Rotor structure with asymmetric magnetic poles, permanent magnet motor and manufacturing method

Abstract

The invention provides a rotor structure with asymmetric magnetic poles, a permanent magnet motor and a manufacturing method, the rotor structure comprises an iron core, the iron core is provided with a shaft hole, a plurality of magnetic steel groups are arranged along the periphery of the shaft hole of the iron core at equal intervals, and each magnetic steel group comprises a plurality of permanent magnet mounting grooves and permanent magnets corresponding to the permanent magnet mounting grooves in number, a permanent magnet is arranged in each permanent magnet mounting groove; wherein the sizes of the plurality of permanent magnet mounting grooves are configured to be different, and the spatial position relationship among the plurality of permanent magnet mounting grooves is arranged to be an asymmetric structure. The sizes of the plurality of permanent magnet mounting grooves are configured to be different, so that the limitation of a traditional symmetrical structure is broken through. The asymmetric design can optimize the magnetic field distribution of the permanent magnet, so that the phase difference between the reluctance torque component and the permanent magnet torque component is greatly reduced, and the effective torque superposition of the reluctance torque component and the permanent magnet torque component under wider working conditions is realized.

Description

Technical Field

[0001] This invention belongs to the technical field of permanent magnet motor design technology, and more specifically, relates to a rotor structure with asymmetric magnetic poles, a permanent magnet motor, and a method for manufacturing it. Background Technology

[0002] Permanent magnet motors, with their significant advantages of high efficiency, high power density, and low loss, have become core power devices in many fields such as new energy vehicles and industrial drives. However, traditional permanent magnet synchronous motors typically employ symmetrical rotor topologies, such as straight-line, V-type, or double-V-type structures. Although these structures can improve the air gap magnetic flux density to some extent through the magnetic focusing effect, their symmetry results in a large phase difference between the reluctance torque component and the permanent magnet torque component, making it difficult to achieve effective superposition of maximum torque. This limits the motor's torque output capability and its adaptability to different operating conditions.

[0003] In existing technologies, taking the V-type permanent magnet layout as an example, although it increases the proportion of reluctance torque through q-axis magnetic circuit equalization, due to the limitation of geometric symmetry, there is still an inherent phase shift between the magnetic field generated by the permanent magnet and the quadrature-axis reluctance path. This phase shift causes the total torque curve to exhibit a "double-peak" phenomenon, making it impossible to maintain optimal output performance over a wide speed range and limiting the application range of the motor under complex operating conditions.

[0004] Furthermore, traditional symmetrical permanent magnet motors are prone to local magnetic saturation during operation, especially under overload or weak magnetic field conditions. This leads to a significant increase in iron losses in the rotor magnetic bridge region, which not only reduces the overall system efficiency but also affects the motor's reliability and lifespan. Therefore, optimizing the rotor structure of permanent magnet motors to address these issues is a pressing technical challenge for those skilled in the art. Summary of the Invention

[0005] To address the aforementioned deficiencies or improvement needs of existing technologies, this invention breaks the limitations of traditional symmetrical structures by configuring several permanent magnet mounting slots with non-uniform dimensions. This asymmetrical design optimizes the magnetic field distribution of the permanent magnets, significantly reducing the phase difference between the reluctance torque component and the permanent magnet torque component, thereby enabling effective torque superposition under a wider range of operating conditions. Specifically, in a first aspect, this invention provides a rotor structure with asymmetrical magnetic poles, comprising: an iron core and a magnet assembly.

[0006] The iron core has a shaft hole, and several groups of magnets are arranged at equal intervals along the outer periphery of the shaft hole of the iron core. Each group of magnets includes: several permanent magnet mounting slots and a number of permanent magnets corresponding to the number of permanent magnet mounting slots. One permanent magnet is installed in each permanent magnet mounting slot.

[0007] Specifically, the dimensions of several permanent magnet mounting slots are configured to be different, so as to adjust the phase relationship between the reluctance torque component and the permanent magnet torque component by arranging the different dimensions. In addition, the spatial positional relationship between the several permanent magnet mounting slots is arranged into an asymmetrical structure, thereby directionally controlling the magnetic circuit reluctance and local saturation, and improving the total torque.

