Improved Bearing Compartment Sealing for Gas Turbine Engines

A technical approach to gas path seal design is described that provides a unique combination of benefits. It has broad application to gas seals including those applied to bearing sumps and gas paths. It is a direct replacement for conventional carbon face, labyrinth, brush, and similar gas seals. It prevents all leakage flow between rotating and static structure without the requirement for a contacting interface. As a result, it can accommodate large excursions due to shaft modes and thermal differentials with very loose interface tolerances. It uses no buffering gas, thus eliminates the parasitic losses of buffering air as well as eliminating the direct leakage losses. Its primary application is in medium to large gas turbine engines and is equally applicable to both military and commercial configurations. What makes it particularly unique is that it has the potential to accomplish these benefits with a design that is lower in acquisition cost and requires no maintenance.