HYDRODYNAMIC BEARING DEVICE

摘要

A hydrodynamic bearing device that is low cost and has excellent bearing characteristics and a long endurance life. A thrust bearing portion of the hydrodynamic bearing has a second thrust face (7c1) where a hydrodynamic groove area (P) with hydrodynamic grooves is formed at least in part of the area in a radial direction. Pressure is generated in a thrust bearing gap between a flange portion end face of a shaft member and the second thrust face (7c1) by dynamic effect of a lubricant, and this pressure supports without contact the shaft member in a thrust direction. The hydrodynamic groove area of the second thrust face (7c1) is formed by pressing, and a height difference (H1) between an inner peripheral edge portion of and an outer peripheral edge portion of the surface of the dynamic groove area is set to a range from 0 mum or more to 2 mum or less.