[0008] In the first aspect, the permanent magnet mounting groove includes a first magnet groove, a second magnet groove, and a third magnet groove;

[0009] There is a first distance between the first magnet slot and the second magnet slot near the outer diameter of the iron core, and there is a second distance between the first magnet slot and the second magnet slot near the shaft hole of the iron core.

[0010] The third magnet slot is located between the first magnet slot and the second magnet slot.

[0011] In the first aspect, the width a1 of the first magnet slot, the width a2 of the second permanent magnet slot, and the width a3 of the third permanent magnet slot satisfy the following: a1 = k1 × a2, k1 = 1.5 - 2 mm; a2 = a3, where k1 is the first width coefficient;

[0012] The permanent magnet includes a first permanent magnet, a second permanent magnet, and a third permanent magnet, which are respectively adapted to be disposed in the first magnet slot, the second magnet slot, and the third magnet slot.

[0013] In the first aspect, the first magnet slot has a first long side, the second magnet slot has a second long side, and the third magnet slot has a third long side;

[0014] Wherein, the angle between the first long side of the first magnet slot and the central axis of the magnet group is a first acute angle, and it is located on one side of the central axis of the magnet group; the angle between the second long side of the second magnet slot and the central axis of the magnet group is a second acute angle, and it is located on the other side of the first magnet slot of the magnet group relative to the central axis.

[0015] In the first aspect, the first magnet slot, the second magnet slot, and the third magnet slot form a first magnetic isolation bridge between the corresponding outer edge of the iron core;

[0016] The outer diameter distance between the first magnet slot, the second magnet slot, and the third magnet slot and the outer edge of the iron core is 0.3-1.5 mm.

[0017] In the first aspect, a second magnetic isolation bridge with a width of a3 is formed between the first magnet slot and the end of the third magnet slot near the axis, and a third magnetic isolation bridge with a width of a4 is formed between the end of the second magnet slot and the end of the third magnet slot near the axis; wherein the width a3 of the second magnetic isolation bridge and the width a4 of the third magnetic isolation bridge satisfy the following: a3=k2×a4, k2=1-1.3mm, and k2 is a second width coefficient.

[0018] In the first aspect, after the first permanent magnet, the second permanent magnet, and the third permanent magnet are respectively installed in the first magnet slot, the second magnet slot, and the third magnet slot, each end of the first magnet slot, the second magnet slot, and the third magnet slot also has an unfilled air area to form an air magnetic barrier.

[0019] In the first aspect, the first permanent magnet has a fourth long side and a fourth short side, the second permanent magnet has a fifth long side and a fifth short side, and the third permanent magnet has a sixth long side and a sixth short side;

[0020] The length l1 of the fourth long side of the first permanent magnet is greater than the length l2 of the fifth long side of the second permanent magnet, and the length l1 of the fourth long side of the first permanent magnet is greater than the length l3 of the sixth long side of the third permanent magnet; the lengths l1 of the fourth long side of the first permanent magnet, l2 of the fifth long side of the second permanent magnet, and l3 of the sixth long side of the third permanent magnet satisfy the following: l1 = k3 × l2, k3 = 1.5 - 2 mm; l2 = k4 × l3, k4 = 1 - 1.2 mm, where k3 and k4 are length coefficients;

[0021] Furthermore, the fifth short side of the second permanent magnet and the sixth short side of the third permanent magnet are of equal length, and the fourth short side of the first permanent magnet is longer than the fifth short side of the second permanent magnet, but shorter than the sum of the fifth short side length of the second permanent magnet and the sixth short side length of the third permanent magnet.

[0022] Secondly, the present invention provides a permanent magnet motor, wherein the permanent magnet motor has the rotor structure with asymmetric magnetic poles described above.

[0023] Thirdly, the present invention provides a method for manufacturing a rotor structure, the method comprising:

[0024] S1. Several installation areas are equally spaced around the circumferential periphery of the iron core shaft hole;

[0025] S2. Each installation area is provided with a set of magnets; the provision of a set of magnets includes: opening a plurality of permanent magnet mounting slots and a number of permanent magnets corresponding to the permanent magnet mounting slots; wherein, the size of the plurality of permanent magnet mounting slots is configured to be different, and the spatial positional relationship between the plurality of permanent magnet mounting slots is arranged in an asymmetrical structure.

