External rotor permanent magnet motor

Abstract

The invention discloses an external rotor permanent magnet motor. The external rotor permanent magnet motor includes a stator and an external rotor; the external rotor includes a rotor iron core and aplurality of rotor steel magnets fixed inside the rotor iron core; the stator includes a stator iron core and a stator winding embedded into a stator groove; a stator tooth includes a tooth body anda tooth boot located on left and right sides of the tooth body; the tooth body and top surfaces of the tooth boots on the left and right sides form a segmented type structure; and a relationship between the number of stator grooves Q and the number of poles of the external rotor 2P meets Q=(2P+ / -1):2P, wherein the P is the number of pole pairs of the rotor. According to the external rotor permanent magnet motor, on the basis of improving performance of the motor, the difficulty of a machining process is reduced, and the manufacturing cost of the motor is reduced; and the external rotor permanent magnet motor has the advantages of high winding coefficient, small harmonic content, low torque pulsation and high torque / power density, and the like, and can be widely applied to fields such as flywheel energy storage, electromobile and electric propulsion.

Description

technical field [0001] The invention relates to the field of motors, in particular to a stator and rotor of an outer rotor permanent magnet motor with high torque density and low ripple and the related motor. Background technique [0002] The outer rotor concentrated winding permanent magnet motor has the advantages of small magnetic flux leakage coefficient and high torque density, and is widely used in various fields. However, due to the existence of the magnetic steel, when the motor is running at a higher speed, due to the change of the magnetic field, additional eddy current loss will be generated on the magnetic steel of the motor. For the eddy current loss, the most commonly used method is to adopt the method of segmenting the magnetic steel. By reducing the volume of the magnetic steel, the eddy current on the magnetic steel is reduced, thereby weakening the eddy current loss generated on the magnetic steel. The more segments the magnetic steel has, the better the e...

AI Technical Summary

Problems solved by technology

However, the more segments the magnetic steel has, the more difficult it is to assemble the motor during manufacturing, and the cost of the magnetic steel will also increase significantly

[0003] Compared with the distributed winding motor, the concentrated winding group has the advantages of small end, low cost, good manufacturability, and high efficiency. However, due to the large air gap flux density harmonics of the concentrated winding group, there are usually large torque fluctuations, vibration and Loud noise etc.

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