Asymmetric rotor structure for improving torque density of motor, motor and method

Abstract

The invention provides an asymmetric rotor structure for improving the torque density of a motor, a motor and a method, the rotor structure comprises an iron core, the iron core is provided with a shaft hole, a plurality of magnetic steel groups are distributed in the circumferential direction of the shaft hole of the iron core at equal intervals, and each magnetic steel group comprises a plurality of permanent magnet mounting groove structures, an air groove structure and a plurality of permanent magnet structures, each permanent magnet mounting groove structure is correspondingly provided with one permanent magnet structure; any number of permanent magnet mounting groove structures are configured to have a first arrangement direction on the iron core, and the air groove structures are configured to have a second arrangement direction on the iron core; wherein the first layout direction and the second layout direction are asymmetrically arranged in a space coordinate; a magnetic flux path is blocked, and magnetic flux leakage is reduced. 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 an asymmetric rotor structure, motor and method for improving motor torque density. Background Technology

[0002] With the increasing severity of energy shortages, permanent magnet motors, due to their significant advantages such as high efficiency, high power density, and low loss, are gradually becoming core power devices in fields such as new energy vehicles and industrial drives. However, most traditional permanent magnet synchronous motors adopt symmetrical rotor topologies, such as the "I" type, V type, or double V type. Although these structures can improve the air gap magnetic flux density through the magnetic focusing effect, their symmetry leads to 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, thus restricting the motor's torque output capability and adaptability to operating conditions.

[0003] In existing technologies, taking the V-type permanent magnet layout as an example, although the proportion of reluctance torque is improved through q-axis magnetic circuit equalization, due to its 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 causes the total torque curve to exhibit a "double-peak" phenomenon, making it impossible to maintain optimal output performance over a wide speed range. In addition, the symmetrical structure is prone to local magnetic saturation problems in actual operation, especially under overload or weak magnetic field conditions, where the iron loss in the rotor magnetic bridge region increases significantly, seriously affecting the system's efficiency and reliability.

[0004] Therefore, the existing symmetrical rotor topology of permanent magnet synchronous motors has many shortcomings in terms of torque output capability, operating condition adaptability, system efficiency and reliability. There is an urgent need for a new rotor structure design that can effectively solve the above problems and address the existing technical issues. 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 an asymmetrical rotor structure for improving motor torque density. The rotor structure includes an iron core with a shaft hole, comprising:

[0006] Several groups of magnets are arranged at equal intervals around the circumference of the shaft hole of the iron core. Each group of magnets includes: several permanent magnet mounting slot structures, air slot structures and several permanent magnet structures. Each permanent magnet mounting slot structure is equipped with one permanent magnet structure.

[0007] Any number of the permanent magnet mounting slot structures are configured to have a first arrangement direction on the iron core, and the air slot structure is configured to have a second arrangement direction on the iron core; wherein the first arrangement direction and the second arrangement direction are asymmetrically arranged in spatial coordinates; and / or, all the permanent magnet mounting slot structures are asymmetrically arranged relative to each other in spatial coordinates; to block magnetic flux paths and reduce magnetic flux leakage.

[0008] In the first aspect, any number of the permanent magnet mounting slot structures are configured to have a first dimension on the iron core, and the air slot structure is configured to have a second dimension on the iron core, wherein the first dimension is different from the second dimension; and / or, all the permanent magnet mounting slot structures have different dimensions from each other; to adjust the phase relationship between the reluctance torque component and the permanent magnet torque component by arranging them with different dimensions.

[0009] In the first aspect, the permanent magnet mounting groove structure includes a first magnet groove and a second magnet groove, and the air groove structure includes a first air groove, wherein the first air groove is disposed between the first magnet groove and the second magnet groove;

[0010] The first magnet slot and the second magnet slot have a first distance between their ends near the outer diameter of the iron core, and the first magnet slot and the second magnet slot have a second distance between their ends near the shaft hole of the iron core.

[0011] In the first aspect, the width a1 of the first permanent magnet groove and the width a2 of the second permanent magnet groove satisfy the following relationship: a1 = k1 × a2, k1 = 1 - 2 mm, where k1 is the width coefficient.

