| 摘要 |
PURPOSE:To start a rotary sleeve rotating with a small starting torque by disposing an actuator for pushing up the rotary sleeve in the direction of the shaft center line in an insertion hole bored in the upper portion of a fixed shaft in the above bearing incorporated in a motor for driving a polygon mirror or the like. CONSTITUTION:An insertion hole 15 is bored in the upper portion of a fixed shaft 1, and an actuator 16 adapted to make point-contact with a rotary sleeve 4 on the shaft center line and push up the rotary sleeve in the direction of the shaft center line is disposed in the insertion hole 15. At the time of starting rotation, the actuator 16 is operated immediately before the rotary sleeve 4 starts rotation to push up the rotary sleeve 4. At this time, the rotary sleeve 4 is out of contact with the fixed shaft 1 and makes point-contact with the actuator 16, so that the starting torque may be small. |
