Permanent magnet motor and magnetic steel

Abstract

This invention relates to the field of permanent magnet motor technology, specifically to a permanent magnet motor and its magnets. The motor includes a housing, a safety cooling mechanism, and a protective mechanism. One end of the housing is bolted to an end cap, and mounting plates are fixedly connected to both sides of the housing. A rotating shaft is disposed inside the housing. Magnet bodies are disposed on the surface of the rotor core. A first groove is formed on one side of each magnet body, and a first boss is slidably connected inside each of the first and second grooves. A coil is uniformly wound around the center of each stator body. A controller is disposed at the top of the housing. This device can automatically cut off power, thereby preventing demagnetization due to temperature cycling and improving the device's service life. It also increases the motor's power density, improves the linearity of the motor's torque output, and reduces the harmonic content of the back EMF.

Description

Technical Field

[0001] This invention relates to the field of permanent magnet motor technology, specifically to a permanent magnet motor and a magnet. Background Technology

[0002] A permanent magnet synchronous motor is a synchronous motor that uses permanent magnets to generate a magnetic field. The speed of its rotor is consistent with the current frequency of the stator winding. A permanent magnet synchronous motor consists of components such as stator, rotor and end cover. The stator is basically the same as that of a common induction motor. It adopts a laminated structure to reduce iron loss during motor operation. The rotor can be made solid or laminated. The armature winding can be a concentrated full-pitch winding, a distributed short-pitch winding or an unconventional winding.

[0003] Currently, some motors have poor heat dissipation in use. If used under load for a long time, they will generate high temperatures, which will reduce magnetism, shorten the life of the motor, and result in low energy utilization efficiency, high back EMF harmonic content, and high cogging torque. Summary of the Invention

[0004] The purpose of this invention is to provide a permanent magnet motor and magnets to solve the problems mentioned in the background art, such as poor heat dissipation in some motors during use, high temperature generated under long-term load use, which reduces magnetism, shortens motor life, low energy utilization efficiency, high back EMF harmonic content, and high cogging torque. This device can automatically cut off power to avoid demagnetization caused by temperature cycle changes, thereby improving the service life of the device. At the same time, it can also improve the power density of the motor, improve the linearity of the motor torque output, and reduce the back EMF harmonic content.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a permanent magnet motor and magnets. The permanent magnet motor includes a housing, a safety cooling mechanism, and a protective mechanism. One end of the housing is bolted to an end cap, and mounting plates are fixedly connected to both sides of the housing. A rotating shaft is disposed inside the housing, and one end of the rotating shaft is rotatably connected to one end of the housing via a bearing. The other end of the rotating shaft is connected to the end cap via a bearing. A rotor core is fixedly connected to the middle of the rotating shaft, and the rotor core has an octagonal cross-section. Magnet bodies are disposed on the surface of the rotor core. A first groove is formed on one side of each magnet body. A first boss is slidably connected inside each of the first grooves, and the first bosses are fixedly connected to the rotor cores. Stator bodies are uniformly disposed inside the housing, and the stator bodies interlock with each other. A second groove is formed on one side of each stator body. A second boss is slidably connected inside each of the second grooves, and one side of each second boss is fixedly connected to the inner wall of the housing. Coils are uniformly wound in the middle of each stator body. A controller is disposed at the top of the housing.

[0006] Preferably, all the coils are electrically connected to the controller to facilitate the operation of the device.

[0007] Preferably, the safety cooling mechanism includes a contact, a support plate, a contact pressure plate, a first spring, an electric push rod, a first control board, a second control board, a water collection tank, a water distribution tank, a circulation pipe, a cooling box, a connecting pipe, a cooling plate, a water pump, an inclined plate, a first temperature sensor, and a second temperature sensor. The inner wall of the bottom of the controller is provided with a contact. The middle of the controller is fixedly connected to a support plate. The top of the support plate is connected to a contact pressure plate via a rotating shaft, and one end of the contact pressure plate is in contact with the contact. Three sets of first springs are evenly fixedly connected to one end of the contact pressure plate, and the top ends of the first springs are all fixedly connected to the inner wall of the controller. The inner wall of the bottom of the controller is provided with an electric push rod, and the output end of the electric push rod is in contact with the bottom of the contact pressure plate. A second control board is provided on one side of the support plate, and a first control board is provided on one side of the second control board. A water collection tank is opened at one end of the housing, and the other end of the housing... The device has a water distribution trough at one end, and circulation pipes are evenly distributed inside the housing, with both ends of the circulation pipes connected to the water collection trough and the water distribution trough, respectively. A cooling box is located at one end of the housing, and a connecting pipe is connected to one end of the cooling box, which is also connected to the water collection trough. A cooling plate is located at the top of the cooling box, and a water pump is located on one side of the cooling box, with the output end of the water pump connected to the water distribution trough. Two sets of inclined plates are fixedly connected inside the cooling plate, and both inclined plates are inclined. One end of the connecting pipe is located between one set of inclined plates and the cooling plate, with the inclined plate at one end of the connecting pipe higher than the other end. A first temperature sensor is located inside the cooling box, and the first temperature sensor is located at one end of the connecting pipe. A second temperature sensor is located inside the cooling box, and the second temperature sensor is located at one end of the water pump. This design improves the safety of the device and extends its service life.