[0012] In the first aspect, the permanent magnet structure includes a first permanent magnet and a second permanent magnet, wherein the first permanent magnet is disposed in the first magnet slot and the second permanent magnet is disposed in the second magnet slot;

[0013] The first permanent magnet, the second permanent magnet, the first magnet slot, and the second magnet slot all have a long side and a short side. The long side of the first permanent magnet is set close to the long side of the first magnet slot, and the long side of the second permanent magnet is set close to the long side of the second magnet slot.

[0014] In the first aspect, the angle between the 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 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 angle range of both the first acute angle and the second acute angle is 30°-90°.

[0016] In the first aspect, the first magnet slot and the second magnet slot are arranged in a V-shape, one end of the first air slot is connected to the side of the second magnet slot, and is arranged in a Y-shape with the second magnet slot.

[0017] In the first aspect, the first magnet slot, the first air slot, and the second magnet slot near the outer edge of the iron core form a first magnetic isolation bridge with the outer edge of the iron core, and the distance between the first magnet slot, the first air slot, and the second magnet slot near the outer edge of the iron core and the outer edge of the iron core is 0.3-1.5mm.

[0018] In the first aspect, a second magnetic bridge is formed between the ends of the first magnet slot and the second magnet slot near the shaft hole, and the distance between the first magnet slot and the second magnet slot is 0.3-1mm.

[0019] In the first aspect, the air trough structure is further configured such that, after the first permanent magnet and the second permanent magnet are respectively installed in the first magnet trough and the second magnet trough, the two ends of the first magnet trough and the second magnet trough respectively have unfilled air regions to form a second air trough.

[0020] In the first aspect, the length l1 of the long side of the first permanent magnet is greater than the length l2 of the long side of the second permanent magnet, the length l3 of the short side of the first permanent magnet is greater than the length l4 of the short side of the second permanent magnet, the length of the first air groove is less than the length of the long side of the second permanent magnet, and the length of the short side of the first air groove is less than the length of the short side of the second permanent magnet.

[0021] In the first aspect, the length l1 of the long side of the first permanent magnet and the length l2 of the long side of the second permanent magnet satisfy the following: l1 = k3 × l2, k3 = 1.5 - 2 mm; l3 = k4 × l4, k4 = 1 - 1.5 mm, where k3 is the first length coefficient and k4 is the second length coefficient.

[0022] Secondly, the present invention provides a permanent magnet motor, the permanent magnet motor including the asymmetric rotor structure described above.

[0023] Thirdly, the present invention provides a method for manufacturing a rotor, 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, air 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 an asymmetrical rotor structure that effectively improves the torque density of a motor. This structure utilizes asymmetrical permanent magnet mounting slots and air slots on the iron core, ensuring that the first and second mounting directions are asymmetrically arranged in spatial coordinates, or that all permanent magnet mounting slots are asymmetrically arranged relative to each other in spatial coordinates. This asymmetrical design blocks magnetic flux paths, reduces magnetic flux leakage, and thus improves the motor's magnetic field utilization. Compared to traditional symmetrical rotor structures, the asymmetrical structure can more effectively guide magnetic flux flow, avoiding excessive concentration of magnetic flux in local areas, thereby reducing iron and copper losses and significantly improving the motor's efficiency and power density.

[0028] 2. Furthermore, by optimizing the installation position of the permanent magnets and the layout of the air slots, this asymmetric rotor structure can improve the magnetic field distribution of the motor, enhance the synergistic effect of reluctance torque and permanent magnet torque, and further improve the motor's torque output capability. This design not only achieves better torque output over a wide speed range but also enhances the motor's adaptability under different operating conditions, improving the overall performance and reliability of the system.

[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 4This is a diagram showing the location distribution of the second air trough in this embodiment;

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

[0035] Figure 6 This is a schematic diagram showing the change of the total motor torque 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. Second magnet slot;

[0041] 5. First air tank;

[0042] 6. Air Zone One;

[0043] 7. Air Zone Two;

[0044] 8. Air Zone Three;

[0045] 9. Air Zone Four;

[0046] 10. Magnet assembly;

[0047] 11. First magnetic isolation bridge;

[0048] 12. Second magnetic isolation bridge;

[0049] 13. The first permanent magnet;

[0050] 14. Second permanent magnet;

[0051] 15. Second air tank. Detailed Implementation

[0052] 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.

