Aircraft motor and magnetic steel array thereof

Abstract

The utility model discloses an aircraft motor and a magnetic steel array thereof, and the magnetic steel array comprises a plurality of radial magnetic steels which are arranged along the radius direction of an aircraft motor rotor and are used for providing a radial magnetic field for the aircraft motor; a plurality of tangential magnetic steels arranged along the tangential direction of the rotor of the aircraft motor and used for providing a tangential magnetic field for the aircraft motor and providing a magnetic circuit for the radial magnetic field; the tangential magnetic steel is installed in a gap of a rotor yoke part of the aircraft motor. Through the innovative magnetic steel magnetizing structure and layout, the performance of the aircraft motor is remarkably improved, and the output power and the torque of the motor are enhanced on the premise that the weight and the size of the motor are not increased. Meanwhile, the installation stability of the magnetic steel is further improved through the notch design of the rotor yoke part and the fixing mode of the magnetic steel, the problem of excessive saturation of magnetic flux density is avoided, and long-term reliable operation of the motor is ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of aircraft motors, and particularly relates to an aircraft motor and its magnet array. Background Art

[0002] The requirement for the lightweight of motors in aircraft is much higher than that of vehicle motors. The improvement of power density can bring a significant increase in load capacity, and the traditional structure of vehicle motors can no longer meet the requirements of aircraft motors.

[0003] The Halbach magnetic ring combines the radial and parallel arrangements of magnets. If the end effect is ignored and the permeability of the surrounding magnetic conductive material is regarded as infinite, the above permanent magnet structure finally forms a unilateral magnetic field.

[0004] The structure of the conventional surface-mounted Halbach array motor is to add trapezoidal tangential magnets on the basis of the surface-mounted outer rotor motor structure to provide a tangential magnetic field and improve the performance of the motor. However, the utilization rate of the magnetic field generated by the permanent magnets is not high. The magnetic force lines of the radial magnets on both sides of the tangential magnets are not completely parallel to the magnets, and curved magnetic force lines in the direction of the tangential magnets need to be generated, resulting in a large loss of the magnetic field. Summary of the Utility Model

[0005] The technical problem to be solved by the embodiments of the utility model is to provide an aircraft motor and its magnet array to reduce magnetic field loss and improve the output performance of the motor.

[0006] To solve the above technical problem, the utility model provides an aircraft motor magnet array, including:

[0007] A plurality of radial magnets arranged along the radius direction of the rotor of the aircraft motor, used to provide a radial magnetic field for the aircraft motor;

[0008] A plurality of tangential magnets arranged along the tangent direction of the rotor of the aircraft motor, used to provide a tangential magnetic field for the aircraft motor and provide a magnetic path for the radial magnetic field; the tangential magnets are installed in the notch of the rotor yoke of the aircraft motor.

[0009] Preferably, the thickness of the notch in the radius direction of the rotor of the aircraft motor is the product of the thickness of the rotor yoke and a preset constraint coefficient.

[0010] Preferably, the tangential magnets include trapezoidal magnets and rectangular magnets. Among them, the trapezoidal magnets are accommodated in the notch, and one rectangular magnet is assembled on each side of the trapezoidal magnet. The trapezoidal magnet and the two rectangular magnets form a tangential magnet group.

[0011] Preferably, the tangential magnet includes a trapezoidal magnet and rectangular magnets assembled on both sides of the trapezoidal magnet. The rectangular magnets are respectively received in the notches, and the trapezoidal magnet and the two rectangular magnets form a tangential magnet group.

[0012] Preferably, the radial magnets are symmetrically assembled on both sides of the tangential magnet group.

[0013] Preferably, the tangential magnet or the radial magnet adopts an annular magnetization method, and the center of the annular magnetization is located in the air gap between the stator assembly and the rotor assembly.

[0014] Preferably, the radial magnet adopts a parallel magnetization method, and the magnetization direction is parallel to the radial magnet and faces the inner diameter or the outer diameter of the rotor of the aircraft motor.

