Spindle motor
US5572078A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 20, 1995 |
| Grant date | Nov 5, 1996 |
| Priority date | — |
| Expiry date | Sep 20, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02K5/173
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A motor, such as a spindle motor, and a method for making such motor, wherein the motor has a stationary part, a rotary part mounted on the stationary part rotatably with respect thereto by a bearing and a magnetic fluid seal mechanism interposed in a radial gap between the stationary part and the rotary part is disclosed. The magnetic fluid seal; mechanism comprises a magnetic ring mounted on the stationary part, a ringlike magnet unit mounted on the rotary part and a magnetic fluid held in a gap between the ringlike magnet unit and the magnetic ring. The magnetic ring is made of a sintered metal made by baking a magnetic metal powder. At last the outer peripheral surface of the magnetic ring is preferably treated with a water-repelling treatment which includes impregnation with resin. All of the surfaces of the magnetic ring are non-cut surfaces.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.