A method of realizing the air-gap magnetic field of the outer rotor approaching a sinusoidal waveform by using multiple permanent magnets

Abstract

The invention discloses a method for allowing an air-gap field to approach a sinusoidal waveform of an outer rotor by using multiple pieces of permanent magnets, belonging to the technical field of the outer rotor of a synchronous permanent-magnet motor. The method comprises the following steps of (a) carrying out parallel magnetizing on each piece in even numbers of tile-shaped permanent magnet pieces to form an S pole and an N pole; (b) embedding the tile-shaped permanent magnet pieces into radially-partitioned slots of an outer rotor iron core one by one, wherein adjacent tile-shaped permanent magnet pieces are installed in polarity opposite way, the outer rotor iron core is provided with a round outer side surface, even numbers of radial and inward inner convex parts and limitation straight teeth are uniformly arranged in the outer rotor iron core, the radially-partitioned slot is connected between each limitation straight tooth and adjacent inner convex parts in a transition way, and the quantities of the inner convex parts, the limitation straight teeth and the tile-shaped permanent magnet pieces are the same; and (c) placing an inner support in an inner hole of the outer rotor iron core to allow each tile-shaped permanent magnet piece to prop against the inner support and allow a concave curved surface of each tile-shaped permanent magnet piece to be in contact with an inner convex curved surface of each inner convex part. With the method, the air-gap field inside the outer rotor approaches the sinusoidal waveform, and the loss brought by the action of a harmonic magnetic field can be reduced.

Description

【Technical field】 [0001] The invention relates to a method for realizing that the air-gap magnetic field of an outer rotor approaches a sine waveform by using a plurality of permanent magnets, and belongs to the technical field of the outer rotor of a permanent magnet synchronous motor. 【Background technique】 [0002] The outer rotor permanent magnet synchronous motor has the advantages of simple structure, small size, high operating efficiency, high power factor, high power density, large output torque at low speed, and simple maintenance. fields have more and more extensive applications. [0003] The magnetic steel adopts the surface-mounted outer rotor, and the internal air-gap magnetic field can generally only form a trapezoidal waveform. The magnetic field contains many harmonics, which have a negative impact on the performance of the motor. [0004] Whether the design of the air gap magnetic field of the outer rotor is reasonable or not, and the design of the permanen...

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Problems solved by technology

[0003] The magnetic steel adopts the surface-mounted outer rotor, and the internal air-gap magnetic field can only form a trapezoidal waveform. The magnetic field contains a lot of harmonics, which will have a negative impact on the performance of the motor.

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