The camshaft is a part of a piston engine. Its function is to control the opening and closing of the valve. Although the speed of the camshaft in a four-stroke engine is half that of the crankshaft (the speed of the camshaft is the same as that of the crankshaft in a two-stroke engine), it usually has a high speed and requires a lot of torque.Therefore, the design of camshaft in the strength and support requirements are very high, its material is generally special cast iron, occasionally forgings. Because the law of valve motion is related to the power and running characteristics of an engine, camshaft design plays a very important role in the design process of engine.