Catapult shuttle wheel bearing loading is a function of the aircraft take-off weight and the acceleration of the catapult. The resultant load on the bearings of the existing catapult has significantly changed from the time the subject bearings were selected in 1980. If the projected aircraft take-off weight is 100,000 lbs., the bearing life will be reduced by approximately 94%. The Phase I objective will be to develop and demonstrate the feasibility of a long life, highly loaded catapult shuttle wheel bearing subjected to high acceleration and deceleration. An existing bearing computer code will be used to conduct a non steady state analysis of the bearing system. Alternate bearing materials and lubrication means will be evaluated. Hybrid solid film-cage lubricated bearings will be studied where maintenance and other resources required for the bearing are reduced. Both roller and ball bearings will be investigated and analyzed. The work will generate a more rigorous bearing system life analysis and an alternate bearing design eliminating grease and other type liquid lubricants. New designs will be benchmarked to the current design and operating conditions. The design, manufacturing feasibility, and manufacturing and use costs will be performed in consultation with The Timken Company.
Benefit: The implementation of this new bearing technology is anticipated to enable a new level of reliability with longer lives for bearings used under high stress conditions such as high acceleration and deceleration. It will provide the Electromagnetic (EMALS) and Steam Catapults a bearing system that has long life and no or minimal grease degradation. Thus reducing the down time whereby the bearings have to be replaced or re-greased. The Timken Company is very interested in this technology and has agreed to support Nastec if a Phase II is granted. They will provide facilities for Nastec to test the various bearing formulations and will assist in bearing analysis. Nastec will lease the technology to them to manufacture these bearings for use in high stress conditions.
Keywords: Roller Bearings, Roller Bearings, Ball Bearings, Electromagnetic Aircraft Launch System, high-speed catapult, long-life bearings, Solid Lubrication, hybrid lubrication, hybrid materials
