Patent ID: 7056030

Claim:
A pivot bearing for a swing arm of a hard disk drive device comprising: a stepped shaft including an enlarged diameter shaft portion and a reduced diameter shaft portion, wherein an inner ring raceway is provided directly around an outer periphery of the enlarged diameter shaft portion for a lower row of balls; a sleeve outer ring surrounding the enlarged diameter shaft portion of the stepped shaft, wherein an outer ring raceway is provided directly around the inner periphery of the sleeve outer ring; a plurality of balls of the lower row adapted to be interposed between the inner and outer ring raceways; and a ball bearing including inner and outer rings and a plurality of balls interposed therebetween, wherein the inner ring of the ball bearing is secured around the reduced diameter shaft portion while applying an appropriate amount of pre-load on an upper end surface of the inner ring, and a lower surface of the outer ring is urged onto an upper surface of the sleeve outer ring so as to contact intimately therewith.