Patent ID: 6259176
Filing Date: 2001-07-10
Classification: H02K

Abstract:
A multi-phase outer-type PM stepping motor comprising:a rotor constituted by a cylindrical permanent magnet in which north N and south S poles are magnetized alternately on an inner circumferential surface of said rotor;stator cores respectively having pole teeth disposed in opposition to said N and S poles of said rotor through a predetermined gap; andexcitation coils wound in said stator cores for uni-directionally magnetizing said stator cores to thereby rotate said rotor,wherein, when a number of said stator cores is 3 and a magnetization pitch of said permanent magnet is P, said pole teeth of said stator cores arc arranged so that the pole teeth of one stator core are shifted by an angle of 2P/3 from the pole teeth of an adjacent stator core with a resultant step rotation of said motor by P/3.