Dynamic pressure bearing device

Abstract

A dynamic pressure bearing device, comprising: a shaft member; a bearing member relatively rotatably supporting the shaft member; a plurality of dynamic pressure generation parts provided on a peripheral face either of the shaft member or the bearing member; and a perfect circle part formed at least on a shaft end side at a region which is axially adjacent to the dynamic pressure generation part on the peripheral face where a protruded part and a recessed part are formed, wherein the dynamic pressure generation parts are respectively formed in a circumferential direction at equal angular intervals and extended in an axial direction so as to form a protruded part which makes a dimension of a minute gap between the shaft member and the bearing member to be the smallest and a recessed part which makes the dimension of the minute gap the largest, and the dimension of the minute gap in the perfect circle part is set to be the same as that in the protruded part.

Dependencies are inferred from the claim text.