| 摘要 |
PROBLEM TO BE SOLVED: To provide a motor capable of preventing damage to a fluid dynamic pressure bearing. SOLUTION: A ball 51 is force-fitted into the end surface 12b of a shaft body 12a so as to situate the tip end of the ball 51 in a position higher than the end surface 10b of an annular body 10. While the shaft 12 is stopped in rotation, the ball 51 is abutted against the upper surface 11a of a counter plate 11 with the end surface 10b of the annular body 10 being floated from the upper surface 11a of the counter plate 11, thereby avoiding the end surface 10b of the annular body 10 and the upper surface 11a of the counter plate 11 from coming into fully contact with each other. Consequently, in starting the rotation of the shaft, the circulation of the fluid is increased in speed to form a fluid film layer quickly, thereby improving the blocking action of film lubrication that is unavoidable in prior art, and surely preventing the occurrence of scratches caused by the starting of the rotation in closed contact state as well.
|
