The camshaft is a part of a piston engine. Its function is to control the opening and closing action of the valve. Although the speed of camshaft in four stroke engine is half of that of crankshaft (in two stroke engine, the speed of camshaft is the same as that of Crankshaft), usually its speed is still very high, and it needs to bear a lot of torque. Therefore, in the design, the requirements for the strength and support of camshaft are very high, and its material is generally high-quality alloy steel or alloy steel. Because the law of valve movement is related to the power and running characteristics of an engine, camshaft design plays a very important role in the engine design process.