What Is The Function Of The Piston Ring

The functions of the piston ring include four functions: sealing, adjusting oil (oil control), conducting heat (heat transfer), and guiding (support). Sealing: refers to sealing the gas, preventing the gas from the combustion chamber from leaking to the crankcase, controlling the gas leakage to the minimum, and improving thermal efficiency. Air leakage will not only reduce the power of the engine, but also deteriorate the oil, which is the main task of the air ring; Adjust the oil (oil control): scrape off the excess lubricating oil on the cylinder wall, and at the same time make the cylinder wall thin The thin oil film ensures the normal lubrication of the cylinder, piston and ring, which is the main task of the oil ring. In modern high-speed engines, special attention is paid to the role of the piston ring to control the oil film; heat conduction: the heat of the piston is transferred to the cylinder liner through the piston ring, that is, cooling. According to reliable data, 70-80% of the heat received by the piston crown in the uncooled piston is transmitted to the cylinder wall through the piston ring, and 30-40% of the cooled piston is transmitted to the cylinder through the piston ring Support: The piston ring keeps the piston in the cylinder, prevents direct contact between the piston and the cylinder wall, ensures smooth movement of the piston, reduces frictional resistance, and prevents the piston from knocking on the cylinder. Generally, the piston of a gasoline engine uses two gas rings and one oil ring, while a diesel engine usually uses two gas rings and one oil ring.