A permanent magnet synchronous motor with active heat dissipation function

Abstract

This invention discloses a permanent magnet synchronous motor with active heat dissipation function, belonging to the field of permanent magnet synchronous motor technology. The permanent magnet synchronous motor includes a body, a drive unit, a temperature control device, and a compensation device. The body has a drive cavity, and the drive unit is placed inside the drive cavity. The temperature control device is connected to the body, and the compensation device is connected to the temperature control device. The temperature control device is used to actively dissipate heat from the body. The body serves as the main supporting foundation for installing and fixing other components. By energizing the drive unit, torque is output under the influence of a magnetic field. During continuous torque output, the temperature control device actively dissipates heat from the drive unit inside the body to ensure operational stability. The compensation device automatically compensates for heat dissipation, improving the uniformity of heat dissipation.

Description

Technical Field

[0001] This invention relates to the field of permanent magnet synchronous motor technology, specifically a permanent magnet synchronous motor with active heat dissipation function. Background Technology

[0002] Permanent magnet synchronous motors (PMSMs) have advantages such as high torque density and high control precision, and are widely used in various fields for power supply, especially in aviation conditions. However, conventional PMSMs cannot meet the thermal management requirements of the extreme environments in aviation.

[0003] During power supply, due to the uneven heat distribution inside the motor, conventional oil-immersed cooling can only provide equal-power cooling, easily causing localized heat accumulation inside the motor, thereby increasing copper losses and affecting the motor's service life. Furthermore, the differences between the internal hot zones of the motor vary under different operating conditions; a fixed cooling supply cannot adjust the cooling efficiency of these hot zones in real time according to the operating conditions. Summary of the Invention

[0004] The purpose of this invention is to provide a permanent magnet synchronous motor with active heat dissipation function to solve the problems mentioned in the prior art.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] The permanent magnet synchronous motor includes a body, a drive unit, a temperature control device, and a compensation device. The body has a drive cavity, the drive unit is placed inside the drive cavity, the temperature control device is connected to the body, and the compensation device is connected to the temperature control device. The temperature control device is used to actively dissipate heat from the body.

[0007] The main body serves as the primary support foundation for mounting and securing other devices. By energizing the drive unit, torque is output under the influence of a magnetic field. During continuous torque output, the temperature control device actively dissipates heat from the drive unit inside the main body to ensure operational stability. A compensation device automatically compensates for heat dissipation, improving heat dissipation uniformity.

[0008] Furthermore, the machine body is provided with a liquid inlet, and the drive device includes a rotor, a drive shaft and a stator. The drive shaft and the drive cavity are rotatably connected. The rotor is sleeved on the drive shaft, and the stator is located on the outer layer of the rotor and placed inside the drive cavity.

[0009] The temperature control device includes a circulating pump, a mounting plate, a ring pipe, and a guide pipe. Several mounting plates are arranged around the circumference of the drive cavity, and several ring pipes are arranged along the outer circle formed by the mounting plates. Cooling intervals are provided between adjacent ring pipes, and the length of the cooling intervals is gradually changed. The stator is in contact with the mounting plate. The guide pipe is connected to the liquid inlet pipe. The liquid delivery direction of the guide pipe is along the axis of the power output of the drive shaft. The guide pipe is connected to the ring pipe.

[0010] Coolant is supplied through the inlet. The rotor, mounted on the drive shaft, has permanent magnets. When power is supplied to the stator windings, the magnetic field generated by the stator interacts with the magnetic field generated on the permanent magnets of the rotor, thereby driving the drive shaft to output torque. Active cooling is achieved by a circulating pump. After the coolant enters the guide pipe through the inlet, it is pumped into each annular pipe for cooling. The space between two adjacent annular pipes is defined as the cooling zone. The length of the cooling zone is gradually adjusted according to the temperature gradient inside the drive cavity, thereby regulating the local cooling supply and ensuring temperature uniformity inside the drive cavity.

