Self-circulating heat dissipation outer rotor motor and control method

Abstract

The present invention discloses a self-circulating heat dissipation outer rotor motor and a control method, which belongs to the field of outer rotor motors. A self-circulating heat dissipation outer rotor motor comprises: a base, the base is connected with a plurality of first heat dissipation ribs along the circumferential direction, a first air duct is provided between adjacent first heat dissipation ribs, the base is evenly connected with a plurality of mounting ears along the circumferential direction, and the plurality of mounting ears are provided with mounting holes; a stator assembly sleeved outside one end of the base; a rotor assembly rotatably connected to one end of the base, the rotor assembly rotatably sleeved outside the stator assembly; a centrifugal impeller assembly sleeved outside the rotor assembly, the centrifugal impeller assembly and the first air duct are connected; an end cover connected to the other end of the base; an electronic module connected to the base, the electronic module and the stator assembly are electrically connected. The technical effect of the present invention is that it has good self-circulating heat dissipation performance.

Description

Technical Field

[0001] The invention relates to an outer rotor motor, and in particular to a self-circulating heat dissipation outer rotor motor and a control method. Background Art

[0002] An external rotor motor is a motor with the rotor on the outside and the stator on the inside. It has the advantages of simple structure and small axial size. It is widely used in charging piles, energy storage and other fields.

[0003] In order to facilitate heat dissipation, heat dissipation ribs are generally provided on the relevant outer rotor motor, but the heat dissipation performance of the heat dissipation ribs is limited, and it is difficult to circulate heat to the relevant outer rotor motor, which can easily lead to a short service life of the relevant outer rotor motor. At the same time, the force uniformity of the relevant outer rotor motor when fixed is poor. Summary of the invention

[0004] Purpose of the invention: The purpose of the present invention is to provide a self-circulating heat dissipation outer rotor motor and a control method, which not only has good self-circulating heat dissipation performance, but also has good force uniformity when fixed.

[0005] Technical solution:

[0006] A self-circulating heat dissipating outer rotor motor, comprising:

[0007] A base, wherein the base is connected to a plurality of first heat dissipation ribs along a circumferential direction, a first air duct is provided between adjacent first heat dissipation ribs, and the base is evenly connected to a plurality of mounting ears along a circumferential direction, and the plurality of mounting ears are all provided with mounting holes;

[0008] A stator assembly sleeved on one end of the base;

[0009] A rotor assembly rotatably connected to one end of the base, wherein the rotor assembly is rotatably sleeved outside the stator assembly;

[0010] A centrifugal impeller assembly sleeved on the outside of the rotor assembly, wherein the centrifugal impeller assembly is in communication with the first air duct;

[0011] an end cap connected to the other end of the base;

[0012] An electronic module is connected to the base, and the electronic module is electrically connected to the stator assembly.

[0013] Optionally, also include:

[0014] A plurality of through holes provided in the rotor assembly;

[0015] a first spacing formed between the stator assembly and the rotor assembly;

[0016] a second spacing formed between the base and the rotor assembly;

[0017] Wherein, the first spacing is connected to the plurality of through holes, and the second spacing is connected to the first spacing and the centrifugal impeller assembly.

[0018] Optionally, the plurality of through holes are evenly distributed along the circumference of the rotor assembly.

[0019] Optionally, the end cover comprises:

[0020] Cover body;

[0021] A plurality of second heat dissipation ribs are circumferentially connected to the side surface of the cover body, a second air duct is provided between adjacent second heat dissipation ribs, the plurality of second heat dissipation ribs are in corresponding conflict with the plurality of first heat dissipation ribs, and the plurality of second air ducts are correspondingly connected with the plurality of first air ducts.

[0022] Optionally, the end cover further comprises:

[0023] A plurality of heat dissipation rib units connected to the end surface of the cover body, wherein the plurality of heat dissipation rib units and a plurality of the second heat dissipation ribs are connected correspondingly;

[0024] A third air duct is formed between adjacent heat dissipation rib units, and the third air duct is communicated with the second air duct.

[0025] Optionally, the heat dissipation rib unit includes:

[0026] A plurality of bent heat dissipation ribs connected to the end surface of the cover body, wherein the plurality of bent heat dissipation ribs and the plurality of second heat dissipation ribs are connected correspondingly;

[0027] A fourth air duct is formed between adjacent bent heat dissipation ribs, and the fourth air duct is communicated with the second air duct.

