Robust Solid Lubricant Coating for Gears of Cryogenic Fuel Turbopumps

Surfaces Research proposes development of a highly durable solid lubricant coating to eliminate wear and vibration problems in liquid hydrogen turbopump gears. The cryogenic turbopumps are used in rocket engines for Air Force expendable launch vehicles. Our new coating will exceed the cryopump manufacturer's goal life of twice that of the current coating. Our sound, novel approach uses three strategies to greatly increase coating wear life: a more cryogenically-durable polymer binder, a new solid lubricant adjuvant additive, and a hard coat underlayment for the solid lubricant. This approach is strongly supported by wear results at cryogenic temperatures and specifically in liquid hydrogen. We will conduct cryogenic wear life tests by the same method used to qualify the current liquid hydrogen turbopump gear coating. Our approach is particularly advantageous because. Our direct replacement for the current coating preserves the substantial investments already made by Pratt and Whitney, the manufacturer in standards and specifications, automated coating application, and predictive test methods. We are working with Pratt and Whitney to conduct gear rig and actual engine tests of our superior coating within one year of the Phase I feasibility demonstration.