Skewed brushless rotary electric machine

Abstract

Abstract PURPOSE:To reduce a cogging torque and the rate of decrease of an induced voltage by setting the number of salient poles of a stator field core as 1.5 times the number of magnetic poles of a rotor permanent magnet and by applying skew to said rotor permanent magnet or stator field core. CONSTITUTION:In a synchronous type brushless motor, in which the numbers of magnetic poles of a rotor permanent magnet, slots of a field core and driving AC phases are respectively 6, 9 and 3, such skew as shown by a broken line is applied to a ring-shaped plastic permanent magnet 1 fastened on the outer periphery of a rotor by 1/2 of a slot pitch between slots opened in a three-U, V, W-phase excited stator field core 2. Thus, much cogging torque generated cancels each other and the rate of decrease of an induced voltage also is small as compared with that of the existing 1 slot skew.

Inventors

• 👤 Makoto Momiyama

Bibliographic Details