[0053] Example 1:

[0054] Please see Figure 1-6This first embodiment provides a first aspect of the present invention, which provides an asymmetric rotor structure for improving the torque density of a motor. The rotor structure includes an iron core 1 with a shaft hole 2. It includes several groups of magnets 10 arranged at equal intervals around the shaft hole 2 of the iron core 1. Each group of magnets 10 includes several permanent magnet mounting slot structures, air slot structures, and several permanent magnet structures. Each permanent magnet mounting slot structure corresponds to one permanent magnet structure. Any number of permanent magnet mounting slot structures are configured to have a first arrangement direction on the iron core 1, and the air slot structures are configured to have a second arrangement direction on the iron core 1. The first arrangement direction and the second arrangement direction are asymmetrically arranged in spatial coordinates; and / or, all permanent magnet mounting slot structures are asymmetrically arranged relative to each other in spatial coordinates to block magnetic flux paths and reduce magnetic flux leakage.

[0055] Specifically, this invention provides an asymmetrical rotor structure that effectively improves the torque density of a motor. This structure utilizes asymmetrical permanent magnet mounting slots and air slots on the iron core 1, ensuring that the first and second mounting directions are asymmetrically arranged in spatial coordinates, or that all permanent magnet mounting slots are asymmetrically arranged relative to each other in spatial coordinates. This asymmetrical design blocks magnetic flux paths, reduces magnetic flux leakage, and thus improves the motor's magnetic field utilization. Compared to traditional symmetrical rotor structures, the asymmetrical structure guides magnetic flux flow more effectively, avoiding excessive concentration of magnetic flux in local areas, thereby reducing iron and copper losses and significantly improving the motor's efficiency and power density. Furthermore, by optimizing the mounting positions of the permanent magnets and the layout of the air slots 5, this asymmetrical rotor structure improves the motor's magnetic field distribution, enhances the synergistic effect of reluctance torque and permanent magnet torque, and further improves the motor's torque output capability. This design not only achieves superior torque output over a wide speed range but also enhances the motor's adaptability under different operating conditions, improving the overall performance and reliability of the system.

[0056] In one specific embodiment, any number of the permanent magnet mounting slot structures are configured to have a first dimension on the iron core 1, and the air slot structure is configured to have a second dimension on the iron core 1, wherein the first dimension and the second dimension are different; and / or, all the permanent magnet mounting slot structures have different dimensions from each other; this arrangement of different dimensions adjusts the phase relationship between the reluctance torque component and the permanent magnet torque component. This arrangement of different dimensions can effectively adjust the phase relationship between the reluctance torque component and the permanent magnet torque component, making them closer or coincident in phase, thereby achieving more efficient torque superposition. Compared with the traditional symmetrical structure, this design can significantly improve the torque density and output capability of the motor, especially exhibiting superior performance under high load and wide speed range. By adjusting the dimensions of the permanent magnet mounting slots and air slots 5, this structure can better control the distribution and flow path of magnetic flux, further reducing magnetic flux leakage and lowering iron and copper losses. This size-differentiated design not only improves the efficiency and power density of the motor, but also enhances the adaptability and reliability of the motor under different operating conditions, providing a more efficient and reliable motor solution for fields such as new energy vehicles and industrial drives.

[0057] In one specific embodiment, the permanent magnet mounting groove structure includes a first magnet groove 3 and a second magnet groove 4, and the air groove structure includes a first air groove 5. The first air groove 5 is disposed between the first magnet groove 3 and the second magnet groove 4. There is a first distance between the ends of the first magnet groove 3 and the second magnet groove 4 near the outer diameter of the iron core 1, and a second distance between the ends of the first magnet groove 3 and the second magnet groove 4 near the shaft hole 2 of the iron core 1. Further, the width a1 of the first permanent magnet 13 groove and the width a2 of the second permanent magnet 14 groove satisfy: a1 = k1 × a2, k1 = 1-2 mm, where k1 is a width coefficient. Further, in one specific embodiment, the first magnet groove 3 and the second magnet groove 4 are arranged in a V-shape, and one end of the first air groove 5 is connected to the side of the second magnet groove 4 and is arranged in a Y-shape with the second magnet groove 4.

