| Abstract:Due to the use of splash lubrication or inertial oil dumping, the cam-tappet pair of an internal combustion engine is prone to insufficient lubricant supply, leading to lubrication failure. Encouraging the lubricating surface to supply a limited amount of lubricating oil to the contact track to the maximum extent is one of the effective ways to improve the lubrication performance. Based on this, a patterned coating functional surface was designed and prepared to realize the automatic accumulation of a small amount of lubricating oil, and its improvement in the limited lubrication performance of the cam-tappet pair was explored. The results show that the functional surface of the coating causes a wettability gradient on the contact surface, and a limited amount of lubricating oil flows in a directional manner without external force driving, which improves the oil supply in the contact area and thus improves the lubrication performance. The influence of the width of the lipophilic track on the return flow of lubricating oil is not uniform. Appropriate width design can produce a good oil collection effect; high-viscosity lubricating oil is impeded by the pinning effect and hinders its outward flow in the extrusion stage; when the oil supply volume is reduced to 0.5 μL the moving pair is severely starved of oil, and the oil collecting surface cannot improve lubrication. |