Permanent magnet synchronous motor and rotor thereof

Abstract

The invention discloses a rotor of a permanent magnet synchronous motor. Each group of magnetic pole slots is divided into two inner magnetic pole slots positioned on the inner layer and one outer magnetic pole slot positioned on the outer layer along the radial direction of a rotor iron core sheet; two of the magnetic pole groups are first permanent magnets, the other one of the magnetic pole groups is a second permanent magnet, after the first permanent magnets are matched with the inner magnetic pole grooves, the two first permanent magnets are arranged in a V shape, and a magnetic pole straight shaft which is axially symmetric about the two first permanent magnets is arranged between the two first permanent magnets; at least one end of the inner magnetic pole groove extends to form a magnetic isolation groove located on the outer side of the first permanent magnet. After the second permanent magnets are matched with the outer magnetic pole grooves, the symmetry axes of the second permanent magnets coincide with the magnetic pole straight axes, and the distance between the second permanent magnets and the peripheral face of the rotor iron core piece is smaller than the distance between the first permanent magnets and the peripheral face of the rotor iron core piece. According to the invention, the counter electromotive force can be reduced, the no-load counter electromotive force waveform sinusoidal property is improved, the reluctance torque is improved, and the cogging torque is reduced.

Description

technical field [0001] The invention relates to the field of permanent magnet synchronous motors, in particular to a permanent magnet synchronous motor and a rotor thereof. Background technique [0002] In recent years, permanent magnet synchronous motors have been widely used in various fields due to their high torque and power density, small size, light weight, high efficiency, and low rotor electromechanical time constant. [0003] Because the permanent magnet synchronous motor needs a matching controller to work properly. The no-load back EMF of the permanent magnet synchronous motor is often one of the important indicators for the selection of the controller switch tube. To reduce controller cost, lower back EMF is often required without affecting the maximum torque output of the motor. [0004] And because the permanent magnet synchronous motor is matched with the common pole slot of 48 slots and 8 poles, when the rotor of the existing permanent magnet motor rotates ...

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Problems solved by technology

[0004] And because the permanent magnet synchronous motor is aimed at the common pole slot matching of 48 slots and 8 poles, when the rotor of the existing permanent magnet motor rotates along the circumferential direction, a large air gap harmonic magnetic field will be generated, the sinusoidality of the back EMF is poor, and the torque ripple is large And stator cogging effect, etc. lead to motor torque fluctuations and large noise

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