Effects of Particle Size of Solid Lubricants in Oil on Tribological Characteristics

In recent years, there has been a demand for technology that can achieve carbon neutrality, and in order to meet this demand, improvements in gear transmission efficiency have been considered for on-board electric motors. In particular, the shape of the gear tooth surface and the lubricating oil with the dispersed solid lubricant used in the gear significantly influence the transmission efficiency. In this study, using a pin-on-disk friction tester and PAO lubricating oil with dispersed PTFE solid lubricant, the effects of the curvature of the rider on the sliding surface and the particle size of the solid lubricant in the lubricating oil on the tribological characteristics were experimentally analyzed. As a result, the following findings were obtained. The shape of the rider and the difference in the particle size of the solid lubricant dispersed in the lubricating oil affect the tribological characteristics, and when the particle size is small, the coefficient of friction tends to decrease as the rider curvature radius increases.