[0028] Optionally, it also includes a rotating shaft, which is rotatably connected to one end of the base through a bearing, and the rotor assembly is sleeved outside the rotating shaft.

[0029] Optionally, it also includes a fixing ring, which is sleeved on the outside of the rotor assembly and connected to the centrifugal impeller assembly.

[0030] Optionally, the rotor assembly comprises:

[0031] A housing rotatably connected to one end of the base, wherein the centrifugal impeller assembly is sleeved outside the housing;

[0032] A plurality of magnetic tiles are connected to the shell at intervals along the circumferential direction, and the plurality of magnetic tiles are rotatably sleeved outside the stator assembly.

[0033] Optionally, the stator assembly comprises:

[0034] A frame sleeved on one end of the base, wherein the rotor assembly is rotatably sleeved on the outside of the frame;

[0035] A plurality of windings are wound around the frame, and the plurality of windings are electrically connected to the electronic module.

[0036] A control method for a self-circulating heat dissipation outer rotor motor, comprising:

[0037] The controller receives a winding temperature signal from a first temperature sensor, and if the winding temperature exceeds a first preset value, the controller indirectly increases the rotation speed of the rotor assembly and the centrifugal impeller assembly;

[0038] The controller receives a controller temperature signal from a second temperature sensor. If the controller temperature exceeds a second preset value, the controller reduces the output current through magnetic weakening speed regulation, thereby increasing the rotation speed of the rotor assembly and the centrifugal impeller assembly.

[0039] Beneficial effects:

[0040] (1) During heat dissipation, the heat generated by the electronic module and part of the heat generated by the stator assembly are first transmitted to the base and the plurality of first heat dissipation ribs in sequence, and then transmitted to the centrifugal impeller assembly through the plurality of first air ducts, and finally dissipated to the periphery of the self-circulating heat dissipation outer rotor motor of the present embodiment through the centrifugal impeller assembly, thereby having good self-circulating heat dissipation performance and facilitating the improvement of the service life of the self-circulating heat dissipation outer rotor motor of the present embodiment;

[0041] (2) When dissipating heat, the outside air first enters the rotor assembly through a plurality of through holes, then flows through the first spacing, and takes away another part of the heat of the stator assembly, then flows to the centrifugal impeller assembly through the second spacing, and finally dissipates to the surroundings of the self-circulating heat dissipation outer rotor motor of this embodiment through the centrifugal impeller assembly, which has good self-circulating heat dissipation performance, and further facilitates to improve the service life of the self-circulating heat dissipation outer rotor motor of this embodiment;

[0042] (3) A number of mounting ears are evenly connected in the circumferential direction of the base, and mounting holes are provided on the mounting ears, so as to facilitate the fixing of the self-circulating heat dissipating outer rotor motor of the present application and ensure good force uniformity during fixing. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 This is one of the structural diagrams of a self-circulating heat dissipating outer rotor motor according to Embodiment 1 of the present invention;

[0044] Figure 2 This is a second structural diagram of a self-circulating heat dissipating outer rotor motor according to embodiment 1 of the present invention;

[0045] Figure 3 This is a third structural diagram of a self-circulating heat dissipating outer rotor motor according to embodiment 1 of the present invention;

[0046] Figure 4 for Figure 3 One of the cross-sectional views of AA;

[0047] Figure 5 for Figure 3 The second cross-sectional view of AA;

[0048] Figure 6 A speed control signal diagram of a self-circulating heat dissipating outer rotor motor according to Embodiment 1 of the present invention;

[0049] Figure 7 A schematic diagram of the compatibility of 0.9-10VDC analog voltage and pulse width modulation of a self-circulating heat dissipating outer rotor motor according to embodiment 1 of the present invention;

[0050] In the figure: 1. base; 11. first heat dissipation rib; 12. first air duct; 13. mounting ear; 14. mounting hole; 2. stator assembly; 21. frame; 3. rotor assembly; 31. housing; 311. through hole; 32. magnetic tile; 4. centrifugal impeller assembly; 5. end cover; 51. cover body; 52. second heat dissipation rib; 53. second air duct; 54. heat dissipation rib unit; 541. bent heat dissipation rib; 542. fourth air duct; 55. third air duct; 6. electronic module; 71. first spacing; 72. second spacing; 81. rotating shaft; 82. bearing; 9. fixing ring. DETAILED DESCRIPTION

