Rotor structure adopting Halbach magnet array and permanent magnet motor

Abstract

The utility model discloses a rotor structure adopting a Halbach magnet array and a permanent magnet motor, and belongs to the field of motor design and manufacturing. The rotor comprises a rotor body, a plurality of radial magnet blocks and a plurality of transverse magnet blocks, the radial magnet blocks and the transverse magnet blocks are permanent magnets, and the magnetic field directions of the radial magnet blocks and the transverse magnet blocks are perpendicular to each other. The layout of the radial magnet blocks and the transverse magnet blocks on the rotor body adopts a Halbach array; wherein the outer diameter of the transverse magnet sub-blocks is the same as that of the radial magnet sub-blocks, and the inner diameter of the transverse magnet sub-blocks is smaller than that of the radial magnet sub-blocks. The application can reduce the risk of magnet demagnetization.

Description

Technical Field

[0001] This application relates to the field of motor design and manufacturing, and particularly to a rotor structure and a permanent magnet motor using a Halbach magnet array. Background Art

[0002] The rotor structure of a Halbach magnet array is a magnet structure that uses specially arranged permanent magnets to generate a specific magnetic field. This structure was discovered and gradually improved by Klaus Halbach in 1979. Its main feature is that it can converge magnetic field lines on one side of the magnet and weaken magnetic field lines on the other side, thereby obtaining an ideal unilateral magnetic field. The rotor structure of a Halbach magnet array is of great significance in engineering and is widely used in fields such as nuclear magnetic resonance, magnetic levitation, and permanent magnet special motors.

[0003] The rotor structure of a Halbach magnet array can be linear or annular. The linear Halbach array is mainly applied to linear motors, while the annular Halbach array is commonly used in permanent magnet motors. Its air-gap magnetic field is closer to a sine distribution, with a higher air-gap magnetic density and smaller iron losses. In addition, the design of the annular Halbach magnet array can generate a multi-polar magnetic field, which is suitable for application scenarios that require a complex magnetic field configuration.

[0004] For the current motor rotor using an annular Halbach magnet array, the inner and outer diameters of different magnet segments are the same, and the lengths are also the same. This layout results in a relatively low magnetic density in the central region of the inner diameter of the magnet, and the magnet is prone to demagnetization under harsh working conditions. Summary of the Utility Model

[0005] In order to reduce the risk of magnet demagnetization, this application provides a rotor structure and a permanent magnet motor using a Halbach magnet array.

[0006] The rotor structure using a Halbach magnet array provided by this application adopts the following technical solutions:

[0007] A rotor structure using a Halbach magnet array includes a rotor body, a plurality of radial magnet segments, and a plurality of transverse magnet segments. The radial magnet segments and the transverse magnet segments are permanent magnets, the magnetic field directions of the radial magnet segments and the transverse magnet segments are perpendicular to each other, and the layout of the radial magnet segments and the transverse magnet segments on the rotor body adopts a Halbach array;

[0008] Wherein, the outer diameter of the transverse magnet segment is the same as the outer diameter of the radial magnet segment, and the inner diameter of the transverse magnet segment is smaller than the inner diameter of the radial magnet segment.

[0009] By adopting the above technical solution, compared with the solution where the inner and outer diameters of the magnet segments in the traditional HALBACH magnet array are the same, the solution of the present application reduces the inner diameter of the transverse magnet segments while keeping the outer diameter unchanged, which is equivalent to increasing the volume of the transverse magnet segments, enhancing the magnetic field, and at the same time reducing the demagnetization area of the radial magnet segments and lowering the magnet demagnetization risk.

[0010] Optionally, the rotor body is made of non-magnetic material, and the axial length of the transverse magnet segment is greater than the axial length of the radial magnet segment.

[0011] By adopting the above technical solution, the transverse magnet segment is longer than the radial magnet segment in length, and the rotor body is made of non-magnetic material, so as to form an axial magnetic field induction area at the end of the transverse magnet segment to provide a magnetic field for the Hall sensor.

