Rheological and Electro-Pitting Performance of Electric Vehicle Motor Greases with Various Nanoparticle Greases

Abstract As the performance and efficiency requirements of electric vehicles (EVs) continue to expand, the demand for advanced driveline lubricants has grown exponentially. Unlike traditional internal combustion engine (ICE) vehicles, EVs experience unique challenges, including increased acceleration and deceleration rates, higher operating speeds, and elevated drivetrain temperatures. Moreover, EV lubricants must endure exposure to damaging bearing currents, which can lead to morphological damage on bearing surfaces, such as electrical pitting. Addressing these challenges is critical to ensuring the longevity and reliability of EV components. This study aims to explore and validate innovative lubricant solutions tailored explicitly for EV applications. This work provides experimental validation of the capabilities of silver (Ag) and different concentrations of magnetic iron-oxide nanoparticles (NPs) in reducing damage through reciprocating rolling ball-on-disk tests. Additionally, an electrically conductive carbon black lithium-thickened grease was tested under comparable conditions. The significance of this research lies in its potential to revolutionize the EV lubricant industry by offering a robust solution to a prevalent problem. Successful implementation of nanoparticle-enhanced lubricants could lead to increased durability and efficiency of EV drivetrains, reducing maintenance costs and improving overall vehicle performance. This advancement aligns with the evolving demands of the EV market and sets a new standard for lubricant technology in electrified mobility.