Fluid dynamic bearing device

A fluid dynamic bearing device, comprising:

• a shaft member;
• a bearing sleeve having an inner periphery along which the shaft member is inserted;
• a housing having an inner periphery by which the bearing sleeve is held;
• a sealing member comprising an injection-molded product of a resin and having:
• a large-diameter inner peripheral surface which is fixed to an outer peripheral surface of an end portion of the bearing sleeve by press-fitting;
• and
• a small-diameter inner peripheral surface;
• a radial bearing portion for generating a dynamic pressure action of a lubricating oil in a radial bearing gap between an outer peripheral surface of the shaft member and an inner peripheral surface of the bearing sleeve so as to support the shaft member in a radial direction;
• a first seal space formed between the small-diameter inner peripheral surface of the sealing member and the outer peripheral surface of the shaft member so as to seal the lubricating oil filling an inside of the housing;
• a second seal space formed between an outer peripheral surface of the sealing member and an inner peripheral surface of the housing so as to seal the lubricating oil filling the inside of the housing;
• and
• a communication path formed between the sealing member and the bearing sleeve so as to communicate the first seal space and the second seal space to each other,
• wherein an axial groove is formed in the large-diameter inner peripheral surface of the sealing member so as to form the communication path, and
• wherein a weld line as a result of injection molding is formed at a circumferential position out of a deepest portion of the axial groove.