Modern advancements in lubricating grease technology

Grease is one of the major bearing components and the performance of a grease lubricated bearing is strongly determined by the performance of the grease. This paper describes how grease knowledge is linked to improved rolling bearing performance. First the various performance indicators will be described such as rolling bearing life, sealing performance, bearing friction, bearing noise and grease life. Next, the dominating grease parameters and specifications on these aspects will be given. It will also be shown how re-lubrication will enhance the bearing performance. There is synergy between grease formulation and bearing design. In the last years new generation grease lubricated bearings have been developed where grease technology was used to provide significantly lower friction and longer grease life. This was achieved by developing better greases but also by improving the internal bearing design, which could be done by using modern advancements in understanding the lubrication mechanisms. Finally, an outlook will be given on future developments in lubricating greases for rolling bearings. The various test methods are not described in this paper. For an extensive list the reader is referred to [67] (Lugt et al., 2013).