A rotor structure with eccentric inner rotor

Abstract

The invention provides a rotor structure with an eccentric inner rotor, comprising: an outer rotor core, a permanent magnet, a magnetic isolation block, a rotor shaft, and a sleeve; the outer wall of the outer rotor core is fixedly installed on the inner wall of the sleeve, and the inner wall There are several permanent magnets; magnetic spacer blocks are arranged between adjacent permanent magnets; an eccentric inner rotor core is also included; the inner side wall of the eccentric inner rotor core is fixedly installed on the outer side wall of the rotor shaft, and there is a gap between the outer side wall and the permanent magnets; The outline of the eccentric inner rotor core is composed of several eccentric arc groups, and the eccentric arcs correspond to the permanent magnets one by one. The thickness of the air gap between the inner rotor and the permanent magnet of the present invention is not uniform, and the change is more reasonable, the waveform of the air gap magnetic density of the motor is improved, the harmonic content in the air gap magnetic field is reduced, and the air gap magnetic field is close to a sine wave, thereby The back electromotive force waveform of the hollow cup motor is improved, and the performance of the motor is improved; the permanent magnet motor designed based on the technical scheme of the invention has the advantages of small torque ripple and large output torque.

Description

technical field [0001] The invention relates to the field of design and optimization of a permanent magnet motor, in particular to a rotor structure with an eccentric inner rotor. Background technique [0002] When an AC asynchronous motor operates as a drive motor, the three-phase AC magnetic field generated by the stator of the asynchronous motor will generate huge eddy current losses on the rotor hub, which limits the maximum speed of the motor. In order to reduce the eddy current of the rotor hub, the hollow cup permanent magnet motor is usually used at present, that is, the motor rotor is designed in the form of a double rotor structure of the inner and outer rotors, the stator is a hollow cup type, and is placed between the inner and outer rotors, and the permanent magnet is placed between the inner and outer rotors. On the outer rotor core, this structure can greatly reduce the eddy current loss on the rotor hub because the permanent magnet and the inner and outer rot...

AI Technical Summary

Problems solved by technology

[0003] In some prior art documents, a coreless stator coreless motor structure is disclosed, wherein the coreless stator structure can be used in the design of a permanent magnet synchronous motor, so that both the inner and outer rotor cores rotate synchronously with the permanent magnets, so that there is no Loss will be generated in the iron core, and the hollow cup stator makes the stator a cogging-free structure, which can eliminate cogging torque and tooth harmonics, but because of the uniform radial thickness of the air gap, the radial air gap reluctance is consistent, affecting The distribution of the air gap magnetic field makes the harmonic content of the air gap magnetic field larger and the sinusoidality is poor, which affects the performance of the motor

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