[0015] An embodiment of the present invention further provides an aircraft motor, including:

[0016] A stator assembly, which further includes a stator core and a stator winding;

[0017] A rotor assembly, which is disposed opposite to the stator assembly and has an air gap with the stator assembly. The rotor assembly further includes a rotor yoke, radial magnets, and tangential magnets;

[0018] The radial magnets are arranged along the radius direction of the rotor of the aircraft motor and are used to provide a radial magnetic field for the aircraft motor;

[0019] The tangential magnets are arranged along the tangent direction of the rotor of the aircraft motor and are used to provide a tangential magnetic field for the aircraft motor and provide a magnetic path for the radial magnetic field; the tangential magnets are installed in the notches of the rotor yoke.

[0020] Preferably, the thickness of the notch in the radius direction of the rotor of the aircraft motor is the product of the thickness of the rotor yoke and a preset constraint coefficient.

[0021] Preferably, the tangential magnet includes a trapezoidal magnet and rectangular magnets. Among them, the trapezoidal magnet is received in the notch, and one rectangular magnet is assembled on each side of the trapezoidal magnet. The trapezoidal magnet and the two rectangular magnets form a tangential magnet group.

[0022] Preferably, the tangential magnet includes a trapezoidal magnet and rectangular magnets assembled on both sides of the trapezoidal magnet. The rectangular magnets are respectively received in the notches, and the trapezoidal magnet and the two rectangular magnets form a tangential magnet group.

[0023] Preferably, the tangential magnet or the radial magnet adopts an annular magnetization method, and the center of the annular magnetization is located in the air gap between the stator assembly and the rotor assembly.

[0024] Implementing the present utility model has the following beneficial effects: Through the innovative magnet charging structure and layout, the performance of the aircraft motor is significantly improved. Without increasing the weight and volume of the motor, the output power and torque of the motor are enhanced. At the same time, the notch design of the rotor yoke and the fixing method of the magnet further improve the installation stability of the magnet, avoid the problem of excessive magnetic density saturation, and ensure the long-term reliable operation of the motor. The present utility model enables the aircraft to carry a greater load weight, thereby expanding its application range and enhancing its transportation capacity. In addition, the magnet array structure of the present utility model optimizes the magnetic field distribution, reduces torque ripple and cogging torque, thereby improving the operating efficiency and stability of the motor. The present utility model also realizes the efficient utilization of the magnetic field and reduces energy loss. The magnet array structure of the present utility model is applicable not only to outer rotor motors but also to inner rotor motors, with wide applicability, providing new ideas and solutions for the design of aircraft motors. Brief Description of the Drawings

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or in the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0026] Figure 1 It is a schematic structural diagram of a magnet array of an aircraft motor in Embodiment 1 of the present utility model.

[0027] Figure 2 It is a schematic diagram of simulated magnetic force lines when the tangential magnet is charged in a circular ring in the embodiment of the present utility model.

[0028] Figure 3 It is a schematic diagram of simulated magnetic force lines when the tangential magnet is charged in parallel. Detailed Embodiments

[0029] The following descriptions of the embodiments are made with reference to the drawings to exemplify specific embodiments in which the present utility model can be implemented. It should be noted that the directional and positional terms mentioned in the embodiments of the present utility model, such as "upper", "lower", "front", "rear", "left", "right", "inner", "outer", "top", "bottom", "side", etc., are only the directions or positions with reference to the drawings. Therefore, the directional and positional terms used are for explaining and understanding the present utility model, rather than limiting the protection scope of the present utility model.

[0030] Please refer to Figure 1 As shown, Embodiment 1 of the present utility model provides a magnet array for an aircraft motor, including:

[0031] A plurality of radial permanent magnets 106 arranged along the radius direction of the aircraft motor rotor are used to provide a radial magnetic field for the aircraft motor;

[0032] A plurality of tangential permanent magnets 105 arranged along the tangent direction of the aircraft motor rotor are used to provide a tangential magnetic field for the aircraft motor and provide a magnetic circuit for the radial magnetic field; the tangential permanent magnets are installed in the notch 100 of the rotor yoke 104 of the aircraft motor.

[0033] It can be seen from the above settings that the permanent magnet array of the aircraft motor in the embodiment of the present invention is more adaptable to the magnetic field direction, achieving the effect of the Halbach permanent magnet array. Under the original weight and volume requirements of the motor, the output power and output torque of the motor are improved, enabling the aircraft to carry a greater load.

