Polarized electromagnetic drive for a limited operating range of a control element

US4329672A · kind A · utility

Assignee

• Elektro-Mechanik GmbH · DE

Inventors

• Heinz Stahl · Olpe, DE
• Harald Wagner · Verden, DE

Key dates

• Filing date: Nov 20, 1979
• Grant date: May 11, 1982
• Expiry date: Nov 20, 1999

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01F7/13
• WIPO field: Electrical machinery, apparatus, energy
• WIPO sector: Electrical engineering

Abstract

A polarized electromagnetic drive preferably for actuating a turning servo valve comprises an electromagnetic field iron core which has a central open area and a core receiving recess defined in said core on each side of the open recess with a coil therein and with a rotatable armature drive shaft located in the open area of the core which has an armature affixed thereto with a pair of diametrically opposite radially extending arm portions. The core also has a leg portion which is spaced away from each side of the armature arm portions by an amount to define a large air gap between each side of each arm portion and each leg portion. Each of the leg portions has an end part extending outwardly from the associated leg portion and alongside the outer ends of the armature arm portions and spaced from the outer ends by an amount to define a small air gap between each end part and the associated outer end of the armature arm portions. The core has end pieces which extend outwardly from behind each leg portion on each side of the leg portions and which define a permanent magnet receiving recess therebetween alongside each leg portion on each side of the armature arm portions. A permanent …