[0026] In summary, compared with the prior art, the above-described technical solutions conceived by this invention can achieve the following beneficial effects:

[0027] 1. This invention provides a rotor structure with asymmetrical magnetic poles, breaking the limitations of traditional symmetrical structures by configuring several permanent magnet mounting slots with non-uniform dimensions. This asymmetrical design optimizes the magnetic field distribution of the permanent magnets, significantly reducing the phase difference between the reluctance torque component and the permanent magnet torque component, thereby enabling effective torque superposition under a wider range of operating conditions. Compared with existing technologies, this structure significantly improves the motor's torque output capability, especially over a wide speed range, resulting in a smoother total torque curve and avoiding the "double-peak" phenomenon caused by phase shift in traditional structures, thus achieving efficient motor operation under various conditions.

[0028] 2. Furthermore, the rotor structure with asymmetrical magnetic poles effectively alleviates the local magnetic saturation problem that is easily caused by traditional symmetrical structures. Due to the asymmetrical configuration of the permanent magnet mounting slot dimensions, the magnetic field distribution is more uniform, avoiding a significant increase in iron losses in the rotor magnetic bridge area under overload or weak magnetic field conditions. This not only improves the system efficiency of the motor but also enhances its reliability and service life, providing a more efficient and reliable power solution for new energy vehicles, industrial drives, and other fields.

[0029] 3. In general, by optimizing parameters such as magnetic bridge, air magnetic barrier, and pole arc coefficient, the rotor structure of asymmetric magnetic poles can reduce the current angle difference between the maximum permanent magnet and reluctance torque components, increase torque output capability by utilizing the magnetic field offset effect, reduce torque ripple, improve efficiency, and increase the constant torque output range, which is convenient for control. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the rotor structure with asymmetric magnetic poles in this embodiment;

[0031] Figure 2 This is a schematic diagram of the magnet assembly structure of the rotor structure with asymmetric magnetic poles in this embodiment. Figure 1 ;

[0032] Figure 3 This is a schematic diagram of the magnet assembly structure of the rotor structure with asymmetric magnetic poles in this embodiment. Figure 2 ;

[0033] Figure 4 This is a schematic diagram of the magnet assembly structure of the rotor structure with asymmetric magnetic poles in this embodiment. Figure 3 ;

[0034] Figure 5 This is a schematic diagram illustrating how the total torque of the motor changes with the current under the same operating conditions in this embodiment.

[0035] Figure 6 This is a schematic diagram illustrating how the total torque of the motor changes with the current angle under the same operating conditions in this embodiment.

[0036] Explanation of reference numerals in the attached figures:

[0037] 1. Iron core;

[0038] 2. Shaft hole;

[0039] 3. First magnet slot;

[0040] 4. Third magnet slot;

[0041] 5. Second magnet slot;

[0042] 6. Air Zone One;

[0043] 7. Air Zone Two;

[0044] 8. Air Zone Three;

[0045] 9. Air Zone Four;

[0046] 10. Air Zone Five;

[0047] 11. Air Zone Six;

[0048] 12. Magnet assembly;

[0049] 13. First magnetic isolation bridge;

[0050] 15. Second magnetic isolation bridge;

[0051] 16. The third magnetic isolation bridge;

[0052] 17. The first permanent magnet;

[0053] 18. Second permanent magnet;

[0054] 19. The third permanent magnet. Detailed Implementation

[0055] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0056] Example 1:

[0057] Please see Figure 1-6 This embodiment provides a rotor structure with asymmetric magnetic poles provided by the present invention, including: an iron core 1 and a magnet assembly 12;

[0058] The iron core 1 has a shaft hole 2, and several groups of magnet groups 12 are equally spaced along the outer periphery of the shaft hole 2 of the iron core 1. Each magnet group 12 includes: several permanent magnet mounting slots and a number of permanent magnets corresponding to the number of permanent magnet mounting slots. One permanent magnet is installed in each permanent magnet mounting slot. The dimensions of the several permanent magnet mounting slots are configured to be different, so as to adjust the phase relationship between the reluctance torque component and the permanent magnet torque component by arranging them with different dimensions. The spatial position relationship between the several permanent magnet mounting slots is arranged as an asymmetrical structure, thereby directionally controlling the magnetic circuit reluctance and local saturation, and improving the total torque.

