A Z-shaped rotor tooth double-stator axial magnetic field flux-switching permanent magnet motor

Abstract

The present invention discloses a Z-type rotor tooth double-stator axial magnetic field flux-switching permanent magnet motor, which includes two stators with salient pole structures arranged coaxially. The two stators have the same structure. The rotor is arranged coaxially between the two stators, facing the two stators and having the same air gap length. In the traditional axial magnetic field flux-switching permanent magnet motor, the slotting of the stator and rotor results in a relatively large cogging torque of the motor, which has a particularly obvious impact on torque ripple at medium and low speeds. As a low-speed high-torque drive motor, the axial magnetic field flux-switching permanent magnet motor needs to suppress the cogging torque and improve the running stability without reducing the output torque. The present invention can effectively suppress the cogging torque of the axial magnetic field flux-switching permanent magnet motor and reduce the torque ripple through the design of the Z-type rotor teeth; the middle tooth of the stator iron core is slotted and an auxiliary permanent magnet is embedded to form a quasi-Halbch magnetic field, improve the sinusoidality of the air-gap magnetic density, improve the utilization rate of the permanent magnet, reduce the torque ripple, and improve the operating efficiency of the motor.

Description

Technical Field

[0001] The present invention relates to a double-stator axial-field flux-switching permanent magnet motor, belonging to the technical field of permanent magnet motors. Background Art

[0002] Due to the advantages of high power density, high efficiency, simple structure, etc. of permanent magnet synchronous motors, with the continuous improvement of the performance of rare earth permanent magnet materials, permanent magnet synchronous motors have rapidly obtained wide applications in industries, aerospace and other fields. For permanent magnet motors, due to the slotting, the magnetic reluctance of the magnetic circuits corresponding to each pole of the motor is unbalanced. The magnetic lines of force generated by the magnetic field always tend to take the path with small magnetic reluctance, and the magnetic lines of force pull the rotor to the position with the minimum magnetic reluctance path, thereby generating cogging torque. And large cogging torque will affect the starting performance and the smoothness of the output torque of the motor. Therefore, the suppression of cogging torque has become a research hotspot of permanent magnet motors. Summary of the Invention

[0003] Object of the Invention: Aiming at the above-mentioned prior art, a Z-shaped rotor tooth double-stator axial-field flux-switching permanent magnet motor is proposed to solve the problem of large cogging torque of axial-field flux-switching motors.

[0004] Technical Solution: A Z-shaped rotor tooth double-stator axial-field flux-switching permanent magnet motor includes a first stator, a second stator and a rotor coaxially arranged, and the rotor is located between the first stator and the second stator;

[0005] The first stator and the second stator have the same structure, and both include an E-shaped magnetic conductive core and a permanent magnet. A plurality of E-shaped magnetic conductive cores are evenly arranged along the circumference to form a circular ring. The openings of the E-shaped magnetic conductive cores face the rotor. A permanent magnet is embedded between two adjacent E-shaped magnetic conductive cores. The magnetization direction of the permanent magnet is alternately magnetized along the circumference; a slot is opened on the middle tooth of the E-shaped magnetic conductive core and an auxiliary permanent magnet is embedded; a single armature winding is commonly wound on the adjacent teeth of two adjacent E-shaped magnetic conductive cores. Two armature windings radially opposite to each other along the stator are connected in series to form a phase winding, and four armature windings on both sides radially opposite to each other form two sets of in-phase windings;

[0006] The rotor includes Z-shaped magnetic conductive rotor teeth and Z-shaped non-magnetic conductive rotor teeth alternately arranged in sequence along the circumference. The rotor respectively has the same length of air gaps left between it and the first stator and the second stator.

[0007] Further, the auxiliary permanent magnet is of a rectangular structure, the material is alnico, the magnetization direction is axially alternately magnetized, and the coercive force is the same.

[0008] Further, the long axes of the Z-shaped magnetic conductive rotor teeth and the Z-shaped non-magnetic conductive rotor teeth are arranged along the radial direction of the rotor, and the adjacent Z-shaped magnetic conductive rotor teeth and Z-shaped non-magnetic conductive rotor teeth are mutually engaged together.

