Effect of asymmetric elliptical shapes of the sealing ring sliding surface on the main parameters of the oil film

Piotr Wróblewski

doi:10.19206/ce-2017-114

Abstract

This article discusses the results of simulation studies of the effect of selected sealing ring sets with asymmetrical elliptical sliding surfaces on the oil layer thickness distribution over the whole operating range of an internal combustion engine. The problem of calculating the sliding surface coverage with visco-elastic oil film as well as in mixed friction conditions is discussed. The effect of asymmetrical elliptical sliding surfaces particularly on the dimensionless slip and squeeze indicators was determined, defining these surfaces ability to produce an oil film. The research results presented in this article show that there exists a real possibility of friction loss re-duction in the cylinder and sealing rings contact area, while maintaining the oil film continuity between the sliding surfaces.

Highlights

During piston engine operation, the lubrication conditions of the piston and the rings mounted on it are constantly changing
For the given engine kinematic assemblies geometry and the assumed values of the temperatures in the combustion chamber, the data defining the thermal conductivity of the spheroidal cast iron and the selected aluminum alloy used in the manufacture of the pistons, the geometrical data of the main engine assembly, for the duration of combustion flame acting on the cylinder walls surface from its ignition to decay, just before and during the exhaust stroke, and for the ignition temperature of synthetic oil with a dynamic viscosity of 0.0152 Pa×s in the range of 200 to 250°C, the total amount of oil consumed due to its combustion in the cylinder will hypothetically increase from 16%
− Analyzing the most important effective shaping aspects of the upper sealing ring sliding surfaces by changing the extrusion and slip coefficients values, it is necessary to determine the area of its operation in which mixed friction may occur

Summary

Piotr WRÓBLEWSKI

This article discusses the results of simulation studies of the effect of selected sealing ring sets with asymmetrical elliptical sliding surfaces on the oil layer thickness distribution over the whole operating range of an internal combustion engine. The problem of calculating the sliding surface coverage with visco-elastic oil film as well as in mixed friction conditions is discussed. The effect of asymmetrical elliptical sliding surfaces on the dimensionless slip and squeeze indicators was determined, defining these surfaces ability to produce an oil film. The research results presented in this article show that there exists a real possibility of friction loss re-duction in the cylinder and sealing rings contact area, while maintaining the oil film continuity between the sliding surfaces

Introduction

Friction power of a piston ring set

Reference piston ring set

Conclusions

Findings

Hourly oil consumption