To overcome the problem of slip in belt drive or rope drive, chain drive is used. A schematic diagram of chain drive is shown in Figure 15.8. The velocity ratio in chain drive remains constant. But, chain drive is heavier than the belt drive and there is gradual stretching in its strength. Time to time some of its links have to be removed. Lubrication of its parts is also desired. The wheel over which chains are run, corresponding to the pulleys in a belt is known as sprocket having projected teeth that fit into the recess in the chain.
Figure 15.8 Chain Drive
Pitch: Distance between two consecutive roller centres is known as pitch, p.
Pitch Circle: The circle drawn through the roller centres of a wrapped chain round a sprocket is called the pitch circle.
Let T is number of teeth on a sprocket
ø is angle subtended by chord of link at the centre
r is radius of pitch circle
Leave a Reply