Sealing device for rotary machines containing hydraulic fluid

摘要

A sealing device for rotary machines containing hydraulic fluid, such as centrifugal pumps, compressors, steam turbines and the like. An annular gasket/valve has a flexible lip which seals around the pump or other type machine shaft when the machine is inoperative. An annular sealing chamber is defined between the gasket/valve and an annular cavity defined inside a hollow rotary body fixed around the end of the shaft to be sealed. When the machine shaft rotates at normal speed, the sealing chamber is filled with liquid so that leakage flow is delivered to the annular cavity whereby a liquid ring is formed by centrifugal force around the outer periphery of the cavity. Recovery means in the form of a pitot tube keeps the depth of the liquid ring constant and restores excess liquid to the sealing chamber.