SERVOMOTOR FOR AUTOMATIC GATE VALVE Russian patent published in 1999 - IPC

FIELD: shifting valve rod of automatic gate. SUBSTANCE: servomotor includes hydraulic actuating member with cylinder where piston is mounted for sliding and sealing; piston is connected with rod and with compression spring counteracting to actuating member. Servomotor has starting mechanism with delivery field which may be loaded by hydraulic fluid medium, pressure field which is communicated via diaphragm with delivery field and is connected to actuating member, discharge field form which hydraulic fluid medium may be evacuated without pressure and change-over member which connects pressure field with discharge field when pressure differential from pressure field to delivery field becomes opposite; in other times it shuts off discharge field. EFFECT: enhanced operational reliability. 10 cl, 2 dwg