[0059] Specifically, by configuring several permanent magnet mounting slots with non-uniform dimensions, the limitations of traditional symmetrical structures are broken. This asymmetrical design optimizes the magnetic field distribution of the permanent magnets, significantly reducing the phase difference between the reluctance torque component and the permanent magnet torque component, thereby enabling effective torque superposition under a wider range of operating conditions. Compared with existing technologies, this structure significantly improves the motor's torque output capability, especially over a wide speed range, resulting in a smoother overall torque curve and avoiding the "double-peak" phenomenon caused by phase shift in traditional structures. This enables efficient motor operation under various conditions. Furthermore, the rotor structure with asymmetrical magnetic poles effectively alleviates the local magnetic saturation problem easily caused by traditional symmetrical structures. Due to the asymmetrical configuration of the permanent magnet mounting slot dimensions, the magnetic field distribution is more uniform, avoiding a significant increase in iron losses in the rotor magnetic bridge region under overload or weak magnetic field conditions. This not only improves the motor's system efficiency but also enhances its reliability and service life, providing a more efficient and reliable power solution for new energy vehicles, industrial drives, and other fields.

[0060] Furthermore, the magnet group 12 can be set to an even number of groups. The optimal setting in this embodiment is 10 groups. It should be noted that the number of groups of magnet groups 12 should not be a limitation on the implementation of the invention. Any other number of groups can play the same role as the groups disclosed in this embodiment, and are also within the protection scope of Embodiment 1 of this application.

[0061] In a preferred embodiment, the permanent magnet mounting slot includes a first magnet slot 3, a second magnet slot 5, and a third magnet slot 4; a first distance exists between the ends of the first magnet slot 3 and the second magnet slot 5 near the outer diameter of the iron core 1, and a second distance exists between the ends of the first magnet slot 3 and the second magnet slot 5 near the shaft hole 2 of the iron core 1; wherein, the third magnet slot 4 is located between the first magnet slot 3 and the second magnet slot 5. Due to the positional relationship of the first magnet slot 3, the second magnet slot 5, and the third magnet slot 4, the permanent magnets disposed in each magnet slot also have correspondingly similar structural shapes. This shape reduces the angle between the permanent magnet torque and the reluctance torque, thereby increasing the torque density of the motor.

[0062] In a preferred embodiment, the width a1 of the first magnet slot 3, the width a2 of the second permanent magnet slot 18, and the width a3 of the third permanent magnet slot 19 satisfy the following: a1 = k1 × a2, k1 = 1.5-2 mm; a2 = a3, where k1 is a first width coefficient; the permanent magnets include a first permanent magnet 17, a second permanent magnet 18, and a third permanent magnet 19, which are correspondingly and appropriately arranged in the first magnet slot 3, the second magnet slot 5, and the third magnet slot 4. Through this specific size configuration, the magnetic field distribution of the permanent magnets can be made more reasonable, the phase relationship between the reluctance torque and the permanent magnet torque can be optimized, thereby achieving efficient torque superposition and improving the performance of the motor.

[0063] In a preferred embodiment, the first magnet slot 3 has a first long side, the second magnet slot 5 has a second long side, and the third magnet slot 4 has a third long side;

[0064] The angle between the first long side of the first magnet slot 3 and the central axis of the magnet group 12 is a first acute angle, which ranges from 30° to 90° and is located on one side of the central axis of the magnet group 12. The angle between the second long side of the second magnet slot 5 and the central axis of the magnet group 12 is a second acute angle, which ranges from 30° to 90° and is located on the other side of the first magnet slot 3 of the magnet group 12 relative to the central axis.

[0065] In a preferred embodiment, the first magnet slot 3, the second magnet slot 5, and the third magnet slot 4 form a first magnetic isolation bridge 13 between the corresponding outer edge of the iron core 1. This design, by setting a magnetic isolation bridge between the permanent magnet and the outer edge of the iron core 1, can effectively reduce magnetic flux leakage, optimize the magnetic field distribution, and further improve the performance of the motor.