[0009] Beneficial effects: (1) The rotor structure of the present invention is simple. By arranging the Z-shaped magnetic-conducting rotor teeth and the Z-shaped non-magnetic-conducting rotor teeth in an alternating manner, the rotor structure is made more firm and compact, improving the reliability of the motor operation. Compared with the traditional fan-shaped magnetic-conducting rotor teeth, the Z-shaped magnetic-conducting rotor teeth change the air-gap permeance on both sides of the rotor, weaken the asymmetry of the air-gap magnetic circuit between the stator and the rotor, and reduce the cogging torque of the motor. From Figure 6 It can be clearly seen that compared with the fan-shaped magnetic-conducting rotor teeth, this structure has a smaller cogging torque.

[0010] (2) The middle teeth of the stator are slotted to embed auxiliary permanent magnets, forming a quasi-Halbch magnetic field with the stator permanent magnets, improving the utilization rate of the permanent magnets, enhancing the air-gap magnetic density and sinusoidality, being beneficial to providing a large output torque, reducing torque ripple and improving efficiency. Description of the drawings

[0011] Figure 1 is a two-dimensional structural schematic diagram of a Z-shaped rotor tooth double-stator axial magnetic field flux-switching permanent magnet motor;

[0012] Figure 2 is a schematic diagram of the rotor structure;

[0013] Figure 3 is a schematic diagram of the magnetic-conducting rotor teeth;

[0014] Figure 4 is a schematic diagram of the non-magnetic-conducting rotor teeth;

[0015] Figure 5 is a schematic diagram of the armature winding structure;

[0016] Figure 6 is the cogging torque diagram of the Z-shaped rotor teeth with a stagger angle of 0° and 6°. Detailed implementation manners

[0017] The following further explains the present invention with reference to the drawings.

[0018] As Figure 1 shown, a Z-shaped rotor tooth double-stator axial magnetic field flux-switching permanent magnet motor includes a first stator 1, a second stator 2 and a rotor 3 arranged coaxially. The rotor 3 is located between the first stator and the second stator 2.

[0019] The first stator 1 and the second stator 2 have the same structure, both including an E-shaped magnetic core 4 and a permanent magnet 5. A number of E-shaped magnetic cores 4 are evenly arranged along the circumference to form a circular ring. The opening of the E-shaped magnetic core 4 faces the rotor 3. A permanent magnet 5 is embedded between two adjacent E-shaped magnetic cores 4. The magnetization direction of the permanent magnet 5 is alternately magnetized along the circumference. A slot is opened in the middle of the E-shaped magnetic core 4 and an auxiliary permanent magnet 6 is embedded. The auxiliary permanent magnet 6 is of a rectangular structure, made of alnico, magnetized alternately in the axial direction, and has the same coercive force. A single armature winding 7 is wound around the adjacent teeth of two adjacent E-shaped magnetic cores 4. Two armature windings 7 that are radially opposite to each other along the stator are connected in series to form a phase winding, and four armature windings 7 on both sides that are radially opposite form two sets of in-phase windings;

[0020] As Figures 2 to 4 shown, the rotor 3 includes a number of Z-shaped magnetic rotor teeth 8 and a number of Z-shaped non-magnetic rotor teeth 9 that are alternately arranged in sequence along the circumference. The rotor 3 has the same length of air gap left between it and the first stator 1 and the second stator 2 respectively. The Z-shaped magnetic rotor teeth 8 and the Z-shaped non-magnetic rotor teeth 9 have the same structure. The long axes of the Z-shaped magnetic rotor teeth 8 and the Z-shaped non-magnetic rotor teeth 9 are arranged along the radial direction of the rotor. The adjacent Z-shaped magnetic rotor teeth 8 and Z-shaped non-magnetic rotor teeth 9 are staggered and interlocked with each other to form the whole rotor.

