Patent ID: 7513689

Claim:
A hydrodynamic bearing device comprising: a sleeve having a bearing bore with a dynamic pressure generating groove formed on an inner surface of the bearing bore, the dynamic pressure generating groove being defined by at least one crest portion adjacent to the dynamic pressure generating groove; a shaft disposed in the bearing bore of the sleeve in a relatively rotatable manner; a thrust flange disposed on an end of the shaft; a thrust member opposed to the thrust flange; a dynamic pressure generating groove formed on at least one of opposing surfaces of the thrust flange and the thrust member; and working fluid filled in a gap between the shaft and the bearing bore, and between the thrust flange and the thrust member, the sleeve being a sintered body including a sintering material containing at least one selected from a group containing iron, an iron alloy, copper and a copper alloy, such that pores in the at least one crest portion adjacent to the dynamic pressure generating groove of the sintered body are independent pores in which respective neighboring pores do not communicate with each other, and a diameter of the independent pores is smaller than each of a width and a depth of the at least one crest portion adjacent to the dynamic pressure generating groove.