[0008] Preferably, the control terminals of the electric actuator, cooling plate, water pump, first temperature sensor, and second temperature sensor are all electrically connected to an external power source through a second control board, and the coils are all electrically connected to an external power source through a first control board, contacts, and contact pressure plate, which facilitates the operation of this device.

[0009] Preferably, the protective mechanism includes heat sinks, grooves, connecting rods, sliding rods, second springs, elastic plates, and third springs. Heat sinks are uniformly fixedly connected to both sides of the housing. Grooves are uniformly opened on one side of each heat sink. A connecting rod is provided on one side of each heat sink. Sliding rods are slidably connected inside each groove, and one end of each sliding rod is fixedly connected to the connecting rod. A second spring is fixedly connected to one end of each sliding rod, and one end of each second spring is fixedly connected to one end of each groove. An elastic plate is fixedly connected to one side of each connecting rod, and a third spring is uniformly fixedly connected to one side of each elastic plate, and one end of each third spring is fixedly connected to the connecting rod. The elastic plate is elastic, preventing the magnet body from demagnetizing, thereby improving the service life of the device.

[0010] A magnet includes a first groove with a radius of R5. The outer side of the magnet body is composed of several arc-shaped curves. The center of the magnet body is an arc I with a radius of R1. Arcs IV, III, and II are symmetrically arranged on both sides of arc I, with radii of R4, R3, and R2 respectively. The arcs on both sides of the magnet body are symmetrically distributed, and the radius of the arc decreases with distance from the center line, satisfying R2 < R3 < R5. The arcs of R4 and R3 are mainly used to eliminate the third harmonic content in the back EMF, the arcs of R3 are mainly used to eliminate the fifth harmonic content in the back EMF, and the arcs of R2 are mainly used to eliminate the seventh harmonic content in the back EMF. The effect is more significant for motors with delta connections and satisfies 0.85×(R2 / H2)<R3 / H3<1.1×(R4 / H4), where H2, H3, and H4 are the distances from the lowest point of arc two, arc three, and arc four to the contact point between the magnet body and the rotor core, respectively.

[0011] Preferably, the width of the magnet body is W1, the height of the magnet body is H1, and W1 / H1 = (R1 / R3) × (R2 / R4).

[0012] Preferably, the inner and outer diameters of the stator body are R7 and R9, respectively, the inner diameter of the rotating shaft is R8, and the air gap between the magnet body and the stator body is G, satisfying (R7 / R9) + H1 ≥ (R8 / R1) + G, where H1 represents the distance from the highest point of the arc to the point where the magnet body and the rotor core are in contact.

[0013] Preferably, the radius of the first boss is R6 and the height is T1, and the condition 1.2×R6<T1<1.5×R6 is met.

[0014] Preferably, the gaps between the stator bodies are stator slots, and the slot width is W2, satisfying G / W2≥W1 / H1, thereby improving the motor power density, enhancing the linearity of the motor torque output, and reducing the harmonic content of the back EMF.

[0015] Preferably, the number of stator slots is N1, the number of magnet bodies is P1, and N1 = P1 ± 2, and N1 < 20.

[0016] Preferably, the stator body adopts a segmented structure, and each segment has a stepped structure, thereby improving the slot fill factor. Both sides of the stator body include steps one, two, three, four, five, six, seven, and eight. Step one is perpendicular to the outer surface of the stator body, step one is perpendicular to step two, step two is perpendicular to step three, step three is perpendicular to step four, step four is perpendicular to step five, and so on. Step 5 is perpendicular to Step 6, Step 6 is perpendicular to Step 7, Step 7 is perpendicular to Step 8, Step 2 has a height of H5, Step 4 has a height of H6, the height between Step 2 and Step 8 is H7, the height between Step 4 and Step 6 is H8, and the height between the outer surface of the stator body and the inner wall of the stator slot is H9. H5, H6, H7, H8 and H9 satisfy H5 / H6 > H8 / H7 and also satisfy 2.5 × H7 < H9 < 3.5 × H7.

[0017] Preferably, the magnet body and the rotating shaft are in the same direction, and the magnet body is manufactured using a mold injection molding process.

