A permanent magnet motor with a composite heat dissipation structure

Abstract

The present invention relates to the technical field of permanent magnet motor heat dissipation and motor thermal management, and provides a permanent magnet motor with a composite heat dissipation structure, comprising a rotor shaft, a rotor core, permanent magnets, a heat pipe, a heat dissipation fin assembly, and a stator assembly. The rotor core is mounted with permanent magnets, the rotor core is sleeved on the rotor shaft, and the rotor core is provided with multiple assembly holes; multiple heat pipes are installed in the multiple assembly holes; the heat pipes include a first pipe section and a second pipe section connected to each other, the first pipe section and the second pipe section being arranged at an angle; the heat dissipation fin assembly includes multiple heat dissipation fins, each having multiple heat pipe holes; two groups of heat dissipation fin assemblies are sleeved on the rotor shaft and respectively located at the axial ends of the rotor core; multiple heat pipes are installed in the multiple heat pipe holes of the heat dissipation fins; and the stator assembly is sleeved on the outer periphery of the rotor core and the two groups of heat dissipation fin assemblies. The optimized structure of the heat pipes and the heat dissipation fin assembly achieves a better heat dissipation effect.

Description

Technical Field

[0001] The present invention relates to the technical field of permanent magnet motor heat dissipation and motor thermal management, and in particular to a permanent magnet motor with a composite heat dissipation structure. Background Art

[0002] As new energy vehicles become more widespread and mature, the demand for higher power density and stronger overload capacity in permanent magnet motors (PMMs) is posing new challenges to their heat dissipation and overload heat dissipation capabilities. Currently, high-power density PMMs are primarily cooled through circulating fluid channels in the stator casing and oil cooling at the ends of the rotor shaft. However, since the rotors are welded together after production, the heat dissipation capacity of the mid-section of the rotor is weaker than that of the ends during operation. This leads to uneven heating and poor heat dissipation in the rotor. In severe cases, this can lead to localized loss of thermal expansion balance in the rotor and demagnetization of the permanent magnets due to high temperatures.

[0003] A heat pipe is a rapid heat transfer structure based on phase change and convection. The refrigerant in the pipe evaporates and changes phase in the evaporation section, taking away heat. This heat is the latent heat of evaporation of the working fluid. The steam flows from the central channel to the condensation section of the heat pipe, condenses into liquid, and releases latent heat. Under the action of capillary force or other forces, the liquid flows back to the evaporation section, completing a heat transfer cycle. The thermal conductivity of the heat pipe exceeds that of any metal currently known. In the condensation zone of the heat pipe, a heat exchanger or a heat sink fin group structure is usually used for heat transfer. Existing heat dissipation structures of rotors based on heat pipes and heat sink fins are mostly a combination of single functions. There is a lack of systematic combination between the various structures. There is no specialized and functional design between the various structures, especially for the path optimization of the two-phase fluid system of enclosed gas and cooling oil in the motor housing. Summary of the Invention

[0004] The purpose of the present invention is to provide a permanent magnet motor with a composite heat dissipation structure to solve the problem in the prior art that the structural design of heat pipes and heat dissipation fins is unreasonable, resulting in poor heat dissipation effect of the permanent magnet motor.

[0005] In order to achieve the above-mentioned object, the present invention provides a permanent magnet motor with a composite heat dissipation structure, characterized in that it includes: a rotor shaft; a rotor core and permanent magnets, the rotor core is mounted with permanent magnets, the rotor core is sleeved on the rotor shaft, and the rotor core is provided with a plurality of assembly holes; the assembly holes include a first hole segment and a second hole segment connected, and the first hole segment and the second hole segment are arranged at an angle; a plurality of heat pipes, the plurality of heat pipes are mounted in a one-to-one correspondence in the plurality of assembly holes; along the length direction of the heat pipe, the heat pipe includes a first pipe segment and a second pipe segment connected, and the first pipe segment is connected to the second pipe segment. The first tube section and the second tube section are arranged at an angle and are adapted to the first hole section and the second hole section; the heat dissipation fin group includes a plurality of heat dissipation fins, and each heat dissipation fin has a plurality of heat pipe holes; the two groups of heat dissipation fin groups are sleeved on the rotor shaft and are respectively located at the axial ends of the rotor core; the plurality of heat pipes are installed in the plurality of heat pipe holes of the heat dissipation fins in a one-to-one correspondence; the heat pipe holes on each heat dissipation fin are arranged closer to the front and rear ends of the rotor shaft and farther away from the axis as the heat dissipation fins are arranged; the stator assembly, the stator assembly is sleeved on the rotor core and the two groups of heat dissipation fins

[0006] The outer peripheral side of the heat dissipation fin group.

[0007] The present invention optimizes the structure of the heat pipe and the heat dissipation fin group. By cooperating with the heat pipe and the heat dissipation fin group, the rate at which the liquefied refrigerant in the condensation zones at both ends flows back to the inside of the rotor core can be accelerated, thereby improving the heat dissipation effect.

[0008] Furthermore, the rotor heat pipe has a symmetrical "V"-shaped structure, and the angle between the first pipe section and the second pipe section is 175° to 180°.

[0009] Furthermore, the cross-section of the outer wall of the heat pipe includes a first arc segment, a second arc segment, a third arc segment and a fourth arc segment connected in sequence end to end, the center of the first arc segment and the center of the third arc segment are on a straight line, the radius of the first arc segment is smaller than the radius of the third arc segment, the two ends of the second arc segment are tangent to the first end of the first arc segment and the first end of the third arc segment respectively, the two ends of the fourth arc segment are tangent to the second end of the first arc segment and the second end of the third arc segment respectively, the centers of the first arc segment and the third arc segment are located on the inner side of the heat pipe, and the centers of the second arc segment and the fourth arc segment are located on the outer side of the heat pipe; a plurality of spaced-apart protruding tooth ridge structures are provided on the inner wall of the heat pipe, and tooth grooves are formed between two adjacent tooth ridge structures.

[0010] Furthermore, the third arc segment of the heat pipe is closer to the axis of the rotor core than the first arc segment.

[0011] Furthermore, along the length direction of the heat pipe, the multiple spaced tooth ridge structures on the inner circumferential wall of the first tube segment and the multiple spaced tooth ridge structures on the inner circumferential wall of the second tube segment all extend to the symmetry center plane; the multiple tooth ridge structures on the inner circumferential wall of the first tube segment and the multiple tooth ridge structures on the inner circumferential wall of the second tube segment are symmetrically arranged relative to the symmetry center plane; the cross-sectional shape of the tooth ridge structure includes a first isosceles trapezoid and a second isosceles trapezoid connected with each other; the first isosceles trapezoid is located on the side of the second isosceles trapezoid close to the tooth root; the lower base of the first isosceles trapezoid is close to the tooth root, the upper base of the first isosceles trapezoid is connected to the lower base of the second isosceles trapezoid, and the upper base of the second isosceles trapezoid is located on the side close to the tooth top; the length of the lower base of the first isosceles trapezoid is greater than the length of the upper base of the first isosceles trapezoid, the length of the lower base of the second isosceles trapezoid is greater than the length of the upper base of the second isosceles trapezoid, and the length of the upper base of the first isosceles trapezoid is equal to the length of the lower base of the second isosceles trapezoid.

[0012] Furthermore, the heat dissipation fin includes: a fin body; a mounting hole, a mounting hole is provided on the axial end face of the fin body; a plurality of heat dissipation holes, a plurality of heat dissipation holes are provided on the axial end face of the fin body, and the plurality of heat dissipation holes are all located on the outer peripheral side of the mounting hole; a plurality of heat pipe holes, a plurality of heat pipe holes are provided on the axial end face of the fin body, and the plurality of heat pipe holes are all located on the outer peripheral side of the mounting hole; the plurality of heat pipe holes and the plurality of heat dissipation holes are arranged at intervals; a plurality of heat dissipation ridges, a plurality of heat dissipation ridges are protrudingly provided on the axial end face of the fin body, and the plurality of heat dissipation ridges are located on the outer peripheral side of the mounting hole; each heat dissipation ridge is arranged obliquely relative to the fin body; a plurality of heat dissipation slits, a plurality of heat dissipation slits are provided on the axial end face of the fin body, and a corresponding heat dissipation slit is provided under each heat dissipation ridge.

[0013] Furthermore, the plurality of heat dissipation holes include a plurality of first heat dissipation holes near the axis of the fin body, and a plurality of second heat dissipation holes near the outer peripheral edge of the fin body; a circular mounting hole is provided in the center of the fin body; the plurality of first heat dissipation holes are spaced around the outer peripheral side of the mounting hole; the plurality of heat pipe holes are spaced around the outer peripheral side of the plurality of first heat dissipation holes; the plurality of second heat dissipation holes are spaced around the outer peripheral side of the plurality of heat pipe holes; the plurality of heat dissipation ridges include a plurality of first heat dissipation ridges and a plurality of second heat dissipation ridges; the plurality of heat dissipation slots include a plurality of first heat dissipation slots and a plurality of second heat dissipation slots; the plurality of first heat dissipation ridges are all protrudingly provided on the first axial end face of the fin body, and the plurality of first heat dissipation ridges are spaced around the outer peripheral side of the plurality of first heat dissipation holes; the first end of each first heat dissipation ridge is close to the first heat dissipation hole and the like. The heat dissipation device is configured to dissipate heat from the first heat dissipation ridge and the like, and the heat dissipation device is configured to dissipate heat from the first heat dissipation ridge and the like. The heat dissipation device is configured to dissipate heat from the first heat dissipation ridge and the like, and the heat dissipation device is configured to dissipate heat from the first heat dissipation ridge and the like.

