Four stroke engine valve drive - with timing variation achieved by changing eccentricity of three link system driving cam shaft

摘要

The engine cam shaft drive is transmitted from the cam shaft to a crank which is connected by an intermediate lever to a second crank mounted on the cam shaft. The angle between these cranks can be varied by a mechanism which connects the intermediate lever to a point on a rotating member eccentric to the cam shaft. Changing the degree of eccentricity between crankshaft and rotating member changes the angle between the cranks and so changes the valve timing.