Camshaft

Camshaft is a shaft which is equipped with cams that turns in time with the crankshaft. It is used in piston engines to operate poppet valves. It comprises of a cylindrical rod which runs along the length of the cylinder bank. It also has a number of lobes or cams originating from it, one for each valve.

The engine camshaft is connected to the crankshaft either directly, by a gear mechanism, or indirectly by a belt or chain called a timing belt or timing chain.

Types of Camshafts
Basically, there are two types of Camshafts:

• Flat-Tappet: More popular and less expensive. It uses a tappet or a lifter.
• Roller-Tappet: Use a roller follower which allows the follower to roll over the face of the cam lobe. Minimum friction happens with this kind of camshafts.

Functions of Camshaft

• Opens the valves physically and hold them open for a specific period of time.
• Controls the air/fuel mixture entering and exiting the cylinder.
• Controls the valve timing and in the process ensures that the intake valves open at the proper time to feed air and fuel into the engine

Materials used for making Camshaft
The most commonly used materials used for making camshaft are:

• Cast Iron
• High Carbon Steel

Maintenance of Camshaft

• To reduce the friction between the surface of the cam and the cam follower, lubricants should be used.
• When either of them is replaced, the other should also be replaced because they are designed to wear-in together.