Enhancements in the Performance of Journal Bearing Grease

Wheelsets are removed from service for many reasons by North American Interchange Service. For example, journal bearings can be the cause of wheelset removal when operating temperature or acoustic signatures recorded by wayside detectors exceed certain limits. The Association of American Railroads (AAR) has established 13 failure progression modes to categorize the reason a bearing sets off one of these two detection systems. This study focuses on two failure progression modes: water etch caused by corrosion and issues associated with lubrication (grease). Greases for rail journal bearings are expected to satisfy a wide variety of requirements such as moisture tolerance, mechanical stability, vibration tolerance, range of operating temperatures and oxidation resistance, to name a few. This paper provides the reader an overview of several experiments and tests that were conducted with the goal of extending service life and reducing corrosion, including field tests used in the development of advanced journal bearing greases for the rail industry. One such new grease formulation was tested in the UK with good results.