Hydrodynamic gas bearing and manufacturing method thereof

Abstract

A hydrodynamic gas bearing structure which can effectively prevent the half speed whirl phenomenon and prevent wear at the time of activation or stopping of rotation is implemented in a simple manner. The hydrodynamic gas bearing includes a shaft body having an outer periphery, and a cylindrical bearing body arranged around the shaft body with a space maintained therebetween in the radial direction. The shaft body has a hollow portion extending in the axial direction. In a cross section perpendicular to the axial line of the shaft body, the hollow portion has a not-complete-round, symmetrical shape with respect to a line passing through the center of the cross section, for example, an approximately regular triangular shape. A first distance from the center of the cross section to an outline corresponding to an inner periphery of the hollow portion changes along the peripheral direction of the shaft body as a second distance from the center of the cross section to an outline corresponding to the outer periphery of the shaft body also changes along the peripheral direction of the shaft body.

Dependencies are inferred from the claim text.