Low friction variable valve actuation device

摘要

A variable valve train device for use on an internal combustion engine having a rotary camshaft with adjacent valve-opening and valve-closing lobes. The device is mounted on the engine head and is pivotable about the camshaft to alter the timing and lift of a fuel intake valve. A command link controls the rotational position of the apparatus with respect to the camshaft and is rotationally supported by a cylindrical shell bearing mounted on the engine head coaxial with the camshaft. The shell bearing is supported by an hydraulic lash adjuster or an adjustable ball joint to minimize mechanical lash in the device. The command link includes a ring gear which meshes with a control shaft gear for advancing or retarding the valve timing. The command link pivotably supports a rocker assembly for following the rotary motion of the valve-opening and valve-closing cam lobes. The rocker assembly is linked to an output cam disposed between the camshaft and a roller finger follower for actuating the valve.