[0058] Specifically, by optimizing the layout and dimensional relationship of the permanent magnet mounting slot structure and the air slot structure, the performance of the motor is further improved. The permanent magnet mounting slot structure includes a first magnet slot 3 and a second magnet slot 4, and the air slot structure includes a first air slot 5, with the first air slot 5 positioned between the first magnet slot 3 and the second magnet slot 4. This V-shaped slot structure design, combined with the Y-shaped distribution of the first air slot 5 and the second magnet slot 4, can effectively guide the flow of magnetic flux and optimize the magnetic field distribution. Simultaneously, by setting different distances between the first magnet slot 3 and the second magnet slot 4 near the outer diameter of the iron core 1 and the end of the shaft hole 2, the magnetic flux path is further adjusted, making the phase relationship between the reluctance torque component and the permanent magnet torque component more reasonable, thereby achieving more efficient torque superposition and significantly improving the motor's torque output capability. Furthermore, this embodiment further limits the width a1 of the first magnet slot 3 and the width a2 of the second magnet slot 4 to satisfy a1 = k1 × a2, where k1 = 1-2 mm. This precise dimensional design ensures optimal magnetic field distribution and flux utilization efficiency within a limited space. Through this optimized design, the motor maintains high efficiency and power density under various operating conditions, while effectively reducing flux leakage and localized magnetic saturation. This significantly improves the overall performance and reliability of the motor, providing a more efficient and reliable motor solution for fields such as new energy vehicles and industrial drives.

[0059] In one specific embodiment, the permanent magnet structure includes a first permanent magnet 13 and a second permanent magnet 14. The first permanent magnet 13 is installed in the first magnet slot 3, and the second permanent magnet 14 is installed in the second magnet slot 4. Each of the first permanent magnet 13, the second permanent magnet 14, the first magnet slot 3, and the second magnet slot 4 has a long side and a short side. The long side of the first permanent magnet 13 is positioned close to the long side of the first magnet slot 3, and the long side of the second permanent magnet 14 is positioned close to the long side of the second magnet slot 4. This design ensures that the long sides of the permanent magnets are closely fitted to the long sides of the magnet slots, thereby maximizing the utilization of the space within the slots, improving the installation stability of the permanent magnets, and ensuring efficient magnetic field conduction. This not only enhances the mechanical connection strength between the permanent magnets and the magnet slots but also reduces magnetic flux leakage caused by gaps, further improving the utilization rate of the magnetic field and the efficiency of the motor.

[0060] In one specific embodiment, the angle between the long side of the first magnet slot 3 and the central axis of the magnet assembly 10 is a first acute angle, and it is located on one side of the central axis of the magnet assembly 10. The angle between the long side of the second magnet slot 4 and the central axis of the magnet assembly 10 is a second acute angle, and it is located on the other side of the first magnet slot 3 of the magnet assembly 10 relative to the central axis. The angle range of the first acute angle and the second acute angle is 30°-90°.

[0061] In one specific embodiment, a first magnetic bridge 11 is formed between the ends of the first magnet slot 3, the first air slot 5, and the second magnet slot 4 near the outer edge of the iron core 1 and the outer edge of the iron core 1, and the distance between the ends of the first magnet slot 3, the first air slot 5, and the second magnet slot 4 near the outer edge of the iron core 1 and the outer edge of the iron core 1 is 0.3-1.5 mm. Furthermore, a second magnetic bridge 12 is formed between the ends of the first magnet slot 3 and the second magnet slot 4 near the shaft hole 2, and the distance between the first magnet slot 3 and the second magnet slot 4 is 0.3-1 mm.