[0014] Furthermore, each heat dissipation ridge is pulled out obliquely at an acute angle to the main surface of the fin; the thickness of the heat dissipation ridge is equal to the thickness of the fin main body; the heat dissipation ridge is streamlined as a whole, and the heat dissipation slit is streamlined as a whole; the rotor shaft is a symmetrical hollow stepped structure, and the rotor shaft has a hollow hole; the rotor shaft includes two oil outlet shaft sections, a connecting shaft section connecting the two oil outlet shaft sections, and two stepped shaft end sections respectively located at the outer ends of the two oil outlet shaft sections, the outer diameter of the oil outlet shaft section is adapted to the mounting hole of the heat dissipation fin, and the outer peripheral wall of the oil outlet shaft section is provided with a card groove extending and passing through along its axial direction, and multiple card grooves are arranged around the oil outlet shaft section. The shaft segments are arranged at circumferential intervals; an oil outlet hole extending radially thereof is also provided on the outer circumferential wall of the oil outlet shaft segment where no slot is provided, and the oil outlet hole is connected to the hollow hole; the hollow hole includes two first hollow hole segments located in the two oil outlet shaft segments, a connecting hole segment connected between the two first hollow hole segments, and two second hollow hole segments located at both ends of the two first hollow hole segments, the diameter of the first hollow hole segment is greater than the diameter of the second hollow hole segment, and the diameter of the connecting hole segment is equal to the diameter of the second hollow hole segment; the heat dissipation fin also includes a buckle, and a plurality of buckles are arranged at intervals on the inner circumferential wall of the mounting hole, and the plurality of buckles are arranged in one-to-one correspondence with the plurality of slots.

[0015] Furthermore, along the axial direction of the fin body, the first heat dissipation ridge includes a first edge connected to the fin body and a second edge away from the fin body; along the extension direction of the axial end face of the fin body, the first heat dissipation slit includes a third edge connected to the first heat dissipation ridge and a fourth edge away from the first heat dissipation ridge; the first edge coincides with the third edge, and the second edge and the fourth edge have the same shape; the height of each point on the second edge to the plane where the fin body is located is equal; along the axial direction of the fin body, the second heat dissipation ridge includes a fifth edge connected to the fin body and a sixth edge away from the fin body; along the extension direction of the axial end face of the fin body, the second heat dissipation slit The fins are connected to each other in a direction of rotation and are connected to each other with a forward looking slotting door which is located in the center of the heat sink. The fins are connected to the top of the heat sink and the forward looking slotting door is located in the center of the heat sink. The fins are connected to the top of the heat sink and the forward looking slotting door is located in the center of the heat sink.

[0016] Furthermore, the heat pipe is filled with a vaporizable phase-change liquid refrigerant; the rotor core is made of silicon steel; and the heat sink fins are made of copper or aluminum.

[0017] The structure of the present invention does not destroy the original oil cooling function of the stator winding end. Under the action of centripetal force, the cooling oil and the air in the shell shuttle between the various heat sink fins through the channel formed by the heat sink fin group, thereby enhancing heat exchange. After leaving the heat sink fins, the cooling oil will also be thrown to the end of the stator winding to cool the winding end. The permanent magnet motor heat dissipation design of the present invention completes the heat exchange and heat transfer process within the motor housing. The heat exchange between the motor cavity, rotor and stator end and the outside world is completed only through the cooling oil. The airtightness of the motor operation is greatly improved, and it is suitable for more complex working conditions, such as sewage, sand and dust and other harsh environments.

[0018] Based on the implementation methods provided in the above aspects, this application can also be further combined to provide more implementation methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of 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.

[0020] Figure 1A schematic diagram of a three-dimensional assembly structure of a permanent magnet motor with a composite heat dissipation structure provided in an optional embodiment of the present invention;

[0021] Figure 2 for Figure 1 Schematic diagram of the disassembled structure of the permanent magnet motor;

[0022] Figure 3 for Figure 1 Schematic diagram of the three-dimensional structure of the heat pipe of the permanent magnet motor;

[0023] Figure 4 for Figure 3 A partial cross-sectional schematic diagram of the heat pipe in FIG.

[0024] Figure 5 for Figure 4 An enlarged view of a portion of the heat pipe structure;

[0025] Figure 6 for Figure 1 Schematic diagram of the three-dimensional structure of the rotor core of the permanent magnet motor;

[0026] Figure 7 for Figure 1 A schematic diagram of the three-dimensional structure of the rotor shaft of the permanent magnet motor;

[0027] Figure 8 for Figure 6 A front view of the rotor shaft;

[0028] Figure 9 for Figure 7 A cross-sectional view of a rotor shaft;

[0029] Figure 10 for Figure 1 Schematic diagram of the structure of the heat dissipation fins of the permanent magnet motor;

[0030] Figure 11 for Figure 9 Enlarged view of point A in the middle;

[0031] Figure 12 for Figure 9 Enlarged view of point B in the middle;

[0032] Figure 13 for Figure 1 A schematic diagram of the three-dimensional structure of the stator assembly of the permanent magnet motor;

[0033] Figure 14 A cross-sectional view of a fin group unit in a permanent magnet motor with a composite heat dissipation structure provided in an optional embodiment of the present invention;

[0034] Description of Figure Numbers:

[0035] 1. Heat sink fin; 110. Fin body; 111. Heat pipe hole; 112. Mounting hole; 113. First heat sink; 114. Second heat sink; 16. Heat sink ridge; 115. First heat sink ridge; 1151. First edge; 1152. Second edge; 116. Second heat sink ridge; 1161. Fifth edge; 1162. Sixth edge; 17. Heat sink slot; 117. First heat sink slot; 1171. Third edge; 1172. Fourth edge; 118. Second heat sink slot; 1181. Seventh edge; 1182. Eighth edge; 8. Buckle; 2. Heat pipe; 100. First pipe section; 200. Second pipe section; 101. First arc segment; 102. Second arc segment; 103. Three arc segments; 104, fourth arc segment; 3, rotor core; 31, assembly hole; 4, rotor shaft; 41, oil outlet shaft segment; 42, connecting shaft segment; 43, stepped shaft end segment; 44, slot; 18, hollow hole; 181, first hollow hole segment; 182, connecting hole segment; 183, second hollow hole segment; 7, oil outlet; 5, stator assembly; 6, cooling fin group; 60, fin group unit; 61, first cooling fin; 62, second cooling fin; 9, oil outlet area; 10, "gourd" shaped special-shaped section; 12, tooth edge structure; 13, permanent magnet; 14, circular hole of cooling fin; 19, air circulation path; 20, center plane of symmetry; 21, tooth groove; 22, first isosceles trapezoid; 23, second isosceles trapezoid. DETAILED DESCRIPTION

[0036] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work should fall within the scope of protection of the present invention. Unless otherwise specified, the technical means used in the embodiments are conventional means well known to those skilled in the art.

[0037] like Figures 1 to 14As shown, the present invention provides a permanent magnet motor with a composite heat dissipation structure, comprising: a rotor shaft 4; a rotor core 3 and a permanent magnet 13, wherein the rotor core 3 is mounted with the permanent magnet 13, the rotor core 3 is sleeved on the rotor shaft 4, and the rotor core 3 is provided with a plurality of assembly holes 31; the assembly holes 31 include a first hole segment and a second hole segment connected to each other, and the first hole segment and the second hole segment are arranged at an angle; a plurality of heat pipes 2, wherein the plurality of heat pipes are mounted in the plurality of assembly holes 31 in a one-to-one correspondence; along the length direction of the heat pipe 2, the heat pipe 2 includes a first pipe segment 100 and a second pipe segment 200 connected to each other, and the first pipe segment 100 and the second pipe segment 200 are arranged at an angle to each other. The heat pipes 2 and the heat pipes 1 are arranged at an angle to each other and are adapted to the first hole section and the second hole section; the heat dissipation fin group 6 includes a plurality of heat dissipation fins 1, and each heat dissipation fin 1 has a plurality of heat pipe holes 111; the two groups of heat dissipation fin groups 6 are mounted on the rotor shaft 4 and are respectively located at the axial ends of the rotor core 3; the plurality of heat pipes 2 are installed in the plurality of heat pipe holes 111 of the heat dissipation fins 1 in a one-to-one correspondence; the heat pipe holes 111 on each heat dissipation fin 1 are arranged closer to the front and rear ends of the rotor shaft 4 and farther away from the axis; the stator assembly 5, the stator assembly 5 is mounted on the outer peripheral side of the rotor core 3 and the two groups of heat dissipation fin groups 6. In this way, the structure of the heat pipes 2 and the heat dissipation fin group 6 is optimized. By using the heat pipes 2 in conjunction with the heat dissipation fin group 6, the rate at which the liquefied refrigerant in the condensation zones at both ends flows back to the inside of the rotor core 3 can be accelerated, thereby improving the heat dissipation effect.

[0038] In this way, the permanent magnet motor with a composite heat dissipation structure provided by the present invention has a better heat dissipation effect through the combination of the heat pipe and the heat dissipation fin group after structural optimization, which is beneficial to improving the performance of the permanent magnet motor.

[0039] Alternatively, as Figure 3 As shown, the plane at the intersection of the first pipe section 100 and the second pipe section 200 forms a symmetric center plane 20, and the first pipe section 100 and the second pipe section 200 are symmetrically arranged relative to the symmetric center plane 20. Since the heat pipe 2 is a rotating structure, ensuring the symmetry of the structural layout is conducive to ensuring its stability during rotation.

[0040] Alternatively, as Figure 3 and Figure 4 As shown, the rotor heat pipe is a symmetrical "V" shaped structure, and the angle between the first pipe section 100 and the second pipe section 200 is 175° to 180°. When the motor rotates at an angular velocity ω, the V-shaped structure will generate a centripetal force along the first pipe section and the second pipe section. The component acceleration is ω 2rsinθ, where r is the distance from the rotor axis to the center of mass of the special-shaped heat pipe. The liquefied refrigerant is simultaneously subjected to capillary forces and a partial acceleration, accelerating the return flow. The radial area where the heat pipe can be installed, from the permanent magnets on the rotor core to the rotor axis, is limited and must not radially exceed the permanent magnets and the rotor shaft. When the first and second sections of the special-shaped heat pipe are arranged axially symmetrically about the rotor core and the heat pipe cross-section is radially symmetrical, the included angle should not be too small. An excessively small included angle can significantly alter the rotor's axial structural distribution, causing the interface to be too far from the axis and the ends to be too close. This change can degrade the mechanical stability of the rotation and reduce the uniformity of the axial electromagnetic field distribution of the rotor core. The included angle is set within the above range based on engineering experience.

