Extended duration cam lobe for variable valve actuation mechanism

摘要

An output cam for a variable valve mechanism includes a body configured for being pivotally associated with and driven by an input shaft. A lift profile of the output cam includes a base circle portion, a cam portion and a fixed radius portion. The base circle portion is adjacent to and continuous with the cam portion, and the cam portion is adjacent to and continuous with the fixed radius portion. The base circle portion has a base radius, the cam portion has a cam radius and the fixed radius portion has a fixed radius. The base and fixed radii are substantially constant. The fixed radius is a predetermined amount greater than the base radius. The cam radius increases from a value approximately equal to the base radius adjacent the base circle portion to a value approximately equal to the fixed radius adjacent the fixed radius portion.