, the condensation section 122 is spaced apart from an axial end face of the motor rotor 2, that is, the circumferential side wall of the condensation section 122 can be directly cooled by the cooling oil in the cooling cavity 13, and the influence of the heat of the motor rotor 2 on the heat dissipation of the condensation section 122 can also be reduced.

[0081] With continued reference to FIGS. 1 and 4, in some embodiments, the cooling groove 11 extends along the axial direction of the motor rotor 2, which can make the installation and removal of the evaporation section 121 of the heat pipe 12 easier, and can also prevent the interference of the cooling groove 11 with the installation positions of the permanent magnets 22, etc. The cooling groove 11 may also be inclined at a set angle with the axial direction of the motor rotor 2, as long as it can be ensured that the heat pipe 12 can stably and reliably dissipate heat inside the motor rotor 2.

[0082] In a further embodiment, cooling grooves 11 extend through the motor rotor 2, openings 111 are formed on two axial end faces of the motor rotor 2, and two heat pipes 12 disposed opposite to each other in the axial direction of the motor are provided within each of the cooling grooves 11. Specifically, the evaporation section 121 of the heat pipe 12 may be inserted through the openings 111, and with such symmetrical arrangement, the condensation section 122 for heat exchange with the cooling cavity 13 can be disposed at two axially opposite positions of the motor rotor 2, thereby improving the space utilization of the cooling cavity 13.

[0083] In some embodiments, a reserved gap exists between the evaporation ends 1211 of two oppositely disposed evaporation sections 121, and the reserved gap may specifically be 2 mm, so as to prevent interference during the assembly process. By means of adhesive filling, the heat pipe 12 and the rotor iron core 21 may be fixed using either an interference fit or a clearance fit with adhesive.

[0084] In a further embodiment, the reserved gap is filled with a thermally conductive adhesive 15, wherein the thermally conductive adhesive 15 may be one or more of an ultra-high temperature thermally conductive adhesive, a silicone thermally conductive adhesive, an epoxy resin AB adhesive, a polyurethane adhesive, a polyurethane thermally conductive electrically conductive adhesive, and a thermally conductive silicone grease, as long as the rapid heat conduction between the two oppositely disposed evaporation ends 1211 can be achieved. By filling the thermally conductive adhesive 15 into the reserved gap, the heat equalizing effect of the evaporation sections 121 of the two oppositely disposed heat pipes 12 can be achieved, thereby ensuring the overall cooling balance of the entire motor rotor 2 and preventing the problem of excessive local temperature difference.

[0085] With continued reference to FIGS. 9 to 11, in some embodiments, the motor cooling structure further includes a supporting block 16. The supporting block 16 includes a fixed connecting portion for connecting the end plate 4 and / or the motor rotor 2, and a limiting section that limits and cooperates with the condensation section 122 in the circumferential direction of the motor.

[0086] In a further embodiment, the end plate 4 is a dynamic balance plate that rotates with the motor rotor 2. The fixed connecting portion is connected to the end plate 4, the limiting section extends along the axial direction of the motor, and the end of the limiting section facing the motor rotor 2 is provided with a matching surface that matches the peripheral side surface of the condensation section 122.

[0087] In some embodiments, an end of the limiting section is located within the projection range of the condensation section 122 in the direction perpendicular to the axis of the motor, that is, the end of the limiting section has an overlapping portion with the condensation section 122 in the direction of the axis of the motor, and does not exceed the condensation section 122, thereby preventing the interference of the limiting section on the end face of the motor rotor 2, and ensuring the ability of the limiting section to limit the condensation section 122 in the circumferential direction.

[0088] Specifically, both sides of one condensation section 122 in the circumferential direction of the motor are provided with limiting sections that limit and cooperate with the same, and the two limiting sections limit and fix the condensation section 122.

[0089] In a second aspect, the present embodiment provides a motor, including the motor cooling structure as described above, and further including a central shaft 3, wherein the motor rotor 2 and the central shaft 3 are coaxially driven; and the motor can achieve a significant improvement in the temperature of the rotor iron core 21 and / or permanent magnets 22 by means of the foregoing motor cooling mechanism.

[0090] In the description of the present specification, the description of the reference terms “an embodiment”, “some embodiments”, “example”, “specific example”, or “some examples” and the like means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0091] In addition, the terms “first” and “second” are used for descriptive purposes only and are not to be constmed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined with “first” and “second” may explicitly or implicitly include at least one of the features. In the description of the present application, “a plurality of’ means at least two, such as two, three, etc., unless otherwise specifically defined.