[0062] In this embodiment, the magnetic field distribution and performance of the motor are further optimized by setting a first magnetic isolation bridge 11 and a second magnetic isolation bridge 12 in the rotor structure. Specifically, a first magnetic isolation bridge 11 is formed between the end of the first magnet slot 3, the first air slot 5, and the second magnet slot 4 near the outer edge of the iron core 1 and the outer edge of the iron core 1, and the size of the magnetic isolation bridge is in the range of 0.3-1.5mm. This design can effectively block the direct leakage path of magnetic flux at the outer edge of the iron core 1, reduce magnetic flux loss, and improve the utilization efficiency of the magnetic field. At the same time, by precisely controlling the size range of the first magnetic isolation bridge 11, the structural strength of the motor is reduced due to the magnetic isolation bridge being too large, and the problem of ineffective control of magnetic flux leakage due to the magnetic isolation bridge being too small is also prevented. In addition, the presence of the first magnetic isolation bridge 11 can also enhance the local magnetic field strength of the motor, further improving the torque output capability of the motor, especially showing better performance under high load and wide speed range. Furthermore, this invention also includes a second magnetic isolation bridge 12 between the ends of the first magnet slot 3 and the second magnet slot 4 near the shaft hole 2, with a spacing of 0.3-1mm between the first magnet slot 3 and the second magnet slot 4. This design further optimizes the magnetic flux flow path, reducing leakage and cross-interference of magnetic flux inside the rotor. By precisely controlling the size range of the second magnetic isolation bridge 12, the magnetic field distribution of the motor can be effectively balanced, enhancing the synergistic effect of reluctance torque and permanent magnet torque, and further improving the torque density and efficiency of the motor. Simultaneously, this double magnetic isolation bridge design can also reduce iron and copper losses during motor operation, improving the overall reliability of the system, especially under weak magnetic field conditions, where the motor's performance is more stable. Through this optimized design, this invention provides a more efficient and reliable motor solution for fields such as new energy vehicles and industrial drives, meeting the demands of modern industry for high-performance motors.

[0063] In one specific embodiment, the air slot structure is further configured such that after the first permanent magnet 13 and the second permanent magnet 14 are respectively installed in the first magnet slot 3 and the second magnet slot 4, the two ends of the first magnet slot 3 and the second magnet slot 4 respectively have unfilled air regions to form a second air slot 15. The second air slot 15 is specifically distributed on the first magnet slot 3 and the second magnet slot 4, including: air region 1 6, air region 2 7, air region 3 8, and air region 4 9. This design retains some air regions after the first permanent magnet 13 and the second permanent magnet 14 are installed, making the magnetic flux path more complex and controllable. The presence of the second air slot 15 can effectively adjust the distribution of magnetic flux density, reduce the occurrence of local magnetic saturation, especially under high load and weak magnetic conditions, significantly reducing the iron and copper losses of the motor. Simultaneously, the second air slot 15 can also guide the flow direction of magnetic flux, further optimizing the synergistic effect of reluctance torque and permanent magnet torque, improving the motor's torque output capability and efficiency.

[0064] In one specific embodiment, the length l1 of the long side of the first permanent magnet 13 is greater than the length l2 of the long side of the second permanent magnet 14, the length l3 of the short side of the first permanent magnet 13 is greater than the length l4 of the short side of the second permanent magnet 14, the length of the first air groove 5 is less than the length of the long side of the second permanent magnet 14, and the length of the short side of the first air groove 5 is less than the length of the short side of the second permanent magnet 14.

[0065] In one specific embodiment, the length l1 of the long side of the first permanent magnet 13 and the length l2 of the long side of the second permanent magnet 14 satisfy the following: l1 = k3 × l2, k3 = 1.5-2 mm; l3 = k4 × l4, k4 = 1-1.5 mm, where k3 is the first length coefficient and k4 is the second length coefficient.

[0066] In summary, by optimizing parameters such as magnetic bridge, air magnetic barrier, and pole arc coefficient, the rotor structure with 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, thus facilitating control.

[0067] Please see Figure 5 The figures represent the torque output of the asymmetric rotor structure and the V-type rotor structure under different currents. A represents the V-type motor structure and B represents the asymmetric rotor motor structure. As shown in the figure, the asymmetric rotor structure can achieve higher torque at lower currents, and its torque increases faster as the current increases, eventually reaching a higher torque value than the V-type rotor structure at high currents.

