Double-layer Halbach array permanent magnet vernier motor structure

Abstract

A double-layer Halbach array permanent magnet vernier motor structure disclosed by the present invention comprises a stator iron core, a rotor iron core, a stator winding and a double-layer non-uniform Halbach permanent magnet array, a rotor is arranged outside the stator iron core, the rotor iron core and the stator iron core are coaxially arranged, a main shaft is arranged at the center of the rotor, the stator iron core adopts a straight groove, and the stator winding is arranged in the straight groove. The double-layer non-uniform Halbach permanent magnet array is installed on the rotor core and located between the rotor core and the stator core, the stator winding is installed on the stator core, the stator core is of a split tooth structure, and the stator core and the stator winding use a three-phase fractional slot concentrated winding and are wound in a two-antipode mode. In the structural design of the rotor, ferrite auxiliary magnetic poles are ingeniously introduced, and the usage amount of rare earth permanent magnets is effectively reduced. The strategy not only reduces the manufacturing cost of the motor, but also improves the utilization rate of the permanent magnet material, and achieves a win-win situation of economic benefits and environmental protection benefits.

Description

Technical Field

[0001] The invention relates to the technical field of motor structures, and in particular to a double-layer Halbach array permanent magnet vernier motor structure. Background Art

[0002] Permanent magnet vernier motor (PMVM), with its excellent torque density and simplified mechanical structure, has become the preferred solution for low-speed, high-torque direct drive fields such as mining and ship propulsion. The core concept of magnetic field modulation technology is to finely control the input magnetic field through sophisticated structural design and strategic deployment of magnetic materials to achieve efficient coupling between magnetic poles and smooth transmission of torque. PMVM was born based on the magnetic field modulation mechanism of magnetic gears. Its unique "magnetic gear effect" gives the motor the ability to output strong electromagnetic torque at low speeds, so it has attracted much attention from academia and industry.

[0003] The PMVM series motors are all based on the same working principle - the "magnetic gear effect". They can be regarded as a clever fusion of permanent magnet motors and magnetic gear transmission systems. In this mechanism, the two sides of the modulation teeth carry magnetic fields generated by the rotor permanent magnets and the armature windings at different speeds. The magnetic field excited by the armature winding is carefully regulated by the modulation teeth, and its speed is synchronized with the magnetic field of the rotor permanent magnet, thereby achieving efficient energy conversion between the stator and the rotor.

[0004] Although the traditional PMVM motor structure is simple and efficient and can generate considerable electromagnetic torque, it also exposes the significant shortcoming of torque pulsation. To overcome this challenge, the present invention introduces the Halbach array, an innovative double-layer permanent magnet arrangement strategy, and uses ferrite as the excitation source of the auxiliary magnetic pole. A major highlight of this design is that the Halbach array can generate an enhanced magnetic field on a specific side, effectively weakening the air gap magnetic density harmonics, reducing leakage magnetic phenomena, and thus improving energy conversion efficiency. This series of improvements not only significantly enhances the torque density of PMVM, but also significantly improves the problem of torque pulsation.

[0005] The traditional PMVM motor structure is as follows Figure 1 shown. Figure 1 In the figure, 1 is the stator core, 2 is the stator winding, 3 is the rotor core, 4 is the stator modulation tooth, 5-1 and 5-2 are the rotor main magnetic poles, where the magnetizing direction of 5-1 is at an angle of 0° to the radial direction, and the magnetizing direction of 5-2 is at an angle of 180° to the radial direction, that is, the magnetizing directions of 5-1 and 5-2 are opposite, and the single layers are arranged alternately.

[0006] The present invention adopts a Halbach array, that is, a new double-layer permanent magnet arrangement, and uses ferrite excitation for auxiliary magnetic poles. Its main feature is that it can generate a strong magnetic field on one side, reduce air gap magnetic density harmonics, reduce leakage magnetic flux, and improve energy conversion efficiency. It enhances the torque density of the permanent magnet vernier motor and improves torque pulsation. At the same time, the addition of ferrite significantly reduces the amount of rare earth permanent magnets, reduces the motor manufacturing cost, and improves the utilization rate of the permanent magnets of the motor.