[0066] Specifically, the outer diameter distance between the outer edge of the first magnet slot 3, the second magnet slot 5, and the third magnet slot 4 and the outer edge of the corresponding iron core 1 is 0.3-1.5 mm. This size range ensures that the magnetic isolation bridge can effectively block magnetic flux leakage while avoiding the impact on the overall strength and stability of the rotor structure due to an excessively large magnetic isolation bridge. By precisely controlling the size of the magnetic isolation bridge, the reliability and durability of the system can be improved while ensuring the efficient operation of the motor.

[0067] In a preferred embodiment, a magnetic isolation bridge structure is further formed between the first magnet slot 3, the second magnet slot 5, and the third magnet slot 4 on the iron core 1 of the rotor structure to optimize the magnetic field distribution and enhance motor performance. Specifically, a second magnetic isolation bridge 15 with a width of a3 is formed between the first magnet slot 3 and the end of the third magnet slot 4 near the shaft center, and a third magnetic isolation bridge 16 with a width of a4 is formed between the end of the second magnet slot 5 and the end of the third magnet slot 4 near the shaft center. This magnetic isolation bridge design can effectively adjust the magnetic flux path, reduce the fluctuation of magnetic reluctance torque, and further improve the operating efficiency and stability of the motor. The width a3 of the second magnetic isolation bridge 15 and the width a4 of the third magnetic isolation bridge 16 satisfy the relationship: a3 = k2 × a4, where k2 is a second width coefficient with a value range of 1-1.3 mm. Through this specific dimensional ratio relationship, the width of the magnetic isolation bridge can be precisely controlled, thereby optimizing the magnetic field distribution, reducing magnetic flux leakage, and avoiding magnetic reluctance torque fluctuations caused by unreasonable magnetic isolation bridge design. This design not only improves the motor's torque output capability, but also enhances the motor's adaptability and reliability under different operating conditions, making it particularly suitable for applications that have strict requirements for high-efficiency and high-stability motor systems.

[0068] In a preferred embodiment, after the first permanent magnet 17, the second permanent magnet 18, and the third permanent magnet 19 are respectively installed in the first magnet slot 3, the second magnet slot 5, and the third magnet slot 4, each of the first magnet slot 3, the second magnet slot 5, and the third magnet slot 4 has an unfilled air region at both ends to form an air magnetic barrier. This air region is triangular or trapezoidal in shape. Figure 2 As shown, the air regions in this embodiment are divided into air region 1 (6), air region 2 (7), air region 3 (8), air region 4 (9), air region 5 (10), and air region 6 (11).

[0069] In a specific embodiment, the angle between the first permanent magnet 17 and the third permanent magnet 19 should be greater than the angle between the third permanent magnet 19 and the second permanent magnet 18, and the electrical angle between the first permanent magnet 17 and the air magnetic barrier should be less than 180°.

[0070] In a preferred embodiment, the first permanent magnet 17 has a fourth long side and a fourth short side, the second permanent magnet 18 has a fifth long side and a fifth short side, and the third permanent magnet 19 has a sixth long side and a sixth short side;

[0071] The length l1 of the fourth long side of the first permanent magnet 17 is greater than the length l2 of the fifth long side of the second permanent magnet 18, and the length l1 of the fourth long side of the first permanent magnet 17 is greater than the length l3 of the sixth long side of the third permanent magnet 19; the length l1 of the fourth long side of the first permanent magnet 17, the length l2 of the fifth long side of the second permanent magnet 18, and the length l3 of the sixth long side of the third permanent magnet 19 satisfy the following: l1 = k3 × l2, k3 = 1.5-2 mm; l2 = k4 × l3, k4 = 1-1.2 mm, where k3 and k4 are length coefficients;

[0072] Furthermore, the fifth short side of the second permanent magnet 18 and the sixth short side of the third permanent magnet 19 are of equal length, and the fourth short side of the first permanent magnet 17 is longer than the fifth short side of the second permanent magnet 18, but shorter than the sum of the fifth short side length of the second permanent magnet 18 and the sixth short side length of the third permanent magnet 19.

