Valve train assembly

摘要

A rocker arm assembly for a valve train includes a hydraulic lash adjuster (6) for accommodating slack in the valve train. There is also a lost-motion connection preferably between the axle of a roller (14) which is operated upon by a cam and the rocker arm (4) itself. Excessive expansion of the lash adjuster (6) will not prevent closing of the valve (11) because the closing movement is accommodated by the lost-motion connection. A spring (22) is provided to maintain the lost-motion connection despite the tendency of the hydraulic lash adjuster (6) to expand. Greater tolerance in the cam base circle radius is allowed, permitting the use of net-shaped cams.