Patent ID: 7591591

Claim:
A dynamic bearing device comprising: a housing having an inner circumferential surface; a bearing sleeve having an end surface, an inner circumference, and fixed to the inner circumferential surface of the housing; an axial member including a flange part having an outer circumference and an axial part having an outside diameter, the axial member being inserted into the inner circumference of the bearing sleeve and the flange part thrusting out toward the outside diameter of the axial part; a thrust bearing part including a gap facing the flange part, the thrust bearing part being configured to support the axial member in a thrust direction in a non-contact manner by an action of a dynamic pressure generated by a fluid in the gap in the thrust bearing part; and a projecting part in contact with the end surface of the bearing sleeve and facing the outer circumference of the flange part, said projecting part being provided on the housing, wherein the flange part is formed of a resin and has a linear expansion coefficient in an axial direction equal to or larger than a linear expansion coefficient of the projecting part in the axial direction.