[0034] Specifically, in the embodiment of the present invention, the aircraft motor includes two parts: a stator assembly and a rotor assembly. There is an air gap 103 between the stator assembly and the rotor assembly. The stator assembly specifically includes components such as a stator core 101 and a stator winding 102, and the rotor assembly specifically includes components such as a rotor yoke 104, a radial permanent magnet 106, and a tangential permanent magnet 105. Figure 1 The figure shows a partial period model of the aircraft motor in this embodiment. The stator core 101 has stator slots for accommodating the stator winding 102, and the rotor yoke 104 is generally annular. The radial permanent magnet 106 and the tangential permanent magnet 105 can be fixedly connected to the rotor yoke 104 through glue or other mechanical fits. In order to limit the tangential permanent magnet 105 on the rotor yoke 104, which is more conducive to assembly, the embodiment of the present invention provides a notch 100 on the rotor yoke 104 to place the tangential permanent magnet 105 to prevent the tangential permanent magnet 105 from moving. The notch 100 faces the stator core 101, and the tangential permanent magnet 105 placed in the notch 100 can interact with the stator core 101 to form the required magnetic field.

[0035] In the structural design of the notch 100, the embodiment of the present invention has the following constraints on it:

[0036] H1 = k × H

[0037] Wherein, H is the thickness of the rotor yoke 104, H1 is the thickness of the notch 100 in the radius direction of the aircraft motor rotor, and k is a constraint coefficient. In this embodiment, its value range is 0.1 - 0.3.

[0038] Specifically, the notch 100 needs to have a certain height so that the tangential permanent magnet 105 can be placed therein. If H1 is too small, the permanent magnet may not be placed or fixed correctly. For example Figure 1As shown, the thickness H1 of the notch 100 specifically refers to the distance from the inner surface of the rotor yoke 104 to the bottom of the notch 100. The thickness H of the rotor yoke 104 determines its mechanical strength, such as Figure 1 As shown, the thickness H of the rotor yoke 104 specifically refers to the distance from its inner surface to the outer surface. If the thickness H1 of the notch 100 is too large, it may weaken the strength of the rotor yoke 104, affecting the overall stability and durability of the motor. If the permanent magnet is placed too deep or the rotor yoke is too thin, it may cause too high magnetic density in the permanent magnet or the rotor yoke, thus causing magnetic saturation (magnetic saturation means that the magnetization intensity in the magnetic material reaches its maximum value and cannot be further increased), affecting the performance of the motor. The constraint coefficient k defines the magnitude relationship between the thickness H1 of the notch 100 and the thickness H of the rotor yoke 104.

[0039] Through the above settings, the tangential permanent magnet 105 can be correctly placed in the notch 100 of the rotor yoke 104, while maintaining the mechanical strength of the rotor yoke 104 and avoiding the occurrence of magnetic saturation, thereby optimizing the performance and reliability of the motor.

[0040] Furthermore, the tangential permanent magnet 105 includes a trapezoidal permanent magnet and a rectangular permanent magnet. Among them, the trapezoidal permanent magnet is first placed in the notch 100 for positioning, and then a rectangular permanent magnet is assembled on each side of the trapezoidal permanent magnet, thereby forming a tangential permanent magnet group composed of one trapezoidal permanent magnet and two rectangular permanent magnets. As another example, the rectangular permanent magnets located on both sides of the trapezoidal permanent magnet can also be respectively accommodated in the notch 100, and the trapezoidal permanent magnet and the two rectangular permanent magnets form a tangential permanent magnet group. In this case, the two rectangular permanent magnets are first respectively placed in the notch 100 for positioning, and then the trapezoidal permanent magnet is assembled between the two rectangular permanent magnets, thereby also forming a tangential permanent magnet group composed of one trapezoidal permanent magnet and two rectangular permanent magnets.

[0041] The radial permanent magnet 106 is a rectangular permanent magnet and is symmetrically assembled on both sides of the tangential permanent magnet group. The tangential permanent magnet 105 can be magnetized in a circular ring or non-circular ring, such as parallel magnetization, sector magnetization, etc. The choice of magnetization method depends on the required magnetic field distribution, specific requirements of the motor design, and feasibility of the manufacturing process.

