| 摘要 |
Provided is a fluid dynamic bearing device (1), including: a bearing member (22) on a rotary side, which is made of a porous material; a housing (7) on a stationary side, which is configured to receive the bearing member (22) on an inner periphery of the housing (7) ; a sealing member (9) configured to open an upper side of the bearing member (22) to atmosphere through a sealing gap (S) ; a radial bearing gap to be formed between an outer peripheral surface (22a) of the bearing member (22) and an inner peripheral surface (7a2) of the housing (7); and a thrust bearing gap to be formed between a lower end surface (22c) of the bearing member (22) and an inner bottom surface (7b1) of the housing (7). The radial bearing gap and the thrust bearing gap are filled with lubricating oil (11) . The bearing member (22) is supported respectively in a radial direction and a thrust direction by an oil film to be formed in the radial bearing gap and an oil film to be formed in the thrust bearing gap. An axial gap (10) containing air is formed between an upper end surface (22b) of the bearing member (22) and a lower end surface (9b) of the sealing member (9), which faces the upper end surface (22b) of the bearing member (22). |
