Permanent magnet motor

Abstract

The invention provides a permanent magnet motor. The permanent magnet motor comprises a rotor assembly (1) and a stator assembly (2); the rotor assembly (1) comprises consequent poles (4) and permanent magnet poles (3), which are circumferentially and alternatively arranged; the stator assembly (2) comprises stator tooth portions (5) positioned at the inner peripheral side and peripherally arranged at intervals; first air gaps (6) are formed between the inner peripheral sides of the stator tooth portions (5) and the outer peripheral sides of the permanent magnet poles (3); second air gaps (7) are formed by the inner peripheries of the stator tooth portions (5) and the outer peripheries of the consequent poles (5); and an average thickness of the first air gaps (6) is delta 1, and an average thickness of the second air gaps (7) is delta 2, wherein a ratio of delta 2 to delta 1 is greater than or equal to 0.4 and smaller than or equal to 0.9. According to the permanent magnet motor provided by the invention, asymmetry of flux density magnitudes of the air gaps which the permanent magnet poles and the consequent poles face can be reduced, and torque fluctuation is reduced.

Description

technical field [0001] The invention belongs to the technical field of motor equipment, and in particular relates to a permanent magnet motor. Background technique [0002] A traditional permanent magnet motor, such as an 8-pole permanent magnet motor, has 8 sets of permanent magnets arranged around the center of the rotor along the direction of rotation, and adjacent sets of permanent magnets have different magnetization directions. The magnetic force lines starting from the N pole of a permanent magnet pass through the stator core to reach the S pole of the adjacent permanent magnet. A magnetic field line passes through at least two sets of permanent magnets with different magnetization directions in the circuit, therefore, the permanent magnets are not fully utilized, and thus the cost of the motor is high. [0003] An alternating pole permanent magnet motor is proposed in the prior art, still taking an 8-pole motor as an example, there are only 4 sets of permanent magne...

AI Technical Summary

Problems solved by technology

[0004] The usual alternating pole permanent magnet motor, due to the different materials and structures of the adjacent magnetic poles, if designed according to the conventional permanent magnet motor, the adjacent magnetic pole surface and the corresponding stator core tooth shoe surface have the same air gap thickness, There will be a problem of asymmetry in the back EMF waveform

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