External rotor motor and permanent magnet magnetizing method

Abstract

The invention discloses an external rotor motor. The external rotor motor comprises a stator formed by stacking stator punching sheets, permanent magnets and a rotor magnet yoke, wherein the permanentmagnets are the ones with non-uniform thickness; the plurality of permanent magnets are uniformly annularly arranged on the inner side surface of the rotor magnet yoke; the stator punching sheets areplaced on the inner sides of the permanent magnets; the permanent magnets with non-uniform thickness are magnetized in an unequal-diameter magnetizing manner; the permanent magnets with non-uniform thickness provides magnetic flows as well as magnetic circuits. The external rotor motor is reasonable in design; the permanent magnets with non-uniform thickness are magnetized in the unequal-diametermagnetizing manner, so that the magnetic flows are concentrated at the center of magnetic poles, the closed magnetic circuit is formed between the adjacent permanent magnets with non-uniform thickness, the magnetic flux passing through the closed rotor magnet yoke is reduced, and thus higher power can be output under a same size, the power density of the motor is improved, and the requirement onthe material of the rotor magnet yoke is also reduced.

Description

technical field [0001] The invention relates to the technical field of motors, in particular to an outer rotor motor and a permanent magnet magnetization method. Background technique [0002] The external rotor motor is compact in design and saves space, and its rotor yoke is usually made of ordinary steel, which is easy to process and manufacture, and relatively low in cost, suitable for a wide range of applications. However, its structural characteristics determine that it has two shortcomings that limit the application of external rotor motors: First, the permanent magnets are segmented and installed inside the rotor yoke, and the harmonics of the air gap magnetic field are relatively large, and the load torque The pulsation and noise performance are poor; second, the saturation magnetic flux density of ordinary steel is low, which limits the use of external rotor motors and the improvement of power density. Contents of the invention [0003] The first object of the pr...

AI Technical Summary

Problems solved by technology

However, its structural characteristics determine that it has two shortcomings that limit the application of external rotor motors: First, the permanent magnets are segmented and installed inside the rotor yoke, and the harmonics of the air gap magnetic field are relatively large, and the load torque The pulsation and noise performance are poor; second, the saturation flux density of ordinary steel is low, which limits the use of external rotor motors and the improvement of power density

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