To enhance the effect of a capillary seal for a fluid dynamic-pressure bearing.
The fluid dynamic-pressure bearing includes a flanged shaft 1 having a shaft 2 and a flange 3, a sleeve 4, and a ring-shaped lid member 5, and is configured so that a lubricating fluid F is charged into a single-sack fluid-filling section having a ring-shaped opening between an external peripheral surface of the shaft 1 and an internal peripheral surface of a through hole of the ring-shaped lid member 5, i.e., a single-sack fluid-filling section formed between those bearing components. Also the fluid dynamic-pressure bearing is configured such that the diameter outside the through hole of the ring-shaped lid member 5 is tapered so as to be smaller than the diameter inside the hole, the diameter outside the upper-side shaft 2 positioned inside the through hole of the ring-shaped lid member 5 is tapered so as to be smaller than the diameter inside the hole, and the angle of inclination of a former tapered face is made to be larger than an angle of inclination of a latter tapered face. Therefore, the ring-shaped opening that functions as the capillary seal is shaped as a reversed-funnel-like ring-shaped opening of which outside diameter is smaller than its inside diameter, and the lubricating fluid F is forcibly drawn into the bearing by a capillary force when the bearing is not moving, and drawn by a centrifugal force and a capillary force when the bearing is rotating.
COPYRIGHT: (C)2008,JPO&INPIT
| JP2001317548 | FLUID BEARING DEVICE |
| JP4861441 | Disk drive |
KUMAGAI TORU
GOTO HIROMITSU
NAKAYAMA YUKIHIRO
TAZAWA KAZUHIRO
IWAMOTO MITSUHARU
YONEYAMA RYOJI
| JP2000179541A | 2000-06-27 | |||
| JPH09182367A | 1997-07-11 | |||
| JPH1182509A | 1999-03-26 |