Rolling Element Damage and the Influence of Test Conditions and Conductive Nanoparticle Grease Additives

With a growing emphasis on renewable power generation and sustainable transportation, the popularity of electric vehicles (EVs) is expanding rapidly. As a result, ensuring the efficient and sustainable performance of gears and rolling element bearings within tribological contacts is imperative. EVs typically experience elevated component loads and drivetrain temperatures, but concerns also arise regarding damaging electric leakage currents that cause electrical arcing across mechanical surfaces. Preliminary research indicates that blending conductive nanoparticles into grease can mitigate pitting damage on mechanical contacts under electrical loads. This study employs a rolling ball on disk test under electro-tribological loads to compare the performance of nanoparticle-enriched greases with neat and fully formulated oils under various conditions. Rotational tests were initially run with limited pitting damage. However, electrical damage was evident when a reciprocating motion was used at different track lengths and speeds. When conductive nanoparticle greases were incorporated, damage was reduced. These results suggest that incorporating conductive nanoparticles in additive packages enhances performance and reduces surface damage, extending lubricant and bearing operating life. These findings benefit EV technology and hold promise for power generation and transformer applications where electrical discharges are common.