Electromagnetic drive for valves servo- mechanism - has adjustable pole assembly to alter magnetic force on axial movable core

摘要

The electromagnetic drive for valve servo-mechanisms has an electromagnetic coil surrounding a core connected to the valve servo-mechanism, and enclosed in a housing of soft-magnetic material. A pole fits inside one end of the electromagnet, and, is also made of soft-magnetic material. The core is enclosed by a tube sealed at its lower end to the valve top plate by a sealing ring, and with another sealing ring to the lower end of the pole. The housing pole consists of an inner part and an outer part. The outer part moves relative to the fixed inner part and alters the magnetic forces acting on the core.