[0018] Compared with the prior art, the beneficial effects of the present invention are:

[0019] When the user uses this device, the coil, after being energized, causes the rotating shaft, rotor core, and magnet body to rotate. The outer side of the magnet body is used to eliminate harmonics in the back EMF. Specifically, the arc of R4 primarily eliminates the 3rd harmonic content in the back EMF, the arc of R3 primarily eliminates the 5th harmonic content, and the arc of R2 primarily eliminates the 7th harmonic content. The effect is more significant for motors with a delta connection. When the stator slot width satisfies G / W2≥W1 / H1, it can improve the motor's power density, enhance the linearity of the motor's torque output, and reduce the harmonic content of the back EMF. During operation, the device dissipates heat through heat sinks. When the side of the casing is impacted, this... First, the elastic plate and the third spring partially offset the impact. Under the remaining impact force, the connecting rod drives the sliding rod to move into the inside of the receiving groove, thereby compressing the second spring. At this time, the second spring again offsets the impact force, preventing the magnet inside the shell from losing its magnetism due to external impacts, thus reducing the lifespan of the device. Simultaneously, a water pump allows the coolant inside the cooling box to circulate internally, thereby reducing the temperature generated by the device. The coolant inside the cooling box enters the water distribution tank through the water pump, then enters the circulation pipe, and finally returns to the upper part of the cooling box through the collection tank and connecting pipe. Multiple evenly distributed circulation pipes ensure sufficient heat transfer with the temperature generated by the device, thereby improving the cooling effect. Due to the inclined... The inclined plate design increases the contact area between the heated coolant and the cooling plate, thereby improving the cooling efficiency and effect of the cooling plate on the high-temperature coolant. The coolant flows in an S-shape inside the cooling box. A first temperature sensor monitors the temperature of the coolant entering the cooling box, and a second temperature sensor monitors the temperature of the coolant entering the shell. This allows for the calculation of the coolant's temperature rise and the amount of heat carried away by the coolant. The first control board controls the cooling effect of the cooling plate, ensuring a stable shell temperature and preventing thermal stress caused by repeated temperature changes in the magnet body. This prevents changes in the microstructure of the magnet body due to repeated thermal stress, thus preventing long-term damage. Demagnetization occurs after a certain period of time. When the high temperature generated by this device exceeds the maximum set temperature, the output end of the electric actuator extends, separating the contact plate and the contact. At this time, the contact plate compresses the first spring, causing the device to stop working and preventing the device's service life from being reduced due to high temperature, thus reducing user losses. When the device temperature drops, the electric actuator resets, and the contact plate, under the action of the first spring, adheres to the contact, allowing the device to continue working. This device can automatically shut off power, thus preventing demagnetization caused by temperature cycles, thereby improving the device's service life. It can also improve the motor's power density, increase the linearity of the motor's torque output, and reduce the harmonic content of the back EMF. Attached Figure Description

[0020] Figure 1 This is a three-dimensional schematic diagram of the present invention;

[0021] Figure 2 This is a cross-sectional perspective view of the present invention;

[0022] Figure 3 This is a front view of the housing, coil, and rotor core in this invention;

[0023] Figure 4 This is a three-dimensional cross-sectional view of the controller and the contact pressure plate in this invention;

[0024] Figure 5 This is a three-dimensional cross-sectional view of the shell and water collection tank in this invention;

[0025] Figure 6 This is a three-dimensional cross-sectional view of the water distribution tank and the cooling plate in this invention;

[0026] Figure 7 This is a three-dimensional cross-sectional view of the heat sink and the groove in this invention;

[0027] Figure 8 This is a front view of the magnet body and the stator body in this invention;

[0028] Figure 9 This is a front view of the main body of the magnet in this invention;

[0029] Figure 10 This is a front view of the rotor core and the first boss in this invention;

[0030] Figure 11 This is a schematic diagram of the connection of the stator body in this invention;

[0031] Figure 12 This is a schematic diagram of the stator body in this invention;

[0032] Figure 13 A comparison diagram of the back EMF waveforms of the original technology and the technology in this invention;

[0033] Figure 14 The Fourier analysis diagram of the back potential of the original technology;

[0034] Figure 15 This is the Fourier analysis diagram of the back potential of the technology in this invention.

