TENSIONING MECHANISM FOR TRANSMISSION BELT FOR DRIVING VALVE ACTUATING CAM SHAFT OF INTERNAL COMBUSTION ENGINE

摘要

168/123 A V-type internal combustion engine having double overhead camshafts contains automatic mechanism for maintaining tension in the endless timing chain which drives the camshafts from the engine crankshaft. The two sides of the V-type engine are substantial duplicates. A tensioner body engages the slack side of the chain and is caused to move in a direction to tighten the chain to maintain desired chain tension. The tensioner body is operated by a curved arm member which is pivoted to a stationary support at a position in the dead space between the driven sprockets for the two camshafts. Resilient means acts on the curved arm member in a direction to tighten the tensioner body against the chain and a rocking member acted on by the resilient means prevents retrograde movement of the curved arm member, so that chain tension is maintained even when the chain stretches after a period of use.