[0011] Furthermore, the length of the cooling zone is set to decrease gradually along the liquid delivery direction of the guide pipe.

[0012] During the output torque process, the temperature in the drive chamber decreases from the rotor to the stator and increases along the output direction of the drive shaft. The length of the cooling zone decreases along the liquid delivery direction of the guide tube. That is, the closer to the output end of the drive shaft, the shorter the length of the cooling zone, which makes the contact heat exchange area larger per unit time and improves the heat exchange efficiency.

[0013] Furthermore, the guide pipe is provided with a main channel, which is connected to the inlet pipe. Several branch channels are provided at the lower end of the main channel, and the branch channels are connected to the adjacent ring pipe respectively. The compensation device includes a cut-off plate. A rotating groove is provided on one side of the branch channel, which is connected to the main channel. The cut-off plate and the rotating groove are rotatably connected. One end of the cut-off plate is inserted into the main channel, and the cut-off plate is arranged at an angle.

[0014] The coolant is connected to the inlet via the main channel and injected into each ring pipe through the branch channels. The ring pipes and mounting plates are supported by materials with high thermal conductivity, which can cool the coolant in the drive cavity and the stator coils respectively. The branch channels and rotating grooves are arranged sequentially along the liquid delivery direction of the guide pipe. Under different power consumption conditions, the temperature difference between adjacent cooling zones is different. The higher the temperature, the greater the temperature difference between adjacent cooling zones. The amount of coolant entering each ring pipe is adjusted by setting a flow cutter plate. When the coolant flows along the main channel, the flow cutter plate is tilted downward to cut off the coolant and guide it into the branch channel below the flow cutter plate. The remaining part continues to flow forward, thereby making real-time adjustments.

[0015] Furthermore, the compensation device also includes an upper curved plate and a lower curved plate. One side of the upper curved plate is fastened to the lower curved plate. One end of the upper curved plate and the lower curved plate are fastened to the baffle plate, and the other end abuts against the rotating groove. The thermal expansion coefficient of the upper curved plate is greater than that of the lower curved plate.

[0016] By setting up upper and lower curved plates and inserting them into each cooling zone, they come into contact with the coolant for heat exchange. The plates are designed based on their different coefficients of thermal expansion, with the one with the higher coefficient of thermal expansion contacting the rotating trough. Initially, the upper and lower curved plates are flat. When heated and expanding, because the upper and lower curved plates are fixed on one side and one end is tightly connected to the baffle plate, the coefficient of thermal expansion of the upper plate is greater than that of the lower plate. Since they are both placed in the drive chamber, when they come into contact with the coolant and rise to the same temperature, the expansion of the upper plate is greater than that of the lower plate. By contacting the rotating trough, the baffle plate is pushed to rotate, increasing the angle between the baffle plate and the horizontal plane, thereby increasing the vertical flow area and improving the flow rate. By automatically adjusting the local cooling capacity according to the temperature within the cooling zone, cooling uniformity is ensured.

[0017] Furthermore, a rotating shaft is fitted onto the throttling plate, and the throttling plate is rotatably connected to the rotating groove through the rotating shaft.

[0018] The throttling plate is guided by a rotating shaft, with the outer surface of the shaft and the rotating groove maintaining contact for localized sealing, preventing leakage during throttling and ensuring accurate cold air distribution. The throttling plate is eccentrically positioned at its rotation center, with the lower section shorter than the upper section. This ensures that, initially, the portion inserted into the main flow channel maintains a small angle with the horizontal plane, facilitating subsequent adjustments.

[0019] Furthermore, the machine body is provided with a circulation channel, which is connected to the liquid inlet pipe. The outer ring of the drive shaft is provided with several guide seats, the outer side of the guide seats is provided with an arc surface, the inner side of the guide seats is provided with a horizontal flow surface, the drive shaft is provided with a drainage channel, which is connected to the circulation channel pipe, and the outer ring of the drainage channel is provided with several drain ports.

