Patent ID: 7625123

Claim:
A hydrodynamic bearing device comprising: a sleeve having an inner peripheral face extending linearly in the axially direction of the sleeve, and hydrodynamic grooves formed in the inner peripheral face of the sleeve; a shaft inserted in the sleeve so as to be capable of rotation relative to the inner peripheral face of the sleeve, the shaft having an outer peripheral face formed with an annular recess provided in an axially middle portion of the shaft and opposing the inner peripheral face of the sleeve, thereby defining an axially effective length of the hydrodynamic grooves; and a lubricant provided in a space between the inner peripheral face of the sleeve and the outer peripheral face of the shaft, said hydrodynamic grooves including plural V-shaped grooves, the V-shaped grooves being arranged continuously in the axial direction such that each linear portion of the V-shaped grooves extends at a predetermined angle relative to the axial direction, and said annular recess being located so as to oppose part of the V-shaped grooves.