Actuator shaft seal for variable nozzle turbocharger

摘要

A shaft seal for use with a unison ring actuator crank is disposed within a center or bearing housing of a variable nozzle turbocharger to reduce leakage of hot exhaust gas from an adjacent turbine housing. A seal ring is disposed within the turbine housing backing plate which has two differently sized diameter sections. The seal ring is positioned within a relatively larger diameter opening section and has an inside diameter sized to permit independent rotation around the shaft and an outside diameter sized to cover a relatively smaller diameter opening section. A relieved back surface directed towards the center housing such as a conical back surface that is tapered axially inwardly moving radially from the outside diameter to the inside diameter of the seal ring provides the desired sealing while not adding to the operating friction of the crank.