[0051] In order to make the technical solution of the present invention clearer, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0052] Example 1

[0053] like Figure 1 , Figure 4 - Figure 5 The present embodiment provides a self-circulating heat dissipation outer rotor motor, comprising: a base 1, the base 1 is connected with a plurality of first heat dissipation ribs 11 along the circumferential direction, a first air duct 12 is provided between adjacent first heat dissipation ribs 11, the base 1 is evenly connected with a plurality of mounting ears 13 along the circumferential direction, and the plurality of mounting ears 13 are provided with mounting holes 14; a stator assembly 2 sleeved on the outside of one end of the base 1; a rotor assembly 3 rotatably connected to one end of the base 1, the rotor assembly 3 rotatably sleeved on the outside of the stator assembly 2; a centrifugal impeller assembly 4 sleeved on the outside of the rotor assembly 3, the centrifugal impeller assembly 4 and the first air duct 12 are connected; an end cover 5 connected to the other end of the base 1; an electronic module 6 connected to the inside of the base 1, and the electronic module 6 and the stator assembly 2 are electrically connected.

[0054] Specifically, during heat dissipation, the heat generated by the electronic module 6 and a part of the heat generated by the stator assembly 2 are first transmitted to the base 1 and a plurality of first heat dissipation ribs 11 in sequence, and then transmitted to the centrifugal impeller assembly 4 through a plurality of first air ducts 12, and finally dissipated to the surroundings of the self-circulating heat dissipation outer rotor motor of this embodiment through the centrifugal impeller assembly 4, which has good self-circulation heat dissipation performance and is convenient for improving the service life of the self-circulation heat dissipation outer rotor motor of this embodiment.

[0055] Among them, the base 1 is used to carry a number of first heat dissipation ribs 11, and the first heat dissipation ribs 11 cooperate with a number of first air ducts 12 for heat dissipation. The first heat dissipation ribs 11 are preferably evenly distributed along the circumference of the base 1, so that the first air ducts 12 are evenly distributed along the circumference of the base 1 to ensure good heat dissipation uniformity. A number of mounting ears 13 can also be evenly connected to the circumference of the base 1, and mounting holes 14 are provided on the mounting ears 13 to facilitate the fixing of the self-circulating heat dissipation outer rotor motor of this embodiment and to ensure good force uniformity during fixing; the stator assembly 2 is used to generate a magnetic field; the rotor assembly 3 is used to drive the centrifugal impeller assembly 4 to rotate around the stator assembly 2; the centrifugal impeller assembly 4 is used to form a negative pressure, which is convenient for transferring the heat from the first air ducts 12 to the surroundings of the self-circulating heat dissipation outer rotor motor of this embodiment; the end cover 5 is used to make the self-circulating heat dissipation outer rotor motor of this embodiment closed, thereby protecting the electronic module 6, the stator assembly 2 and other internal parts; the electronic module 6 can specifically include a controller, a sensor, etc., which are used to control the stator assembly 2.

[0056] Further, such as Figure 4 - Figure 5 , and also includes: a plurality of through holes 311 provided in the rotor assembly 3; a first spacing 71 formed between the stator assembly 2 and the rotor assembly 3; a second spacing 72 formed between the base 1 and the rotor assembly 3; wherein the first spacing 71 and the plurality of through holes 311 are connected, and the second spacing 72 is connected to the first spacing 71 and the centrifugal impeller assembly 4.

[0057] Specifically, during heat dissipation, the outside air first enters the rotor assembly 3 through the plurality of through holes 311, then flows through the first spacing 71, and takes away another portion of the heat of the stator assembly 2, then flows to the centrifugal impeller assembly 4 through the second spacing 72, and finally dissipates to the surroundings of the self-circulating heat dissipation outer rotor motor of this embodiment through the centrifugal impeller assembly 4, having good self-circulating heat dissipation performance, and further facilitating the improvement of the service life of the self-circulating heat dissipation outer rotor motor of this embodiment.