[0012] Optionally, a limiting portion is provided on the outer peripheral surface of the rotor body, the limiting portion is arranged axially close to the end face of the rotor body, and one end of the radial magnet segment abuts against the limiting portion.

[0013] By adopting the above technical solution, the stable position of the radial magnet segment on the rotor body can be ensured, and the reliability of the structure and the performance stability are enhanced.

[0014] Optionally, a plurality of grooves are formed on the outer peripheral surface of the rotor body, the plurality of grooves are arranged at intervals in the circumferential direction of the rotor body, one side of the transverse magnet segment is inserted into the groove, and the radial magnet segment is inserted between adjacent transverse magnet segments and one side of the radial magnet segment abuts against the outer peripheral surface of the rotor body.

[0015] By adopting the above technical solution, the positions of the transverse magnet segments and the radial magnet segments can be fixed in stages during the rotor assembly process, improving the rotor assembly processability.

[0016] Optionally, an adaptation groove is formed at the groove corner of the groove.

[0017] By adopting the above technical solution, the stability and positioning accuracy of the transverse magnet segment in the groove can be further increased.

[0018] Optionally, the groove penetrates through both ends of the rotor body axially, and the end face of the transverse magnet segment is flush with the end face of the rotor body.

[0019] By adopting the above technical solution, the transverse magnet segment can be assembled with the rotor body both axially and radially, simplifying the assembly process, and the groove penetrates through both ends, also simplifying the processing process.

[0020] Optionally, the groove is a dovetail groove.

[0021] By adopting the above technical solution, after assembly, the lateral magnet segments are prevented from moving radially, improving the structural installation stability.

[0022] Optionally, the thickness of the lateral magnet segments remains consistent in the radial direction, and the thickness of the radial magnet segments gradually increases from the inside to the outside in the radial direction.

[0023] By adopting the above technical solution, it helps to further optimize the magnetic field distribution and reduce the demagnetized area of the radial magnet segments.

[0024] A permanent magnet motor includes the rotor structure adopting the above Halbach magnet array.

[0025] In summary, the present application includes at least one of the following beneficial technical effects:

[0026] 1. Compared with the solution where the inner and outer diameters of the magnet segments in the traditional HALBACH magnet array are the same, the solution of the present application reduces the inner diameter of the lateral magnet segments while keeping the outer diameter unchanged, which is equivalent to increasing the volume of the lateral magnet segments, enhancing the magnetic field, and at the same time reducing the demagnetized area of the radial magnet segments and lowering the magnet demagnetization risk.

[0027] 2. The lateral magnet segments are longer than the radial magnet segments, and the rotor body is made of non-magnetic material, thereby forming an axial magnetic field induction area at the end of the lateral magnet segments to provide a magnetic field for the Hall sensor.

[0028] 3. Various optimized structural designs, such as the limiting part, the groove, and the dovetail groove, etc., not only improve the stability of the magnet segment installation but also enhance the rotor assembly processability. Description of the Drawings

[0029] Figure 1 is the overall structural schematic diagram of the embodiment of the present application.

[0030] Figure 2 is the exploded schematic diagram of the overall structure of the embodiment of the present application.

[0031] Figure 3 is the partial structure enlarged view of the axial view of the overall structure of the embodiment of the present application.

[0032] Figure 4 is the partial structure enlarged view of the radial view of the overall structure of the embodiment of the present application.

[0033] Description of the Reference Numerals:

[0034] 1. Rotor body; 11. Groove; 12. Adaptation groove; 13. Limiting part; 2. Radial magnet segment; 3. Lateral magnet segment; 4. Hall sensor. Detailed Embodiment

[0035] The following further elaborates on this application in conjunction with the attached Figures 1-4 drawings.

[0036] Among them, the outer diameter of the transverse magnet segment 3 and the outer diameter of the radial magnet segment 2 refer to the data measured with the center of the rotor body 1 as the center of the circle when the transverse magnet segment 3 and the radial magnet segment 2 are installed on the rotor body 1. The inner diameter of the transverse magnet segment 3 and the inner diameter of the radial magnet segment 2 are the same in principle.