[0041] Alternatively, as Figure 4 As shown, the cross section of the outer wall of the heat pipe 2 includes a first arc segment 101, a second arc segment 102, a third arc segment 103 and a fourth arc segment 104 which are connected end to end in sequence. The center of the first arc segment 101 and the center of the third arc segment 103 are on a straight line. The radius of the first arc segment 101 is smaller than the radius of the third arc segment 103. The two ends of the second arc segment 102 are respectively connected to the first end of the first arc segment 101 and the third arc segment 104. 3 is tangent to the first end of the heat pipe 2, and the two ends of the fourth arc segment 104 are tangent to the second end of the first arc segment 101 and the second end of the third arc segment 103 respectively. The centers of the first arc segment 101 and the third arc segment 103 are located on the inner side of the heat pipe 2, and the centers of the second arc segment 102 and the fourth arc segment 104 are located on the outer side of the heat pipe 2. The inner wall of the heat pipe 2 is provided with a plurality of spaced-apart protruding tooth ridge structures 12, and tooth grooves 21 are formed between two adjacent tooth ridge structures. In this way, the present application optimizes the cross-sectional shape of the outer wall of the heat pipe 2, including the first arc segment 101, the second arc segment 102, the third arc segment 103 and the fourth arc segment 104 connected end to end in sequence, arranged in a gourd shape, which is beneficial to increase the contact area between the heat pipe 2 and the heat source, thereby improving the heat dissipation effect and effectively improving the heat exchange efficiency.

[0042] In addition, the gourd-shaped cross-section is also beneficial for reducing the use of refrigerant and improving the centripetal force burden caused by the rotor core 3 when rotating at high speed. Compared with circular heat pipes, the gourd-shaped heat pipe increases the effective contact area of ​​the inner peripheral wall, especially increases the curvature of the first arc. When using the same amount of refrigerant, the refrigerant deposited on the peripheral wall in the first arc region of the shaped heat pipe will obtain a larger inner peripheral wall contact area than a circular heat pipe with an equivalent radius of the shaped heat pipe. Therefore, less refrigerant can achieve the same heat exchange effect, thereby reducing the use of refrigerant. At the same time, the heat pipe is arranged in the same position section of the rotor core from the axis. The centroid of the cross-section of the shaped heat pipe is closer to the rotor axis. After considering the addition of less refrigerant, when the motor rotates, the center of mass of the shaped heat pipe is closer to the axis than the circular heat pipe with an equivalent radius.

[0043] At the same time, the present application also optimizes the structure of the inner wall of the heat pipe 2. After optimization, the inner wall of the heat pipe 2 is provided with a plurality of spaced protruding tooth ridge structures 12, and tooth grooves 21 are formed between two adjacent tooth ridge structures. Compared with the traditional sintered or mesh liquid absorption structure, the tooth ridge structure 12 can improve the capillary force to enhance the adsorption and reflux effect of the refrigerant. The multiple protruding tooth ridges provide more tooth ridge surfaces, which can greatly increase the heat exchange contact area of ​​the refrigerant medium in the pipe, perform well under high heat flux conditions, and have better heat dissipation effect. The tooth ridge structure 12 and the heat pipe are manufactured as one, have better structural stability, and can withstand greater thermal stress and mechanical stress.

[0044] Alternatively, as Figure 3 and Figure 4 As shown, the straight line where the center of the first arc segment 101 and the center of the third arc segment 103 are located forms a reference line, and the second arc segment 102 and the fourth arc segment 104 are symmetrically arranged relative to the reference line.

[0045] Alternatively, as Figure 1 As shown, the third arc segment 103 of the heat pipe 2 is closer to the axis of the rotor core 3 relative to the first arc segment 101 .

[0046] Alternatively, as Figures 3 to 5As shown, along the length of the heat pipe 2, the multiple spaced-apart serrations 12 on the inner circumferential wall of the first pipe segment 100 and the multiple spaced-apart serrations 12 on the inner circumferential wall of the second pipe segment 200 both extend to the center plane of symmetry 20; the multiple serrations 12 on the inner circumferential wall of the first pipe segment 100 and the multiple serrations 12 on the inner circumferential wall of the second pipe segment 200 are symmetrically arranged relative to the center plane of symmetry 20. The rotational structure should ensure the symmetry of the structural layout. Therefore, the serrations 12 of this special-shaped heat pipe should extend to the interface. This maximizes the serration surface area of ​​the serrations 12, thereby maximizing the heat exchange area for the refrigerant, while also ensuring a symmetrical distribution extending to the interface. The cross-sectional shape of the tooth ridge structure 12 includes a first isosceles trapezoid 22 and a second isosceles trapezoid 23 connected to each other; the first isosceles trapezoid 22 is located on the side of the second isosceles trapezoid 23 close to the tooth root; the lower base of the first isosceles trapezoid 22 is close to the tooth root, the upper base of the first isosceles trapezoid 22 is connected to the lower base of the second isosceles trapezoid 23, and the upper base of the second isosceles trapezoid 23 is located close to the tooth top; the lower base of the first isosceles trapezoid 22 is longer than the upper base of the first isosceles trapezoid 22, the lower base of the second isosceles trapezoid 23 is longer than the upper base of the second isosceles trapezoid 23, and the upper base of the first isosceles trapezoid 22 is equal to the lower base of the second isosceles trapezoid 23. Without increasing the manufacturing difficulty, the tooth ridge structure 12 is free of localized thickness reductions in various regions, ensuring its structural strength. When the motor operates at an uneven speed or generates high-order magnetic harmonics on the rotor, the tooth ridge structure 12 can withstand the stress deformation caused by acceleration torque and harmonic electromagnetic torque.

[0047] Optionally, the radius of first arc segment 101 is R; the radius of third arc segment 103 is 2R; the radius of second arc segment 102 and the radius of fourth arc segment 104 are both 2R; the distance between the center of first arc segment 101 and the center of third arc segment 103 is 2.2R; where R>0. In this way, while maintaining the aforementioned advantages of reduced refrigerant usage, reduced centripetal force, and larger refrigerant heat exchange area compared to equivalent circular tubes, the curvature of the heat pipe cross-section can be made more uniform and less locally excessive, which is beneficial for improving the magnetic field distribution described below. In theory, the larger the center distance, the longer the second arc segment and the fourth arc segment, the more tooth edge structures 12 in the area where they are located are, which is also more conducive to heat dissipation. However, this will cause the shortest straight-line distance between the second arc segment and the fourth arc segment to become smaller, that is, narrower. At this time, the channel connecting the inner cavity in the first arc area of ​​the heat pipe and the cavity in the third arc area becomes narrower, which will be detrimental to the refrigerant phase conversion heat transfer of the heat pipe. At the same time, if the heat pipe is too long in the radial direction, it will exceed the limit of the radial area where the heat pipe can be set from the permanent magnet on the rotor core to the rotor axis. Taking all factors into consideration, setting the center distance to 2.2R is a more reasonable specification. The value of R is related to the size of the motor rotor core. Under the premise that the mechanical and electromagnetic properties of the rotor are not affected after the introduction of the special-shaped heat pipe, the value of R tends to increase.

[0048] Alternatively, as Figure 3 As shown, the heat pipe 2 includes a first annular enclosure, a second annular enclosure, a first end plate, a second end plate, and a partition. The second end of the first enclosure is connected to the first end of the second enclosure, the first end plate is connected to the first end of the first enclosure, and the second end plate is connected to the second end of the second enclosure. The partition is arranged at the junction of the first and second enclosures. The first enclosure, the first end plate, and the partition form a first pipe section 100, and the second enclosure, the second end plate, and the partition form a second pipe section 200. The first pipe section 100 has a first enclosed space for filling with refrigerant, and the second pipe section 200 has a second enclosed space for filling with refrigerant. The two enclosed spaces operate independently, and the amount of refrigerant added can be adjusted based on the different heating conditions of the rotor core in the areas where the first and second pipe sections of different motors are located under actual operating conditions to improve heat dissipation capacity.

[0049] Alternatively, as Figure 5 As shown, the cross-sectional shape of the tooth groove 21 includes a first cross-sectional shape and a second cross-sectional shape that are connected. The first cross-sectional shape is arranged close to the bottom of the tooth groove. The first cross-sectional shape is a structure that is wide at the top and narrow at the bottom or a rectangular structure with equal widths at the top and bottom, wherein the side close to the bottom of the tooth groove 21 is the bottom; the shape of the second cross-sectional shape is controlled by the first isosceles trapezoid and the second isosceles trapezoid, and is not specifically limited here.

[0050] The generation of the first cross-sectional shape is affected by the size relationship between L1 and L2, and is driven. When selecting the values ​​of L1 and L2, it should be ensured that the first cross-sectional shape is not narrow at the top and wide at the bottom. The lower bottom of the first cross-sectional shape refers to the bottom close to the tooth root, and the upper bottom refers to the bottom connected to the first cross-sectional shape. The first cross-sectional shape is the main part of the tooth groove of the tooth edge structure 12, and it should be ensured to be a rectangular shape with a wide top and a narrow bottom or equal widths at the top and bottom. This is an open shape, which is conducive to the attachment of liquefied refrigerant. If it is narrow at the top and wide at the bottom, this is a sealed shape, which will be unfavorable for the attachment of liquefied refrigerant. Because the shape of the second cross-sectional shape is controlled by the first isosceles trapezoid and the second isosceles trapezoid, it is driven.

