Oil and Material Compatibility for Improved Bearing and Gear Durability

The recognized risks associated with the introduction of new material and oil formulations for propulsion system bearings and gears have created a crisis with respect to urgent needs for increased load, speed and temperature. Conventional test methods formaterials and oils have insufficient linkage to service performance and mechanisms that control life and durability. The recognition of the current state of affairs and the need for a cultural change in the industry for material, oil and componentdeveloped was highlighted in a two-day workshop with industry leaders during Phase I. If suface technologies and oil formulations are developed as a contact system (tribo-system) with a highly flexible and science-based testing capability currently beingdeveloped, significant performance gains can be realized. Tribology data generated with preliminary test methods during Phase I show the potential of the approach. Phase I has resulted in two new projects with these test methods to identify urgentlyneeded material/oil performance limits. A going forward plan is proposed to link testing to service performance and to provide guidance for innovative surface technologies and oil formulation. An empirical approach to tribo-system performance modeling isproposed to provide a realistic input to engine component life and durability models.