Effect of chevron-shaped wetting patterns on oil film thickness in cylinder-on-disc contact under starved lubrication or limited lubricant supply

This study addresses the oil starvation problem in roller bearing line contacts and proposes a novel Chevronshaped wetting/oleophilic pattern on the bearing track to enhance oil replenishment. Validation through optical cylinder-on-disc lubrication film tests reveals the impact of the pattern on inlet oil supply and film thickness. Notably, a Chevron pattern oriented opposite to disc movement significantly increases film thickness. Wetting is more pronounced in oleophilic areas (Chevron pattern), forming an inverted V-shaped "virtual wall" that directs lubricant backflow toward the center and reduces side leakage. A pattern length equal to the bearing track width was found to be more effective compared to smaller sizes, as the oil side ridges are located on the oleophobic and oleophilic boundaries, which capitalizes the wettability step effect more effectively. This research provides a basis for designing oleophobic surfaces with improved anti-wear and anti-friction properties.