| 摘要 |
<P>PROBLEM TO BE SOLVED: To reduce a rotation torque of a fluid dynamic bearing device that uses a bearing member formed with a radial dynamic pressure generating part by pressing part of the area in the axial direction of an outer peripheral surface. <P>SOLUTION: When a radial dynamic pressure generating part (dynamic pressure grooves G1, G2) is to be formed at the bearing member, the end (relief part E side) of the center side in the axial direction of areas P1, P2 pressing the outer periphery surface 8d of the bearing member (a bearing sleeve 8) is positioned within the area in the axial direction of the dynamic pressure grooves G1, G2. Then, the relief part E of the inner peripheral surface 8a of the bearing sleeve 8 does not become pressed from the outer diameter side, the relief depth D<SB POS="POST">E</SB>of the relief part E can be made sufficiently large and the torque can be reduced. <P>COPYRIGHT: (C)2012,JPO&INPIT |
