Motor rotor structure to reduce eddy current loss

Abstract

The present invention discloses a motor rotor structure capable of reducing the eddy-current loss and belongs to the technical field of motor mechanical structures. The motor rotor structure comprises a cylindrical sheath, an axially segmented hollow cylindrical permanent magnet array and a solid cylindrical rotor yoke. The inner circumferential surface of the permanent magnet array is in interference fit with the outer circumferential surface of the rotor yoke. The outer circumferential surface of the permanent magnet array is in interference fit with the inner hole of the sheath. The permanent magnet array comprises at least two groups of axially distributed permanent magnet hollow magnetic rings different in thickness. Each group of permanent magnet hollow magnetic rings is formed through splicing sector-shaped permanent magnets of different polarities. The outer circumferential surface of the sheath is axially provided with a plurality of annular grooves diversified in width and slot pitch along the circumferential direction. According to the technical scheme of the invention, the distribution of the eddy current is improved through non-uniform slots along the axial position of the sheath and the axial non-uniform sections of permanent magnets.

Description

technical field [0001] The invention discloses a motor rotor structure for reducing eddy current loss, and belongs to the technical field of motor mechanical structures. Background technique [0002] At present, for the surface-mounted motor with permanent magnets on the rotor, when the motor rotor rotates at high speed, the tooth harmonics generated by the change of the air gap magnetic density caused by the motor cogging structure, the space harmonics formed by the distributed magnetomotive force of the motor winding, and non-sinusoidal The time harmonics generated by the current will cause eddy current loss in the motor rotor. The higher the motor rotor speed, the greater the eddy current loss. At the same time, it is difficult for the rotor to dissipate heat. The eddy current loss will cause the temperature rise of the rotor to increase. When the temperature rise reaches a certain stage, the permanent magnet will undergo irreversible demagnetization. , therefore, eddy cu...

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Problems solved by technology

[0004] The technical problem to be solved by the present invention is to provide a motor rotor structure that reduces eddy current loss in view of the above-mentioned deficiencies in the background technology. On the basis of the existing sheath slotting and permanent magnet segmentation, carefully study the distribution effect of the three-dimensional eddy current ring end Finally, the eddy current loss of the rotor is further reduced through the non-uniform slotting method of the sheath and the non-uniform axial segmentation of the permanent magnet, which solves the technical problem of the poor effect of reducing the eddy current loss at the end of the rotor in the prior art

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