| 摘要 |
PROBLEM TO BE SOLVED: To provide a spindle motor having a dynamic pressure bearing capable of stably supporting the rotation of the motor for a desired period without deviating the quantity of buffer oil. SOLUTION: Tapered seals S1, S2, S3, S4, and S5 communicable with the outside air are formed in the end part in the opposite side of one thrust dynamic pressure bearings side 26 and 28 of radial dynamic pressure bearings 22 and 24 and air-liquid interface between the oil and the air is formed and retained inside the tapered seals. A pair of tapered seals are formed in the outer circumferential face of the thrust plate 4 by providing a pair of mutually opposite inclined surfaces and a communicating hole extended radially to be communicated with the outside air is formed in a sleeve 10 so as to communicate the pair of tapered seals with the outside air. The oil retained by one thrust dynamic pressure bearing and the other thrust dynamic pressure bearing respectively is separated by the air retained by the pair of tapered seals. |