[0035] In the diagram: 1. Housing; 2. End cover; 3. Mounting plate; 4. Rotating shaft; 5. Rotor core; 6. Magnet body; 7. First groove; 8. First boss; 9. Stator body; 10. Second groove; 11. Second boss; 12. Coil; 13. Controller; 14. Contact; 15. Support plate; 16. Contact pressure plate; 17. First spring; 18. Electric actuator; 19. First control board; 20. Second control board; 21. Water collection tank; 22. Water distribution tank; 23. Circulation pipe; 24. 25. Cooling box; 26. Connecting pipe; 27. Cooling plate; 28. Water pump; 29. ​​Inclined plate; 20. First temperature sensor; 31. Second temperature sensor; 32. Heat sink; 33. Collection groove; 34. Connecting rod; 35. Sliding rod; 36. Second spring; 37. Elastic plate; 38. Third spring; 39. Stator slot; 40. Step 1; 41. Step 2; 42. Step 3; 43. Step 4; 44. Step 5; 45. Step 6; 46. Step 7; 47. Step 8. Detailed Implementation

[0036] 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.

[0037] Please see Figures 1-15 One embodiment provided by the present invention:

[0038] A permanent magnet motor and its magnets are disclosed. The permanent magnet motor includes a housing 1, a safety cooling mechanism, and a protective mechanism. One end of the housing 1 is bolted to an end cover 2. Mounting plates 3 are fixedly connected to both sides of the housing 1. A rotating shaft 4 is disposed inside the housing 1, and one end of the rotating shaft 4 is rotatably connected to one end of the housing 1 via a bearing. The other end of the rotating shaft 4 is connected to the end cover 2 via a bearing. A rotor core 5 is fixedly connected to the middle of the rotating shaft 4, and the rotor core 5 has an octagonal cross-section. Magnet bodies 6 are disposed on the surface of the rotor core 5. A first groove 7 is provided on one side of the 6. A first protrusion 8 is slidably connected inside the first groove 7. The first protrusion 8 is fixedly connected to the rotor core 5. Stator bodies 9 are evenly arranged inside the housing 1. The stator bodies 9 are interlocked with each other. A second groove 10 is provided on one side of the stator body 9. A second protrusion 11 is slidably connected inside the second groove 10. One side of the second protrusion 11 is fixedly connected to the inner wall of the housing 1. A coil 12 is evenly wound in the middle of the stator body 9. A controller 13 is provided at the top of the housing 1.

[0039] Please see Figures 1-6In this embodiment, the safety cooling mechanism includes a contact 14, a support plate 15, a contact pressure plate 16, a first spring 17, an electric push rod 18, a first control board 19, a second control board 20, a water collection tank 21, a water distribution tank 22, a circulation pipe 23, a cooling box 24, a connecting pipe 25, a cooling plate 26, a water pump 27, an inclined plate 28, a first temperature sensor 29, and a second temperature sensor 30. The inner wall of the bottom of the controller 13 is provided with the contact 14. The support plate 15 is fixedly connected to the middle of the controller 13. The top of the support plate 15 is connected to the contact pressure plate 16 via a rotating shaft, and one end of the contact pressure plate 16 is in contact with the contact 14. Three sets of first springs 17 are evenly fixedly connected to one end of the contact pressure plate 16, and the tops of the first springs 17 are all in contact with the inner wall of the controller 13. A fixed connection is provided. An electric actuator 18 is installed on the inner wall of the bottom of the controller 13, and the output end of the electric actuator 18 is in contact with the bottom of the contact plate 16. A second control plate 20 is installed on one side of the support plate 15, and a first control plate 19 is installed on one side of the second control plate 20. A water collection tank 21 is provided at one end of the housing 1, and a water distribution tank 22 is provided at the other end of the housing 1. Circulation pipes 23 are evenly distributed inside the housing 1, and both ends of the circulation pipes 23 are connected to the water collection tank 21 and the water distribution tank 22, respectively. A cooling box 24 is provided at one end of the housing 1, and a connecting pipe 25 is connected to one end of the cooling box 24, which is connected to the water collection tank 21. A cooling plate 26 is provided at the top of the cooling box 24, and a water pump 27 is provided on one side of the cooling box 24. The output end of pump 27 is connected to water distribution tank 22. Two sets of inclined plates 28 are fixedly connected inside the cooling plate 26, and both inclined plates 28 are inclined. One end of the connecting pipe 25 is located between one set of inclined plates 28 and the cooling plate 26, with one end of the inclined plate 28 higher than the other end. A first temperature sensor 29 is installed inside the cooling box 24, located at one end of the connecting pipe 25. A second temperature sensor 30 is installed inside the cooling box 24, located at one end of the water pump 27. The water pump 27 enables the coolant inside the cooling box 24 to circulate internally, thereby reducing the temperature generated by the device. The coolant inside the cooling box 24 enters the water distribution tank 22 through the water pump 27, and then... The coolant enters the circulation pipe 23 through the trough 22 and finally returns to the upper part of the cooling box 24 through the collection trough 21 and connecting pipe 25. Multiple evenly distributed circulation pipes 23 ensure sufficient heat transfer with the device, thereby improving the cooling effect. The inclined plate 28 increases the contact area between the hot coolant and the cooling plate 26, thus improving the cooling efficiency and effect of the cooling plate 26 on the high-temperature coolant. The coolant flows in an S-shape inside the cooling box 24. The temperature of the coolant entering the cooling box 24 can be monitored by the first temperature sensor 29, and the temperature of the coolant entering the housing 1 can be monitored by the second temperature sensor 30. This allows for the calculation of the coolant's temperature rise and the amount of heat carried away by the coolant.The cooling effect of the cooling plate 26 is controlled by the first control board 19, thereby ensuring that the temperature of the shell 1 remains stable. This avoids thermal stress caused by repeated temperature changes in the magnet body 6, preventing changes in the internal microstructure of the magnet body 6 due to repeated thermal stress and thus preventing demagnetization over time. When the high temperature generated by this device exceeds the maximum set temperature, the output end of the electric push rod 18 extends, separating the contact plate 16 and the contact 14. At this time, the contact plate 16 compresses the first spring 17, causing the device to stop working and preventing the device's service life from being reduced due to high temperature, thereby reducing losses for the user. When the temperature of the device decreases, the electric push rod 18 resets, and the contact plate 16, under the action of the first spring 17, contacts the contact 14, allowing the device to continue working, improving the safety of the device and extending its service life.

