| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a fluid dynamic pressure bearing device supporting relative rotation both in normal and reverse directions in which desired bearing performance may be maintained stably. <P>SOLUTION: A fluid dynamic pressure bearing device 1 comprises a dynamic pressure groove region B where a plurality of axially inclined dynamic pressure grooves 4 are arranged in a circumferential direction is disposed at an outer circumferential surface 2a of a shaft member 2 or an inner circumferential surface 3a of a bearing member 3 forming a radial bearing clearance, wherein the dynamic pressure groove region B includes: a first region B1 generating fluid dynamic pressure at the radial bearing clearance when the bearing member 3 and the shaft member 2 rotate relatively in the normal direction; and a second region B2 generating fluid dynamic pressure at the radial bearing clearance when the bearing member 3 and the shaft member 2 rotate relatively in the reverse direction. An annular convex portion 6, which is closer to the shaft member 2 as the counter side member than to a fillet of the dynamic pressure groove 4, is disposed at a region forming an end of a side open to the atmosphere of the radial bearing clearance in the dynamic pressure groove region B disposed in the inner circumferential surface 3a of the bearing member 3. <P>COPYRIGHT: (C)2012,JPO&INPIT |