[0042] As an example, the above-mentioned tangential permanent magnet group is first magnetized in a circular ring, and then assembled with the radially magnetized permanent magnet 106 that has been magnetized in parallel. The magnetization direction of the circular ring magnetization is as shown in Figure 1 108 in the figure. According to the arrangement of the N and S poles, the orientation is different. The center 109 of the circular ring magnetization is located in the air gap 103. Generally, the center is located on the midline of the N and S poles, and the optimal performance of the motor can also be achieved by adjusting the deviation angle of the midline. The center is radially arranged within the air gap 103, and by adjusting the radial position of the center in the air gap 103, smaller harmonic content, torque ripple, and cogging torque can be achieved.

[0043] The radial permanent magnet 106 is magnetized in parallel, as Figure 1 shown by the radial magnetization direction 507. Its magnetization direction is generally parallel to the radial permanent magnet 106, and the direction is towards the inner diameter of the aircraft motor rotor or towards the outer diameter of the aircraft motor rotor, providing a radial magnetic field for the aircraft motor. As an example, the radial permanent magnet 106 can also adopt an annular magnetization method, and the center 109 of the annular magnetization is located within the air gap 103.

[0044] It can be understood that the tangential permanent magnet 105 forms an annular magnetic field by adopting an annular magnetization method, with less magnetic field loss and better performance. As Figure 2 shown in the simulation diagram, the magnetic force line direction of the motor is circular, and the best magnetic field utilization effect can be achieved. The tangential permanent magnet of the present utility model adopts annular magnetization adapted to the magnetic field direction, which can further provide the working point of the permanent magnet, improve the utilization rate of the permanent magnet, and reduce the number of magnetic force lines generated by the rotor yoke 104 by 40% under the same performance. As Figure 3 shown, if an approximately annular magnetic field is formed by splicing straight lines with parallel magnetization, there will be magnetic field loss, and the simulation performance loss is 1%-2%. It should also be noted that the tangential permanent magnet 105 magnetized by the annular magnetization can provide tangential and radial magnetic forces for the rotor, and assist in magnetizing the radial permanent magnet 106. The tangential magnetic force can greatly strengthen the air gap magnetic density, improve the motor output performance, and can provide a magnetic circuit for the radial permanent magnet 106, reducing the dependence on the magnetic circuit of the rotor yoke 104. The rotor yoke 104 can reduce the thickness, thereby reducing the weight of the motor. While strengthening the air gap magnetic density, it will improve the sine degree of the no-load back electromotive force, reduce harmonics, reduce motor losses, and further improve the motor efficiency.

[0045] As can be seen from the above, the magnetic steel array of the aircraft motor in the embodiment of the present utility model forms a Halbach magnetic steel array structure, which has all the advantages of the Halbach magnetic steel array structure, such as large power density, no need for skewing of the stator and rotor, the rotor can be thinned or non-iron core materials can be used, high utilization rate of permanent magnets, and the use of concentrated windings, etc.

[0046] When the magnetic steel array of this embodiment is assembled with the aircraft motor, the stator assembly is generally fixed by a bracket to ensure that the stator does not move. The rotor is fixed to the rotating shaft through bearings, and then the torque is transmitted through other structures. The stator winding 102 is wound with copper wire into the stator core slots. First, the trapezoidal magnetic steel is placed into the notch 100 for positioning, and then a rectangular magnetic steel is assembled on each side of the trapezoidal magnetic steel, thereby forming a tangential magnetic steel group composed of one trapezoidal magnetic steel and two rectangular magnetic steels. After the tangential magnetic steel group is magnetized by the annular magnetization, the magnetized radial permanent magnet is assembled on both sides of the tangential magnetic steel group; all the rotor magnetic steels are assembled along the circumferential direction of the rotor yoke 104 in the same way. After the stator winding 102 is energized, a magnetic field is generated through the stator, which interacts with the rotor magnetic field to generate torque, and the torque is output as power to the transmission mechanism.

[0047] Corresponding to the motor magnet array of the aircraft of the foregoing embodiment of the present invention, Embodiment 2 of the present invention further provides an aircraft motor, including:

[0048] A stator assembly, the stator assembly further includes a stator core 101 and a stator winding 102;

[0049] A rotor assembly, which is disposed opposite to the stator assembly and has an air gap 103 with the stator assembly. The rotor assembly further includes a rotor yoke 104, a radial magnet 106, and a tangential magnet 105;

[0050] The radial magnets 106 are arranged along the radius direction of the rotor of the aircraft motor to provide a radial magnetic field for the aircraft motor;

[0051] The tangential magnets 105 are arranged along the tangent direction of the rotor of the aircraft motor to provide a tangential magnetic field for the aircraft motor and provide a magnetic path for the radial magnetic field; the tangential magnets 105 are installed in the notch 100 of the rotor yoke 104.