[0040] Please see Figure 1 and Figure 7 In this embodiment, the protective mechanism includes a heat sink 31, a groove 32, a connecting rod 33, a sliding rod 34, a second spring 35, an elastic plate 36, and a third spring 37. Heat sinks 31 are uniformly fixedly connected to both sides of the housing 1. Grooves 32 are uniformly opened on one side of each heat sink 31. A connecting rod 33 is provided on one side of each heat sink 31. A sliding rod 34 is slidably connected inside each groove 32, and one end of each sliding rod 34 is fixedly connected to the connecting rod 33. A second spring 35 is fixedly connected to one end of each sliding rod 34, and one end of each second spring 35 is fixedly connected to one end of each groove 32. An elastic plate 36 is fixedly connected to one side of each connecting rod 33, and one side of each elastic plate 36 is uniformly fixedly connected to the groove 37. A third spring 37 is fixedly connected to the connecting rod 33, and one end of the third spring 37 is fixedly connected to the connecting rod 33. The elastic plate 36 is elastic and can dissipate heat through the heat sink 31 during operation. When the side of the housing 1 is impacted, the elastic plate 36 and the third spring 37 first offset part of the impact. Under the action of the remaining impact force, the connecting rod 33 drives the sliding rod 34 to move into the inside of the receiving groove 32, thereby compressing the second spring 35. At this time, under the action of the second spring 35, the impact force is offset again, preventing the magnet body 6 inside the housing 1 from losing magnetism due to external impact, thus reducing the service life of the device and preventing the magnet body 6 from demagnetizing, thereby improving the service life of the device.

[0041] It should be noted that all coils 12 are electrically connected to the controller 13 to facilitate the operation of this device. The control terminals of the electric push rod 18, the cooling plate 26, the water pump 27, the first temperature sensor 29, and the second temperature sensor 30 are all electrically connected to the external power supply through the second control board 20. All coils 12 are electrically connected to the external power supply through the first control board 19, the contact 14, and the contact pressure plate 16 to facilitate the operation of this device.

[0042] Please see Figures 8-12 One embodiment provided by the present invention:

[0043] A magnet includes a first groove 7 with a radius of R5. The outer side of the magnet body 6 is composed of seven arc-shaped curves. The center of the magnet body 6 is an arc 1 with a radius of R1. Arcs 4, 3, and 2 are symmetrically arranged on both sides of arc 1, with radii of R4, R3, and R2 respectively. The arcs on both sides of the magnet body 6 are symmetrically distributed, and the radius of the arc decreases with distance from the center line, satisfying R2 < R3 < R4. The arc of R4 is mainly used to eliminate the third harmonic content in the back EMF, the arc of R3 is mainly used to eliminate the fifth harmonic content in the back EMF, and the arc of R2 is mainly used to eliminate the seventh harmonic content in the back EMF. The effect is more significant for motors with delta connection and satisfies 0.85×(R2 / H2)<R3 / H3<1.1×(R4 / H4), where H2, H3, and H4 are the distances from the lowest point of arc two, arc three, and arc four to the contact point between the magnet body 6 and the rotor core 5, respectively.

