Patent ID: 8128289

Claim:
A fluid dynamic bearing device, comprising: a shaft member including a shaft portion and a flange portion; a porous body formed in a cylindrical shape and provided with the shaft portion which is disposed along an inner periphery of the cylindrical shape, an end surface of the porous body being opposed to one end surface of the flange portion; a housing made of a resin which has a small diameter inner peripheral surface, a large diameter inner peripheral surface, and a radial shoulder surface formed between the small diameter inner peripheral surface and the large diameter inner peripheral surface, the small diameter inner peripheral surface holding an outer peripheral surface of the porous body, the radial shoulder surface being opposed to the one end surface of the flange portion; a radial bearing gap having one axial end which constitutes an air-outlet side and another axial end which constitutes a sealed side; a thrust bearing gap which is formed between the one end surface of the flange portion of the shaft portion and the radial shoulder surface of the housing and which is communicating with the another axial end side of the radial bearing gap; and a thrust dynamic pressure generating portion facing the thrust bearing gap, for exerting a dynamic pressure effect of a lubricating fluid, wherein the outer peripheral surface of the porous body is positioned on a radially inside with respect to the thrust dynamic pressure generating portion, and wherein the end surface of the porous body is positioned at substantially a same axial location as the radial shoulder surface of the housing.