CONTACTLESS END SEAL Russian patent published in 2001 - IPC

FIELD: hydromechanical engineering; variable-speed turbo- machines. SUBSTANCE: seal has sealing ring locked in position against turning and free to move in axial direction; it is tightly mounted on flexible members by means of secondary rubber seal in casing to form sealing slot together with shaft-mounted revolving ring; it also has clearance adjusting device mounted on butt-end sealing surface of revolving ring and made in the form of coupled helical gas-dynamic grooves. The latter communicate through common inlet with high-pressure cavity; they are arranged in opposition over circumference and joined together by means of strap through inner diameter. Seal is designed to raise carrying capacity and stiffness of gas layer and to control clearance at any sense of rotation when turbo-machine is running. EFFECT: improved stability of seal characteristics throughout its operating period, enhanced efficiency and service life. 2 dwg