[0068] Please see Figure 6The figure shows the torque output of two structures at different current angles. C represents the V-type rotor structure, and D represents the asymmetric rotor structure. As can be seen from the figure, the asymmetric rotor structure achieves higher torque at smaller current angles, 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 smaller current angles, but the torque gradually increases with the current angle, reaching its peak at slightly larger current angles, and then also rapidly decreases. This indicates that the asymmetric rotor structure has better torque output at smaller current angles, which helps improve the motor's response speed and dynamic performance.

[0069] Example 2:

[0070] This invention provides a permanent magnet motor, which includes the aforementioned asymmetric rotor structure. By setting asymmetric permanent magnet mounting slots and air slots on the iron core of the rotor structure, the first and second mounting directions are asymmetric in spatial coordinates, or all permanent magnet mounting slots are asymmetric relative to each other in spatial coordinates. This asymmetric design can block magnetic flux paths, reduce magnetic flux leakage, and thus improve the magnetic field utilization rate of the motor. Compared with traditional symmetrical rotor structures, the asymmetric structure can more effectively guide magnetic flux flow, avoid excessive concentration of magnetic flux in local areas, thereby reducing iron and copper losses and significantly improving the efficiency and power density of the motor.

[0071] Example 3:

[0072] This invention provides a method for manufacturing a rotor structure, the method comprising:

[0073] S1. Several installation areas are equally spaced around the circumferential periphery of the iron core shaft hole;

[0074] 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.

[0075] For step S2, this embodiment three proposes a specific implementation method: a plurality of permanent magnet mounting slot structures, an air slot structure, and a plurality of permanent magnet structures. Each of the permanent magnet mounting slot structures corresponds to one of the permanent magnet structures. At the same time, any number of the permanent magnet mounting slot structures are configured to have a first arrangement direction on the iron core, and the air slot structure is configured to have a second arrangement direction on the iron core. The first arrangement direction and the second arrangement direction are asymmetrically arranged in spatial coordinates; and / or, all the permanent magnet mounting slot structures are asymmetrically arranged relative to each other in spatial coordinates; to block the magnetic flux path and reduce magnetic flux leakage.

[0076] Furthermore, any number of the permanent magnet mounting slot structures are configured to have a first dimension on the iron core, and the air slot structure is configured to have a second dimension on the iron core, wherein the first dimension is different from the second dimension; and / or, all the permanent magnet mounting slot structures have different dimensions from each other; to adjust the phase relationship between the reluctance torque component and the permanent magnet torque component by arranging them with different dimensions.

[0077] 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. An asymmetric rotor structure for improving the torque density of a motor, the rotor structure comprising an iron core (1), the iron core (1) having a shaft hole (2), characterized in that, include: Several groups of magnets (10) are arranged at equal intervals around the shaft hole (2) of the iron core (1). Each group of magnets (10) includes: several permanent magnet mounting slot structures, air slot structures and several permanent magnet structures. Each permanent magnet mounting slot structure is equipped with one permanent magnet structure. Any number of the permanent magnet mounting slot structures are configured to have a first arrangement direction on the iron core (1), and the air slot structure is configured to have a second arrangement direction on the iron core (1); wherein the first arrangement direction and the second arrangement direction are asymmetrically arranged in spatial coordinates; and / or, all the permanent magnet mounting slot structures are asymmetrically arranged relative to each other in spatial coordinates; to block the magnetic flux path and reduce magnetic flux leakage.

2. The asymmetric rotor structure for improving motor torque density according to claim 1, characterized in that: Any number of the permanent magnet mounting slot structures are configured to have a first dimension on the iron core (1), and the air slot structure is configured to have a second dimension on the iron core (1), wherein the first dimension is different from the second dimension; and / or, all the permanent magnet mounting slot structures have different dimensions from each other; to adjust the phase relationship between the reluctance torque component and the permanent magnet torque component by arranging them with different dimensions.

3. The asymmetric rotor structure for improving motor torque density according to claim 2, characterized in that: The permanent magnet mounting groove structure includes a first magnet groove (3) and a second magnet groove (4), and the air groove structure includes a first air groove (5), with the first air groove (5) disposed between the first magnet groove (3) and the second magnet groove (4); The first magnet slot (3) and the second magnet slot (4) 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 (4) have a second distance between their ends near the shaft hole (2) of the iron core (1).