[0073] In the above embodiments, the shapes and dimensions of the first permanent magnet 17, the second permanent magnet 18, and the third permanent magnet 19 have been further designed to achieve better magnetic field distribution and torque output performance. Specifically, the first permanent magnet 17 has a fourth long side and a fourth short side, the second permanent magnet 18 has a fifth long side and a fifth short side, and the third permanent magnet 19 has a sixth long side and a sixth short side.

[0074] The fourth long side length of the first permanent magnet 17 is l1, the fifth long side length of the second permanent magnet 18 is l2, and the sixth long side length of the third permanent magnet 19 is l3. The fourth long side length l1 of the first permanent magnet 17 is greater than the fifth long side length l2 of the second permanent magnet 18, and greater than the sixth long side length l3 of the third permanent magnet 19. The fourth long side length l1 of the first permanent magnet 17, the fifth long side length l2 of the second permanent magnet 18, and the sixth long side length l3 of the third permanent magnet 19 satisfy the following relationship: l1 = k3 × l2, where k3 is a first length coefficient with a value range of 1.5-2; l2 = k4 × l3, where k4 is a second length coefficient with a value range of 1-1.2 mm. Through this specific size ratio relationship, the magnetic field coupling between the permanent magnets can be optimized, further improving the torque output capability and efficiency of the motor.

[0075] Furthermore, the fifth short side of the second permanent magnet 18 and the sixth short side of the third permanent magnet 19 are of equal length, while the fourth short side of the first permanent magnet 17 is longer than the fifth short side of the second permanent magnet 18, but shorter than the sum of the fifth short side lengths of the second permanent magnet 18 and the sixth short side lengths of the third permanent magnet 19. This design ensures the stability of the permanent magnets within the mounting slot, optimizes the magnetic field distribution, reduces magnetic flux leakage, and further improves the overall performance of the motor.

[0076] Please see Figure 5 The values ​​represent the torque output of the asymmetric rotor structure and the V-type rotor structure under different currents. A indicates the asymmetric rotor motor structure and B indicates the V-type motor structure. The test results of this embodiment show that the asymmetric rotor structure can generate higher torque at low currents, and the torque increases more significantly with increasing current, eventually reaching a higher torque value than the V-type rotor structure at high currents.

[0077] Please see Figure 6 The figures represent the torque output of the two structures at different current angles, where C represents the V-type rotor structure and D represents the asymmetric rotor structure. The asymmetric rotor structure can generate higher torque at a smaller current angle, and the torque rapidly reaches its peak as the current angle increases, then gradually decreases. In contrast, the V-type rotor structure has lower torque at a smaller current angle, and the torque gradually increases with the current angle, reaching its peak at a slightly larger current angle, and then also rapidly decreases.

[0078] It is evident that the asymmetric rotor structure exhibits better performance in terms of torque output, especially under conditions of low current and small current angle, giving it an advantage in applications requiring high efficiency and fast response.

[0079] Example 2:

[0080] This invention provides a permanent magnet motor with a rotor structure featuring asymmetric magnetic poles. This asymmetric rotor structure configures several permanent magnet mounting slots with non-uniform dimensions, breaking the limitations of traditional symmetrical structures. This asymmetric design optimizes the magnetic field distribution of the permanent magnets, significantly reducing the phase difference between the reluctance torque component and the permanent magnet torque component, thereby enabling effective torque superposition under a wider range of operating conditions. Compared to existing technologies, this structure significantly improves the motor's torque output capability, especially over a wide speed range, resulting in a smoother total torque curve and avoiding the "double-peak" phenomenon caused by phase shift in traditional structures. This achieves high-efficiency operation of the motor under various operating conditions.

[0081] Furthermore, the rotor structure of the permanent magnet motor also includes an iron core. The iron core has a shaft hole, and several groups of magnets are evenly spaced along the outer circumference of the shaft hole. Each magnet group includes several permanent magnet mounting slots and a number of permanent magnets corresponding to the number of mounting slots. One permanent magnet is installed in each mounting slot. Specifically, the permanent magnet mounting slot has several sub-slots, the number of which can be set according to actual needs, and each sub-slot contains one permanent magnet.

