Rotor assembly and consequent-pole motor

Abstract

The application provides a rotor assembly and a consequent-pole motor. The rotor assembly includes a rotor core. The rotor core includes permanent magnet poles and a consequent pole arranged alternately along the circumferential direction. Each permanent magnet pole includes an installation slot in which a permanent magnet is installed. The polarities of the permanent magnets facing the outer periphery of the rotor core are the same. A first air slot and second air slots are arranged in the rotor core on the radial outer side of each installation slot, wherein the first air slot is located onthe center line of the magnetic pole, the at least two second air slots are arranged at intervals and located on the two sides of the center line of the magnetic pole, and the distance between the radial outer edge of each second air slot and the outer periphery of the rotor core is greater than the distance between the radial outer edge of the first air slot and the outer periphery of the rotor core. By adopting the rotor assembly of the application, improvement can be made on the problem of torque ripple increase caused by the rich content of back electromotive force harmonics of the consequent-pole motor, the content of back electromotive force harmonics can be significantly reduced, and the motor performance can be improved.

Description

technical field [0001] The present application relates to the technical field of motors, in particular to a rotor assembly and an alternating pole motor. Background technique [0002] The number of permanent magnets used by the alternating pole permanent magnet synchronous motor is only half of that of the traditional permanent magnet synchronous motor. Therefore, it can fully utilize the permanent magnets, which can significantly reduce the amount of permanent magnets used, thereby reducing the cost of the motor. [0003] However, its special magnetic circuit structure also brings many problems, including the decrease of output torque caused by the reduction in the use of permanent magnets, and the problem of increased torque fluctuation caused by the asymmetry of adjacent magnetic pole structures, which limits the further promotion of alternating pole motors. application. [0004] Some alternating pole motors in the prior art improve the torque ripple by optimizing the po...

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Problems solved by technology

[0003] However, its special magnetic circuit structure also brings many problems, including the decrease of output torque caused by the reduction in the use of permanent magnets, and the problem of increased torque fluctuation caused by the asymmetry of adjacent magnetic pole structures, which limits the further promotion of alternating pole motors. application

[0004] Some alternating pole motors in the prior art improve the torque ripple by optimizing the pole arc coefficient, which is mainly aimed at the torque ripple caused by the cogging torque, but has no effect on the torque ripple caused by the non-sinusoidal back EMF. Therefore, for the problem of increased torque ripple caused by the rich content of back EMF harmonics in alternating pole motors, the effect is not good.

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