Patent ID: 6357916
Filing Date: 2002-03-19
Classification: F16C

Abstract:
A hydrodynamic bearing device, comprising:a stationary shaft supported at each end thereof, a rotary sleeve rotatably supported about the stationary shaft for pumping a lubricating fluid between the stationary shaft and the rotary sleeve for a non-contact rotation of the device, the stationary shaft comprising a stationary thrust ring, the rotary sleeve comprising a recessed portion defined by the faces thereof opposed to upper and lower faces and an outer circumferential surface of the stationary thrust ring, wherein lubricating fluid filled in a gap defined between the stationary thrust ring and the recessed portion has a surface tension of about 25 dyn/cm at 29Â° C., and the following expression is satisfied: &Dgr;L=t+10 &mgr;m to 30 &mgr;m wherein t is a thickness of the stationary thrust ring and &Dgr;L is a height of the recessed portion.