Study on the effect of diketone lubricant on the tribological properties of angular contact ball bearings with skidding behavior

Skidding in angular contact ball bearings can significantly increase friction, wear, and temperature, affecting bearing performance and service life. Despite its important impact, few studies have systematically investigated lubrication behavior under skidding conditions, where conventional lubricants often fail to provide stable low-friction operation. To address this issue, this study first calculated the critical skidding parameters of angular contact ball bearings using a quasi-static model. Then, the experimental parameters of bearings with skidding and non-skidding were selected to study their tribological behaviors under lubrication with three different lubricants (base oil, commercial lubricant, and diketone lubricant). The study found that when the bearing had skidding behavior, the lowest coefficient of friction and temperature rise (0.0008, 2.8 °C) can be achieved only under lubrication with polyalphaolefin (PAO) = 14 (20%) (diketone lubricant). In addition, the bearings lubricated with diketone show excellent anti-wear performance and an extremely short running-in period. The mechanism of the excellent tribological performance of diketone-based lubricants came from the synergistic effect of the diketone molecular adsorption layer and chelation, which can reduce friction and temperature rise. These findings highlight the potential of diketone lubricants to improve bearing performance and durability under extreme operating conditions.