[0052] Preferably, the thickness H1 of the notch 100 in the radius direction of the rotor of the aircraft motor is the product of the thickness H of the rotor yoke 104 and a preset constraint coefficient k.

[0053] Preferably, the tangential magnets 105 include trapezoidal magnets and rectangular magnets. Among them, the trapezoidal magnets are accommodated in the notch, and a rectangular magnet is assembled on each side of the trapezoidal magnet. The trapezoidal magnet and the two rectangular magnets form a tangential magnet group.

[0054] Preferably, the tangential magnets 105 include trapezoidal magnets and rectangular magnets assembled on both sides of the trapezoidal magnets. The rectangular magnets are respectively accommodated in the notch 100. The trapezoidal magnet and the two rectangular magnets form a tangential magnet group.

[0055] Preferably, the tangential magnets 105 or the radial magnets 106 adopt a circular ring magnetization method, and the center of the circular ring magnetization is located in the air gap 103 between the stator assembly and the rotor assembly.

[0056] The radial magnets 106 adopt parallel magnetization, as shown by the radial magnetization direction 507 in Figure 1 Its magnetization direction is generally parallel to the radial magnets 106, and the direction is towards the inner diameter or the outer diameter of the motor to provide a radial magnetic field for the motor.

[0057] When assembling the aircraft motor, the stator assembly is generally fixed by a bracket to ensure that the stator does not move. The rotor is fixed to the rotating shaft through bearings, and then the torque is transmitted through other structures. The stator winding 102 is wound with copper wire into the stator core slots. First, the trapezoidal permanent magnet is placed in the notch 100 for positioning, and then a rectangular permanent magnet is assembled on each side of the trapezoidal permanent magnet, thereby forming a tangential permanent magnet group composed of one trapezoidal permanent magnet and two rectangular permanent magnets. After the tangential permanent magnet group is magnetized by a circular ring, the magnetized radial permanent magnets are assembled on both sides of the tangential permanent magnet group; all the rotor permanent magnets are assembled in the circumferential direction of the rotor yoke 104 in the same way. It can be understood that the rotor permanent magnet group on the rotor yoke 104, including the tangential permanent magnet group and the radial permanent magnet 106, is arranged in the circumferential direction of the rotor in a closely arranged manner, and there is no gap between the arrangements of each permanent magnet group, ensuring the continuity of the magnetic field and the optimization of the motor performance. Multiple rotor permanent magnet groups can also be arranged at equal intervals in the circumferential direction of the rotor to form a complete rotor permanent magnet array, ensuring the uniform distribution of the magnetic field. After the stator winding 102 is energized, a magnetic field is generated through the stator, and interacts with the rotor magnetic field to generate torque, and the torque is output as power to the transmission mechanism.

[0058] Regarding the working principle and process of the above embodiments, refer to the description of Embodiment 1 of the present invention above, and details will not be repeated here.

[0059] It can be seen from the above description that compared with the prior art, the beneficial effects of the present invention are as follows: Through the innovative permanent magnet magnetization structure and layout, the performance of the aircraft motor is significantly improved, and the output power and torque of the motor are enhanced without increasing the weight and volume of the motor. At the same time, the notch design of the rotor yoke and the fixing method of the permanent magnet further improve the installation stability of the permanent magnet, avoid the problem of excessive magnetic flux saturation, and ensure the long-term reliable operation of the motor. The present invention enables the aircraft to carry a greater load, thereby expanding its application range and improving its transportation capacity. In addition, the permanent magnet array structure of the present invention optimizes the magnetic field distribution, reduces torque ripple and cogging torque, thereby improving the operating efficiency and stability of the motor. The present invention also realizes the efficient utilization of the magnetic field and reduces energy loss. The permanent magnet array structure of the present invention is not only applicable to outer rotor motors but also to inner rotor motors, and has wide applicability, providing new ideas and solutions for the design of aircraft motors.

