Analysis Of Lubrication And Seal Characteristics Of Piston Ring-Cylinder Liner System

The lubrication and seal performances of piston ring-cylinder liner system have great influence on the working performances and reliability of internal combustion engine. The calculation of dynamic oil film pressure and oil film thickness for piston ring are very important for analysis of lubrication characteristics of the piston ring-cylinder liner system. In this dissertation, the lubrication characteristics of piston ring is studied, and it provides theoretical basis to improve the lubrication performances of piston ring-cylinder liner system.The main contents are as follows:(1) Based on the hydrodynamic lubrication theory, the piston ring-cylinder liner system lubrication model is established, the Reynolds equation is solved by the finite difference method. The change of the minimum oil film thickness, friction force and friction power consumption of the piston ring-cylinder liner system with the change of crank angle are obtained. The lubrication performances of the piston ring-cylinder liner system are analyzed and contrasted with and without consideration of the particles.(2) The outer contours of three different axial cross sections are analyzed, and the lubrication performances of piston ring with different axial cross sections are analyzed, then the change of the minimum oil film thickness, friction force and friction power consumption of the piston with different cross sections are obtained.(3) The surface plastic deformation and the cutting effect of the impurity particles are analyzed, and the wear of the piston ring-cylinder liner system caused by the impurity particles is modeled. The effect of the particle concentration and particle size on the wear of the cylinder liner is analyzed, and then the change of the wear of the cylinder liner from the top dead center to the bottom dead center is obtained.(4) The gas flow model in the piston ring-cylinder liner system is established, and then the gas flow is analyzed. The gas flow in the single chamber and the three chambers are studied,and the change of the gas pressure with the change of the time in the single chamber and the three chambers are analyzed.The research in this dissertation can provide the theoretical basis to the design of piston ring-cylinder liner system.