| 摘要 |
PROBLEM TO BE SOLVED: To suppress precession generated between a shaft and a sleeve rotating relative to one another by preventing adhesion of the shaft with the sleeve without increasing the size of a dynamic fluid bearing.SOLUTION: During stop of rotation of a shaft 2, a tip of a tip-side contact shaft part 22 of a support shaft 20 is supported by a bottom surface 18b of a bearing hole 18, a micro clearance 6 is held between a taper-shaped outer peripheral surface 15 of a truncated cone-shaped convex part 3 and a taper-shaped inner peripheral surface 24 of a truncated cone-shaped concave part 5, and adhesion of the taper-shaped outer peripheral surface 15 of the truncated cone-shaped convex part 3 with the taper-shaped inner peripheral surface 24 of the truncated cone-shaped concave part 5 is prevented. During rotation of the shaft 2, even if an external force for generating precession acts on the shaft 2, one-end side of the shaft 2 is rotatably supported by a bearing (not shown), and the support shaft 20 positioned on the-other-end side (tip side) of the shaft 2 is rotatably supported by the bearing hole 18. Therefore, the precession of the shaft 2 can be effectively suppressed. |
