Klaass, R. and DellaCorte, C., "The Quest for Oil-Free Gas Turbine Engines," SAE Technical Paper 2006-01-3055, 2006, doi:10.4271/2006-01-3055.
Since the 1960s, aerospace research and development (R&D) has been on a quest to eliminate oil lubrication systems from gas turbine engines. Beginning with small solar power dynamic “engines” for space applications, U.S. Government and industry have invested millions of dollars to mature this technology for incorporation into modern aircraft propulsion engines. This paper traces the evolution of oil-free rotor support systems that have actually been tested in advanced demonstrators, and the technology that enables this revolutionary engine configuration. However, this technology has yet to be fielded in aerospace products. The key factors of 45 years of Government and industry R&D and a vision to mature oil-free gas turbine engines are presented herein.