[0020] By setting up a circulating channel, the coolant flowing out of the inlet is diverted and enters the guide channel. During the rotation of the drive shaft, centrifugal force causes the coolant to be centrifugally discharged from the drain port, and convective heat transfer occurs to the high-temperature coolant in the drive chamber. Simultaneously, by uniformly arranging guide seats around the drive shaft, the forces are balanced. The arc-shaped surface and the horizontal flow surface are arranged in an arc shape with the same starting and ending points, but the arc-shaped surface has a greater curvature. This results in a faster flow velocity of the coolant flowing through the arc-shaped surface, meaning the cooling pressure is lower on the outer arc-shaped surface. This causes the coolant in the inner horizontal flow surface to flow outwards, improving the radial flow performance of the coolant and ensuring cooling efficiency.

[0021] As an optimization, the machine body is equipped with a liquid outlet, the end of the distribution channel is connected to the liquid outlet pipe, the drive chamber is connected to the liquid outlet pipe, and the end of the liquid outlet is connected to the circulation pump pipe. By setting the liquid outlet, the liquid that has been heated after participating in the cooling is diverted, that is, the liquid at the outlet of the distribution channel and inside the drive chamber flows out through the liquid outlet, is cooled, and then re-enters the liquid inlet through the circulation pump for a new round of cooling.

[0022] As an optimization, several heat exchange surfaces are provided on the inner side of the ring pipe, and these surfaces contact the mounting plate. By setting up these heat exchange surfaces, heat exchange is conducted between the surfaces and the mounting plate, thereby improving heat exchange efficiency.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows: When the coolant enters the guide pipe through the inlet, it is pumped into each ring pipe along the guide pipe for cooling. The space between two adjacent ring pipes is defined as the cooling zone. The length of the cooling zone is gradually adjusted according to the temperature gradient inside the drive chamber, thereby regulating the local cooling supply and ensuring the temperature uniformity inside the drive chamber. The length of the cooling zone decreases along the liquid delivery direction of the guide pipe, that is, the closer to the output end of the drive shaft, the shorter the length of the cooling zone, so that the contact heat exchange area is larger per unit time, improving the heat exchange efficiency. Under different power consumption conditions, the temperature difference between adjacent cooling zones is different. The higher the temperature, the greater the temperature difference between adjacent cooling zones. By setting a baffle plate to control the coolant entering each ring pipe... The flow rate is adjusted. When the coolant flows along the main channel, the baffle plate is tilted downwards to intercept the coolant and guide it into the branch channel below the baffle plate. The remaining part continues to flow forward, thus allowing for real-time adjustment. When the coolant expands due to heat, the upper and lower curved plates are fixed on one side and one end is tightly connected to the baffle plate. The thermal expansion coefficient of the upper curved plate is greater than that of the lower curved plate. Since they are both placed in the drive chamber, when they come into contact with the coolant and exchange heat to reach the same temperature, the expansion of the upper curved plate is greater than that of the lower curved plate. By abutting against the rotating groove, the baffle plate is pushed to rotate, increasing the angle between the baffle plate and the horizontal plane, thereby increasing the vertical interception area and improving the interception flow rate. By automatically adjusting the local cooling capacity according to the temperature in the cooling zone, the cooling uniformity is ensured. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0025] Figure 2 This is a schematic diagram of the internal structure of the drive cavity of the present invention;

[0026] Figure 3 This is a schematic diagram of the gradual change in the cooling range of the present invention;

[0027] Figure 4 This is a schematic diagram of the ring pipe structure of the present invention;

[0028] Figure 5 This is a schematic diagram of the coolant flow path according to the present invention;

[0029] Figure 6 for Figure 5 A magnified view of a portion of the view;

[0030] Figure 7 This is a schematic diagram of the rotor and guide seat transmission of the present invention.

