The camshaft is a component in a piston engine. Its role is to control the opening and closing actions 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 is usually still high in speed and needs to withstand a large amount of torque.
The camshaft has high requirements on strength and support. Its material is generally special cast iron, and occasionally it uses forged steel. Because the valve motion is related to the power and running characteristics of an engine, the camshaft design occupies a very important position in the engine design process.