Outer surface structure of magnetic steel embedded rotor

Abstract

The invention relates to an outer surface structure of a magnetic steel embedded rotor. The magnetic steel embedded rotor comprises a rotor iron core on which even axial through magnetic steel grooves are evenly distributed; the magnetic steels are embedded in the magnetic steel grooves alternately in N and S poles; the part of the rotor iron core corresponding to each magnetic steel groove is an arc surface of a sine air gap and the part corresponding to the part between two adjacent magnetic steel grooves is a circular surface of an even air gap. The outer surface structure of the magnetic steel embedded rotor of the invention ensures that an alternating state of sine air gaps and even gaps is formed between the rotor and stator. Relative to the traditional sine air gap, the invention markedly decreases the magnetic resistance of a quadrature-axis magnetic circuit of a motor, increases the magnetic resistance torque component of the motor, weakens the negative influence from the traditional sine air gap to the power density and the torque density of the motor; therefore, compared with the traditional sine air gap type magnetic steel embedded rotor, the invention can generate more magnetic resistance torque components and enhance the power density and the torque density of the motor.

Description

technical field [0001] The invention relates to a motor rotor, in particular to an outer surface structure of a magnetic steel embedded rotor. Background technique [0002] If the outer surface of the magnetic steel embedded rotor is a circular surface, the gap between the outer surface and the stator is uniform, that is, a uniform air gap is formed between the rotor and the stator. This kind of uniform air gap will have adverse effects on back EMF, cogging torque and torque ripple due to more harmonics contained in the air gap flux density. The traditional solution is to make the outer surface of the rotor into an arc surface with an uneven air gap, that is, to form a sinusoidal air gap between the rotor and the stator, so as to weaken the harmonics of the magnetic field. The outer surface structure and Q-axis magnetic circuit of the traditional sinusoidal air gap rotor are as follows: figure 1 As shown, the air gap on the Q-axis magnetic circuit is large, so the reluctan...

AI Technical Summary

Problems solved by technology

The outer surface structure and Q-axis magnetic circuit of the traditional sinusoidal air gap rotor are as follows: figure 1 As shown, the air gap on the Q-axis magnetic circuit is large, so the reluctance of the Q-axis magnetic circuit is often large, resulting in a small quadrature-axis inductance, which will greatly weaken the reluctance torque component of the motor

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