Low-Cost Ball/Air/Magnetic Hybrid Bearing System for Extended-Life Micro Gas Turbine Engines

Micro gas turbine engines with state-of-the-art ultra-compact recuperators could be a real game-changer for small unmanned air vehicles and portable power generation. A key enabling technology for these engines is a low-cost, high speed bearing system that has long life, while operating without either a separate lubrication system, or oil in the fuel. For this Phase I STTR effort, Xdot Engineering and Analysis will evaluate the feasibility of a novel non-contact oil-free thrust bearing. This thrust bearing is particularly well suited for a hybrid arrangement where grease-lubricated rolling element bearings provide the radial support for a small, very high speed shaft. This thrust bearing is expected to have load capacity, stiffness and life suitable for these gas turbine applications. The bearing combines high levels of performance with very low production costs, even for small production volumes. The Phase I evaluation effort will include high speed testing of a prototype bearing, as well as an analytical evaluation of a self-contained thermal management strategy. The Phase I Option focuses on analysis/design tool development, and a potential way to further decrease the production cost.