It has been reported that 90% of greases are used for the lubrication of rolling element bearings. Greases are important systemic components which greatly influence the life of the bearings besides the dynamic test conditions encountered throughout its operation such as load, speed, temperature and bearing design. The greases may be used in bearings running in open condition or using shields to prevent it being leaked or thrown off during operation.
The dynamic life of grease is determined by tests run on multiple sets at elevated temperatures till failure is encountered. These tests measure the grease life as well as the bearing life. Simulated tests in conditions close to real life applications are possible using this method. The FE9 test rig is one of the commonly used test rigs for finding the dynamic grease life. In this paper, grease candidates with differing composition were evaluated at different elevated temperatures in the open and shielded conditions to attempt to find out whether a correlation exists between these two operating conditions.
