Patent ID: 8403565

Claim:
A fluid dynamic bearing device, comprising: a radial bearing portion for rotatably supporting a shaft member through an oil film formed in a radial bearing clearance; a housing for accommodating the radial bearing portion therein, the housing is formed through injection molding of a resin; a lubricant oil filling an inner space of the housing; a seal member for sealing an opening of the housing; a first seal space is formed on an inner peripheral surface of the seal member; and a second seal space is formed on an outer peripheral surface of the seal member, wherein the housing has a small diameter portion and a large diameter portion, an outer peripheral surface of the large diameter portion having a diameter larger than a diameter of an outer peripheral surface of the small diameter portion, an inner peripheral surface of the large diameter portion having a diameter larger than a diameter of an inner peripheral surface of the small diameter portion, wherein the second seal space is formed between the outer peripheral surface of the seal member and the large diameter inner peripheral surface of the housing, and wherein the second seal space has the lubricant oil drawn therein due to a capillary force so as to seal the opening of the housing.