Patent ID: 6917130

Claim:
A fluid dynamic bearing arrangement comprising a fixed shaft adapted to be supported between a base and a top cover plate and including a thrust plate supported from the shaft between a journal bearing and the top cover plate, the second end of the shaft being adapted to be fastened to the top cover, the fluid bearing arrangement further comprising a sleeve rotating over the shaft and defining a gap including the journal bearing between an inner surface of the sleeve and an outer surface of the shaft, fluid in the gap between the sleeve and the shaft end thrust plate supporting the sleeve for rotation around the shaft, fluid bearing means including said gap supporting said sleeve for rotation over said shaft and a single axially directed thrust bearing defined between an axially facing surface of the shaft and a facing surface of either the sleeve or counterplate, and magnetic biasing means for maintaining the gap between the thrust plate and the sleeve and the thrust plate and a counterplate during rotation of the sleeve over the shaft and thrust plate.