[0021] In this embodiment, the Z-shaped rotor tooth double-stator axial magnetic field flux-switching permanent magnet motor is a double-air-gap axial magnetic field flux-switching permanent magnet motor composed of two stators and one rotor. For a three-phase motor, each stator is composed of 6 E-shaped magnetic cores 4, 6 permanent magnets 5, 6 auxiliary permanent magnets 6 and 6 armature windings 7. The rotor 3 is composed of 14 Z-shaped magnetic rotor teeth 8 and 14 Z-shaped non-magnetic rotor teeth 9.

[0022] As Figure 5 shown, 12 armature windings 8 are respectively wound around 12 stator permanent magnets 5 and the adjacent teeth of two adjacent E-shaped magnetic cores 4 adjacent to them, forming two sets of three-phase armature windings. In each set of three-phase armature windings, two coils that are radially opposite are connected in series to form an in-phase winding. Here, taking the A-phase winding as an example, A1 and A3 are the A-phase coils that are radially opposite in the stator 1, and A2 and A4 are the A-phase windings that are radially opposite in the stator 2. A1 and A3 are connected in series, and A2 and A4 are connected in series respectively to obtain two sets of A-phase windings of the motor. Similarly, two sets of windings for the B-phase and C-phase are obtained.

[0023] The Z-type rotor tooth double-stator axial magnetic field flux-switching permanent magnet motor of the present invention combines the advantages of axial magnetic field permanent magnet motors and flux-switching permanent magnet motors, with small axial dimensions, high power and torque density, and high efficiency. By adding auxiliary permanent magnets, the sinusoidality of the air-gap magnetic density is improved, and the output torque and efficiency of the motor are increased. The E-type stator core has intermediate teeth, which is beneficial to the physical isolation between phase windings and has good fault tolerance. The Z-type magnetic rotor teeth and Z-type non-magnetic rotor teeth are evenly distributed and staggered on the circumference, playing a role of mutual positioning and fixing, improving the reliability of the motor operation, and this kind of rotor has the advantages of simple structure, strong heat dissipation ability, convenient assembly and mass production.

[0024] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A Z-type rotor tooth double-stator axial magnetic field flux-switching permanent magnet motor, characterized in that: It includes a first stator (1), a second stator (2) and a rotor (3) which are coaxially arranged, and the rotor (3) is located between the first stator (1) and the second stator (2); The first stator (1) and the second stator (2) have the same structure, and both include an E-shaped magnetic conductive core (4) and a permanent magnet (5). A number of E-shaped magnetic conductive cores (4) are evenly arranged along the circumference to form an annular shape. The opening of the E-shaped magnetic conductive core (4) faces the rotor (3). A permanent magnet (5) is embedded between two adjacent E-shaped magnetic conductive cores (4). The magnetization direction of the permanent magnet (5) is alternately magnetized along the circumference; A groove is formed in the middle tooth of the E-shaped magnetic conductive core (4) and an auxiliary permanent magnet (6) is embedded; A single armature winding (7) is commonly wound on the adjacent teeth of two adjacent E-shaped magnetic conductive cores (4). Two armature windings (7) that are radially opposite to each other along the stator are connected in series to form a phase winding, and four armature windings (7) on both sides that are radially opposite to each other form two sets of in-phase windings; The rotor (3) includes Z-shaped magnetic conductive rotor teeth (8) and Z-shaped non-magnetic conductive rotor teeth (9) which are alternately arranged in sequence along the circumference. The rotor (3) has an air gap with the same length left between it and the first stator (1) and the second stator (2) respectively; The long axes of the Z-shaped magnetic conductive rotor teeth (8) and the Z-shaped non-magnetic conductive rotor teeth (9) are arranged along the radial direction of the rotor, and the adjacent Z-shaped magnetic conductive rotor teeth (8) and Z-shaped non-magnetic conductive rotor teeth (9) are fitted together.

2. The Z-shaped rotor tooth double-stator axial magnetic field flux-switching permanent magnet motor according to claim 1, wherein: The auxiliary permanent magnet (6) is of a rectangular structure, made of alnico, magnetized alternately in the axial direction, and has the same coercive force.

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