Schaeffler_Kolloquium_2010_20_en-Chain drive.pdfVIP

Schaeffl er SYMPOSIUM 2010 20 Chain drive 278 Schaeffl er SYMPOSIUM 2010 279 20Chain drive 20 20 Chain drive The missing link From a simple component to a sophisti cated chain drive system Bolko Schuseil Steff en Lehmann Stefan Wehmeyer, IFT Clausthal Zellerfeld Christopher Lehne, IFT Clausthal Zellerfeld Schaeffl er SYMPOSIUM 2010 20 Chain drive 280 Schaeffl er SYMPOSIUM 2010 281 20Chain drive 20 Introducti on Over 90 years ago, chains were for the fi rst ti me used for linking the crankshaft and camshaft of internal combusti on engines. The bush chains used in this applicati on were based on a patent of Swiss inventor Hans Renold from 1880. Since then, the chain drive has become a highly com- plex system the development of which requires an in-depth understanding of systems due to its interacti on with other engine components. Start- ing from the component “hydraulic chain ten- sioner”, the Schaeffler Group has taken on this challenge with state-of-the-art development methods. It off ers customers not only all compo- nents of a chain drive system but also the relevant systems engineering. Components and functi on Chain tensioners INA developed the fi rst chain tensioners based on a customer request in 1982. These elements were introduced to the market in a six-cylinder engine in 1984. The structure and functi on of the tensioning ele- ments were derived from hydraulic valve lash ad- justment elements (HVA). They work according to the principle of leakage gap damping that acts pro- porti onal to the speed. A piston that can be moved longitudinally is posi- ti oned in a cylindrical housing so that a high-pres- sure chamber (red) is created that is linked with the engine oil circuit (blue) via a check valve. The extremely narrow gap (leakage gap) between the piston and the housing seals the high-pressure chamber almost com- pletely against external infl uences. The rota- ti onal irregularity of the crankshaft and/or camshaft leads to