Working of cam and follower:

Cam is mounted or fixed on a camshaft, which gets its motion from the rotation of flywheel by coupling it with a toothed wheel mounted on crankshaft. As flywheel rotates at high speed therefore a smaller wheel is coupled with a big wheel so that its motion can be reduced.

• The base circle of a cam can be divided into four parts that is angle of ascent, angle of dwell, angle of descent and angle of dwell again. During the first sector. i.e. angle of ascent , cam lifts the follower which with the help of arm and guide opens the valve then period of dwell comes into picture in which there is negligible displacement of follower takes place and the valve remains open for some time. During third sector. i.e. angle of descent , cam descents down and also the follower which closes the valve and then again dwell period comes into picture as a result valve remains closed for some time .These events occur in a cycle and in this way cam functions.