| 摘要 |
Provided is a fluid dynamic bearing device (1) including a stationary body (2B), a rotary body (2A), a bearing member (22) (sleeve portion) made of a sintered metal arranged on the rotary body (2A), having end surfaces (22b, 22c) on both sides in an axial direction, a thrust bearing gap formed by a lower end surface (22c) of the bearing member (22), filled with lubricating oil (11), and a thrust dynamic pressure generating portion (B). A dynamic pressure generating action is caused in the lubricating oil in the thrust bearing gap along with rotation of the rotary body (2A) to support the rotary body (2A) in one thrust direction in a non-contact manner. The bearing member (22) has an oil permeability of 4% or more to 15% or less with respect to a mass flow rate of the lubricating oil (11) flowing along the thrust dynamic pressure generating portion (B) during the rotation of the rotary body (2A). |
