Actuator for process stream valve for controlling vapor supply for turbine in power plant region, has spindle drivable through drive shaft, and clutches making spindle to be in operative engagement at certain stroke with shaft

摘要

The actuator (1) has a spindle nut (2) axially movable toward opening and closed positions by an adjusting cylinder (36) i.e. pneumatic cylinder. The spindle nut is meshed with a spindle (12) and axially movable together with the spindle nut. The spindle nut is urged toward the closed position by spring force of a restoring spring (42). The spindle is drivable though a drive shaft (22) i.e. sleeve shaft, of a drive motor (24) i.e. electric motor. Clutches (18, 20) make the spindle to be in operative engagement at a certain stroke with the drive shaft.