Disk drive device rotationally driving recording disk
US8368282B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 21, 2010 |
| Grant date | Feb 5, 2013 |
| Priority date | — |
| Expiry date | Mar 29, 2031 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02K29/03
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A disk drive device includes: a hub on which a recording disk is to be mounted; a base configured to rotatably support the hub via a bearing; a core that is fixed to the base and includes a circular portion and S salient poles (where S is a natural number greater than or equal to 3) extending from the circular portion in the diameter direction; a three-phase coil that is formed by being wound around each of the S salient poles; and a magnet that is fixed to the hub and faces the S salient poles in the diameter direction, and that is provided with P driving magnetic poles in the circumferential direction (where P is a natural number greater than or equal to 2). In the disk drive device, the fundamental frequency component of the cogging torque based on the LCM (Least Common Multiple) of S and P (where S is the number of the salient poles of the core and P is the number of the driving magnetic poles of the magnet), is smaller than the second frequency component of the cogging torque, the frequency of which is twice the fundamental frequency.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.