Patent ID: 8210748

Claim:
A fluid dynamic bearing device, comprising: a bearing sleeve having a radial bearing surface; a shaft member inserted in an inner periphery of the bearing sleeve; a housing having the bearing sleeve fixed to its inner periphery; a radial bearing gap formed between the radial bearing surface of the bearing sleeve and an outer peripheral surface of the shaft member; a radial bearing portion for supporting in a radial direction the shaft member to be supported with an oil film formed in the radial bearing gap; a seal space opened to external air; and a seal portion forming the seal space, wherein the seal portion is formed of a non-porous metal material or resin material, formed separately from the bearing sleeve, and has an end surface exposed to the external air, a step portion in an axial direction is formed at the end surface of the seal portion, the end surface is defined into a first end surface and a second end surface by the step portion, the second end surface is arranged closer to an inside bearing side than the first end surface, and an oil-repellent film is formed on the second end surface, and the first end surface is a pressure-receiving surface subjected to pressure at a time of assembly.