US Patent 6881027 Gearless/oilless gas turbine engine

The complex mechanical gear trains and lubrication systems of conventional engine configurations are eliminated by using combinations of hydrodynamic air foil bearings, hydrodynamic solid geometry carbon seals/bearings, magnetic bearings, and electrical starter/generators that can also act as bearings to support the high speed shafts of gas turbine engines. The various bearing types and the starter/generators are arranged in such a way as to share peak loads experienced by the engine shaft during maximum aircraft maneuvers. This results in a minimal bearing and engine size.