NASA 1996 SBIR Phase I

PROPOSAL NUMBER : 96-1 04.04-9547

PROJECT TITLE : : High Temperature Foil Thrust Bearings


Recent advances in compliant surface foil bearings (CSFBs) and solid lubricant coatings, make potentially revolutionary engine improvements possible, as evidenced by journal CSFB operation in excess of 4.7 million DN, 6500C temperatures, specific load carrying capability higher than any existing bearing (5000 pound-per-pound of bearing weight), 100 lb-sec/in damping levels, and thousands of start stop cycles. Parallel developments addressing lubricant and performance requirements of thrust CSFBs have been lacking but, are essential if these technologies are to impact the advanced engines being pursued by NASA. While typical thrust CFSB tip speeds are limited to 800 ft/sec, speeds approaching or exceeding Mach 1 are expected. Of particular concern is the impact that the high temperatures and velocities (e.g., shock wave) will have on thrust bearing/lubricant performance and life.

The ultimate objective of this program is to develop an advanced thrust CSFB/solid lubricant system forhigh-speed and temperature turbomachinery. The outcome of Phase I will be a preliminary design of an oil-free test rig designed to operate to 80,000 rpm, temperatures >12000F, and loads to 300 pounds. This rig will be used in Phase II to develop and characterize full-scale, high-speed/temperature, thrust CSFB/lubricant systems for gas turbine engines, APUs and turbochargers.

Commercial potential exists for high temperature foil bearings in the aviation and automotive sectors as evidenced by their sustained interest in this technology and this proposed program. Aviation applications in small gas turbine engines, auxiliary power units and turbochargers will be realizable with these advanced foil bearings. Elimination of the lubricant supply system will permit simpler, lighter weight and more reliable engine designs capable of operating at higher temperatures and lower cooling flow requirements for more efficient engines. Dry expendable engines also become feasible with increased range and/or loiter time. Applications in the automotive sector exist for both turbochargers and gas turbine engines. Oil-free turbochargers eliminate sealing problems and their adverse effects on pollutioncontrol and engine durability. Expansion of market presence will also be enhanced in cryogenicturbopumps, air cycle machinery, and turboexpanders with the introduction of advanced solid lubricated foil bearing systems. NAME AND ADDRESS OF PRINCIPAL Hooshang Heshmat, Ph.D. Mohawk Innovative Technology, Inc. 1059 Belridge Rd. Niskayuna, NY 12309-4717
Mohawk Innovative Technology, Inc.
1059 Belridge Rd.
Niskayuna, NY 12309-4717