SOLID FILM LUBRICATION RESEARCH. PART II.

Abstract : This report describes the second and final year's effort on a twenty-seven month program that had as its objective the development of self-contained, solid lubricated ball bearing systems with long-term operating capabilities over a temperature range of -40 F to +1500 F. The program encompassed speeds of 10,000 to 30,000 rpm and loads up to 100 lbs thrust - 150 lbs radial. The bearing systems were required to operate under these conditions in both an air environment and one simulating a 200,000 ft altitude. During the second year's effort, the program concentrated on further developing solid lubricant-gallium/indium composites and on obtaining parametric design data relating bearing operating life with load, bearing size, bearing design, speed, temperature and atmospheric environments. The work has resulted in the development of 204 and 207 size self-lubricated ball bearing systems capable of long-term operation at 10,600 rpm over a temperature range of -225 to +900 F. The capability of reliable operation under a 100 lb thrust/150 lb radial load on the 204 system at 600 F and 10,600 rpm was demonstrated. It was also found that the life of these self-contained, self-lubricated ball bearings is sharply reduced when (1) operating speeds of 21,500 rpm and higher and/or (2) temperatures of 1,200 to 1,500 F are encountered. (Author)