Comparison of Material and Processes for VVT Sprocket Manufacturing
For the purpose of this paper the author will use VVT (Variable Valve Timing) to describe the function of these components. Other common names are VCT (Variable Camshaft Timing), cam phasers, VVT's were introduced in Japan in the late 1990,s in series production. The benefit to the end user is improved fuel economy, an increase in the power output and a reduction in emissions. Globally there are 8 major suppliers of VVT assemblies. The purpose of this paper is to compare the various systems from the selection of PM materials and the subsequent post operation processes specifically related to sprockets.