[0007] To this end, we urgently need to design a double-layer Halbach array permanent magnet vernier motor structure to solve the above problems. Summary of the invention

[0008] The purpose of the present invention is to provide a double-layer Halbach array permanent magnet vernier motor structure to address the deficiencies of the prior art and solve the problems raised in the background technology.

[0009] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a double-layer Halbach array permanent magnet vernier motor structure, comprising a stator core, a rotor core, a stator winding and a double-layer non-uniform Halbach permanent magnet array, the rotor is placed outside the stator core and the rotor core is coaxially arranged with the stator core, the main shaft is arranged at the center of the rotor, the stator core adopts straight slots, the double-layer non-uniform Halbach permanent magnet array is installed on the rotor core and is located between the rotor core and the stator core, the stator winding is installed on the stator core, the stator core adopts a split tooth structure, the stator core and the stator winding use three-phase fractional slot concentrated windings, and are wound in a two-pole manner.

[0010] As a preferred technical solution of the present invention, each magnetic pole of the double-layer non-uniform Halbach permanent magnet array is composed of 5 permanent magnets and is divided into two layers. The two layers of permanent magnets adopt different Halbach magnetization methods, and the outer layer of permanent magnets includes 1 rotor main magnetic pole 2, 1 rotor tangential auxiliary magnetic pole 2 and 1 rotor tangential auxiliary magnetic pole 1.

[0011] As a preferred technical solution of the present invention, the inner permanent magnet includes one rotor main magnetic pole 1 and two rotor oblique auxiliary magnetic poles 1 and 2. At the same time, the main magnetic poles and auxiliary magnetic poles of the two layers of Halbach array can be of unequal width and thickness.

[0012] As a preferred technical solution of the present invention, there is no inter-pole spacing between adjacent magnetic poles of the double-layer non-uniform Halbach permanent magnet array, and the rotor main magnetic pole 1 and the rotor main magnetic pole 2 are both magnetized in the radial positive direction or reverse direction.

[0013] As a preferred technical solution of the present invention, the magnetizing direction of the rotor main magnetic pole 2 is tangential magnetizing, and the angle between the magnetizing direction of the rotor main magnetic pole 1 and the rotor main magnetic pole 2 and the radial direction is 0°.

[0014] As a preferred technical solution of the present invention, the angle between the magnetizing direction of the rotor oblique auxiliary magnetic pole 1 and the rotor oblique auxiliary magnetic pole 2 and the radial direction is 30° to 60°.

[0015] As a preferred technical solution of the present invention, the angle between the magnetizing direction of the rotor oblique auxiliary magnetic pole 1 and the radial direction is 135°, and the angle between the magnetizing direction of the rotor oblique auxiliary magnetic pole 2 and the radial direction is 45°.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] The core of the invention lies in its innovative double-layer non-uniform Halbach array design, which effectively improves the torque density of the motor and significantly enhances the output torque capacity of the motor. This improvement directly meets the stringent requirements of motor performance in the field of low-speed, high-torque direct drive, and provides strong support for technological progress and application expansion in related fields.

[0018] Compared with traditional technologies, the present invention achieves significant suppression of torque pulsation through fine magnetic field modulation and structural design. The smoothness of the motor during operation is greatly improved, and the vibration and noise levels are significantly reduced, thereby improving the motor's working accuracy and long-term operating stability. This improvement is of great significance to improving the overall performance of the equipment and extending its service life.

[0019] In the rotor structure design, the present invention cleverly introduces ferrite auxiliary magnetic poles, effectively reducing the use of rare earth permanent magnets. This strategy not only reduces the manufacturing cost of the motor, but also improves the utilization rate of permanent magnet materials, achieving a win-win situation in economic and environmental benefits.

