Patent ID: 7455457
Filing Date: 2008-11-25
Classification: F16C,G11B

Abstract:
1. A hydrodynamic bearing device comprising: a shaft bush having a substantially conical inclined dynamic pressure surface around the outer circumference thereof being relatively rotatably inserted in a bearing sleeve having a substantially conical inclined dynamic pressure surface around the inner circumference thereof, a substantially conical inclined bearing space being created in the gap between said inclined dynamic pressure surfaces of said bearing sleeve and shaft bush; lubricant fluid being filled inside said inclined bearing space; a dynamic pressure generating means being formed on at least one of said inclined dynamic pressure surfaces of said shaft bush and bearing sleeve; said lubricant fluid being pressurized by said dynamic pressure generating means to generate dynamic pressure, by which said shaft bush and said bearing sleeve are relatively elevated in the radial and thrust directions so that their rotations are supported in a non-contact manner; a circulating hole being provided in at least either said shaft bush or bearing sleeve, passing through said shaft bush or bearing sleeve in a straight line and having an opening at each end in a hole passing direction, to create a circulation path so that the lubricant fluid that has leaked from said inclined bearing space is moved through said circulating hole to cancel the differential pressure generated between the two ends of said inclined bearing space; and at least one of the two said openings of said circulating hole being formed with an opening face formed on said shaft bush or bearing sleeve, which extends nearly perpendicularly to the hole passing direction.