[0051] Alternatively, as Figure 5 As shown, the length of the lower base of the first isosceles trapezoid 22 is L1, and the length of the lower base of the second isosceles trapezoid 23 is L2, L1>L2; Where H is the height of the first isosceles trapezoid 22, and m is the number of ridges that the arc segment should have if it is a complete circle, reflecting the ridge density of the arc segment. In this way, the requirement that the first cross-sectional shape does not appear narrow at the top and wide at the bottom can be met.

[0052] Alternatively, as Figure 4 As shown, the cross-sections of the multiple tooth ridge structures 12 form multiple tooth-shaped surfaces, and at least some of the multiple tooth-shaped surfaces meet the following requirements: a first vector is formed from the midpoint of the tooth bottom of the tooth-shaped surface to the midpoint of the tooth top, and a second vector is formed from the center of the first circular arc segment 101 to the center of the third circular arc segment 103, and the angle between the first vector and the second vector is less than 90°. The tooth-shaped surface of the tooth ridge structure 12 in the area where the second circular arc segment 102, the fourth circular arc segment 104, and the portion of the third circular arc segment 103 connected to the second circular arc segment 102 and the fourth circular arc segment 104 meet the above requirements. That is, the tooth bottom of the tooth ridge surface of the partial tooth-shaped structure points in the direction of the tooth top, and the angle between the direction from the center of the first circular arc segment 101 to the center of the second circular arc segment 102 is less than 90°. When the included angle of some tooth surfaces is less than 90°, it can ensure that the tooth grooves of this part adsorb the liquefied refrigerant. When the motor rotates, the centripetal force in the radial direction will generate a component force along the tooth groove direction. This component force helps to adsorb the liquefied refrigerant in the tooth groove, thereby increasing the contact area between the refrigerant and the inner wall of the heat pipe and the capillary structure, thereby improving the heat transfer efficiency.

[0053] The rotor core 3 is made of many thinner silicon steel sheets that are axially spliced ​​together and welded together after the splicing is completed. During manufacturing or maintenance, connection holes reserved for installing permanent magnets and assembly holes 31 for installing heat pipes can be opened in advance. It is worth noting that since the heat pipe is V-shaped, the radial distances of the assembly holes 31 on each silicon steel sheet from the axis are different in the axial direction. The interface distance is the farthest, and the distances on the silicon steel sheets on the front and rear end faces are the closest. From the interface to the axial direction of the rotor core end face, the radial distance of the assembly hole 31 from the axis decreases gradually. Each silicon steel sheet should determine the radial distance of the assembly hole 31 from the axis according to its position after splicing.

[0054] The first assembly method is given below: It should be noted that the silicon steel sheets and heat pipes are not absolutely rigid, and both have a certain elasticity and deformation capacity. At the same time, the fit between the assembly hole 31 and the heat pipe is not perfect, so there is a certain margin of movement when the heat pipe is inserted into the silicon steel sheet. First, insert the second pipe sections of all heat pipes into all the silicon steel sheets arranged in a predetermined position and order in the area. The heat pipe must be longer than the axial length of the rotor core, so all the silicon steel sheets on the second pipe section can move between the interface of the heat pipe and the end of the heat pipe. The assembly holes 31 of the silicon steel sheets close to the interface in the first pipe section area are farther away, because the ends of all the heat pipes at the end of the first pipe section are evenly arranged circumferentially and closer to the axis. In order to insert the silicon steel sheets of the first pipe section into the first pipe section in sequence, first move all the silicon steel sheets of the second pipe section to the end of the second pipe section. At this time, the radial distance from the end of all the heat pipes evenly arranged circumferentially at the end of the first pipe section to the axis will become larger, so as to facilitate the insertion of the silicon steel sheets close to the interface in the first pipe section area. Similarly, by flexibly moving all the silicon steel sheets of the second pipe section, changing the radial distance of all the heat pipes of the first pipe section, and sequentially inserting the silicon steel sheets from the interface to the end, the assembly is completed.

[0055] The second assembly method: Arrange all the silicon steel sheets in the area where the first pipe section and the second pipe section are located in sequence and fix them softly to form two groups. Place all the heat pipes evenly and circumferentially according to the established arrangement, increase the radial distance of each heat pipe from the axis so that the radial distance between the end of the first pipe section and the second pipe section and the axis is the same as the radial distance between the silicon steel sheet assembly hole 31 at the interface and the axis. At this time, insert the two groups of silicon steel sheets from both ends at the same time, and the heat pipes are guided by the channels formed by the assembly holes 31 at an angle to the axial direction of the silicon steel sheet group and return to the predetermined position to complete the assembly. After the assembly is completed, weld the silicon steel sheets and fill the gap of the rotor assembly hole 31 with silicone grease, liquid gold or other thermal conductive materials.

[0056] The heat pipe 2 structure of the present invention is conducive to reducing the use of refrigerant and improving the centripetal force burden caused by the rotor core 3 when rotating at high speed. Compared with circular heat pipes, the gourd-shaped heat pipe increases the effective contact area of ​​the inner wall, especially increases the curvature of the first arc. When the same amount of refrigerant is used, the refrigerant deposited on the inner wall of the first arc region of the shaped heat pipe will obtain a larger inner wall contact area than a circular heat pipe with an equivalent radius of the shaped heat pipe. Therefore, less refrigerant can achieve the same heat exchange effect, thereby reducing the use of refrigerant. The structure of the heat pipe 2 of the present invention increases the contact area with the heat source and effectively improves the heat exchange efficiency. Compared with a circular pipe with an equivalent radius, the heat pipe increases the arc length by combining the first, second, third and fourth arc segments of the outer wall, and stretches a larger contact area in the axial direction. Since the second arc segment and the fourth arc segment are concave, the heat pipe shape creates a larger contact area with a smaller cross-sectional area.

[0057] Alternatively, as Figures 10 to 12 As shown, the heat dissipation fin includes: a fin body 110; a mounting hole 112, a mounting hole 112 is provided on the axial end surface of the fin body 110; a plurality of heat dissipation holes, a plurality of heat dissipation holes are provided on the axial end surface of the fin body 110, and the plurality of heat dissipation holes are all located on the outer peripheral side of the mounting hole 112; a plurality of heat pipe holes 111, a plurality of heat pipe holes 111 are provided on the axial end surface of the fin body 110, and the plurality of heat pipe holes 111 are all located on the outer peripheral side of the mounting hole 112; the plurality of heat pipe holes 111 and the plurality of heat dissipation holes are arranged at intervals; a plurality of heat dissipation ridges 16, a plurality of heat dissipation ridges 16 are protrudingly provided on the axial end surface of the fin body 110, and the plurality of heat dissipation ridges 16 are located on the outer peripheral side of the mounting hole 112; each heat dissipation ridge 16 is inclined relative to the fin body 110; a plurality of heat dissipation slits 17, a plurality of heat dissipation slits 17 are provided on the axial end surface of the fin body 110, and a heat dissipation slit 17 is correspondingly provided below each heat dissipation ridge 16. The present application optimizes the structure of the heat sink fins. The mounting holes are used to assemble with the rotating shaft of the permanent magnet motor, and the heat pipe holes are used to assemble with the heat pipes of the permanent magnet motor. The function of the heat sink ridges and heat sink slots is to guide the cooling oil to shuttle through the surfaces of each heat sink fin in the heat sink fin group. In the permanent magnet motor provided by the present application, the heat sink fin group 6 assembled by the heat sink fins 1 forms a fluid channel connecting each stacked layer. When the motor rotates, the cooling oil and the air in the shell will flow in the channel according to a certain path rule, that is, the heat sink fin group 6 assembled by the heat sink fins will form a stacked two-phase fluid flat channel. Under the action of centripetal force, the cooling oil can flow along the heat sink ridges and heat sink slots and shuttle through the surfaces of each heat sink fin 1. The rotation of the heat sink fin group 6 generates air runoff and axial flow toward the axis, which will tend to form convection with the cooling oil flowing outward, thereby greatly improving the gas-liquid convection intensity and forcing the cooling oil to flow along the wall to increase the heat exchange efficiency and heat transfer efficiency, reduce the temperature of the permanent magnet motor, and thus help improve the heat dissipation effect of the heat sink fin 1.

[0058] Optionally, the axial end face of the fin body 110 is circular, which facilitates the processing of the heat dissipation fin 1 and facilitates assembly and use with the rotor shaft 4 and stator assembly 5 of the permanent magnet motor. The heat dissipation fin 1 is configured as a thin piece, and the thickness of the fin body 110 is less than the radius of the heat dissipation fin; each heat dissipation ridge 16 is pulled out obliquely at an acute angle to the fin body surface, thereby ensuring that the path of the cooling oil and the air in the shell flowing under the guidance of the heat dissipation ridge will not have a large change in path curvature and can increase the heat dissipation area of ​​the heat dissipation ridge; the thickness of the heat dissipation ridge 16 is equal to the thickness of the fin body 110, which facilitates the processing of the heat dissipation ridge; the heat dissipation ridge 16 is streamlined as a whole, and the heat dissipation slit 17 is streamlined as a whole, so that the length of the heat dissipation ridge is lengthened by the streamline to increase the overall heat dissipation area, while facilitating the flow of air and cooling oil.

