Electro-hydraulic control actuator for turbine valves

Claim 1

An electrohydraulic control assembly for a valve comprising, integrated in a compact control unit connectible with a housing for a valve, hydraulic control cylinder, an hydraulic fluid reservoir, an hydraulic fluid pump driven by an electric motor and an electrohydraulic converter connected to said control cylinder, said reservoir and said pump for adjusting the flow of hydraulic fluid to and from said control cylinder and said reservoir in accordance with electric signals transmitted thereto, two mutually spaced-apart support plates vertically disposed on a base plate connectible with the valve housing, said hydraulic cylinder being fastened to respective ends of said support plates facing away from said base plate, a transverse plate secured to respective edges of said support plates and extending across the space therebetween, a control piston disposed in said cylinder and having a shaft connectible with a shaft of the valve, said control piston being displaceable in a valve-opening and a valve-closing direction, a force-storing spring located between said support plates for loading said piston in said valve-closing direction, said hydraulic fluid reservoir being fastened to respective edges of said support plates facing away from said transverse plate, said pump and the electric motor for said pump being fastened to said transverse plate, an hydraulic pressure accumulator connected to said pump being fastened to said support plates, and hydraulic connecting means for hydraulically inter-connecting said hydraulic control cylinder, said hydraulic fluid reservoir, said electrohydraulic converter and said pump, said hydraulic connecting means being at least partly made up of channels formed in said support plates.