FLUID DYNAMIC PRESSURE BEARING, MOTOR, AND RECORDING DISK DRIVE DEVICE

摘要

In a bearing mechanism, flow paths and gaps inside the mechanism are filled with lubrication oil. The lubrication oil is held by a first tapered seal section provided on the outer side in the radial direction of a sleeve and by a second tapered seal section provided between an upper cap attached to the upper part of the sleeve and a shaft. Grooves in the inner peripheral surface of the upper cap and projections on the lower surface of the upper part of the upper cap increase the cross-sectional area of flow paths which, between the upper cap and the sleeve, interconnect the first tapered seal section and the second tapered seal section.