[0031] In the diagram: 1. Body; 11. Drive chamber; 12. Liquid inlet; 13. Circulation channel; 14. Liquid outlet; 2. Drive unit; 21. Rotor; 22. Drive shaft; 221. Drain channel; 222. Drain port; 23. Stator; 24. Guide seat; 241. Arc surface; 242. Horizontal surface; 3. Temperature control device; 31. Circulation pump; 32. Mounting plate; 33. Ring pipe; 331. Heat exchange surface; 34. Guide pipe; 341. Main channel; 342. Branch channel; 343. Rotary trough; 4. Compensation device; 41. Cut-off plate; 42. Upper curved plate; 43. Lower curved plate; 44. Rotating shaft. Detailed Implementation

[0032] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] Example: Figures 1-7 As shown, the present invention provides a permanent magnet synchronous motor technology solution with active heat dissipation function.

[0034] The permanent magnet synchronous motor includes a body 1, a drive unit 2, a temperature control device 3, and a compensation device 4. The body 1 is provided with a drive cavity 11, the drive unit 2 is placed in the drive cavity 11, the temperature control device 3 is connected to the body 1, and the compensation device 4 is connected to the temperature control device 3. The temperature control device 3 is used to actively dissipate heat from the body 1.

[0035] The main body 1 serves as the primary support base for mounting and securing other devices. By energizing the drive device 2, torque is output under the influence of a magnetic field. During the continuous output of torque, the temperature control device 3 actively dissipates heat from the drive device 2 inside the main body 1 to ensure operational stability. The compensation device 4 automatically compensates for the heat dissipation, improving the uniformity of heat dissipation.

[0036] Furthermore, the machine body 1 is provided with a liquid inlet 12, and the drive device 2 includes a rotor 21, a drive shaft 22 and a stator 23. The drive shaft 22 and the drive cavity 11 are rotatably connected. The rotor 21 is sleeved on the drive shaft 22, and the stator 23 is located on the outer layer of the rotor 21 and placed inside the drive cavity 11.

[0037] The temperature control device 3 includes a circulating pump 31, a mounting plate 32, a ring pipe 33, and a guide pipe 34. Several mounting plates 32 are arranged around the drive cavity 11. Several ring pipes 33 are arranged along the outer circle formed by the mounting plates 32. A cooling interval is provided between adjacent ring pipes 33. The length of the cooling interval is gradually changed. The stator 23 is in contact with the mounting plate 32. The guide pipe 34 is connected to the liquid inlet 12. The liquid delivery direction of the guide pipe 34 is along the axis of the power output of the drive shaft 22. The guide pipe 34 is connected to the ring pipe 33.

[0038] Coolant is supplied through inlet 12. Rotor 21 is mounted on drive shaft 22 and has permanent magnets on it. When power is supplied to the windings of stator 23, the magnetic field generated by stator 23 and the magnetic field generated by the permanent magnets of rotor 21 interact, thereby driving drive shaft 22 to output torque through rotor 21. Active cooling is achieved by pumping coolant through circulation pump 31. After the coolant enters the guide pipe 34 through inlet, it is pumped into each ring pipe 33 along the guide pipe 34 for cooling. The space between two adjacent ring pipes 33 is defined as the cooling zone. The length of the cooling zone is gradually set according to the temperature gradient inside drive cavity 11, thereby adjusting the local cooling supply and ensuring the temperature uniformity inside drive cavity 11.

[0039] Furthermore, the length of the cooling zone is set to decrease along the liquid delivery direction of the guide pipe 34.

[0040] During the output torque process, the temperature in the drive chamber 11 decreases from the rotor 21 to the stator 23 and increases along the output direction of the drive shaft 22. The length of the cooling zone decreases along the liquid delivery direction of the guide tube 34. That is, the closer to the output end of the drive shaft 22, the shorter the length of the cooling zone, which makes the contact heat exchange area larger per unit time and improves the heat exchange efficiency.