[0020] In terms of the environment, the optimization of motor performance reduces torque pulsation, thereby reducing environmental pollution that may be caused by problems such as vibration and noise, and helps achieve green production and sustainable development. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a traditional PMVM motor structure;

[0022] Figure 2 It is the DNH-PMVM motor structure. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] The following is combined with Figure 1 With reference to the accompanying drawings and a number of embodiments, specific embodiments of the present invention are described in detail.

[0025] The motor design parameters are shown in Table 1. The number of slots is 6, the number of rotor pole pairs is 16, the number of stator pole pairs is 2, the pole arc coefficient is 0.65, the number of modulation teeth is 18, the air gap width is 1.5 mm, the rotor outer diameter is 830 mm, the rotor inner diameter is 706 mm, the rotor main pole material is NdFeb35, the rotor auxiliary pole material is Y30BH, and the stator auxiliary pole material is Y30BH.

[0026] Table 1 Motor design parameters

[0027]

[0028]

[0029] The double-layer non-uniform Halbach permanent magnet vernier motor described in this embodiment mainly includes the following parts: a stator and a rotor, which are coaxially arranged. Among them, the rotor is tightly nested on the outside of the stator, and there is a certain air gap space between the stator and the rotor. It should be pointed out that the rotor has a unique double-layer non-uniform Halbach array structure. In order to express and distinguish it more clearly, we divide it into two parts: the outer layer and the inner layer.

[0030] The stator comprises: a stator core 1, a stator winding 2 and a stator modulating tooth 4. The stator core 1 is a split slot type. The number of stator poles is 4.

[0031] The specific situation of the split slot structure is: slotting is performed on the top of each stator tooth to form three modulation teeth 4. In addition, the tooth pitches between adjacent stator modulation teeth are equal. Through such a design, other sub-operating harmonics can be introduced, thereby effectively improving the electromagnetic performance of the motor, making the motor perform better during operation, and achieving a more efficient and stable working state.

[0032] The rotor includes: a rotor core 3, a rotor main magnetic pole 1 5-1, a rotor main magnetic pole 2 5-2, a rotor main magnetic pole 3 5-3, a rotor main magnetic pole 4 5-4, a rotor tangential auxiliary magnetic pole 1 6-1, a rotor tangential auxiliary magnetic pole 2 6-2 and a rotor oblique auxiliary magnetic pole 1 7-1, a rotor oblique auxiliary magnetic pole 2 7-2, a rotor oblique auxiliary magnetic pole 3 7-3, and a rotor oblique auxiliary magnetic pole 4 7-4.

[0033] The rotor permanent magnets are arranged longitudinally in two different non-uniform Halbach arrays, divided into outer and inner layers.

[0034] The outer Halbach array of the rotor has 4 permanent magnets per pair of poles, the inner Halbach array has 6 permanent magnets per pair of poles, and each pair of poles of the rotor has a total of 10 permanent magnets.

[0035] Among them, the magnetizing direction of the rotor main magnetic pole 1 5-1 and the rotor main magnetic pole 2 5-2 has a radial angle of 0°, and the magnetizing direction of the rotor main magnetic pole 3 5-3 and the rotor main magnetic pole 4 5-4 has a radial angle of 180°.

[0036] The rotor tangential auxiliary magnetic pole 1 6-1 and the rotor tangential auxiliary magnetic pole 2 6-2 are rotor tangential auxiliary magnetic poles, wherein the magnetizing direction of the rotor tangential auxiliary magnetic pole 1 6-1 and the radial angle are 270°, and the magnetizing direction of the rotor tangential auxiliary magnetic pole 2 6-2 and the radial angle are 90°.

