Motor having index detection mechanism used for disc apparatus and disc apparatus using such a motor
US5245235A · kind A · utility
13Cited by
8References
13Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | May 15, 1992 |
| Grant date | Sep 14, 1993 |
| Priority date | — |
| Expiry date | May 15, 2012 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02K21/24
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A spindle motor able to reduce leaking of magnetic flux of an index magnet to a magnetic head of a disc apparatus. In an axial gap type spindle motor having a rotor case rotatably supported by a base plate, an index magnet is provided to a face of the rotor case opposite to the base plate. A hall device is provided in an open space between a plurality of coils arranged radially on the base plate at a position opposite to the index magnet. A magnetic flux forms a closed loop by passing through the rotor case, and thus leaking of magnetic flux to the outside is reduced.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.