[0082] For the slots of the permanent magnet mounting groove, an air groove can be set up as a first air magnetic barrier. When permanent magnets are placed in other non-air grooves, gaps can be reserved at both ends of the permanent magnets to form a second air magnetic barrier. This combination of the first and second air magnetic barriers effectively blocks the direct conduction path of magnetic flux. Since the magnetic permeability of air is much lower than that of ferromagnetic materials, magnetic flux is significantly impeded when passing through the air magnetic barrier, thus reducing magnetic flux leakage. At the same time, the air magnetic barrier can adjust the distribution of the magnetic field, making it more uniform. In motor design, by rationally arranging the position and size of the air magnetic barriers, the strength and direction of the magnetic field can be optimized, avoiding excessive concentration or uneven distribution of the magnetic field.

[0083] Example 3:

[0084] This invention provides a method for manufacturing a rotor structure, the method comprising:

[0085] S1. Several installation areas are equally spaced around the circumferential periphery of the iron core shaft hole;

[0086] For step S1, several mounting areas are equally spaced around the circumferential periphery of the iron core shaft hole. These mounting areas are used for subsequent installation of permanent magnets. The number of mounting areas is determined according to the number of poles of the motor and design requirements, and is usually matched with the number of poles of the motor to ensure the uniformity and symmetry of the magnetic field distribution. For example, for a 4-pole motor, 4 or 8 mounting areas can be opened, depending on design requirements and performance optimization goals.

[0087] S2. Each installation area is equipped with a set of magnets; the set of magnets includes: opening a plurality of permanent magnet mounting slots and a number of permanent magnets corresponding to the permanent magnet mounting slots; wherein, the dimensions of the plurality of permanent magnet mounting slots are configured to be different. This design of different dimensions can optimize the magnetic field distribution, reduce the phase difference between the reluctance torque component and the permanent magnet torque component, thereby achieving more effective torque superposition. The widths a1, a2, and a3 of the first magnet slot satisfy the following relationship: a1 = k1 × a2, where k1 is the first width coefficient, with a value range of 1.5-2. The widths a2 and a3 of the second magnet slot are equal, i.e., a2 = a3. The length l1 of the fourth long side of the first permanent magnet is greater than the length l2 of the fifth long side of the second permanent magnet, and greater than the length l3 of the sixth long side of the third permanent magnet. The specific relationship is as follows: l1 = k3 × l2, where k3 is the first length coefficient, with a value range of 1.5-2; l2 = k4 × l3, where k4 is the second length coefficient, with a value range of 1-1.2 mm.

[0088] Furthermore, the spatial relationships between the various permanent magnet mounting slots are arranged in an asymmetrical structure.

[0089] Those skilled in the art will readily understand that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A rotor structure with asymmetric magnetic poles, characterized in that, include: The iron core (1) has a shaft hole (2) and several sets of magnet groups (12) are arranged at equal intervals along the outer periphery of the shaft hole (2) of the iron core (1). Each set of magnet groups (12) includes: several permanent magnet mounting slots and a number of permanent magnets corresponding to the number of permanent magnet mounting slots. One permanent magnet is installed in each permanent magnet mounting slot. Specifically, the dimensions of several permanent magnet mounting slots are configured to be different, so as to adjust the phase relationship between the reluctance torque component and the permanent magnet torque component by arranging the different dimensions. In addition, the spatial positional relationship between the several permanent magnet mounting slots is arranged into an asymmetrical structure, thereby directionally controlling the magnetic circuit reluctance and local saturation, and improving the total torque.

2. The rotor structure with asymmetric magnetic poles according to claim 1, characterized in that: The permanent magnet mounting slot includes a first magnet slot (3), a second magnet slot (5), and a third magnet slot (4); The first magnet slot (3) and the second magnet slot (5) have a first distance between their ends near the outer diameter of the iron core (1), and the first magnet slot (3) and the second magnet slot (5) have a second distance between their ends near the shaft hole (2) of the iron core (1); The third magnet slot (4) is located between the first magnet slot (3) and the second magnet slot (5).

3. The rotor structure with asymmetric magnetic poles according to claim 2, characterized in that: The width a1 of the first magnet slot (3), the width a2 of the second permanent magnet slot (18) and the width a3 of the third permanent magnet slot (19) satisfy the following: a1 = k1 × a2, k1 = 1.5-2 mm; a2 = a3, k1 is the first width coefficient; The permanent magnet includes a first permanent magnet (17), a second permanent magnet (18), and a third permanent magnet (19), which are respectively adapted to be disposed in the first magnet slot (3), the second magnet slot (5), and the third magnet slot (4).

