| 摘要 |
A disk drive device includes a rotating body, a fluid dynamic bearing unit that rotatably supports the rotating body, and a drive unit. The fluid dynamic bearing unit has: a lubricant holding portion in which lubricant is held; a first thrust dynamic pressure groove with which a first thrust dynamic pressure generating portion for generating the dynamic pressure in the pump-in direction, which is oriented toward the inside of the lubricant holding portion, is structured; and a second thrust dynamic pressure groove with which a second thrust dynamic pressure generating portion for generating at least the dynamic pressure in the pump-out direction, is structured. The first thrust dynamic pressure generating portion and the second thrust dynamic pressure generating portion have dynamic pressure generation characteristics in which, when the rotating body is biased in the rotational axis direction from the state where the rotating body is floating in the lubricant, the sum of the changes in the dynamic pressure in the pump-out direction is larger than that of the changes in the dynamic pressure in the pump-in direction.
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