Rotary drive coupler for actuated valve

摘要

A rotary-driven valve is coupled to a rotary actuator. The coupling includes a shaft having longitudinally extending drive pins offset from the shaft axis. The drive pins contact drive surfaces of drive plates which have a valve stem opening which mates with the valve stem. The drive plates can slide relative to the valve stem with one degree of freedom, and the drive pins can slide relative to the drive plates with a second degree of freedom. Sliding movement of the first drive plate and/or the second drive plate allow the shaft axis to be angled and/or laterally displaced relative to the valve stem axis. The drive plates provide a dynamic adjustment freedom so bending moments and radial forces are not imposed on the valve stem. The drive plates may also provide thermal insulation between the valve stem and the actuator.