[0041] Furthermore, the guide pipe 34 is provided with a main channel 341, which is connected to the inlet pipe 12. The lower end of the main channel 341 is provided with several branch channels 342, which are respectively connected to the adjacent ring pipe 33. The compensation device 4 includes a cut-off plate 41. A rotating groove 343 is provided on one side of the branch channel 342, which is connected to the main channel 341. The cut-off plate 41 and the rotating groove 343 are rotatably connected. One end of the cut-off plate 41 is inserted into the main channel 341, and the cut-off plate 41 is arranged at an angle.

[0042] The coolant is connected to the inlet 12 via the main channel 341 and injected into each ring pipe 33 via the branch channel 342. The ring pipe 33 and the mounting plate 32 are supported by materials with high thermal conductivity, which can cool the coolant in the drive cavity 11 and the coil of the stator 23 respectively. The branch channel 342 and the rotating groove 343 are arranged sequentially along the liquid delivery direction of the guide pipe 34. Under different power consumption conditions, the temperature difference between adjacent cooling zones is different. When the temperature is higher, the temperature difference between adjacent cooling zones is greater. The amount of coolant entering each ring pipe 33 is adjusted by setting the flow cut-off plate 41. When the coolant flows along the main channel 341, the flow cut-off plate 41 is arranged at an angle downward to cut off the coolant and guide it into the branch channel 342 below the flow cut-off plate 41. The remaining part continues to flow forward, thereby making real-time adjustments.

[0043] Furthermore, the compensation device 4 also includes an upper curved plate 42 and a lower curved plate 43. One side of the upper curved plate 42 and the lower curved plate 43 are fastened together. One end of the upper curved plate 42 and the lower curved plate 43 are fastened together with the baffle plate 41, and the other end abuts against the rotating groove 343. The thermal expansion coefficient of the upper curved plate 42 is greater than that of the lower curved plate 43.

[0044] By setting an upper curved plate 42 and a lower curved plate 43 and inserting them into each cooling zone, they come into contact with the coolant for heat exchange. The plate is set based on the difference in thermal expansion coefficients, with the one having the larger coefficient abutting against the rotating groove 343. Initially, the upper curved plate 42 and the lower curved plate 43 are in a straight state. When heated and expanding, since the upper curved plate 42 and the lower curved plate 43 are fixed on one side and one end is tightly connected to the baffle plate 41, the thermal expansion coefficient of the upper curved plate 42 is greater than that of the lower curved plate 43. Because they are both placed in the drive cavity 11, when they come into contact with the coolant and rise to the same temperature, the expansion amount of the upper curved plate 42 is greater than that of the lower curved plate 43. By abutting against the rotating groove 343, the baffle plate 41 is pushed to rotate, increasing the angle between the baffle plate 41 and the horizontal plane, thereby increasing the vertical flow interception area and improving the flow rate. By automatically adjusting the local cooling capacity according to the temperature within the cooling zone, cooling uniformity is ensured.

[0045] Furthermore, a rotating shaft 44 is fitted onto the throttling plate 41, and the throttling plate 41 is rotatably connected to the rotating groove 343 via the rotating shaft 44.

[0046] The throttling plate 41 is guided by a rotating shaft 44. The outer surface of the rotating shaft 44 and the rotating groove 343 are kept in contact to achieve a partial seal, preventing leakage during throttling and affecting the accuracy of cold energy distribution. The throttling plate 41 is eccentrically positioned at its rotation center, with the lower section being shorter than the upper section. This ensures that, in the initial state, the portion inserted into the main flow channel 341 maintains a small angle with the horizontal plane, facilitating subsequent adjustments.

[0047] Furthermore, the body 1 is provided with a circulation channel 13, which is connected to the liquid inlet 12. The outer ring of the drive shaft 22 is provided with several guide seats 24. The outer side of the guide seat 24 is provided with an arc surface 241, and the inner side of the guide seat 24 is provided with a horizontal flow surface 242. The drive shaft 22 is provided with a drainage channel 221, which is connected to the circulation channel 13. The outer ring of the drainage channel 221 is provided with several drain ports 222.

