Piston rings are widely used in a variety of power machinery, such as steam engines, diesel engines, petrol engines, compressors, hydraulic presses, etc., widely applied in automobiles, trains, ships, yachts and so on. General piston ring is installed in the piston ring groove, it and piston, cylinder liner, cylinder head and other components composition chamber work.
The piston ring is the core part of the fuel engine, which completes the sealing of the fuel gas with the cylinder, the piston and the cylinder wall. Automobile engine has two kinds of diesel and gasoline engine, because of its different fuel performance, the use of the piston ring is not the same, the early piston ring by casting, but with the progress of technology, steel high power piston ring was born, and with the engine function, environmental requirements continue to improve, a variety of advanced surface treatment applications, such as thermal spraying, electroplating, chromium plating, gas nitriding, physical deposition, surface coating, zinc and manganese phosphating treatment, etc., so that the function of the piston ring greatly improved.
Piston ring action includes sealing, adjusting oil (oil control), heat conduction (heat transfer), guiding (supporting) four functions. Seal: Refers to the sealed gas, does not let the combustion chamber gas leak to the crankcase, the gas leakage control at the lowest limit, enhances the thermal efficiency. Gas leakage will not only reduce the engine power, but also make the oil deterioration, this is the main task of the gas ring, regulating oil (oil control): The cylinder wall of excess lubricating oil, but also make the cylinder wall cloth thin oil film, to ensure that the cylinder and the piston and the normal lubrication of the ring, this is the main task of oil ring. In modern high speed engine, special attention is paid to the action of piston ring to control oil film; heat conduction: the piston heat conduction to the cylinder sleeve, that is, cooling effect. According to reliable data, the heat in the piston top of the non cooled piston is $number by passing the piston ring to the cylinder wall. The $number in the cooling piston is dispersed through the piston ring to the cylinder wall; Support: piston ring to keep the pistons in the cylinder, to prevent direct contact between the piston and the cylinder wall, to ensure the smooth movement of the piston , reducing friction resistance and preventing the piston from knocking the cylinder. The piston of the general petrol engine uses two gas rings and a oil ring, while the diesel engine usually uses two gas rings and an oil ring.