F16C33/745

Fluid dynamic bearing apparatus, spindle motor, and disk drive apparatus
09964148 · 2018-05-08 · ·

A fluid dynamic bearing apparatus includes a stationary body, a rotating body, and a lubricating oil arranged therebetween. One of the stationary and rotating bodies includes a shaft. Another one of the stationary and rotating bodies includes a sleeve. The sleeve includes a communicating hole arranged to pass therethrough in an axial direction or obliquely with respect to the axial direction. A groove array is defined in the stationary body or the rotating body to cause the lubricating oil to flow into the communicating hole. An opening area of an inlet of the communicating hole may be arranged to be greater than a cross-sectional area of a tubular portion of the communicating hole to make it easier for the lubricating oil to flow into the communicating hole. Further, the shape of the inlet may be modified to make a loss coefficient at the inlet lower than a loss coefficient at an outlet. This contributes to preventing a leakage of the lubricating oil.

Spindle motor having a fluid dynamic bearing system and a stationary shaft

The invention relates to a spindle motor having a fluid dynamic bearing system comprising axial and radial bearings that contains a rotor component (14) which encloses a stationary shaft (12), which in turn is connected at both its ends to axially aligned bearing parts (16; 18) that are fashioned such that they form capillary sealing gaps (32; 34), a recirculation channel (28) filled with bearing fluid that connects the remote regions of the bearing to each other, and an electromagnetic drive system (42, 44) for driving the rotor component.