[0044] It should be noted that the width of the magnet body 6 is W1, the height of the magnet body 6 is H1, and W1 / H1 = (R1 / R3) × (R2 / R4) is satisfied. The inner and outer diameters of the stator body 9 are R7 and R9, respectively. The inner diameter of the rotating shaft 4 is R8. The air gap between the magnet body 6 and the stator body 9 is G, and (R7 / R9) + H1 ≥ (R8 / R1) + G is satisfied. Here, H1 represents the distance from the highest point of the arc to the point where the magnet body 6 and the rotor core 5 are in contact. The radius of the first boss 8 is R6, and its height is T1, and it satisfies 1.2 × R 6 < T1 < 1.5 × R6, the gap between the stator bodies 9 is the stator slot 38, and the slot width of the stator slot 38 is W2, satisfying G / W2 ≥ W1 / H1, thereby improving the motor power density, increasing the linearity of the motor torque output, and reducing the harmonic content of the back EMF. The number of stator slots 38 is N1, the number of magnet bodies 6 is P1, and satisfying N1 = P1 ± 2, and N1 < the second control board 20. The stator body 9 adopts a segmented structure, and each segment is a stepped structure, thereby improving the slot fill factor. The two sides of the stator body 9 All include steps 39, 40, 41, 42, 43, 44, 45, and 46. Step 39 is perpendicular to the outer surface of the stator body 9. Step 39 is perpendicular to step 40. Step 40 is perpendicular to step 31. Step 41 is perpendicular to step 42. Step 42 is perpendicular to step 53. Step 53 is perpendicular to step 64. Step 64 is perpendicular to step 75. All seven steps 45 are perpendicular to each other with step eight 46. The height of step two 40 is H5, the height of step four 42 is H6, the height between step two 40 and step eight 46 is H7, the height between step four 42 and step six 44 is H8, and the height between the outer surface of the stator body 9 and the inner wall of the stator slot 38 is H9. Among them, H5, H6, H7, H8 and H9 satisfy H5 / H6>H8 / H7 and also satisfy 2.5×H7<H9<3.5×H7. The magnet body 6 and the rotating shaft 4 are in the same direction. The magnet body 6 is made by mold injection molding process.

[0045] Please see Figures 13-15 To further explain, from Figure 13 As can be seen from the comparison of the back EMF waveforms of the original technology and the patented technology, the waveform of the back EMF of the present invention is smoother than that of the original technology. Figure 14 From the Fourier analysis of the back potential of the original technology, it is known that the Fourier decomposition contains 1% to 1.2% of the 5th and 7th back potential harmonics. Figure 15As can be seen from the Fourier analysis diagram of the back EMF of the present invention, the 5th and 7th back EMF harmonics are no longer visible after Fourier analysis. Therefore, the back EMF harmonics of the present invention are greatly improved compared with the prior art, which can further improve the performance of the present invention.

[0046] When the user uses this device, the coil 12, after being energized, causes the rotating shaft 4, rotor core 5, and magnet body 6 to rotate. The outer side of the magnet body 6 is used to eliminate harmonics in the back EMF. Specifically, the arc of R4 is mainly used to eliminate the 3rd harmonic content in the back EMF, the arc of R3 is mainly used to eliminate the 5th harmonic content, and the arc of R2 is mainly used to eliminate the 7th harmonic content. The effect is more significant for motors with a delta connection. When the width of the stator slot 38 satisfies G / W2≥W1 / H1, the power density of the motor can be increased, the linearity of the motor's torque output can be improved, and the harmonic content of the back EMF can be reduced. During operation, the device can dissipate heat through the heat sink 31. Upon impact, the elastic plate 36 and the third spring 37 first offset part of the impact. Under the remaining impact force, the connecting rod 33 drives the sliding rod 34 to move into the receiving groove 32, thereby compressing the second spring 35. At this time, the second spring 35 offsets the impact force again, preventing the magnet body 6 inside the housing 1 from losing its magnetism due to external impact and reducing the service life of the device. At the same time, the water pump 27 enables the coolant inside the cooling box 24 to circulate internally, thereby reducing the temperature generated by the device. The coolant inside the cooling box 24 enters the water distribution tank 22 through the water pump 27, enters the circulation pipe 23 through the water distribution tank 22, and finally returns to the upper part of the cooling box 24 through the water collection tank 21 and the connecting pipe 25. The evenly distributed circulation pipes 23 can fully transfer heat to the device, thereby improving the cooling effect. The inclined plate 28 increases the contact area between the heated coolant and the cooling plate 26, thus improving the cooling efficiency and effect of the cooling plate 26 on the high-temperature coolant. The coolant flows in an S-shape inside the cooling box 24. The first temperature sensor 29 monitors the temperature of the coolant entering the cooling box 24, and the second temperature sensor 30 monitors the temperature of the coolant entering the shell 1. This allows for the calculation of the coolant's temperature rise and the amount of heat carried away by the coolant. The first control board 19 controls the cooling effect of the cooling plate 26, ensuring that the temperature of the shell 1 remains stable. This avoids thermal stress caused by repeated temperature changes in the magnet body 6, preventing changes in the internal microstructure of the magnet body 6 due to repeated thermal stress and thus preventing demagnetization over time. When the high temperature generated by this device exceeds the maximum set temperature, the output end of the electric actuator 18 extends, separating the contact plate 16 and the contact 14. At this time, the contact plate 16 compresses the first spring 17, causing the device to stop working, thus preventing the device's service life from being reduced due to high temperature and minimizing user losses. When the device temperature drops, the electric actuator 18 resets, and the contact plate 16, under the action of the first spring 17, contacts the contact 14, allowing the device to continue working. This device can automatically cut off power.This avoids demagnetization caused by temperature cycling, thus extending the lifespan of the device. It also increases motor power density, improves the linearity of torque output, and reduces harmonic content of the back EMF.

