| 摘要 |
PROBLEM TO BE SOLVED: To obtain high starting reliability without devising a complicated structure. SOLUTION: On the inside of a motor case 2 with a cylindrical circumferential wall part 4 comprising a magnetic body, an annular stator core 32 with a plurality of pole pieces inwardly projecting radially with equal intervals and a stator 28 with coils wound on the pole pieces are disposed. A rotor magnet is rotatably disposed inside the stator 28, and a pair of open windows 8 are symmetrically formed in the cylindrical circumferential wall part 4, and both open windows 8 are disposed so that an arbitrary pole piece 30 coming nearest to the center of the circumferential wall part 4 between both open windows 8 is shifted from the center line passing the center of the circumferential wall part 4. |