4. The rotor structure with asymmetric magnetic poles according to claim 2, characterized in that: The first magnet slot (3) has a first long side, the second magnet slot (5) has a second long side, and the third magnet slot (4) has a third long side; The angle between the first long side of the first magnet slot (3) and the central axis of the magnet group (12) is a first acute angle, and it is located on one side of the central axis of the magnet group (12). The angle between the second long side of the second magnet slot (5) and the central axis of the magnet group (12) is a second acute angle, and it is located on the other side of the first magnet slot (3) of the magnet group (12) relative to the central axis.

5. The rotor structure with asymmetric magnetic poles according to any one of claims 1-4, characterized in that: The first magnet slot (3), the second magnet slot (5) and the third magnet slot (4) form a first magnetic isolation bridge (13) between the outer edge of the iron core (1) on the corresponding side; The outer diameter distance between the first magnet slot (3), the second magnet slot (5) and the third magnet slot (4) near the outer edge of the corresponding iron core (1) and the outer edge of the iron core (1) is 0.3-1.5mm.

6. The rotor structure with asymmetric magnetic poles according to claim 5, characterized in that: A second magnetic isolation bridge (15) with a width of a3 is formed between the first magnetic groove (3) and the third magnetic groove (4) near the axis, and a third magnetic isolation bridge (16) with a width of a4 is formed between the second magnetic groove (5) and the third magnetic groove (4) near the axis; wherein, the width a3 of the second magnetic isolation bridge (15) and the width a4 of the third magnetic isolation bridge (16) satisfy the following: a3=k2×a4, k2=1-1.3mm, k2 is the second width coefficient.

7. The rotor structure with asymmetric magnetic poles according to claim 3, characterized in that: After the first permanent magnet (17), the second permanent magnet (18), and the third permanent magnet (19) are respectively installed in the first magnet slot (3), the second magnet slot (5), and the third magnet slot (4), the two ends of the first magnet slot (3), the second magnet slot (5), and the third magnet slot (4) respectively still have unfilled air areas to form air magnetic barriers.

8. The rotor structure with asymmetric magnetic poles according to claim 7, characterized in that: The first permanent magnet (17) has a fourth long side and a fourth short side, the second permanent magnet (18) has a fifth long side and a fifth short side, and the third permanent magnet (19) has a sixth long side and a sixth short side; The length l1 of the fourth long side of the first permanent magnet (17) is greater than the length l2 of the fifth long side of the second permanent magnet (18), and the length l1 of the fourth long side of the first permanent magnet (17) is greater than the length l3 of the sixth long side of the third permanent magnet (19); the length l1 of the fourth long side of the first permanent magnet (17), the length l2 of the fifth long side of the second permanent magnet (18), and the length l3 of the sixth long side of the third permanent magnet (19) satisfy the following: l1 = k3 × l2, k3 = 1.5-2 mm; l2 = k4 × l3, k4 = 1-1.2 mm, where k3 and k4 are length coefficients; Furthermore, the fifth short side of the second permanent magnet (18) and the sixth short side of the third permanent magnet (19) are of equal length, and the fourth short side of the first permanent magnet (17) is longer than the fifth short side of the second permanent magnet (18) and shorter than the sum of the fifth short side length of the second permanent magnet (18) and the sixth short side length of the third permanent magnet (19).

9. A permanent magnet motor, characterized in that, The permanent magnet motor includes the rotor structure with asymmetric magnetic poles as described in any one of claims 1-8.

10. A method for manufacturing a rotor structure, characterized in that, The manufacturing method includes: S1. Several installation areas are opened at equal intervals around the circumferential periphery of the shaft hole (2) of the iron core (1); S2. Each installation area is provided with a set of magnet groups (12); the provision of a set of magnet groups (12) includes: opening a plurality of permanent magnet mounting slots and a number of permanent magnets corresponding to the permanent magnet mounting slots; wherein, the size of the plurality of permanent magnet mounting slots is configured to be different, and the spatial position relationship between the plurality of permanent magnet mounting slots is arranged in an asymmetrical structure.

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