[0059] Furthermore, the shape of the projection of each heat dissipation ridge 16 on the fin body 110 is the same as the shape of the corresponding heat dissipation slot 17. In order to ensure that when each heat dissipation fin is assembled into a heat dissipation fin group, the upper edge of the heat dissipation ridge from the adjacent heat dissipation fin can be exactly matched with the lower edge of the heat dissipation slot of the heat dissipation fin, so that the two can be welded or fixed as one. This is conducive to the formation of the fluid channel and at the same time, it is convenient for the processing of the heat dissipation ridge and the heat dissipation slot. The width of each heat dissipation slot is S1, and the width of the projection of the corresponding heat dissipation ridge on the fin body is S2. The degree is S2, S1≤S2; 0≤S2-S1≤ΔS, ΔS is the projection error caused by the thickness of the ridge, that is, the width of each heat dissipation slot 17 is slightly less than or equal to the width of the projection of the corresponding heat dissipation ridge 16 on the fin body 110. Because the ridge has a certain thickness, in order to ensure that when each heat dissipation fin is assembled into a heat dissipation fin group, the upper edge of the heat dissipation ridge of the adjacent heat dissipation fin can be exactly matched with the lower edge of the heat dissipation slot of the heat dissipation fin, so that the two can be welded or fixed as one, such a width setting leaves a certain installation margin. The height of each heat dissipation ridge is the same, in order to ensure that when each heat dissipation fin is assembled into a heat dissipation fin group, the upper edge of the heat dissipation ridge of the adjacent heat dissipation fin can be exactly matched with the lower edge of the heat dissipation slot of the heat dissipation fin, so that the two can be welded or fixed as one. At the same time, it is convenient to process the heat dissipation ridge and to facilitate the assembly of multiple heat dissipation fins into a heat dissipation fin group stack.

[0060] Alternatively, as Figures 10 to 12As shown, the plurality of heat dissipation holes include a plurality of first heat dissipation holes 113 close to the axis of the fin body 110, and a plurality of second heat dissipation holes 114 close to the outer peripheral edge of the fin body 110; a circular mounting hole 112 is provided in the center of the fin body 110; the plurality of first heat dissipation holes 113 are spaced apart around the outer peripheral side of the mounting hole 112; the plurality of heat pipe holes 111 are spaced apart around the outer peripheral side of the plurality of first heat dissipation holes 113; the plurality of second heat dissipation holes 114 are spaced apart around the outer peripheral side of the plurality of heat pipe holes 111; the plurality of heat dissipation ridges 16 include a plurality of first heat dissipation ridges 115 and a plurality of second heat dissipation ridges 116; the plurality of heat dissipation slots 17 include a plurality of first heat dissipation slots 117 and a plurality of second heat dissipation slots 118; the plurality of first heat dissipation ridges 115 are all protruded and arranged on the first axial end surface of the fin body 110, and the plurality of first heat dissipation ridges 115 are spaced apart around the outer peripheral side of the plurality of first heat dissipation holes 113; the first end of each first heat dissipation ridge 115 is close to the first heat dissipation hole 11 3 and are spaced apart from the first heat dissipation hole 113, the second end of each first heat dissipation ridge 115 extends to the heat pipe hole 111; a first heat dissipation slit 117 is correspondingly provided below each first heat dissipation ridge 115; a corresponding first heat dissipation ridge 115, a first heat dissipation slit 117 and a heat pipe hole 111 form a group of first heat dissipation units; a plurality of second heat dissipation ridges 116 are protrudingly provided on the first axial end surface of the fin body 110, a second heat dissipation ridge 116 is provided between two adjacent first heat dissipation ridges 115, the first end of each second heat dissipation ridge 116 is close to the first heat dissipation hole 113 and is spaced apart from the first heat dissipation hole 113, and the second end of each second heat dissipation ridge 116 extends to the second heat dissipation hole 114; a second heat dissipation slit 118 is correspondingly provided below each second heat dissipation ridge 116; a corresponding second heat dissipation ridge 116, a second heat dissipation slit 118 and a second heat dissipation hole 114 form a group of second heat dissipation units. Thus, when the motor rotates, due to the shape of the heat dissipation ridges, in addition to guiding the flow of cooling oil, they also act as a radial flow and axial fan, drawing air from the housing through the outer edges of the heat dissipation fin assembly, creating a countercurrent state between the cooling oil and the housing air within the stacked heat dissipation fin assembly. The provision of the second heat dissipation holes near the outer edges of the fin body 110 further enhances the heat dissipation effect. Once the housing gas approaches the axis, it will axially flow out through the multiple first heat dissipation holes near the axis, removing a portion of the heat from the center interior of the permanent magnet motor's rotor assembly. The first heat dissipation ridges connect the first heat dissipation holes, the fin body, and the heat pipe holes, facilitating the removal of heat from the heat pipes installed within the heat pipe holes through the heat dissipation fins.

[0061] Further, if Figure 10 、 Figure 11 、 Figure 12 ,as well as Figure 14As shown, the length of the first heat dissipation ridge 115 is less than the length of the second heat dissipation ridge 116. In this way, the lengths of the first heat dissipation ridge 115 and the second heat dissipation ridge 116 are reasonably set by comprehensively considering the relative positions of the heat pipe hole, the first heat dissipation hole and the second heat dissipation hole on the fin body; along the axial direction of the fin body, the first heat dissipation ridge 115 includes a first edge 1151 connected to the fin body 110 and a second edge 1152 away from the fin body 110; along the extension direction of the axial end face of the fin body 110, the first heat dissipation slot 117 includes a third edge 1171 connected to the first heat dissipation ridge 115 and a fourth edge 1172 away from the first heat dissipation ridge 115; the first edge 1151 coincides with the third edge 1171 , the second edge 1152 and the fourth edge 1172 have the same shape; the height of each point on the second edge 1152 to the plane where the fin body is located is equal; along the axial direction of the fin body, the second heat dissipation ridge 116 includes a fifth edge 1161 connected to the fin body 110 and a sixth edge 1162 away from the fin body 110; along the extension direction of the axial end face of the fin body 110, the second heat dissipation slot 118 includes a seventh edge 1181 connected to the second heat dissipation ridge and an eighth edge 1182 away from the second heat dissipation ridge; the fifth edge 1161 coincides with the seventh edge 1181, and the sixth edge 1162 and the eighth edge 1182 have the same shape; the height of each point on the sixth edge 1162 to the plane where the fin body is located is equal. In order to ensure that when the heat sink fins are assembled into a heat sink fin group, the upper edges of the heat sink ridges of adjacent heat sink fins can be exactly matched with the lower edges of the heat sink slots of the heat sink fins, so that the two can be welded or fixed into one. At the same time, it is convenient to process the heat sink ridges and to assemble multiple heat sink fins into a heat sink fin group stack.

[0062] Further, if Figure 14 As shown, each adjacent pair of heat fins in the heat fin group 6 forms a fin group unit 60. Each fin group unit 60 includes a first heat fin 61 located below and a second heat fin 62 located above. The second edge 1152 of the first heat fin 61 located below is butted against the fourth edge 1172 of the second heat fin 62 located above. The sixth edge 1162 of the first heat fin 61 located below is butted against the eighth edge 1182 of the second heat fin 62 located above. Each heat fin 1 serves as both the first heat fin 61 of the fin group unit 60 and the second heat fin 62 of the adjacent fin group unit 60. This allows the heat fin group 6 to be connected as one. The adjacent heat fins are connected by the butting of the corresponding edges, forming the aforementioned channels through which vapor and liquid fluids can flow between the heat fins.

[0063] Alternatively, as Figures 10 to 12As shown, each heat dissipation ridge 16 is drawn out obliquely at an acute angle to the fin body 110; the thickness of the heat dissipation ridge 16 is equal to the thickness of the fin body 110; the heat dissipation ridge 16 is streamlined as a whole, and the heat dissipation slot 17 is streamlined as a whole. In this way, it is ensured that the path of the cooling oil and the air in the shell flowing under the guidance of the heat dissipation ridges will not have a large change in path curvature, so that the flow resistance is small, and at the same time the heat dissipation area of ​​the first heat dissipation ridge and the second heat dissipation ridge can be increased, thereby improving the heat dissipation effect; the second heat dissipation ridge is arranged at a radial inclination relative to the fin body; the first axial end face of the fin body has a reference circle located on the outer peripheral side of the plurality of first heat dissipation holes, and the center of the reference circle coincides with the center of the mounting hole; the first end of the first edge 1151 of each first heat dissipation ridge and the first end of the fifth edge 1161 of each second heat dissipation ridge extend to the reference circle and are alternately arranged at equal intervals. The heat dissipation fin serves as a rotating component, which ensures the uniformity of the structural distribution of the rotating object and facilitates the layout, positioning and processing of the plurality of first heat dissipation ridges and the plurality of second heat dissipation ridges on the fin body. Optionally, as Figures 7 to 9 As shown, the rotor shaft 4 is a symmetrical hollow stepped structure, and the rotor shaft 4 has a hollow hole 18; the rotor shaft 4 includes two oil outlet shaft segments 41, a connecting shaft segment 42 connecting the two oil outlet shaft segments, and two stepped shaft end segments 43 respectively located at the outer ends of the two oil outlet shaft segments. The outer diameter of the oil outlet shaft segment 41 is adapted to the mounting hole 112 of the heat sink fin. A groove 44 extending and passing through the axial direction of the oil outlet shaft segment 41 is provided on the outer peripheral wall of the oil outlet shaft segment 41. A plurality of grooves 44 are arranged at intervals around the circumference of the oil outlet shaft segment 41; the outer peripheral wall of the oil outlet shaft segment 41 without a groove is also provided with an oil outlet hole 7 extending along its radial direction. The hole 7 is connected to the hollow hole 18; the hollow hole 18 includes two first hollow hole sections 181 located in the two oil outlet shaft sections 41, a connecting hole section 182 connected between the two first hollow hole sections 181, and two second hollow hole sections 183 located at both ends of the two first hollow hole sections 181. The diameter of the first hollow hole section 181 is larger than the diameter of the second hollow hole section 183, and the diameter of the connecting hole section 182 is equal to the diameter of the second hollow hole section 183. The heat sink fin also includes a clip 8. A plurality of clips 8 are arranged at intervals on the inner peripheral wall of the mounting hole 112. The plurality of clips 8 are arranged in a one-to-one correspondence with the plurality of slots 44. The assembly method of the clip 8 mainly plays a limiting role, and the transmission of rotational torque is a secondary role. The main sources of the transmitted torque are the inserted heat pipe 2 and the heat sink fin 1 attached to the rotor core 3 at the end of the heat sink fin group.