[0092] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be construed to limit the present application, and those skilled in the art can make changes, modifications, substitutions, and variations to the foregoing embodiments within the scope of the present application.

Claims

CLAIMS1. A motor cooling structure, comprising a motor rotor (2), and characterized by further comprising: a cooling groove (11) formed on the motor rotor (2) and provided with an opening (111) on a surface of the motor rotor (2), the opening (111) being located on an axial end face of the motor rotor (2); a cooling assembly, wherein a heat absorption section of the cooling assembly is inserted into the cooling groove (11) from the opening (111) and is configured to cool the motor rotor (2), and a heat dissipation section of the cooling assembly is located outside the motor rotor (2); and an end plate (4), wherein the end plate (4) is disposed at an end face of the motor rotor (2), a cooling cavity (13) is formed between the end plate (4) and the end face of the motor rotor (2), the cooling cavity (13) is in communication with a main oil passage inside a central shaft (3), and the heat dissipation section is located within the cooling cavity (13).

2. The motor cooling structure according to claim 1, further comprising a first through hole(141), wherein the first through hole (141) extends through a side wall of the central shaft (3 ) along a radial direction of the motor, and is in communication with the main oil passage inside the central shaft (3) and the cooling cavity (13); or the first through hole (141) sequentially extends through the side wall of the central shaft (3) and the end plate (4) along the radial direction of the motor, and is in communication with the main oil passage inside the central shaft (3) and the cooling cavity (13).

3. The motor cooling structure according to claim 2, further comprising a second through hole(142) provided on the end plate (4), wherein the second through hole (142) has a first end connected to an outer peripheral side of the cooling cavity (13), and a second end extending to the outside of the end plate (4) in a direction away from an axis of the motor.

4. The motor cooling structure according to claim 3, wherein the first end of the second through hole (142) is closer to the axis of the motor than the second end of the second through hole.

5. The motor cooling structure according to claim 3, wherein the first through hole (141) and the second through hole (142) are staggered in the radial direction of the motor.

6. The motor cooling structure according to claim 1, wherein a sealing structure (17) is provided at a joint between the end plate (4) and the motor rotor (2).

7. The motor cooling structure according to claim 1, wherein the cooling groove (11) is arranged in at least one layer in a radial direction of the motor.

8. The motor cooling structure according to claim 1, wherein the motor rotor (2) comprises a rotor iron core (21) and at least one layer of permanent magnets (22) that are coaxially arranged; and the cooling groove (11) is located between the permanent magnets (22) and the rotor iron core (21), and / or the cooling groove (11) is located in two adjacent layers of the permanent magnets (22).

9. The motor cooling structure according to any one of claims 1 to 8, wherein the cooling assembly comprises a heat pipe (12), the heat pipe (12) has at least one evaporation section (121) and at least one condensation section (122), the evaporation section (121) forms the heat absorption section, and the condensation section (122) forms the heat dissipation section.

10. The motor cooling structure according to claim 9, wherein at least part of the condensation section (122) is bent towards a side close to the axis of the motor, and a condensation end (1221) of the condensation section (122) is located at a position close to the axis of the motor.

11. The motor cooling structure according to claim 10, wherein the condensation section (122) is bent from a position of the opening (111) and extends in the radial direction of the motor.

12. The motor cooling structure according to claim 9, wherein the cooling grooves (11) extend through the motor rotor (2), the openings (111) are formed on two axial end faces of the motor rotor (2), and two heat pipes (12) disposed opposite to each other in an axial direction of the motor are provided within each of the cooling grooves (11).

13. The motor cooling structure according to claim 12, wherein a reserved gap is provided between evaporation ends (1211) of two oppositely disposed evaporation sections (121).

14. The motor cooling structure according to claim 9, further comprising a supporting block (16), wherein the supporting block (16) comprises a fixed connecting portion configured to connect the end plate (4) and / or the motor rotor (2), and a limiting section configured to limit and cooperate with the condensation section (122) in a circumferential direction of the motor.

15. The motor cooling structure according to claim 14, wherein the end plate (4) is a dynamic balance plate that rotates with the motor rotor (2), the fixed connecting portion is connected to the end plate (4), the limiting section extends along the axial direction of the motor, and an end of the limiting section facing the motor rotor (2) is provided with a matching surface that matches a peripheral side surface of the condensation section (122).

16. A motor, characterized by comprising the motor cooling structure according to any one of claims 1 to 15, and further comprising a central shaft (3), wherein the motor rotor (2) and the central shaft (3) are coaxially driven.

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