ZERO-LEAKAGE NON-CONTACTING MECHANICAL FACE SEAL FOR ROTARY MACHINES

摘要

A B S T R A C TA hydrodynamic, non-contacting end-face seal for a rotary machinecomprises a rotor mounted on the machine shaft and a ring-shapedstator facing the flat and smooth surface of the rotor at a shortdistance. The stator encloses the machine shaft, is eccentricallypositioned in respect of the rotor center, and is urged towards therotor surface by a helical spring. The surface of the stator ringis shaped to form a circular rim separated from the rotor surfaceby a very small gap of varying width, and the space enclosed bythis rim is raised to a higher pressure than the surroundings bythe hydrodynamic action of the surface velocity of the rotor on theliquid in the machine, by making the gap width as follows:-the gap width between rotor and stator is of a mechanically per-missible minimum in all points of therein at which the velocityvector of the rotor surface extends from the inside of the rim tothe outside, and the gap width is larger in all points of the rimat which the velocity vector extends from the outside to the inside.The gap width is changed, in accordance with pressure conditionsin the machine by action of the helical spring.