[0047] 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 motor, characterized in that, The device includes a housing (1), a safety cooling mechanism, and a protective mechanism. One end of the housing (1) is bolted to an end cap (2). Mounting plates (3) are fixedly connected to both sides of the housing (1). A rotating shaft (4) is provided inside the housing (1), and one end of the rotating shaft (4) is rotatably connected to one end of the housing (1) via a bearing. The other end of the rotating shaft (4) is connected to the end cap (2) via a bearing. A rotor core (5) is fixedly connected to the middle of the rotating shaft (4), and the rotor core (5) has an octagonal cross-section. A magnet body (6) is provided on the surface of the rotor core (5), and a magnet body (6) is provided on one side of each magnet body (6). The first groove (7) has a first boss (8) slidably connected inside the first groove (7), and the first boss (8) is fixedly connected to the rotor core (5). The stator body (9) is uniformly arranged inside the housing (1), and the stator bodies (9) are interlocked with each other. The second groove (10) is opened on one side of the stator body (9). The second boss (11) is slidably connected inside the second groove (10), and one side of the second boss (11) is fixedly connected to the inner wall of the housing (1). The coil (12) is uniformly wound in the middle of the stator body (9). The controller (13) is provided at the top of the housing (1). The safety cooling mechanism includes a contact (14), a support plate (15), a contact pressure plate (16), a first spring (17), an electric push rod (18), a first control board (19), a second control board (20), a water collection tank (21), a water distribution tank (22), a circulation pipe (23), a cooling box (24), a connecting pipe (25), a cooling plate (26), a water pump (27), an inclined plate (28), a first temperature sensor (29), and a second temperature sensor (30). The inner wall of the bottom of the controller (13) is provided with a contact (14), and the middle part of the controller (13) is fixedly connected to the support plate (15). The top of the support plate (15) The end is connected to a contact plate (16) via a rotating shaft, and one end of the contact plate (16) is in contact with the contact (14). Three sets of first springs (17) are evenly fixedly connected to one end of the contact plate (16), and the top of each of the first springs (17) is fixedly connected to the inner wall of the controller (13). An electric push rod (18) is provided on the inner wall of the bottom end of the controller (13), and the output end of the electric push rod (18) is in contact with the bottom of the contact plate (16). A second control plate (20) is provided on one side of the support plate (15), and a first control plate (19) is provided on one side of the second control plate (20). One end of the housing (1) A water collection tank (21) is provided at one end of the housing (1), and a water distribution tank (22) is provided at the other end of the housing (1). Circulation pipes (23) are evenly distributed inside the housing (1), and both ends of the circulation pipes (23) are connected to the water collection tank (21) and the water distribution tank (22) respectively. A cooling box (24) is provided at one end of the housing (1), and a connecting pipe (25) is connected to one end of the cooling box (24), and one end of the connecting pipe (25) is connected to the water collection tank (21). A cooling plate (26) is provided at the top of the cooling box (24), and a water pump (27) is provided on one side of the cooling box (24), and the output end of the water pump (27) is connected to the water collection tank (21). The water distribution tank (22) is connected to the cooling plate (26), and two sets of inclined plates (28) are fixedly connected inside the cooling plate (26). The inclined plates (28) are all inclined. One end of the connecting pipe (25) is located between one set of inclined plates (28) and the cooling plate (26). The inclined plates (28) are located at one end of the connecting pipe (25) higher than the other end. The cooling box (24) is equipped with a first temperature sensor (29), and the first temperature sensor (29) is located at one end of the connecting pipe (25). The cooling box (24) is equipped with a second temperature sensor (30), and the second temperature sensor (30) is located at one end of the water pump (27). The protective mechanism includes heat sinks (31) and connecting rods (33). Heat sinks (31) are evenly fixedly connected to both sides of the housing (1), and connecting rods (33) are provided on one side of each heat sink (31).

