| 摘要 |
PROBLEM TO BE SOLVED: To prevent lubricating oil from being excessively drawn in dynamic pressure generating grooves from the oil drawing-in sides of the grooves in a liquid dynamic pressure bearing for spindle motor, when the bearing is rotated at a high speed. SOLUTION: In a liquid dynamic pressure bearing incorporating a flanged cylindrical bearing member 20, a stepped cylindrical bearing member 30, and a disk-like thrust retaining member 40, oil sumps S3-S5 are respectively provided in the inside and outside-diameter sections of the thrust dynamic pressure generating grooves of a first thrust bearing section formed of one surface of a disk- like thrust bearing member 21 formed at the central part of the bearing member 20 in the axial direction and the surface of the thrust retaining member 40 facing the surface of the member 21 and a second thrust bearing section formed of the other surface of the bearing member 21 and the boundary surface between the large and small-diameter cylindrical sections of the stepped cylindrical bearing member 30. In addition, an oil sump S2 is provided on the oil drawing-in side of the radial dynamic pressure generating groove of a radial bearing section. |
