| 摘要 |
PROBLEM TO BE SOLVED: To provide a dynamic pressure bearing device with high reliability and a long life span by reducing a diameter of a thrust bearing portion without deteriorating rigidity of a bearing support portion. SOLUTION: In the dynamic pressure bearing device equipped with upper and lower radial dynamic pressure bearing portions 30, 32 that use air as working fluid and upper and lower thrust dynamic pressure bearing portions 34, 36 that use lubricating liquid as working fluid, since the thrust dynamic pressure bearing portion is provided with a taper seal 16 in the axial direction, the diameter of the thrust bearing portion can be reduced without reducing the diameter of a shaft 2. In addition, since oil 14 is circulated due to an oil circulating hole 38 arranged on a thrust plate 10, air bubble entering into the thrust dynamic pressure bearing portion can be discharged to outside. Due to an air communicating hole 18 arranged on the shaft 2, atmospheric pressure above and below the thrust dynamic pressure bearing portion can be uniformed. COPYRIGHT: (C)2004,JPO
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