Electromagnetic actuator, notably for hydraulic servo-control valve
US4071042A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 14, 1976 |
| Grant date | Jan 31, 1978 |
| Priority date | — |
| Expiry date | May 14, 1996 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T137/7782
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Electromagnetic actuator, especially for actuating a hydraulic servo-control valve, which comprises a magnetic shell constituting a body of revolution and a concentric armature-forming permanent magnet, at least one annular field coil, the field coil and the armature being adapted to move axially in relation to each other. The movable member (field coil or armature) is caused to move by the resultant electromagnetic force resulting from the energization of the field coil to which a control direct current is applied and by the antagonistic force of a repulsion member incorporated in the magnetic shell. The field coil is longer than the armature so that the electromagnetic force is independent of the movement of the movable member and proportional to the control direct current. The movable member is caused to perform simultaneously a cyclic motion superposed to the axial movement in order to eliminate the friction hysteresis of the hydraulic valve.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.