| 摘要 |
PROBLEM TO BE SOLVED: To provide a bearing mechanism capable of enlarging a thrust dynamic pressure bearing portion.SOLUTION: The bearing mechanism 4 includes: a shaft portion 41; a sleeve portion 45; a lower opposing portion 42 facing to a lower end face of the sleeve portion through a lower thrust clearance 52; a lower outer annular portion 44 surrounding an outer peripheral face of the sleeve portion; and an upper opposing portion 43 facing to an upper end face of the sleeve portion through an upper thrust clearance 53. The sleeve portion has a sleeve body 451, and a lower thrust plate 452. A radial dynamic pressure bearing portion 51a is disposed in a radial clearance 51, a lower thrust dynamic pressure bearing portion 52a is disposed in the lower thrust clearance 52, and a lower seal portion 56a is disposed in a lower seal clearance 56 between the sleeve portion 45 and the lower outer annular portion 44. The sleeve portion 45 has a first communication path 541 continuing to an upper seal clearance, and a second communication path 542 formed between the sleeve body 45 and the lower thrust plate 452. A lower opening of the first communication path 541 is axially overlapped to the lower thrust dynamic pressure bearing portion 52a. |
