The complete set of pistons of marine diesel engines with a new o-ring seal during repair

The vast majority of high-speed engines are equipped with aluminum alloy pistons, and since these engines occupy a leading position in shipbuilding, the issue of restoring the piston as the most stressed and wear-prone part is relevant today. Aluminum alloy has a large number of positive qualities that determine their use for high-speed engines. These include low weight, which is necessary to reduce inertial loads, high thermal conductivity, due to which the piston does not overheat during normal operation, and a low coefficient of friction. But for all the advantages of an aluminum alloy, it also has disadvantages of low strength, which significantly reduces its service life. According to statistics, one of the reasons for the failure of aluminum pistons is the wear of the piston grooves, especially the first one. As an alternative to replacing the piston, a repair method is proposed, which consists in boring the first piston groove for the installation of two piston rings. To reduce friction, the ring located in the second groove is being redesigned to provide a more stable oil wedge to increase the efficiency of the new O-ring.