Large valve drive transmission mechanism - has epicyclic gear train with spring loaded worm on splines meshing with sun-wheel actuating detector

摘要

The transmission mechanism has driving and driven members coupled by an epicyclic gear train with one or more rotary sunwheels. A worm (33) mounted on splines (32) on a driving shaft and prevented by springs (38, 39) from moving axially from a set position meshes with teeth on the sun wheel periphery. A detector shows when the worm has moved for a predetermined distance on the shaft from the set position. An electric motor can be coupled to the driving member, the detector being a switch in the motor control circuit.