3-position rotational actuator
US4899073A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 25, 1988 |
| Grant date | Feb 6, 1990 |
| Priority date | — |
| Expiry date | Jul 25, 2008 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01F7/145
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The present invention relates to a 3-position rotational actuator which obtains three stable points by two pairs of field poles, in which the magnetic flux to a rotor due to one pair of field poles of a stator for maintaining the rotor at the first stable point is substantially equal to the magnetic flux to the rotor due to the other pair of field poles of the stator for rotating the rotor from the first stable point. The magnetic flux density of the other pair of field poles of the stator applied to the rotor is set to be smaller than the magnetic flux density of the one pair of field poles of the stator. Therefore, the detention torque can be maintained to the same degree and the drive torque can be improved.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.