| 摘要 |
PURPOSE:To decrease cogging by providing a ring shaped magnetic body on the top or bottom surface of a stator. CONSTITUTION:The ring shaped magnetic body 6 is provided on the top surface of the stator 3 wherein a driving winding 2 is wound around a cross shaped iron core. At this time, a peripheral surface 31 on the gap side of the stator 3 is matched with a peripheral side 61 on the gap side of the ring shaped magnetic body. In this constitution, since the static magnetic attracting force acted between the iron core 1 of the stator 3 and a permanent magnet rotor by the ring shaped magnetic body 6 is alleviated, the cogging can be decreased, and only small starting torque is required at starting. |