[0058] Among them, a plurality of through holes 311 facilitate the outside air to enter the rotor assembly 3, and the number of the plurality of through holes 311 is not limited, and preferably is six; the first spacing 71 and the second spacing 72 are both used for another part of the heat flowing through the stator assembly 2 to facilitate heat dissipation.

[0059] Further, such as Figure 3 The plurality of through holes 311 are evenly distributed along the circumference of the rotor assembly 3. Specifically, the even distribution along the circumference facilitates good heat dissipation uniformity of the other part of the stator assembly 2.

[0060] Further, such as Figure 1 The end cover 5 includes: a cover body 51; a plurality of second heat dissipation ribs 52 circumferentially connected to the side of the cover body 51, a second air duct 53 is provided between adjacent second heat dissipation ribs 52, a plurality of second heat dissipation ribs 52 and a plurality of first heat dissipation ribs 11 correspondingly conflict with each other, and a plurality of second air ducts 53 and a plurality of first air ducts 12 correspondingly communicate with each other.

[0061] Specifically, when heat is dissipated, the air on the side of the cover body 51 first flows through the second air duct 53 and takes away the heat of the second heat dissipation ribs 52, and then flows through the first air duct 12 and takes away the heat of the first heat dissipation ribs 11. The cover body 51 is used to carry the second heat dissipation ribs 52; the second heat dissipation ribs 52 are used for heat dissipation, and the second heat dissipation ribs 52 are preferably evenly distributed along the circumferential direction of the side of the cover body 51, so that the second air ducts 53 are evenly distributed along the circumferential direction of the side of the cover body 51 to ensure good heat dissipation uniformity; the second air duct 53 is used to guide the air on the side of the cover body 51, so that the air on the side of the cover body 51 enters the first air duct 12 along the second air duct 53, so that more air participates in heat dissipation and ensures good heat dissipation performance.

[0062] Further, such as Figure 1 The end cover 5 also includes: a plurality of heat dissipation rib units 54 connected to the end surface of the cover body 51, and the plurality of heat dissipation rib units 54 are correspondingly connected to a plurality of second heat dissipation ribs 52; a third air duct 55 formed between adjacent heat dissipation rib units 54, and the third air duct 55 is connected to the second air duct 53.

[0063] Specifically, during heat dissipation, the air on the end surface of the cover body 51 first flows through the third air duct 55 and takes away the heat of the plurality of heat dissipation rib units 54 , and then flows through the second air duct 53 and takes away the heat of the plurality of second heat dissipation ribs 52 .

[0064] Multiple heat dissipation rib units 54 are all used for heat dissipation. Multiple heat dissipation rib units 54 are preferably evenly distributed along the circumference of the end surface of the cover body 51, so that a number of third air ducts 55 are evenly distributed along the circumference of the end surface of the cover body 51 to ensure good heat dissipation uniformity; the third air duct 55 is used to guide the air on the end surface of the cover body 51, so that the air on the end surface of the cover body 51 enters the second air duct 53 along the third air duct 55, thereby facilitating more air to participate in heat dissipation and ensuring good heat dissipation performance.

[0065] Further, such as Figure 1The heat dissipation rib unit 54 includes: a plurality of bent heat dissipation ribs 541 connected to the end surface of the cover body 51, and the plurality of bent heat dissipation ribs 541 are correspondingly connected to the plurality of second heat dissipation ribs 52; a fourth air duct 542 formed between adjacent bent heat dissipation ribs 541, and the fourth air duct 542 is connected to the second air duct 53.

[0066] Specifically, during heat dissipation, the air on the end surface of the cover body 51 first flows through the fourth air duct 542 and takes away the heat of the bent heat dissipation ribs 541 , and then flows through the second air duct 53 and takes away the heat of the second heat dissipation ribs 52 .

[0067] A plurality of bent heat dissipation ribs 541 are used for heat dissipation. The plurality of bent heat dissipation ribs 541 are preferably evenly distributed radially along the end surface of the cover body 51 to ensure good heat dissipation uniformity. The fourth air duct 542 is used to guide the air on the end surface of the cover body 51, so that the air on the end surface of the cover body 51 enters the second air duct 53 along the fourth air duct 542, thereby facilitating more air to participate in heat dissipation and ensuring good heat dissipation performance.

