Enhanced Carbon Face Seals for Rotorcraft Drive Systems

Seals currently used for rotorcraft gearbox drive systems suffer from a high failure rate. Seals must prevent lubricant from escaping while under operation. Several materials are available for the seals, including carbon, elastomer, and ceramic, and all must withstand extreme shaft speeds (5,000-13,000 RPM) and temperatures (500 degrees F). Carbon face seals, which are predominantly used in rotorcraft either individually or in a magnetic seal assembly, can exhibit short lifetimes due to a variety of factors including debris entrapment at the seal interface, oxidation associated with incompatible lubricating oils and/or contaminants, and misalignment during installation. The time and manpower required to identify seal failures and replace seals is extremely costly and reduces fleet availability. Luna Innovations proposes an enhanced carbon face seal that will enhance seal lifetime and reliability. Modifications to the seal material chemistry and morphology will lead to higher durability and lower failure rate at comparable performance. The solution will be based significantly on previous experience with high performance carbon composites. The Phase I will involve proof-of-concept demonstration through material fabrication, optimization, testing, and collaboration with existing material suppliers, seal assembly manufacturers, and prime contractors.