| 摘要 |
PROBLEM TO BE SOLVED: To provide a dynamic pressure type fluid bearing device capable of preventing an outflow of lubricant oil to the outside by discharging air mixed into the bearing. SOLUTION: A thrust plate 4 is attached to one end side of a sleeve 3 rotatably supported to a fixed shaft 2, thereby clipping a thrust bearing 1 attached to the fixed shaft 2 with leaving a clearance by the sleeve 3 and the thrust plate 4. Asymmetric herringbone dynamic pressure generating grooves 8a, 8b are formed on at least one of the outer peripheral surface of the fixed shaft 2 or the inner peripheral surface of the sleeve 3 opposite to the outer peripheral surface. Lubricant oil is filled between the fixed shaft 2 and the inner peripheral surface of the sleeve 3 and between the sleeve 3 and the thrust plate 4 and thrust bearing 1. A first capillary seal portion 7a formed with a taper surface along an axial direction is formed between one end of the fixed shaft 2 and the sleeve 3, and a second capillary seal portion 7b formed with a taper surface along the axial direction between the other end of the fixed shaft 2 and the thrust plate 4. A groove portion 9 for air vent is formed on an outer surface of the fixed shaft 2 between the first capillary seal portion 7a and the second capillary seal portion 7b.
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