[0060] The above-disclosed are only the preferred embodiments of the present invention. Of course, the scope of the rights of the present invention cannot be limited thereby. Therefore, equivalent changes made according to the claims of the present invention still fall within the scope covered by the present invention.

Claims

1. An aircraft motor magnet array, characterized in that, Comprising: A plurality of radial permanent magnets arranged along the radius direction of the rotor of the aircraft motor, for providing a radial magnetic field for the aircraft motor; A plurality of tangential permanent magnets arranged along the tangent direction of the rotor of the aircraft motor, for providing a tangential magnetic field for the aircraft motor and providing a magnetic path for the radial magnetic field; the tangential permanent magnets are installed in the notches of the rotor yoke of the aircraft motor.

2. The motor magnet array of the aircraft according to claim 1, wherein The thickness of the notch in the radius direction of the rotor of the aircraft motor is the product of the thickness of the rotor yoke and a preset constraint coefficient.

3. The magnet array of the aircraft motor according to claim 1, characterized in that The tangential permanent magnets include trapezoidal permanent magnets and rectangular permanent magnets. Among them, the trapezoidal permanent magnets are accommodated in the notches, and one rectangular permanent magnet is assembled on each side of the trapezoidal permanent magnets. The trapezoidal permanent magnets and the two rectangular permanent magnets form a tangential permanent magnet group.

4. The motor magnet array of the aircraft according to claim 1, characterized in that, The tangential permanent magnets include trapezoidal permanent magnets and rectangular permanent magnets assembled on both sides of the trapezoidal permanent magnets. The rectangular permanent magnets are respectively accommodated in the notches. The trapezoidal permanent magnets and the two rectangular permanent magnets form a tangential permanent magnet group.

5. The magnet array of the aircraft motor according to claim 3 or 4, characterized in that The radial permanent magnets are symmetrically assembled on both sides of the tangential permanent magnet group.

6. The motor magnet array of the aircraft according to claim 1, wherein The tangential permanent magnets or the radial permanent magnets adopt a circular ring magnetization method, and the center of the circular ring magnetization is located in the air gap between the stator assembly and the rotor assembly.

7. The magnet array of the aircraft motor according to claim 1, wherein The radial permanent magnets adopt a parallel magnetization method, and the magnetization direction is parallel to the radial permanent magnets and faces the inner diameter or the outer diameter of the rotor of the aircraft motor.

8. An aircraft motor, characterized in that, Comprising: A stator assembly, which further includes a stator core and a stator winding; A rotor assembly, which is arranged opposite to the stator assembly and has an air gap with the stator assembly. The rotor assembly further includes a rotor yoke, radial permanent magnets and tangential permanent magnets; The radial permanent magnets are arranged along the radius direction of the rotor of the aircraft motor, for providing a radial magnetic field for the aircraft motor; The tangential permanent magnets are arranged along the tangent direction of the rotor of the aircraft motor, for providing a tangential magnetic field for the aircraft motor and providing a magnetic path for the radial magnetic field; the tangential permanent magnets are installed in the notches of the rotor yoke.

9. The aircraft motor according to claim 8, characterized in that, The thickness of the notch in the radius direction of the rotor of the aircraft motor is the product of the thickness of the rotor yoke and a preset constraint coefficient.

10. The aircraft motor according to claim 9, characterized in that, The tangential permanent magnets include trapezoidal permanent magnets and rectangular permanent magnets. Among them, the trapezoidal permanent magnets are accommodated in the notches, and one rectangular permanent magnet is assembled on each side of the trapezoidal permanent magnets. The trapezoidal permanent magnets and the two rectangular permanent magnets form a tangential permanent magnet group.

11. The aircraft motor according to claim 8, wherein The tangential permanent magnets include trapezoidal permanent magnets and rectangular permanent magnets assembled on both sides of the trapezoidal permanent magnets. The rectangular permanent magnets are respectively accommodated in the notches. The trapezoidal permanent magnets and the two rectangular permanent magnets form a tangential permanent magnet group.

12. The aircraft motor according to claim 8, wherein, The tangential permanent magnets or the radial permanent magnets adopt a circular ring magnetization method, and the center of the circular ring magnetization is located in the air gap between the stator assembly and the rotor assembly.

Images