SEED Guides Component Selection - Chain Drives < >

A roller chain consists of a number of inner link assemblies in which adjacent pairs are connected by outer links. An inner link assembly is made up of a pair of inner plates connected by two riveted bushes spaced a set distance apart called the pitch. A roller is free to rotate on either bush. The outer links comprise a pair of outer plates which are attached via a pair of riveted bearing pins which are spaced a pitch distance apart. These pins are free to fit inside the inner link bushes and connect inner links as shown in Figure 5.

Figure 5 Roller Chain Components

A length of chain is joined to form a continuous piece using a connecting link. This is a special type of outer link which permits one of the outer pins to be separated from one of the outer plates as illustrated in Figure 6. Chains engage with a drive and a driven sprocket and these must have the same pitch spacing of teeth (measured at the pitch diameter) as the chain.

Figure 6 Common Types of Connecting Links