[0037] As Figure 1 and Figure 2 shown, the rotor structure adopting a Halbach magnet array provided by the embodiment of this application includes a rotor body 1, a plurality of radial magnet segments 2 and a plurality of transverse magnet segments 3. The radial magnet segments 2 and the transverse magnet segments 3 are permanent magnets, and their magnetic field directions are perpendicular to each other. The radial magnet segments 2 and the transverse magnet segments 3 are assembled on the rotor body 1 according to the layout of the Halbach array.

[0038] Referring to Figure 3 , specifically, the outer diameter of the transverse magnet segment 3 is the same as the outer diameter of the radial magnet segment 2, while the inner diameter of the transverse magnet segment 3 is designed to be smaller than the inner diameter of the radial magnet segment 2. This design makes the magnetic density distribution of the magnet more uniform, reduces the low magnetic density area of the magnet, and reduces the risk of magnet demagnetization.

[0039] Referring to Figure 2 and Figure 4 , the axial length of the transverse magnet segment 3 is greater than the axial length of the radial magnet segment 2. In a preferred embodiment, the transverse magnet segment 3 and the radial magnet segment 2 are parallel. One end of the transverse magnet segment 3 is flush with one end of the radial magnet segment 2, and the other end of the transverse magnet segment 3 extends beyond the other end of the radial magnet segment 2. At the same time, the rotor body 1 is made of a non-magnetic material, so as to form an axial magnetic field induction area at the end of the transverse magnet segment 3 to provide a magnetic field for the Hall sensor 4. The Hall sensor 4 is a prior art and will not be elaborated here.

[0040] Referring to Figure 2 and Figure 3 , in the related art, there is a problem that during the assembly process of the motor rotor, there is a mutual repulsive force between the magnets, making the assembly difficult. To solve the above problem, a plurality of axially extending grooves 11 are provided on the outer peripheral surface of the rotor body 1. The plurality of grooves 11 are arranged at equal intervals along the circumferential direction of the rotor body 1. One side edge of the transverse magnet segment 3 is inserted into the groove 11, and the radial magnet segment 2 is inserted between adjacent transverse magnet segments 3 and one side edge of the radial magnet segment 2 abuts against the outer peripheral surface of the rotor body 1.

[0041] During the assembly process, the transverse magnet segment 3 can be first inserted into the groove 11, and then the radial magnet segment 2 can be inserted between adjacent transverse magnet segments 3, so as to fix the positions of the transverse magnet segment 3 and the radial magnet segment 2 in stages, improving the rotor assembly processability.

[0042] In one embodiment, an adaptation groove 12 is provided at the groove corner of the groove 11, which can further increase the stability of the transverse magnet segment 3 in the groove 11. Additionally, when it is necessary to glue the transverse magnet segment 3 to the rotor body 1, the adaptation groove 12 can accommodate glue, improving the bonding stability.

[0043] Refer to Figure 3 , in one embodiment, the groove 11 is a U-shaped groove, and the transverse magnet segment 3 can be inserted into the groove 11 along the radial or axial direction, improving the assembly flexibility. In another embodiment, the groove 11 is a dovetail groove, and the transverse magnet segment 3 is inserted into the groove 11 along the axial direction, and the transverse magnet segment 3 is immovable in the radial direction, thereby improving the stability of the structure installation.

[0044] In a preferred embodiment, the thickness of the transverse magnet segment 3 remains consistent along the radial direction, while the thickness of the radial magnet segment 2 gradually increases from the inside to the outside. This careful design consideration helps to achieve a more uniform magnetic field distribution and reduce the demagnetization area of the radial magnet segment.

[0045] Refer to Figure 1 and Figure 2 , in order to effectively position the radial magnet segment 2 along the axial direction, a limiting portion 13 is provided on the outer peripheral surface of the rotor body 1. In one embodiment, a limiting portion 13 is arranged along the axial direction and close to the end face of the rotor body 1, and one end of the radial magnet segment 2 is in close contact with the limiting portion 13 to ensure the stable installation of the radial magnet segment 2 on the rotor body 1. In another embodiment, two limiting portions 13 can also be provided, and the two limiting portions 13 are respectively arranged on the two end faces of the rotor body 1, and the radial magnet segment 2 is clamped between the two limiting portions 13, enhancing the assembly convenience.

