CHAMSHAFT

Camshaft is a tool used in the machine to run the poppet valve. It consists of a cylindrical rod. Cam opens the valve by pressing it, or with other assistance mechanisms, as they spin. The relationship between the rotation of camshaft to crankshaft rotation is very important. Since the valves control the flow of fuel input and expenditure, they must be opened and closed at the time appropriate for the piston step. For this reason, camshaft connected to the crankshaft directly (through a gear mechanism) or indirectly through a chain called "chain of time".

Picture 1. Camshaft

In a two-stroke engine that uses a camshaft, each valve opens once for each rotation of the crankshaft in the engine, the camshaft rotates at the same speed with the crankshaft. In a four-stroke engine valves will open a half less, therefore crankshaft two full turns occur in each rotation camshaft.
Sliding friction between the face cam follower depends on the amount of friction. To reduce wear, the cam and the follower has a hard surface, and the modern lubricants contain special ingredients to reduce sliding friction. Lobe of the camshaft are usually tapered, resulting in a follower or valve lifter rotates slightly in each pressure, and a worn components. Usually the face of the cam and follower is designed to wear together, so when one has been worn away so they should be replaced to prevent wear excessive.