| 摘要 |
PROBLEM TO BE SOLVED: To prevent deformation of a hub, to prevent deterioration of concentricity between a ring shaped member and a shaft body, and to prevent deformation of a recording medium and occurrence of rattle. SOLUTION: The fluid dynamic bearing 1 is equipped with the shaft body 9 having a radial shaft part 9a formed in a cylinder shape, a shaft body supporting part 8 rotatably supporting the shaft body 9 through a fluid filled in a gap between the shaft body 9 and it, a flange-shaped thrust part 8b provided on the shaft body supporting part 8 and extended to a radial direction outer side, a hub 5 integrally provided on the shaft body 9 and having a fixing part 5a fixing the thin plate shaped recording medium 3, and the ring shaped member 10 fixed on the hub 5 and holding the thrust part 8b between the hub 5 and it while having a gap in an axial direction. Dynamic pressure generating grooves 14b and 14c are provided on two surfaces of the thrust part 8b in the axial direction or the surfaces of the hub 5 and the ring shaped member 10 confronting the surfaces in the axial direction, and the ring shaped member 10 is fitted in a cylinder outer surface 11a on the hub 5 and is fixed. COPYRIGHT: (C)2008,JPO&INPIT
|
