Spindle motor using hydraulic bearing and disk drive on which spindle motor is mounted
US6836040B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 16, 2002 |
| Grant date | Dec 28, 2004 |
| Priority date | — |
| Expiry date | Aug 15, 2022 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16C2370/12
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A spindle motor using a hydraulic bearing is provided, wherein an R-face or C-face is formed on each of upper and lower edges of an outer periphery of a rotating disk portion rotatable integrally with a spindle, and the R-face or C-face is formed into a mirror-finished surface having a surface roughness of 0.3 s or less in Ra, preferably, 0.1 s or less in Ra. Alternatively, a recess may be formed in a portion, facing to each of the upper and lower edges of the outer periphery of the rotating disk portion, of an inner wall surface of the hydraulic bearing. Such a spindle motor provides a disk drive capable of suppressing a variation in rotational speed of the spindle motor caused by tilting of the spindle due to vibration and impact, thereby ensuring a stable recording or reproducing operation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.