Effect of Temperature and Surface Roughness on the Tribological Behavior of Electric Motor Greases for Hybrid Bearing Materials

Greased bearings in electric motors (EMs) are subject to a wide range of operational requirements and corresponding micro-environments. Consequently, greases must function effectively these conditions. Here, the tribological performance four market-available EM was characterized by measuring friction wear silicon nitride sliding on hardened 52100 steel. The evaluated had similar viscosity grades but different combinations polyurea or lithium thickener with mineral synthetic base oil. Measurements were performed at temperature surface roughness conditions capture behavior multiple lubrication regimes. Results enabled direct comparison products across application-relevant metrics, analysis methods developed can be used as baseline for future studies grease performance.