[0048] By setting up the circulation channel 13, the coolant flowing out of the inlet 12 is diverted and enters the guide channel 221. During the rotation of the drive shaft 22, the coolant is centrifugally discharged from the outlet 222 through centrifugal force, and convective heat transfer is performed on the high-temperature coolant in the drive cavity 11. At the same time, by uniformly arranging the guide seats 24 around the drive shaft 22, the force is balanced. The arc surface 241 and the horizontal surface 242 are arranged in an arc shape and have the same starting and ending points, but the curvature of the arc surface 241 is greater. This makes the coolant flow velocity faster when flowing through the two surfaces. That is, the cooling pressure at the outer arc surface 241 is smaller, which makes the coolant at the inner horizontal surface 242 flow to the outer layer, improving the radial flow performance of the coolant and ensuring the cooling efficiency.

[0049] As an optimization, the body 1 is provided with a liquid outlet 14. The end of the diversion channel 342 is connected to the liquid outlet 14, the drive chamber 11 is connected to the liquid outlet 14, and the end of the liquid outlet 14 is connected to the circulation pump 31. By setting the liquid outlet 14, the liquid that has heated up after participating in the cooling is diverted. That is, the liquid at the outlet of the diversion channel 342 and inside the drive chamber 11 flows out through the liquid outlet 14, and after being cooled, it re-enters the liquid inlet 12 through the circulation pump 31 for a new round of cooling.

[0050] As an optimization, several heat exchange surfaces 331 are provided on the inner side of the ring pipe 33, and the heat exchange surfaces 331 are in contact with the mounting plate 32. By setting the heat exchange surfaces 331, heat exchange is conducted between the heat exchange surfaces 331 and the mounting plate 32, thereby improving the heat exchange efficiency.

[0051] The working principle of this invention is as follows: When the coolant enters the guide pipe 34 through the inlet, it is pumped into each ring pipe 33 along the guide pipe 34 for cooling. The space between two adjacent ring pipes 33 is defined as the cooling zone. According to the temperature gradient inside the drive cavity 11, the length of the cooling zone is gradually adjusted to regulate the local cooling supply and ensure the temperature uniformity inside the drive cavity 11. The length of the cooling zone decreases along the liquid delivery direction of the guide pipe 34, that is, the closer to the output end of the drive shaft 22, the shorter the cooling zone length, so that the contact heat exchange area per unit time is larger, improving the heat exchange efficiency. Under different power consumption conditions, the temperature difference between adjacent cooling zones is different. The higher the temperature, the greater the temperature difference between adjacent cooling zones. The amount of coolant entering each ring pipe 33 is adjusted by setting the baffle plate 41. When the coolant flows along the main channel 341, the baffle plate 41 is arranged at an angle downwards to intercept the coolant and guide it into the branch channel 342 below the baffle plate 41. The remaining part continues to flow forward, thus allowing for real-time adjustment. When the coolant expands due to heat, since the upper curved plate 42 and the lower curved plate 43 are fixed on one side and one end is tightly connected to the baffle plate 41, the thermal expansion coefficient of the upper curved plate 42 is greater than that of the lower curved plate 43. Since they are both placed in the drive cavity 11, when they come into contact with the coolant and exchange heat to rise to the same temperature, the expansion amount of the upper curved plate 42 is greater than that of the lower curved plate 43. By abutting against the rotating groove 343, the baffle plate 41 is pushed to rotate, and the angle between the baffle plate 41 and the horizontal plane increases, thereby increasing the vertical interception area and improving the interception flow rate. By automatically adjusting the local cooling capacity according to the temperature in the cooling zone, the cooling uniformity is ensured.

