Oil Free Rotor Support for Small Turbine Engines

Advanced high-speed gas turbine engines are continually subjected to extreme operating environments making bearings a life limiting component in the engine. Oil-free foil bearings will improve weapon system range, reduce weight and costs, and increase overall system reliability. Foil bearings are successfully used in aircraft environmental control systems. However, there is need for further research and development, because gas turbine engines operate at higher temperatures and are subjected to higher radial and axial loads. Several unique innovations are being proposed which will make foil air bearings suitable for high temperature gas turbine engines. Critical technology barriers have been outlined along with a reasonable work plan and timeline. In Phase I feasibility of foil bearings for gas turbine engines was shown by analysis, modeling and limited testing. In Phase II the process for scaling to larger size bearings, i.e. 2 inch to 4 inch and 6 inch diameter journal bearings will be proven. The larger size bearings, i.e. 4 inch and 6 inch diameter journal bearings will be designed, developed and tested. The bearings will also be tested in a high temperature test rig simulating operating environments of a gas turbine engine including speeds, temperatures, and thrust loads. The technology readiness of larger size bearings required for VAATE XTL 18 and UCAV gas turbine engines will be proven. Simulator testing simulating the rotor dynamics of VAATE XTL 18 and UCAV engines will be accomplished in Phase III.