[0068] Further, such as Figure 4 , further comprising a rotating shaft 81, the rotating shaft 81 is rotatably connected to one end of the base 1 through a bearing 82, and the rotor assembly 3 is sleeved outside the rotating shaft 81. Specifically, the rotating shaft 81 and the bearing 82 facilitate the rotor assembly 3 to rotate around one end of the base 1, and the number of the bearings 82 is preferably two.

[0069] Further, such as Figure 2 , further comprising a fixing ring 9, which is sleeved on the outside of the rotor assembly 3 and connected to the centrifugal impeller assembly 4. Specifically, the fixing ring 9 is used to realize the connection between the rotor assembly 3 and the centrifugal impeller assembly 4, and the connection between the fixing ring 9 and the rotor assembly 3 is preferably an interference fit connection, and the fixing ring 9 and the centrifugal impeller assembly 4 are preferably detachably connected by fasteners.

[0070] Further, such as Figure 4 The rotor assembly 3 includes: a housing 31 rotatably connected to one end of the base 1, a centrifugal impeller assembly 4 sleeved outside the housing 31; a plurality of magnetic tiles 32 connected to the housing 31 at intervals along the circumferential direction, and the plurality of magnetic tiles 32 are rotatably sleeved outside the stator assembly 2. Specifically, the housing 31 is used to carry the centrifugal impeller assembly 4, the plurality of magnetic tiles 32, etc.; the plurality of magnetic tiles 32 are used to magnetically cooperate with the stator assembly 2, and the connection between the plurality of magnetic tiles 32 and the housing 31 is preferably adhesive bonding.

[0071] Further, such as Figure 4The stator assembly 2 includes: a frame 21 sleeved on one end of the base 1, a rotor assembly 3 rotatably sleeved on the outside of the frame 21; a plurality of windings wound on the frame 21, and the plurality of windings are electrically connected to the electronic module 6. Specifically, the frame 21 is used to carry the plurality of windings; and the plurality of windings are used to generate a magnetic field.

[0072] This embodiment also provides a control method for a self-circulating heat dissipation outer rotor motor as in this embodiment, comprising:

[0073] The controller receives a winding temperature signal from a first temperature sensor, and if the winding temperature exceeds a first preset value, the controller indirectly increases the rotation speed of the rotor assembly 3 and the centrifugal impeller assembly 4;

[0074] The controller receives a controller temperature signal from the second temperature sensor. If the controller temperature exceeds a second preset value, the controller reduces the output current through magnetic weakening speed regulation, thereby increasing the rotation speed of the rotor assembly 3 and the centrifugal impeller assembly 4.

[0075] Specifically, the controller, the first temperature sensor and the second temperature sensor constitute the electronic module 6, and the first temperature sensor, the second temperature sensor and the like are electrically connected to the controller; the controller is connected to the base 1, and the controller is used to control the first temperature sensor, the second temperature sensor and the like, and the controller is preferably an intelligent power module, i.e., an IPM; the detection end of the first temperature sensor extends into the interior of the winding, and is used to detect the winding temperature, and transmit the winding temperature signal to the controller, and the first temperature sensor is preferably a thermocouple; the second temperature sensor is embedded in the controller, and is used to detect the controller temperature in real time, and transmit the temperature signal to the controller, and the second temperature sensor is preferably a negative temperature coefficient thermistor, i.e., an NTC thermistor; Figure 6 - Figure 7 The speed control signal of the self-circulating heat dissipating outer rotor motor of this embodiment supports 0.9-10VDC analog voltage and is compatible with pulse width modulation (ie PWM).

[0076] The above embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present invention. It should be pointed out that, for a person of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention patent shall be subject to the attached claims.

Claims

1. A self-circulating heat dissipation outer rotor motor, characterized in that: include: A base (1), the base (1) being connected to a plurality of first heat dissipation ribs (11) along a circumferential direction, a first air duct (12) being provided between adjacent first heat dissipation ribs (11), the base (1) being evenly connected to a plurality of mounting ears (13) along a circumferential direction, and the plurality of mounting ears (13) being provided with mounting holes (14); A stator assembly (2) sleeved on one end of the base (1); A rotor assembly (3) rotatably connected to one end of the base (1), wherein the rotor assembly (3) is rotatably sleeved outside the stator assembly (2); a centrifugal impeller assembly (4) sleeved on the outside of the rotor assembly (3), the centrifugal impeller assembly (4) being in communication with the first air duct (12); an end cover (5) connected to the other end of the base (1); An electronic module (6) is connected to the base (1), and the electronic module (6) is electrically connected to the stator assembly (2).