[0064] Furthermore, the curved surface shape of the heat dissipation ridge is determined by the following method: the upper and lower edges of the heat dissipation ridge are fitted using the upper and lower edges of the B-spline surface, usually by differential fitting.

[0065] The initial heatsink ridge surface is established based on the shortest perpendicular distance between the upper and lower edges of the surface. The surface is optimized based on G2 continuity, adjusting the control points from the upper and lower edges inward to ensure G2 continuity where the lower edge of the heatsink ridge meets the lower edge of the heatsink slot of the adjacent fin, G2 continuity where the upper edge of the heatsink ridge meets the upper edge of the heatsink slot of the current fin, and at least G1 continuity when locally constrained (wavefront advancement method).

[0066] The surface is optimized twice by the optimization algorithm to reduce the overall curvature and average curvature of the surface, improve the smoothness, and expand the G2 continuity range. This patent uses an improved genetic algorithm to form the following optimization function: Overall average curvature of the surface:

[0067] Among them, K r is the Gaussian curvature of the surface, A is the area of ​​the ridge, and Ω is the integral area of ​​the surface; the overall curvature formula is:

[0068] K total =∫ Ω K r dA

[0069] Among them, K r is the Gaussian curvature of the surface, A is the area of ​​the ridge, and Ω is the integral area of ​​the surface;

[0070] Laplace smoothness index:

[0071] Among them, P i,j is the control point of the B-spline surface, u and v are the node vectors in the two directions of the surface, and the second-order partial derivative is and It is a measure of the local variation of the surface; these partial derivatives are obtained by taking the second-order derivatives of the basis functions, not by taking the derivatives directly with respect to fixed coordinates; this metric measures the sum of the squares of the Laplace values ​​of the control points on the surface;

[0072] G2 continuous penalty items:

[0073] in, represents the control point P i,j The second-order derivative of is obtained from the second-order derivative of the basis function;

[0074] Fitness function: f fitness =ω1K avg +ω2K total +ω3S Laplacian +λ1K Local +λ2P G2

[0075] Among them, PG2 is the continuous penalty term of surface G2, K Local is the penalty term for local curvature, K avg is the overall mean curvature of the surface, S Laplacian is the surface Laplace smoothness index, K total The overall curvature of the surface, ω1, ω2, ω3, λ1, λ2 are weight coefficients.

[0076] Preferably, after obtaining a set of optimal solutions and surface graphs, it is determined whether to change the node vectors and optimize the surface again to obtain multiple sets of optimal solutions as needed.

[0077] Due to the high rotational speed, ignoring gravitational acceleration and considering only the centripetal force, the cooling oil released from the rotor shaft flows out from the central area of ​​the heat sink fins in the opposite direction of the rotation. Under the action of capillary forces, the cooling oil adheres to the surface of the fin body 110, clinging to the main surface of the fin body 110. It continues to flow in the tangential direction and, guided by the heat sink ridges 16, passes through the streamlined heat sink slots 17 where the heat sink ridges 16 are located and flows into the back of the heat sink fin in the heat sink fin group or into the front or back of the next lower heat sink fin body 110. The cooling oil repeatedly intersperses the combination of each heat sink ridge 16 and the streamlined heat sink slots 17, gradually moving away from the axis until it leaves the heat sink fin. This is a complete oil path for the cooling oil. On the other hand, due to the layout of the heat sink ridges 16 and the direction of rotation, air in the housing is drawn in along the periphery of the heat sink fin group, flows to the inside of the heat sink fin group, and is discharged through the first heat sink hole 113. This is the air path of the heat sink fin group. Because the two-phase fluids convect in opposite directions, the presence of the air path suppresses the cohesive forces of the cooling oil within the fin group 6, thereby preventing the cooling oil from adhering between the fin groups 6 and improving the utilization of the heat exchange surface of the fin group's flow channels. When the gas-liquid ratio between the fin groups is properly controlled, a relatively ideal gas-liquid stratified convection state is achieved between the fin groups 6, causing the cooling oil flowing between the layers to adhere closely to the front and back surfaces of the two fins. The gas in the housing flows through the center of the fin group 6, dividing the cooling oil that may adhere between the layers onto the fin surfaces on both sides.

[0078] Optionally, the permanent magnet motor with a composite heat dissipation structure further includes a casing, in which the rotor shaft 4, the rotor core 3, the permanent magnet 13, the plurality of heat pipes 2, the heat dissipation fin group 6 and the stator assembly 5 are collectively installed.

[0079] The present invention cleverly combines heat pipe heat transfer, oil cooling of the rotor and stator ends, and air convection heat dissipation in the shell through the special heat dissipation fin group, and further deepens the heat dissipation efficiency and heat dissipation intensity of the rotor without changing the existing mainstream permanent magnet motor oil cooling and heat dissipation. Through the clever combination of specific heat dissipation ridges 16 and streamlined heat dissipation slots 17, the oil circuit and air circuit design are optimized, and when the motor is running, the air circuit and oil circuit in the heat dissipation fin group form a relatively stable two-phase stratified convection, thereby improving the heat exchange efficiency and heat transfer efficiency when the rotor dissipates heat. Based on the permanent magnet motor heat dissipation design of the present invention, the heat exchange and heat transfer process are all completed in the motor housing, and the heat exchange between the motor cavity, the rotor and the stator ends and the outside world is completed only through cooling oil. The airtightness of the motor operation is greatly improved, and it is suitable for more complex working conditions, such as sewage, sand and dust and other harsh environments.

[0080] Optionally, the heat pipe 2 is filled with a vaporizable phase-change liquid refrigerant.

[0081] Optionally, the rotor core 3 is made of silicon steel.

[0082] Optionally, the heat dissipation fins 1 are made of copper or aluminum.

[0083] In an optional embodiment provided by the present invention, a permanent magnet motor with a composite heat dissipation structure is provided, comprising a stator assembly, a rotor shaft, a rotor core, multiple cooling fins, and multiple rotor heat pipes. The rotor heat pipe has a symmetrical "V"-shaped structure with an included angle of 175° to 180°. The heat pipe's outer cross-section now exhibits a "gourd"-shaped structure, consisting of a "large circle," a "small circle," and an arc tangent tangent to both. The inner wall of the heat pipe utilizes a toothed, ridged capillary structure that extends along the heat pipe, replacing the wick portion of a conventional heat pipe. The rotor shaft has a symmetrical hollow stepped structure, with smaller channel inner diameters in the middle section and at the ends. The front and rear oil outlet sections are located near the beginning and end, respectively. The channel inner diameters in the oil outlet areas of the shaft near the ends increase relative to the middle and end steps. The oil outlet area of ​​the rotor shaft is uniformly provided with radial oil holes, arranged symmetrically around the shaft axis. The heat sink fin group is composed of multiple heat sink fins arrayed in the axial direction. Circular holes and oblique ridges symmetrically distributed about the center of the circle are circumferentially distributed on the heat sink fins. The oblique ridges are streamlined and are pulled out obliquely from the surface of the heat sink fin body 110, similar to the shape of a turbofan blade. The area below the oblique ridges projected onto the circular surface of the fins presents strip-shaped streamlined strip-shaped slits. The rotor heat pipes are embedded in the rotor core and arranged evenly circumferentially. The heat pipes are symmetrical about the center plane of the rotor, and the "V"-shaped bending surface of the heat pipes is located exactly on the center plane of the rotor. The cross-section of each heat pipe is arranged radially, with the "small circle" of the gourd-shaped heat pipe cross-section away from the rotor axis and the "large circle" close to the rotor axis. The heat sink fins are embedded in the oil cooling areas before and after the shaft and are tightly arrayed along the axial direction. Because the symmetrically distributed "V"-shaped heat pipes have an angle of 0° to 2.5° with the axial direction, the holes reserved for the heat pipes are evenly arranged circumferentially on each fin. As the fins get closer to the front and rear ends, they move further away from the axis. This ensures that all heat pipes angled to the axial direction can fit neatly through all fins. The heat pipes are filled with a vaporizable phase-change liquid refrigerant. The rotor core is made of silicon steel. The cooling fins are made of copper or aluminum.

[0084] The following is a description of the specific embodiments of the present application with reference to the accompanying drawings: Figure 1 and Figure 2 As shown, a permanent magnet motor with a composite heat dissipation structure is provided, comprising a stator assembly 5, a rotor shaft 4, a rotor core 3, a plurality of rotor heat pipes 2, and a heat dissipation fin group 6. Figures 7 to 9 As shown, the rotor shaft 4 is a symmetrical hollow stepped structure, with smaller inner diameters in the middle and at the ends. The diameter of the inner cavity near the oil outlet areas increases in a stepped manner, i.e., the inner diameter of the first hollow hole section 181 is larger than the inner diameter of the second hollow hole section 183, and the inner diameter of the first hollow hole section 181 is larger than the inner diameter of the connecting hole section 182. The oil outlet area of ​​the rotor shaft 4 is provided with uniform radial oil outlet holes 7, which are evenly arranged in the circumferential direction. The oil outlet area 9 where the oil outlet holes 7 are located is evenly distributed with slots 44. Figure 6 The rotor core 3 is shown. The outer side of the rotor core 3 is lined with strip-shaped slots and permanent magnets 13. Heat pipe holes 111 with a "gourd"-shaped cross section are evenly distributed circumferentially on the inner side near the axis. The longitudinally stretched slots of the heat pipe holes 111 are V-shaped, symmetrical about the center plane 20, and each side forms a 2.5° angle with the axis. Each slot is radially symmetrical about a radial line, with the "small circle" of the cross section away from the rotor axis and the "large circle" closer to the rotor axis. The evenly distributed V-shaped heat pipes 2 are embedded in the V-shaped slots and are longer than the rotor core 3. The protruding portions penetrate the heat dissipation fins 6 in the two oil outlet areas 9 and are fixed to them as a whole. The heat sink fin group 6 is composed of a plurality of heat sink fins 1 arranged in an axial array. Each heat sink fin 1 is tightly fitted and fixed together as a whole, and is firmly fixed to the oil outlet area 9 of the shaft by a clip 8. When the motor is running, the rotor core 3, rotor shaft 4, heat pipe 2, and heat sink fin group 6 rotate synchronously. In addition, since it is beyond the scope of this patent research, the connection and assembly structure and assembly process between the rotor shaft and the rotor core are not mentioned in this embodiment. Its connection and assembly method is the same as the current mainstream and common method.

