Improving efficiency of seals of parts of cylinder piston group of marine diesel engines

Abstract

During the engine operation, the piston rings wear out and the grooves under the piston rings are destroyed, as a result of which there is a decrease in the sealing of the combustion chamber. This problem has been usually solved by replacing the old, spent piston and rings with new ones. There is considered a method of extending the life of the cylinder piston group. The proposed method consists in changing the composition and design of the upper piston ring, which is primarily responsible for sealing the combustion chamber. It is proposed to bore the groove of the upper piston ring, until all defects obtained during the engine operation are eliminated; then, to make two piston rings fitting the size of the groove and install them into the bored groove. Installation of the rings should be done in such a way that the axial locks are positioned in line in the opposite direction. In this position of the rings, gases entering the joint of the upper ring rest against the solid body of the lower ring and the further path for them is terminated. The breakthrough of gases from the working plane into the crankcase is excluded, the indicator efficiency of the engine increases, the wear of the cylinder bushings of pistons and rings decreases, the vibration of the flutter type is eliminated. For installation, standard piston rings are used with a slight modification, which consists in adjusting the height and changing the profile of the rings in order to reduce wear of the cylinder sleeve and rings during operation. According to the test results, conclusions were drawn about the increased service life in the manufacture of the piston rings with optimal geometry and about a positive effect on the engine performance.