Throttle valve for semiconductor vacuum treatment plant has closing mechanism consisting of main shaft, concentric crankshaft, hub connected to main shaft and roller mounted on crankshaft

摘要

The throttle valve comprises a housing (12) with fluid conduit (14) and a sealing plate (30). A closing mechanism moves the plate between open , intermediate and closed positions. This consists of a main shaft mounted in the housing and a crankshaft which is concentric with it. Both of these can be moved along the axis of the housing. A hub (60) is connected to the main shaft and is movably connected to the sealing plate. A roller is mounted on the crankshaft so that it can rotate eccentrically around the axis of the housing and is also connected to the sealing plate. Springs (90, 92) bias the sealing plate towards the intermediate position.