[0085] like Figure 3 and Figure 4 As shown, the heat pipe 2 is "V"-shaped in the longitudinal direction, with an included angle of 175° in this model. The cross section is symmetrical about the center plane of symmetry 20 and is a "gourd"-shaped special-shaped section 10. The capillary structure inside the tube is a toothed ridge structure 12 that is integrated with the heat pipe 2, and the tube is filled with a refrigerant that evaporates during phase change. The heat pipe 2 embedded in the rotor core 3 is radially symmetrical. The "small circle" of the "gourd"-shaped heat pipe is away from the axis and close to the center of symmetry of the permanent magnet 13, while the "large circle" is close to the axis. This layout can reduce the amount of refrigerant used, and when the motor runs at high speed, the less refrigerant in the "small circle" can improve the centripetal pressure of the motor. The "large circle" and the toothed ridge structure 12 can effectively increase the effective contact area of ​​the refrigerant before and after the phase change, thereby improving the heat transfer efficiency.

[0086] The heat dissipation fin group 6 includes a plurality of heat dissipation fins 1, such as Figure 10 As shown, the outer periphery of the heat sink 1 and the portion near the axis are evenly distributed along the circumference with circular heat sink holes 14, namely, the second heat sink hole 114 and the first heat sink hole 113. Each heat sink fin 1 also has a "gourd"-shaped hole reserved for the insertion of the heat pipe, namely, the heat pipe hole 111. Since the heat pipe 2 is at a certain angle to the axis, the distance between the heat pipe hole 111 and the axis of each heat sink fin 1 in the heat sink fin group 6 is different to facilitate the insertion of the heat pipe. Streamlined oblique heat sink ridges 16 with connecting holes are evenly distributed circumferentially around these holes. The shape of the ridges is similar to that of a "turbofan" blade. The streamlined oblique heat sink ridges 16 are projected onto the lower area of ​​the circular surface of the fin body 110, which also has streamlined heat sink slits 17.

[0087] When the area around permanent magnets 13 of the motor's working rotor or the rotor core 3 overheats, the refrigerant in heat pipe 2 absorbs heat and transforms into a gas. Due to the temperature difference between the gas and the condensation zone of oil outlet area 9, the gas flows toward the oil outlet area 9 and condenses under the influence of temperature convection. The condensed refrigerant liquefies, with some adsorbed in the grooves of tooth ridge structure 12, while others accumulate in the "small circle" of the heat pipe. Under the influence of capillary force and the axial component of the centripetal force of motor rotation, both parts of the refrigerant return to the interior of the rotor core 3 and near the permanent magnets 13 for the next heat transfer cycle. This constitutes one cycle of the heat pipe operation.

[0088] The heat transferred from the inside of the rotor core 3 through the heat pipe is transferred to the heat dissipation fin group 6. The cooling oil is introduced into the hollow hole 18 of the rotor shaft 4. The cooling oil is discharged through the oil outlet 7 of the oil cooling area and is thrown into the interlayer gap of the heat dissipation fin group 6 under the action of centripetal force, absorbing the heat pipe 2 and the heat transferred to the heat dissipation fin 1. After absorbing heat, the cooling oil leaves the heat dissipation fin group 6 under the action of centripetal force and is thrown to the winding end of the stator assembly 5 to cool it. After absorbing the heat from the winding end of the rotor and stator assembly 5, it leaves the motor through the channel in the motor housing and enters the next cycle. During the oil cooling process, the cooling oil will shuttle back and forth through the streamlined oblique heat dissipation ridges 16 and the streamlined heat dissipation slits 17, thereby increasing the oil path and improving the heat dissipation efficiency. At the same time, the streamlined oblique heat dissipation ridges 16 act as a fan, sucking the gas in the casing from the periphery of the heat dissipation fin group 6, and flowing out from the heat dissipation fin circular hole 14 near the axis of the heat dissipation fin 1 against the direction of the oil circuit in the heat dissipation fin 1. The air flow direction in the casing is shown in the air circulation path 19.

[0089] The heat sink fins 1 of the present invention incorporate streamlined, oblique heat dissipation ridges 16 in addition to the existing hole structure, and streamlined heat dissipation slots 17 are provided beneath the streamlined, oblique heat dissipation ridges. Compared to conventional heat sink fins 1, this increases the amount of cooling oil flowing through the array of fins 1, guided by the streamlined, oblique heat dissipation ridges 16. This increases the oil's travel distance and enhances heat exchange between the oil and the fins 1. This structure also enhances convection between air and cooling oil. Under certain conditions, this creates a two-phase laminar convection model of air and cooling oil within the housing, further facilitating heat exchange and improving heat transfer efficiency.

[0090] On the basis of the above technical solution, compared with the prior art, the advantages of the present invention are:

[0091] The rotor is cooled by a "V"-shaped heat pipe, and the centripetal force during rotor rotation is combined with the capillary force of the existing tooth edge structure to allow the refrigerant to flow back to the inside of the rotor core and around the permanent magnets more quickly after being cooled in the oil outlet area.

[0092] The V-shaped heat pipe has a gourd-shaped, skewed cross-section, with the "small circle" located away from the axis and the "large circle" located closer to the axis. Compared to traditional heat pipes, this structure reduces refrigerant usage and increases the effective contact area during steam heat transfer. Furthermore, this skewed structure takes into account the rotor's magnetic circuit distribution, placing the heat pipe in an area with less magnetic flux, allowing it to conform to the magnetic circuit and suppressing any additional magnetic leakage introduced by the heat pipe.

[0093] The heat sink fins of this invention incorporate streamlined, oblique ridges in the existing hole structure, with gaps below them. Compared to conventional heat sink fins, these ridges guide the cooling oil through the array of fins, increasing the oil's travel distance and enhancing heat exchange between the oil and the fins. This structure also enhances convection between the air and the cooling oil, creating a two-phase laminar convection model of air and cooling oil within the housing under certain conditions.

[0094] The structure of the present invention does not destroy the original oil cooling function of the stator winding end. Under the action of centripetal force, the cooling oil and the air in the shell shuttle between the various cooling fins through the channels formed by the cooling fin group, thereby enhancing heat exchange. After leaving the cooling fins, the cooling oil will also be thrown to the end of the stator winding to cool the winding end.

[0095] The permanent magnet motor heat dissipation design based on this invention completes all heat exchange and transfer within the motor housing. Heat exchange between the motor cavity, rotor, and stator ends and the outside world is accomplished solely through cooling oil. This significantly improves the airtightness of the motor's operation, making it suitable for more complex operating conditions, such as those in harsh environments like sewage and dust.

[0096] The above are merely specific embodiments of the present application to enable those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be 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 present application. Therefore, the present application will not be limited to the embodiments shown herein, but rather is intended to conform to the widest scope consistent with the principles and novel features of the present application.

[0097] Unless otherwise defined, the technical or scientific terms used in this disclosure should have the usual meanings understood by people with ordinary skills in the field to which this disclosure belongs. The words "first", "second" and similar words used in this disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, words such as "one", "an" or "the" do not indicate a quantity limitation, but rather indicate the existence of at least one. Words such as "include" or "comprise" mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "connect" or "connected" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

