Patent ID: 6702408
Filing Date: 2004-03-09
Classification: F16C

Abstract:
A hydrodynamic bearing cartridge comprising a sleeve and a shaft including a central reservoir,said shaft and said sleeve rotating freely relative to one another, and together defining a journal bearing gap, said shaft further supporting an annular thrust plate on an end thereof, said thrust plate extending into a recess formed by said sleeve and a counterplate supported from the sleeve, a surface of said thrust plate facing an axial surface of said sleeve, and a first surface of said counterplate facing an opposed surface of said thrust plate and cooperating therewith to define a fluid gap, one of the surfaces having a grooved pattern thereon to form an effective fluid pumping region in said hydrodynamic bearing, and fluid in the gap between the thrust plate and the counterplate, thrust plate and sleeve and the shaft and the sleeve wherein said shaft is stationary, and said sleeve supports a hub for rotation with said sleeve about said stationary shaft and is supported for rotation by a fluid dynamic bearing comprising an outer surface of said shaft and an inner surface of said sleeve, said first thrust plate surface cooperating with said recess surface of said sleeve and said first surface of said counterplate cooperating with said second surface of said thrust plate, and said first surface of said counterplate includes a grooved region which extends radially beyond the region overlying said second surface of said thrust plate.