Enhanced Fuel-Lubricated Bearing for Turbine Engine Applications

There is a constant need to reduce the size and part counts of state-of-the-art (SOA) turbine engines. One already demonstrated solution, which offers significant weight and cost payoffs, uses advanced fuel-lubricated (fuel-lubed) bearing. The challenge associated with fuel lubrication is that the fuel does not provide nearly as much lubricity to the bearing components as the traditional oil lubrication does. As a result, fuel-lubed bearings typically use advanced self-lubricating, fuel compatible C-C cages and Si3N4 rolling elements to reduce bearing heat generation and to improve overall bearing performance. To further improve the bearing performance, particularly when the engine bearings are required to operate at extreme conditions of load, speed, and temperature, antiwear additive has to be added to fuel to enhance its tribological properties. In phase I, we propose to first better understand the fundamental tribological behavior of friction pairs under fuel lubrication, and then to develop technological concepts and demonstrate feasibility of technologies that address performance and lubricity issues related to fuel-lubricated bearings. In Phase II, we propose to further optimize our approaches and then to develop, test, and demonstrate an operable prototype in real engine test beds