2. A self-circulating heat dissipating outer rotor motor according to claim 1, characterized in that: Also includes: A plurality of through holes (311) provided on the rotor assembly (3); a first spacing (71) formed between the stator assembly (2) and the rotor assembly (3); a second spacing (72) formed between the base (1) and the rotor assembly (3); The first spacing (71) and the plurality of through holes (311) are both connected, and the second spacing (72) is connected to the first spacing (71) and the centrifugal impeller assembly (4).

3. A self-circulating heat dissipating outer rotor motor according to claim 2, characterized in that: The plurality of through holes (311) are evenly distributed along the circumference of the rotor assembly (3).

4. A self-circulating heat dissipating outer rotor motor according to any one of claims 1 to 3, characterized in that: The end cover (5) comprises: Cover body (51); A plurality of second heat dissipation ribs (52) are circumferentially connected to the side surface of the cover body (51), and a second air duct (53) is provided between adjacent second heat dissipation ribs (52). The plurality of second heat dissipation ribs (52) and the plurality of first heat dissipation ribs (11) are in corresponding contact with each other, and the plurality of second air ducts (53) and the plurality of first air ducts (12) are in corresponding communication with each other.

5. The self-circulating heat dissipating outer rotor motor according to claim 4, characterized in that: The end cover (5) further comprises: a plurality of heat dissipation rib units (54) connected to the end surface of the cover body (51); the plurality of heat dissipation rib units (54) and a plurality of the second heat dissipation ribs (52) being connected correspondingly; A third air duct (55) is formed between adjacent heat dissipation rib units (54), and the third air duct (55) is communicated with the second air duct (53).

6. The self-circulating heat dissipating outer rotor motor according to claim 5, characterized in that: The heat dissipation rib unit (54) comprises: a plurality of bent heat dissipation ribs (541) connected to the end surface of the cover body (51), the plurality of bent heat dissipation ribs (541) and the plurality of second heat dissipation ribs (52) being connected correspondingly; A fourth air duct (542) is formed between adjacent bent heat dissipation ribs (541), and the fourth air duct (542) is connected to the second air duct (53).

7. A self-circulating heat dissipating outer rotor motor according to any one of claims 1 to 3, characterized in that: It also comprises a rotating shaft (81), wherein the rotating shaft (81) is rotatably connected to one end of the base (1) via a bearing (82), and the rotor assembly (3) is sleeved outside the rotating shaft (81).

8. A self-circulating heat dissipating outer rotor motor according to any one of claims 1 to 3, characterized in that: It also comprises a fixing ring (9), wherein the fixing ring (9) is sleeved on the outside of the rotor assembly (3), and the fixing ring (9) is connected to the centrifugal impeller assembly (4).

9. A self-circulating heat dissipating outer rotor motor according to any one of claims 1 to 3, characterized in that: The rotor assembly (3) comprises: A housing (31) rotatably connected to one end of the base (1), the centrifugal impeller assembly (4) being sleeved outside the housing (31); A plurality of magnetic tiles (32) are connected to the housing (31) at intervals along the circumferential direction, and the plurality of magnetic tiles (32) are rotatably sleeved outside the stator assembly (2); The stator assembly (2) comprises: A frame (21) sleeved on one end of the base (1), and the rotor assembly (3) is rotatably sleeved on the outside of the frame (21); A plurality of windings are wound around the frame (21), and the plurality of windings are electrically connected to the electronic module (6).

10. A control method for a self-circulating heat dissipating outer rotor motor according to any one of claims 1 to 9, characterized in that: include: The controller receives a winding temperature signal from a first temperature sensor, and if the winding temperature exceeds a first preset value, the controller indirectly increases the rotation speed of the rotor assembly (3) and the centrifugal impeller assembly (4); The controller receives a controller temperature signal from a second temperature sensor. If the controller temperature exceeds a second preset value, the controller reduces the output current through magnetic field weakening speed regulation, thereby increasing the rotation speed of the rotor assembly (3) and the centrifugal impeller assembly (4).

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