Permanent magnet embedded rotor for direct current brushless motor

Abstract

An imbedded permanent magnet rotor for a direct-current brushless motor, comprising a cylindrical rotor core (A) which is formed by overlying rotor punching plates and is provided with p pairs of strip-shaped permanent magnet grooves (C) and 2p heat-dissipation through holes (B), wherein both the p pairs of permanent magnet grooves (C) and the 2p heat-dissipation through holes (B) are arranged inside the rotor core (A) in the direction of a central shaft of the rotor core (A), and are uniformly distributed around the central shaft of the rotor core (A) at intervals; each of the heat-dissipation through holes (B) is located between two permanent magnet grooves (C); and p pairs of strip-shaped permanent magnets (D) fixedly arranged in the permanent magnet grooves (C), wherein the cross section of each of the permanent magnets (D) is in a trapezoid shape, and p is an integer greater than or equal to 1.

Description

technical field [0001] The invention relates to a rotor for a DC brushless motor, in particular to a permanent magnet embedded rotor for a DC brushless motor. Background technique [0002] In order to reduce the flux leakage coefficient and increase the utilization rate of permanent magnet materials, the existing permanent magnet embedded rotors generally adopt magnetic isolation measures, that is, magnetic isolation air gaps are arranged at the left and right ends of the built-in permanent magnets. [0003] Chinese invention patent "a built-in permanent magnet motor rotor punching and built-in permanent magnet motor rotor" (application number 201210419454.3) discloses a built-in permanent magnet motor rotor punching and built-in permanent magnet motor rotor, including punching The main body, the punching body includes a circular inner layer punching sheet as a whole, a plurality of notches are equidistantly arranged on the edge of the inner layer punching sheet along its ci...

AI Technical Summary

Problems solved by technology

[0007] There is a sudden change in the magnetic circuit structure in the magnetic separation air gap ω and the edge distance b of the existing permanent magnet embedded rotor, such as Figure 1~2 As shown, such a structure leads to two problems:

[0009] 2. Two surface magnetic convex waves appear at the junction of two magnetic poles, such as Figure 5 As shown, the surface magnetic convex wave caused by the structural defect of the magnetic circuit will cause Hall signal jitter, drive waveform distortion, and increase the motor output torque fluctuation and motor loss, so it is necessary to further improve

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