Apparatus for electrically grounding a rotor hub in a disc drive motor
US5473484A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 3, 1994 |
| Grant date | Dec 5, 1995 |
| Priority date | — |
| Expiry date | Jun 3, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B33/1493
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A disc drive includes a disc drive motor for rotating a storage disc. The motor includes a motor base having a fixed member. A rotor is rotatably coupled to the fixed member and carries the storage disc. First and second bearings are positioned between the rotor and the fixed member allowing rotation of the rotor about the fixed member. A permanent magnet is positioned between the first and second bearings. A conductive fluid between the rotor and the fixed member is maintained in operable contact with the rotor and the fixed member by the permanent magnet. The ferrofluid provides a low resistance electrical path between the rotor and the fixed member thereby electrically grounding the rotor to the motor base.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.