Patent ID: 7508108
Filing Date: 2009-03-24
Classification: H02K

Abstract:
1. An AC motor comprising: a rotor having a plurality of magnetic poles, with alternating north poles and south poles circumferentially disposed at equal intervals; a stator having three stator pole groups, each stator pole group formed circumferentially on the stator, with each of adjacent pairs of the three stator pole groups mutually differing in circumferential position by an identical amount; and a plurality of loop-configuration stator windings formed circumferentially on the stator, with each the loop-configuration stator winding disposed immediately adjacent to only one of the three stator pole groups, with respect to an axial direction of the rotor, wherein (−Iu+Iv) current is applied to one of the two stator windings enclosed by the stator pole groups adjacent to each other, and (−Iv+Iw) current is applied to the other of the two stator windings, where Iu, Iv and Iw are three phase AC currents that successively differ in phase by 120 degrees and flow in the loop-configuration stator windings, and wherein the stator poles facing the magnetic poles of the rotor have a combination of the stator poles of an approximate parallelogram shape and the stator poles of an approximate trapezoid shape, in which the top and bottom sides of each stator pole of the approximate parallelogram shape in its axial direction have a same width in a rotational direction of the rotor, and the top and bottom sides of each stator pole of the approximate trapezoid shape in its axial direction have a different width in the rotational direction of the rotor, and each stator pole of the approximate parallelogram shape and each stator pole of the approximate trapezoid shape have a same length in the axial direction.