Piston-sealing device for alternative internal combustion fitter or alternative compressor, and system comprising such a piston

摘要

The piston (2), reciprocating in the cylinder of an internal combustion engine or compressor and dividing its chamber (4) into high pressure (6) and low-pressure (8) sections, has a groove (24) containing a closed elastic seal ring (22) designed to leave a graduated film of oil, preferably between 0.1 and 1 mcm thick on the inner surface (12) of the cylinder as it moves from the high-pressure to the low-pressure chamber. The seal ring, which has a radial thickness between 1 and 5 per cent of the cylinder's diameter, has a perimeter that is slightly greater in its free state than the perimeter of the cylinder surface so that it is subjected to a constant elastic deformation.