[0052] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A permanent magnet synchronous motor with active heat dissipation function, characterized in that: The permanent magnet synchronous motor includes a body (1), a drive device (2), a temperature control device (3) and a compensation device (4). The body (1) is provided with a drive cavity (11). The drive device (2) is placed in the drive cavity (11). The temperature control device (3) is connected to the body (1). The compensation device (4) is connected to the temperature control device (3). The temperature control device (3) is used to actively dissipate heat from the body (1). The machine body (1) is provided with a liquid inlet (12). The drive device (2) includes a rotor (21), a drive shaft (22) and a stator (23). The drive shaft (22) and the drive cavity (11) are rotatably connected. The rotor (21) is sleeved on the drive shaft (22). The stator (23) is located on the outer layer of the rotor (21) and is placed inside the drive cavity (11). The temperature control device (3) includes a circulating pump (31), a mounting plate (32), a ring pipe (33), and a guide pipe (34). The mounting plate (32) is provided with several rings around the drive cavity (11). Several ring pipes (33) are provided along the outer circle formed by the mounting plates (32). A cooling zone is provided between adjacent ring pipes (33). The length of the cooling zone is gradually changed. The stator (23) is in contact with the mounting plate (32). The guide pipe (34) is connected to the liquid inlet (12). The liquid delivery direction of the guide pipe (34) is along the axis of the power output of the drive shaft (22). The guide pipe (34) is connected to the ring pipe (33). The guide pipe (34) is provided with a main channel (341), which is connected to the inlet (12) pipe. The lower end of the main channel (341) is provided with several branch channels (342), which are connected to the adjacent ring pipe (33) respectively. The compensation device (4) includes a cut-off plate (41). A rotating groove (343) is provided on one side of the branch channel (342). The rotating groove (343) is connected to the main channel (341). The cut-off plate (41) and the rotating groove (343) are rotatably connected. One end of the cut-off plate (41) is inserted into the main channel (341). The cut-off plate (41) is arranged at an angle. The compensation device (4) further includes an upper curved plate (42) and a lower curved plate (43). One side of the upper curved plate (42) and the lower curved plate (43) are fastened together. One end of the upper curved plate (42) and the lower curved plate (43) are fastened together with the flow cut-off plate (41), and the other end is abutted against the rotating groove (343). The thermal expansion coefficient of the upper curved plate (42) is greater than that of the lower curved plate (43).

2. A permanent magnet synchronous motor with active heat dissipation function according to claim 1, characterized in that: The length of the cooling zone decreases along the liquid delivery direction of the guide pipe (34).

3. A permanent magnet synchronous motor with active heat dissipation function according to claim 1, characterized in that: A rotating shaft (44) is fitted onto the cut-off plate (41), and the cut-off plate (41) is rotatably connected to the rotating groove (343) via the rotating shaft (44).

4. A permanent magnet synchronous motor with active heat dissipation function according to claim 3, characterized in that: The body (1) is provided with a circulation channel (13), the circulation channel (13) and the liquid inlet (12) are connected by a pipe. The outer ring of the drive shaft (22) is provided with a number of flow guide seats (24). The outer side of the flow guide seat (24) is provided with an arc surface (241), and the inner side of the flow guide seat (24) is provided with a horizontal flow surface (242). The drive shaft (22) is provided with a drainage channel (221), the drainage channel (221) and the circulation channel (13) are connected by a pipe. The outer ring of the drainage channel (221) is provided with a number of discharge ports (222).

5. A permanent magnet synchronous motor with active heat dissipation function according to claim 4, characterized in that: The body (1) is provided with a liquid outlet (14), the end of the diversion channel (342) is connected to the liquid outlet (14) pipe, the drive chamber (11) is connected to the liquid outlet (14) pipe, and the end of the liquid outlet (14) is connected to the circulation pump (31) pipe.

6. A permanent magnet synchronous motor with active heat dissipation function according to claim 5, characterized in that: The inner side of the ring pipe (33) is provided with several heat exchange surfaces (331), and the heat exchange surfaces (331) are in contact with the mounting plate (32).

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