Magnetic fluid bearing unit structure and motor having the same
US5821655A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Jan 24, 1997 |
| Grant date | Oct 13, 1998 |
| Priority date | — |
| Expiry date | Jan 24, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02K5/1677
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A magnetic fluid bearing unit has a bearing housing, a bearing member having magnetic fluid as a lubricating agent, a rotary body rotatively supported by the bearing member, an upper permanent magnet arranged inside the bearing housing, and a lower permanent magnet arranged inside the bearing housing, the bearing member being sandwiched by the upper permanent magnet and the lower permanent magnet. The bearing member is a radial porous oil-containing bearing member in which the magnetic fluid is impregnated. The upper permanent magnet is set to have one direction of magnetic pole orientation, and the lower permanent magnet is set to have the same direction of magnetic pole orientation as the upper permanent magnet. The bearing member is sandwiched by the upper permanent magnet and the lower permanent magnet to confine the magnetic fluid. Over a wide range of rotation speeds, the leakage and the scattering of the magnetic fluid from the bearing unit can be prevented. The bearing unit for a compact size motor having a high rotation accuracy can be obtained.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.