Rotary actuator for positioning magnetic heads in a disk drive
US5041935A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 11, 1989 |
| Grant date | Aug 20, 1991 |
| Priority date | — |
| Expiry date | Aug 11, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01F7/145
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A rotary actuator for positioning magnetic heads in a disk drive, comprising a stator assembly and a rotor assembly. An arm assembly having magnetic heads are fixed to the rotor assembly, which rotates back and forth within a limited angle range around a fixed axis of the rotary actuator due to the forces between plural magnets and driving current which flows though flat coils. Two flat coils are aranged on an arcuate inner surface of the stator such that two adjacent vertical parallel portions thereof closely contact with each other. Two flat coils have an electrical connection with a driving source that the currents through the two adjacently parallel portions flow in the same direction. Three permanent magnets are disposed on the rotor surface, the central magnet having a greater lateral width than that of other two side magnets, and a polarity of the central magnet is opposite to that of other magnets. In another embodiment, each of flat coils comprises an inner coil and an outer coil resulting in enhancing the torque of the rotary actuator. Several modifications of coil and permanent magnet arrangement, and other related improvements in the structure thereof are also disclosed…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.