Development Program for Dynamic Testing of Ausform Finished PYROWEAR 53 Ball Bearing Inner Raceways

Aerospace gearboxes are continually pushing the limits of increased power handling and temperature without increasing the size of the associated bearings. Even with the advancement in bearing materials, ausform finishing of bearing raceways has been investigated to further increase the life of the bearings. Investigations in the 1970’s reported Ausforming to extend the life of bearings 7 to 9 fold. Boeing Rotorcraft in conjunction with McGill Manufacturing Company, a division of Emerson Power Transmission and the Applied Research Laboratories at Pennsylvania State University are developing a PYROWEAR 53 (AMS 6308) ausform finish inner ball bearing program. This program entails designing both a test machine and a bearing suitable for ausform finishing. The test machine must operate bearings at 10,000 rpm and provide stabilized bearing temperatures between 275°F to 285°F. Bearings with a bore of 60 mm and an outer diameter of 100 mm; consisting of PYROWEAR 53 inner and outer rings; and VIM-VAR M50 (AMS 6491) balls will be used as the baseline bearing. These results will be compared with other bearings with similar components except the inner raceways will be ausform finished. A third set of bearings will be comprised of VIM-VAR M50 material for the balls, inner and outer rings to compare the performance of a standard aerospace bearing material with PYROWEAR 53 under similar test conditions.