[0046] Among them, the rotor body 1 is a rotor core. In this embodiment, the limiting portion 13 is integrally formed with the rotor body 1. In other embodiments, the limiting portion 13 can also be welded to the rotor body 1.

[0047] The implementation principle of this embodiment lies in that by cleverly designing the shape, size and layout of the magnet segments, especially the unique design that the inner diameter of the transverse magnet segment 3 is smaller than the inner diameter of the radial magnet segment 2, the magnetic density in the central area of the magnet inner diameter is successfully improved.

[0048] This embodiment also covers a permanent magnet motor, the core feature of which is the integration of the above-mentioned rotor structure with a carefully designed Halbach magnet array. Thanks to the optimization of the rotor structure, this permanent magnet motor shows significant advantages in aspects such as increasing the air-gap magnetic field density, reducing the demagnetization area of the magnets, and lowering the difficulty of the rotor assembly process. At the same time, its robust structural design and precise positioning of the magnet segments also bring excellent performance stability and long service life to the motor.

[0049] The above are all preferred embodiments of this application, and the protection scope of this application is not limited accordingly. Therefore, all equivalent changes made according to the structure, shape, and principle of this application should be covered within the protection scope of this application.

Claims

1. A rotor structure using a Halbach magnet array, characterized in that: The invention comprises a rotor body (1), a plurality of radial magnet blocks (2) and a plurality of transverse magnet blocks (3), wherein the radial magnet blocks (2) and the transverse magnet blocks (3) are permanent magnets, the magnetic field directions of the radial magnet blocks (2) and the transverse magnet blocks (3) are perpendicular to each other, and the layout of the radial magnet blocks (2) and the transverse magnet blocks (3) on the rotor body (1) adopts a Halbach array; The outer diameter of the transverse magnet block (3) is the same as the outer diameter of the radial magnet block (2), and the inner diameter of the transverse magnet block (3) is smaller than the inner diameter of the radial magnet block (2).

2. The rotor structure using the Halbach magnet array according to claim 1, characterized in that: The rotor body (1) is made of non-magnetic material, and the axial length of the transverse magnet segment (3) is greater than the axial length of the radial magnet segment (2).

3. The rotor structure using the Halbach magnet array according to claim 2, characterized in that: A limiting portion (13) is provided on the outer peripheral surface of the rotor body (1), and the limiting portion (13) is provided axially close to the end surface of the rotor body (1), and one end of the radial magnet block (2) abuts against the limiting portion (13).

4. The rotor structure using the Halbach magnet array according to claim 1, characterized in that: The outer circumferential surface of the rotor body (1) is provided with a plurality of grooves (11), the plurality of grooves (11) being arranged at intervals along the circumference of the rotor body (1), one side edge of the transverse magnet block (3) being inserted into the groove (11), the radial magnet block (2) being inserted between adjacent transverse magnet blocks (3), and one side edge of the radial magnet block (2) being in contact with the outer circumferential surface of the rotor body (1).

5. The rotor structure using the Halbach magnet array according to claim 4, characterized in that: An adapting groove (12) is provided at a groove corner of the groove (11).

6. The rotor structure using the Halbach magnet array according to claim 4, characterized in that: The groove (11) axially penetrates through both ends of the rotor body (1), and the end surface of the transverse magnet block (3) is flush with the end surface of the rotor body (1).

7. The rotor structure using the Halbach magnet array according to claim 4, characterized in that: The groove (11) is a dovetail groove.

8. The rotor structure using the Halbach magnet array according to claim 1, characterized in that: The thickness of the transverse magnet blocks (3) remains consistent in the radial direction, and the thickness of the radial magnet blocks (2) gradually increases from the inside to the outside in the radial direction.

9. A permanent magnet motor, characterized in that: A rotor structure using a Halbach magnet array comprising the rotor structure described in any one of claims 1 to 8.

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