FLUID-MOTOR PNEUMATIC ACTUATOR Russian patent published in 2003 - IPC

FIELD: actuators for pipeline valves. SUBSTANCE: actuator has electropneumatic control unit connected to gas conduit for working medium supply and coupled through ducts with fluid-motor rotor whose shaft is kinematically coupled with working shaft; it also has device for limiting torque transferred by the latter and position detectors connected to electric input of mentioned control unit; gas conduit is designed for connection to main gas line; control unit is arranged for changing over main gas line under pressure, and fluid motor shaft is kinematically coupled with working shaft by means of multistep reduction unit incorporating intermediate shaft for mounting manual control means; torque limiting device is made in the form of two jaw half-clutches brought in mesh. EFFECT: enhanced reliability. 5 cl, 8 dwg