Camshaft support assembly for valve operating mechanism in an internal combustion engines

摘要

An overhead camshaft in an engine is rotatably supported by a camshaft support assembly comprising a plurality of bearing bases, a plurality of cam holders mounted on the bearing bases, respectively, and a rigid frame mounted on the cam holders and interconnecting them. The bearing bases and the cam holders jointly define a plurality of bearing surfaces by which the camshaft is rotatably supported. The cam holders may be integrally interconnected by side walls joined to opposite ends of the cam holders. The rigid frame includes an internal longitudinal oil pipe for ejecting lubricating oil onto cam surfaces of the camshaft. The bearing bases and the rigid frame may be made of an aluminum alloy, whereas the cam holders may be made of cast iron. Each of the cam holders has an oil supply port opening into one of the bearing surfaces at a position such that the lubricating oil will be supplied fully around the journal of the camshaft which is rotatably supported by the bearing surface.