Abstract

Electric motors (EM) can require that greases operate in demanding conditions, such as high temperature, and with non-ferrous materials. Evaluating grease formulations for these conditions therefore requires modifications of standard benchtop tests. This study involved tribological characterization of EM greases using four-ball and ball-on-disk tests with materials and conditions modified to better reflect current and emerging applications, including electric vehicles. The hybrid bearing configuration was mimicked by testing with silicon nitride and 52100 steel tribopairs. The market-available and new grease formulations studied had mineral or synthetic base oil, and polyurea or lithium thickener. The friction traces, wear response, energy dissipation, and estimated film thickness were analyzed to enable comparison of the tribological properties of these greases specifically for EM applications.

Biography
   Abhishek Kumar, currently pursuing an M.S. in Mechanical Engineering at the University of California, Merced, has been a member of the Martini Research Laboratory since the Spring of 2021. His research interests lie in the field of experimental tribology, particularly focusing on electric motor grease lubrication to reduce friction, wear, and energy dissipation in hybrid bearings to design more efficient electric vehicles.