| A piston is an important component of internal combustion engine, whichimpacts directly the reliability and durability of internal combustion engine. Apiston skirt is an important part of piston, and the guarantee of its functionality ofpiston skirt-cylinder liner friction pairs is affected directly by its workingconditions. Currently, although a great deal of progress in the research on thelubrication of piston skirt-cylinder line frictional pairs for internal combustionengine has been achieved, there are many problems need to be solved in theresearch on the lubrication of piston skirt-cylinder line frictional pairs due to theextremely complex working condition. In the current research on the lubrication ofpiston skirt-cylinder liner frictional pairs, the lubrication of oil-rich form was usedgenerally in the boundary conditions in calculation and the impact of lubricating oiltransport status in and in front and back of piston skirt-cylinder liner frictionalpairs in actual operation of internal combustion engine is not considered. In thispaper funded by National Natural Science Foundation, the lubricating oil transportstatus in and in front and back of piston skirt-cylinder liner frictional pairs andinvestigates and its effect on the lubricating analysis of piston skirt-cylinder linerfrictional pairs, which will provide the theoretical basis and method to moreaccurate analysis of lubricating oil transport in and in piston assembly and thelubricating analysis of piston assembly.In this paper, the following researches were done:1. Base on a multi-cylinder internal combustion engine, a lubricating analysismodel piston skirt combined of the average Reynolds equation and pistonsecondary motion equation was established, in which the surface roughness andasperity contact of piston skirt and cylinder liner were considered. The numericalmethods to calculate the piston secondary motion equation and average Reynoldsequation as well as the specific calculation process of the analysis of piston skirtlubrication were given.2. The lubricating performance of the piston skirt-cylinder liner frictional pairsand the piston secondary motion in different piston skirt lines and workingcondition of internal combustion engine were analyzed.3. A multi-cylinder internal combustion engine was taken as the studying object, the model of lubricating oil transport between piston skirt and cylinder liner wasestablished based on the principle of fluid mechanics. The amount of lubricating oilstayed on the cylinder liner when the piston moves done and the amount oflubricating oil stayed on the cylinder liner considering the effect of the scraping oilof piston ring were calculated.4. A lubrication analysis model of piston skirt considering the lubricating oiltransport status was established. The lubrication performance of piston skirt andpiston secondary motion at the oil-rich lubricating condition and oil-poorlubricating condition as well as different oil-poor condition were analyzed base onthis model. |
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