FLUID DYNAMIC BEARING APPARATUS, SPINDLE MOTOR, AND DISK DRIVE APPARATUS

摘要

A fluid dynamic bearing apparatus includes a first minute gap, a second minute gap, a third minute gap, a fourth minute gap, and a fifth minute gap. A flow of a lubricating oil from the fifth minute gap to the fourth minute gap is caused by a plurality of dynamic pressure generating grooves arranged within the fluid dynamic bearing apparatus. This flow causes air bubbles mixed in the lubricating oil within the fifth minute gap to flow toward the third minute gap and be discharged to an outside through the third minute gap. The fluid dynamic bearing apparatus further includes a plurality of dynamic pressure generating grooves and an all around groove.