2. A permanent magnet motor according to claim 1, characterized in that: All coils (12) are electrically connected to the controller (13).

3. A permanent magnet motor according to claim 1, characterized in that: The control terminals of the electric actuator (18), cooling plate (26), water pump (27), first temperature sensor (29) and second temperature sensor (30) are all electrically connected to the external power supply through the second control board (20). The coils (12) are all electrically connected to the external power supply through the first control board (19), contact (14) and contact pressure plate (16).

4. A permanent magnet motor according to claim 1, characterized in that: The protective mechanism also includes a groove (32), a slide rod (34), a second spring (35), an elastic plate (36), and a third spring (37). A groove (32) is evenly provided on one side of the heat sink (31). A slide rod (34) is slidably connected inside the groove (32), and one end of the slide rod (34) is fixedly connected to the connecting rod (33). A second spring (35) is fixedly connected to one end of the slide rod (34), and one end of the second spring (35) is fixedly connected to one end of the groove (32). An elastic plate (36) is fixedly connected to one side of the connecting rod (33), and a third spring (37) is evenly fixedly connected to one side of the elastic plate (36), and one end of the third spring (37) is fixedly connected to the connecting rod (33). The elastic plate (36) is elastic.

5. A magnet for use in the permanent magnet motor according to any one of claims 1-4, characterized in that, The first groove (7) has a radius of R5. The outer side of the magnet body (6) is composed of 7 arcs. The middle part of the magnet body (6) is arc one, and the radius of arc one is R1. Arc four, arc three and arc two are symmetrically arranged on both sides of arc one. The radii of arc four, arc three and arc two are R4, R3 and R2 respectively. The arcs on both sides of the magnet body (6) are symmetrically distributed. The radius of the arc is smaller the farther away from the center line. It satisfies R2 < R3 < R4 and 0.85 × (R2 / H2) < R3 / H3 < 1.1 × (R4 / H4). H2, H3 and H4 are the distances from the lowest point of arc two, arc three and arc four to the contact point between the magnet body (6) and the rotor core (5).

6. The magnet according to claim 5, characterized in that: The width of the magnet body (6) is W1, the height of the magnet body (6) is H1, and W1 / H1 = (R1 / R3) × (R2 / R4).

7. The magnet according to claim 5, characterized in that: The inner and outer diameters of the stator body (9) are R7 and R9, respectively. The inner diameter of the rotating shaft (4) is R8. The air gap between the magnet body (6) and the stator body (9) is G, and satisfies (R7 / R9) + H1 ≥ (R8 / R1) + G, where H1 represents the distance from the highest point of the arc to the point where the magnet body (6) and the rotor core (5) are in contact.

8. The magnet according to claim 5, characterized in that, The first boss (8) has a radius of R6 and a height of T1, and satisfies 1.2×R6<T1<1.5×R6.

9. The magnet according to claim 5, characterized in that, The gap between the stator bodies (9) is a stator slot (38), and the slot width of the stator slot (38) is W2, and satisfies G / W2≥W1 / H1.

10. The magnet according to claim 9, characterized in that, The number of stator slots (38) is N1, the number of magnet bodies (6) is P1, and N1 = P1 ± 2, and N1 < 20.

11. The magnet according to claim 10, characterized in that, The stator body (9) is constructed using a segmented structure, with each segment being a stepped structure. Both sides of the stator body (9) include steps one (39), two (40), three (41), four (42), five (43), six (44), seven (45), and eight (46). Step one (39) is perpendicular to the outer surface of the stator body (9), step one (39) is perpendicular to step two (40), step two (40) is perpendicular to step three (41), step three (41) is perpendicular to step four (42), and step four (42) is perpendicular to step five (43). Each of the five steps (43) is perpendicular to the six steps (44), each of the six steps (44) is perpendicular to the seven steps (45), each of the seven steps (45) is perpendicular to the eight steps (46), the height of the two steps (40) is H5, the height of the four steps (42) is H6, the height between the two steps (40) and the eight steps (46) is H7, the height between the four steps (42) and the six steps (44) is H8, and the height between the outer surface of the stator body (9) and the inner wall of the stator slot (38) is H9. H5, H6, H7, H8 and H9 satisfy H5 / H6>H8 / H7 and also satisfy 2.5×H7<H9<3.5×H7.

12. The magnet according to claim 5, characterized in that, The magnet body (6) and the rotating shaft (4) are in the same direction, and the magnet body (6) is made by injection molding.

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