4. The asymmetric rotor structure for improving motor torque density according to claim 3, characterized in that: The width a1 of the first permanent magnet (13) groove and the width a2 of the second permanent magnet (14) groove satisfy the following: a1=k1×a2, k1=1-2mm, where k1 is the width coefficient.

5. The asymmetric rotor structure for improving motor torque density according to claim 1, characterized in that: The permanent magnet structure includes a first permanent magnet (13) and a second permanent magnet (14), wherein the first permanent magnet (13) is installed in the first magnet slot (3) and the second permanent magnet (14) is installed in the second magnet slot (4); The first permanent magnet (13), the second permanent magnet (14), the first magnet slot (3) and the second magnet slot (4) each have a long side and a short side. The long side of the first permanent magnet (13) is set close to the long side of the first magnet slot (3), and the long side of the second permanent magnet (14) is set close to the long side of the second magnet slot (4).

6. The asymmetric rotor structure for improving motor torque density according to claim 5, characterized in that: The angle between the long side of the first magnet slot (3) and the central axis of the magnet group (10) is a first acute angle, and it is located on one side of the central axis of the magnet group (10). The angle between the long side of the second magnet slot (4) and the central axis of the magnet group (10) is a second acute angle, and it is located on the other side of the first magnet slot (3) of the magnet group (10) relative to the central axis.

7. The asymmetric rotor structure for improving motor torque density according to claim 6, characterized in that: The angle range of both the first acute angle and the second acute angle is 30°-90°.

8. The asymmetric rotor structure for improving motor torque density according to claim 6, characterized in that: The first magnet slot (3) and the second magnet slot (4) are arranged in a V-shape. One end of the first air slot (5) is connected to the side of the second magnet slot (4) and is arranged in a Y-shape with the second magnet slot (4).

9. The asymmetric rotor structure for improving motor torque density according to claim 8, characterized in that: The first magnet slot (3), the first air slot (5) and the second magnet slot (4) form a first magnetic isolation bridge (11) between the end of the first magnet slot (3), the first air slot (5) and the end of the second magnet slot (4) near the outer edge of the iron core (1) and the outer edge of the iron core (1), and the distance between the end of the first magnet slot (3), the first air slot (5) and the end of the second magnet slot (4) near the outer edge of the iron core (1) and the outer edge of the iron core (1) is 0.3-1.5mm.

10. The asymmetric rotor structure for improving motor torque density according to claim 9, characterized in that: A second magnetic bridge (12) is formed between the ends of the first magnet groove (3) and the second magnet groove (4) near the shaft hole (2), and the distance between the first magnet groove (3) and the second magnet groove (4) is 0.3-1mm.

11. The asymmetric rotor structure for improving motor torque density according to claim 2, characterized in that: The air groove (5) structure is further configured such that after the first permanent magnet (13) and the second permanent magnet (14) are respectively installed in the first magnet groove (3) and the second magnet groove (4), the two ends of the first magnet groove (3) and the second magnet groove (4) respectively have unfilled air areas to form a second air groove (15).

12. The asymmetric rotor structure for improving motor torque density according to claim 5, characterized in that: The length l1 of the long side of the first permanent magnet (13) is greater than the length l2 of the long side of the second permanent magnet (14), the length l3 of the short side of the first permanent magnet (13) is greater than the length l4 of the short side of the second permanent magnet (14), the length of the first air groove (5) is less than the length of the long side of the second permanent magnet (14), and the length of the short side of the first air groove (5) is less than the length of the short side of the second permanent magnet (14).

13. The asymmetric rotor structure for improving motor torque density according to claim 12, characterized in that: The length l1 of the long side of the first permanent magnet (13) and the length l2 of the long side of the second permanent magnet (14) satisfy the following: l1 = k3 × l2, k3 = 1.5-2 mm; l3 = k4 × l4, k4 = 1-1.5 mm, where k3 is the first length coefficient and k4 is the second length coefficient.

14. A permanent magnet motor, characterized in that, The permanent magnet motor includes the asymmetric rotor structure as described in any one of claims 1-13.

15. A method for manufacturing a rotor, characterized in that, The method includes: S1. Several installation areas are equally spaced around the circumferential periphery of the iron core shaft hole; 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, air 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.

Images