Claims

1. A permanent magnet motor with a composite heat dissipation structure, characterized in that: include: a rotor shaft (4); A rotor core (3) and a permanent magnet (13), wherein the permanent magnet (13) is mounted on the rotor core (3), the rotor core (3) is sleeved on the rotor shaft (4), and a plurality of assembly holes (31) are provided on the rotor core (3); the assembly holes (31) include a first hole segment and a second hole segment connected to each other, and the first hole segment and the second hole segment are arranged at an angle; A plurality of heat pipes (2), the plurality of heat pipes being mounted in a one-to-one correspondence in the plurality of assembly holes (31); along the length direction of the heat pipe (2), the heat pipe (2) comprises a first pipe section (100) and a second pipe section (200) connected to each other, the first pipe section (100) and the second pipe section (200) being arranged at an angle and being adapted to the first hole section and the second hole section; A heat dissipation fin group (6), the heat dissipation fin group (6) comprising a plurality of heat dissipation fins (1), each of the heat dissipation fins (1) having a plurality of heat pipe holes (111); two groups of the heat dissipation fin groups (6) are mounted on the rotor shaft (4) and are respectively located at the axial ends of the rotor core (3); a plurality of the heat pipes (2) are mounted in a one-to-one correspondence in the plurality of heat pipe holes (111) of the heat dissipation fins (1); the heat pipe holes (111) on each heat dissipation fin (1) are arranged closer to the front and rear ends of the rotor shaft (4) and further away from the axis as the heat dissipation fins (1) are arranged; A stator assembly (5), the stator assembly (5) being sleeved on the outer peripheral sides of the rotor core (3) and the two groups of heat dissipation fin groups (6); The heat dissipation fins include: Fin body (110); A mounting hole (112), wherein the mounting hole (112) is provided on the axial end surface of the fin body (110); A plurality of heat dissipation holes, wherein the axial end surface of the fin body (110) is provided with a plurality of heat dissipation holes, and the plurality of heat dissipation holes are all located on the outer peripheral side of the mounting hole (112); A plurality of heat pipe holes (111), wherein the axial end surface of the fin body (110) is provided with the plurality of heat pipe holes (111), and the plurality of heat pipe holes (111) are all located on the outer peripheral side of the mounting hole (112); the plurality of heat pipe holes (111) and the plurality of heat dissipation holes are all arranged at intervals; A plurality of heat dissipation ridges (16), wherein the plurality of heat dissipation ridges (16) are protrudingly provided on the axial end surface of the fin body (110), and the plurality of heat dissipation ridges (16) are located on the outer peripheral side of the mounting hole (112); each of the heat dissipation ridges (16) is arranged obliquely relative to the fin body (110); A plurality of heat dissipation holes (17), wherein the axial end surface of the fin body (110) is provided with a plurality of heat dissipation holes (17), and a corresponding heat dissipation hole (17) is provided below each heat dissipation ridge (16); Each heat dissipation ridge (16) is drawn out obliquely at an acute angle to the surface of the fin body (110); the thickness of the heat dissipation ridge (16) is equal to the thickness of the fin body (110); The heat dissipation ridge (16) is arranged in a streamlined shape as a whole, and the heat dissipation slot hole (17) is arranged in a streamlined shape as a whole; The rotor shaft (4) is a symmetrical hollow stepped structure, and the rotor shaft (4) has a hollow hole (18); the rotor shaft (4) includes two oil outlet shaft segments (41), a connecting shaft segment (42) connecting the two oil outlet shaft segments, and two stepped shaft end segments (43) respectively located at the outer ends of the two oil outlet shaft segments, the outer diameter of the oil outlet shaft segment (41) is adapted to the mounting hole (112) of the heat sink fin, and a groove (44) extending and penetrating along the axial direction of the oil outlet shaft segment (41) is provided on the outer peripheral wall of the oil outlet shaft segment (41), and a plurality of grooves (44) are arranged at intervals around the circumference of the oil outlet shaft segment (41); the outer peripheral wall of the oil outlet shaft segment (41) not provided with the groove is also provided with an oil outlet hole (7) extending along the radial direction thereof, and the oil outlet hole (7) is communicated with the hollow hole (18); The hollow hole (18) comprises two first hollow hole sections (181) located in the two oil outlet shaft sections (41), a connecting hole section (182) connected between the two first hollow hole sections (181), and two second hollow hole sections (183) located at both ends of the two first hollow hole sections (181), wherein the diameter of the first hollow hole section (181) is larger than the diameter of the second hollow hole section (183), and the diameter of the connecting hole section (182) is equal to the diameter of the second hollow hole section (183); The heat dissipation fin further comprises a buckle (8), and a plurality of the buckles (8) are arranged at intervals on the inner peripheral wall of the mounting hole (112), and the plurality of buckles (8) are arranged in a one-to-one correspondence with the plurality of slots (44).

2. The permanent magnet motor according to claim 1, characterized in that The heat pipe has a symmetrical "V"-shaped structure, and the angle between the first pipe section (100) and the second pipe section (200) is 175° to 180°.

3. The permanent magnet motor according to claim 1, characterized in that: The cross section of the outer peripheral wall of the heat pipe (2) comprises a first arc segment (101), a second arc segment (102), a third arc segment (103) and a fourth arc segment (104) connected in sequence end to end, the center of the first arc segment (101) and the center of the third arc segment (103) are on a straight line, the radius of the first arc segment (101) is smaller than the radius of the third arc segment (103), and the two ends of the second arc segment (102) are respectively aligned with the first arc segment. The first end of the (101) is tangent to the first end of the third circular arc segment (103), and the two ends of the fourth circular arc segment (104) are tangent to the second end of the first circular arc segment (101) and the second end of the third circular arc segment (103), respectively. The centers of the first circular arc segment (101) and the third circular arc segment (103) are located inside the heat pipe (2), and the centers of the second circular arc segment (102) and the fourth circular arc segment (104) are located outside the heat pipe (2). A plurality of spaced-apart protruding tooth ridge structures (12) are provided on the inner peripheral wall of the heat pipe (2), and tooth grooves (21) are formed between two adjacent tooth ridge structures (12).

4. The permanent magnet motor according to claim 3, characterized in that: The third circular arc segment (103) of the heat pipe (2) is closer to the axis of the rotor core (3) relative to the first circular arc segment (101).

5. The permanent magnet motor according to claim 2, characterized in that: Along the length direction of the heat pipe (2), the multiple spaced-apart tooth ridge structures (12) on the inner peripheral wall of the first pipe section (100) and the multiple spaced-apart tooth ridge structures (12) on the inner peripheral wall of the second pipe section (200) both extend to the symmetry center plane (20); The multiple tooth ridge structures (12) on the inner peripheral wall of the first pipe section (100) and the multiple tooth ridge structures (12) on the inner peripheral wall of the second pipe section (200) are symmetrically arranged relative to the symmetry center plane (20); The cross-sectional shape of the tooth ridge structure (12) includes a first isosceles trapezoid (22) and a second isosceles trapezoid (23) connected to each other; the first isosceles trapezoid (22) is located on the side of the second isosceles trapezoid (23) close to the tooth root; the lower base of the first isosceles trapezoid (22) is close to the tooth root, the upper base of the first isosceles trapezoid (22) is connected to the lower base of the second isosceles trapezoid (23), and the upper base of the second isosceles trapezoid (23) is located on the side close to the tooth top; the length of the lower base of the first isosceles trapezoid (22) is greater than the length of the upper base of the first isosceles trapezoid (22), the length of the lower base of the second isosceles trapezoid (23) is greater than the length of the upper base of the second isosceles trapezoid (23), and the length of the upper base of the first isosceles trapezoid (22) is equal to the length of the lower base of the second isosceles trapezoid (23).

6. The permanent magnet motor according to claim 1, characterized in that: The plurality of heat dissipation holes include a plurality of first heat dissipation holes (113) close to the axis of the fin body (110), and a plurality of second heat dissipation holes (114) close to the outer peripheral edge of the fin body (110); The center of the fin body (110) is provided with a circular mounting hole (112); a plurality of the first heat dissipation holes (113) are spaced around the outer periphery of the mounting hole (112); a plurality of the heat pipe holes (111) are spaced around the outer periphery of the plurality of the first heat dissipation holes (113); and a plurality of the second heat dissipation holes (114) are spaced around the outer periphery of the plurality of the heat pipe holes (111). The plurality of heat dissipation ridges (16) include a plurality of first heat dissipation ridges (115) and a plurality of second heat dissipation ridges (116); the plurality of heat dissipation slots (17) include a plurality of first heat dissipation slots (117) and a plurality of second heat dissipation slots (118); A plurality of first heat dissipation ridges (115) are all protrudingly arranged on the first axial end surface of the fin body (110), and the plurality of first heat dissipation ridges (115) are spaced around the outer peripheral side of the plurality of first heat dissipation holes (113); the first end of each first heat dissipation ridge (115) is close to the first heat dissipation hole (113) and spaced from the first heat dissipation hole (113), and the second end of each first heat dissipation ridge (115) extends to the heat pipe hole (111); a first heat dissipation slot (117) is correspondingly provided below each first heat dissipation ridge (115); a corresponding first heat dissipation ridge (115), a first heat dissipation slot (117) and a heat pipe hole (111) form a group of first heat dissipation units; A plurality of second heat dissipation ridges (116) are protrudingly arranged on the first axial end surface of the fin body (110); a second heat dissipation ridge (116) is provided between two adjacent first heat dissipation ridges (115); a first end of each second heat dissipation ridge (116) is close to the first heat dissipation hole (113) and is spaced apart from the first heat dissipation hole (113); a second heat dissipation slit (118) is correspondingly provided below each second heat dissipation ridge (116); a corresponding second heat dissipation ridge (116), a second heat dissipation slit (118) and a second heat dissipation hole (114) form a group of second heat dissipation units.

7. The permanent magnet motor according to claim 6, characterized in that: Along the axial direction of the fin body, the first heat dissipation ridge (115) includes a first edge (1151) connected to the fin body (110) and a second edge (1152) away from the fin body; along the extension direction of the axial end face of the fin body (110), the first heat dissipation slot (117) includes a third edge (1171) connected to the first heat dissipation ridge (115) and a fourth edge (1172) away from the first heat dissipation ridge (115); the first edge (1151) and the third edge (1171) coincide with each other, and the second edge (1152) and the fourth edge (1172) have the same shape; the heights of each point on the second edge (1152) to the plane where the fin body (110) is located are equal; Along the axial direction of the fin body (110), the second heat dissipation ridge (116) includes a fifth edge (1161) connected to the fin body (110) and a sixth edge (1162) away from the fin body (110); along the extension direction of the axial end face of the fin body (110), the second heat dissipation slot (118) includes a seventh edge (1181) connected to the second heat dissipation ridge (116) and an eighth edge (1182) away from the second heat dissipation ridge (116); the fifth edge (1161) and the seventh edge (1181) coincide with each other, and the sixth edge (1162) and the eighth edge (1182) have the same shape; the heights of each point on the sixth edge (1162) to the plane where the fin body (110) is located are equal; Each adjacent two heat dissipation fins in the heat dissipation fin group (6) form a group of fin group units (60), and each group of fin group units (60) includes a first heat dissipation fin (61) located below and a second heat dissipation fin (62) located above, the second edge (1152) of the first heat dissipation fin (61) located below is connected to the fourth edge (1172) of the second heat dissipation fin (62) located above, and the sixth edge (1162) of the first heat dissipation fin (61) located below is connected to the eighth edge (1182) of the second heat dissipation fin (62) located above.

8. The permanent magnet motor according to claim 1, characterized in that: The heat pipe (2) is filled with a vaporizable phase-change liquid refrigerant; The rotor core (3) is made of silicon steel; The heat dissipation fins (1) are made of copper or aluminum.

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