[0037] The rotor oblique auxiliary magnetic poles 1 7-1, the rotor oblique auxiliary magnetic pole 2 7-2, the rotor oblique auxiliary magnetic pole 3 7-3 and the rotor oblique auxiliary magnetic pole 4 7-4 are the rotor oblique auxiliary magnetic poles, among which the magnetizing direction of the rotor oblique auxiliary magnetic pole 1 7-1 has a radial angle of 135°, the magnetizing direction of the rotor oblique auxiliary magnetic pole 2 7-2 has a radial angle of 45°, the magnetizing direction of the rotor oblique auxiliary magnetic pole 3 7-3 has a radial angle of 225° and the magnetizing direction of the rotor oblique auxiliary magnetic pole 4 7-4 has a radial angle of 315°.

[0038] The contents not described in detail in this specification belong to the prior art known to professional and technical personnel in the field. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A double-layer Halbach array permanent magnet vernier motor structure, characterized in that: The invention comprises a stator core (1), a rotor core (3), a stator winding (2) and a double-layer non-uniform Halbach permanent magnet array, wherein the rotor (3) is arranged outside the stator core (1) and the rotor core (3) is coaxially arranged with the stator core (1), the main shaft is arranged at the center of the rotor (3), the stator core (1) adopts straight slots, the double-layer non-uniform Halbach permanent magnet array is mounted on the rotor core (3) and is located between the rotor core (3) and the stator core (1), the stator winding (2) is mounted on the stator core (1), the stator core (1) adopts a split tooth structure, the stator core (1) and the stator winding (2) use three-phase fractional slot concentrated windings, and are wound in a two-pole manner.

2. The double-layer Halbach array permanent magnet vernier motor structure according to claim 1 is characterized in that: Each magnetic pole of the double-layer non-uniform Halbach permanent magnet array is composed of five permanent magnets, which are divided into two layers. The two layers of permanent magnets adopt different Halbach magnetization methods. The outer layer of permanent magnets includes one rotor main magnetic pole two (5-2), one rotor tangential auxiliary magnetic pole two (6-2) and one rotor tangential auxiliary magnetic pole one (6-1).

3. The double-layer Halbach array permanent magnet vernier motor structure according to claim 2 is characterized in that: The inner layer permanent magnets include one rotor main magnetic pole 1 (5-1) and two rotor oblique auxiliary magnetic poles 1 (7-1) and two rotor oblique auxiliary magnetic poles 2 (7-2). At the same time, the main magnetic poles and auxiliary magnetic poles of the two layers of Halbach arrays can be of different widths and thicknesses.

4. The double-layer Halbach array permanent magnet vernier motor structure according to claim 2 is characterized in that: There is no inter-pole spacing between adjacent magnetic poles of the double-layer non-uniform Halbach permanent magnet array, and the rotor main magnetic pole one (5-1) and the rotor main magnetic pole two (5-2) are both magnetized in the radial positive direction or reverse direction.

5. The double-layer Halbach array permanent magnet vernier motor structure according to claim 4 is characterized in that: The magnetizing direction of the rotor main magnetic pole 2 (5-2) is tangential magnetizing, and the magnetizing direction of the rotor main magnetic pole 1 (5-1) and the rotor main magnetic pole 2 5-2 has an angle of 0° with the radial direction.

6. The double-layer Halbach array permanent magnet vernier motor structure according to claim 2 is characterized in that: The angle between the magnetizing direction of the rotor oblique auxiliary magnetic pole 1 (7-1) and the rotor oblique auxiliary magnetic pole 2 (7-2) and the radial direction is 30° to 60°.

7. The double-layer Halbach array permanent magnet vernier motor structure according to claim 2 is characterized in that: The magnetizing direction of the rotor oblique auxiliary magnetic pole 1 (7-1) includes an angle of 135° with respect to the radial direction, and the magnetizing direction of the rotor oblique auxiliary magnetic pole 2 (7-2) includes an angle of 45° with respect to the radial direction.

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