Journal Article
A Friction Comparison between Chain and Belt-Drive Systems
2012-04-16
2012-01-0427
Concerns over greenhouse gas emissions are driving governments and the automotive industry to seek out ways of reducing vehicle CO₂ emissions. Engine friction reduction is one means of reducing CO₂ emissions, through fuel consumption improvements. Of the different systems within the engine, the camshaft timing drive can contribute around 5 to 10% of the overall engine friction. It is therefore a system that can benefit from careful optimization. MAHLE has undertaken a motored friction-testing program on a 2.2-liter turbocharged diesel engine with the following different types of camshaft timing drive: - Chain drive with hydraulic tensioner. This is the standard configuration for this engine. - Chain drive with friction tensioner. - Wet belt drive. - Dry belt drive. Testing was conducted to allow the differences in friction between the different drive configurations to be calculated, by comparing each camshaft drive against the standard chain drive system.