| 摘要 |
PROBLEM TO BE SOLVED: To provide a fan motor capable of rotatably driving an impeller with a low current and low noise for a long time. SOLUTION: An output shaft 4 is inserted slidably (idle running) into a shaft hole 8a formed on the axis of rotation of the impeller 8. The tip 4a of the output shaft 4 onto which the impeller 8 is inserted is spherically formed, and is abutted against the bottom of the shaft hole 8a in the impeller 8. On the back face of the impeller 8 opposed to stator yokes 1A and 1B, a holding member 10 comprising a thin ring-shaped permanent magnet is fixed coaxially with the output shaft 4. The tip 4a of the output shaft 4 is attracted toward the stator yokes 1A and 1B by the magnetic force of the holding member 10, and is thereby abutted against the bottom of the shaft hole 8a in the impeller 8 under predetermined pressing force. When a stepping motor is started, the output shaft 4 slides (runs idle) in the shaft hole 8a in the impeller 8. As the stepping motor is thereafter brought into steady state, the impeller 8 is caused to follow the output shaft 4 and rotate by frictional force between the tip 4a of the output shaft 4 and the shaft hole 8a in the impeller 8. COPYRIGHT: (C)2005,JPO&NCIPI |
