SERVOMOTOR OF STEAM TURBINE CONTROL VALVE UNIT Russian patent published in 2005 - IPC

FIELD: turbine manufacture.

SUBSTANCE: invention relates to servomotor of steam turbine control valve unit with successive opening of valves, upper one after lower one, and mainly high parameters of steam. Proposed servomotor contains two rods, first, secured on piston, passes through housing of servomotor in its lower part, being directly connected with rod of lower valve. Second rod is rigidly connected with axle of leverage and plate and contact surfaces in housing drain space for interacting of rods and concentrically installed return outer and inner springs of first and second rods, respectively. Second rod is hollow, and first rod passes inside second rod. Both rods project in upper part of housing. Axle of leverage is arranged in through slot of first rod with clearance relative to slot to provide interacting of rods by contact surfaces and guaranteed closing of valves. Proposed design of servomotor provides increased length of guide surfaces of rod which prevents skewing and wedging of rods and improves reliability of servomotor in operation. Similar to prototype, return spring in transfer system from second rod to upper valve is not installed.

EFFECT: provision of ease of adjustment between contact surfaces of rods, compensation for expansion, improved reliability of operation of servomotor.

2 cl, 3 dwg