Basic Components and Construction of Roller Chain

A chain is made up of link plates, bushings, pins and rollers, as shown in the figure above.

By how the link plates are fastened, roller chains are further divided into A. riveted type and B. cottered type.

Link plate: the part that continuously carries the tension, and at times external shock loads as well, so it must have good tensile strength, shock resistance and fatigue strength.
Pin: supports all the load on the chain. When the chain engages the sprocket the pin acts as a bearing, so it must have good shear strength and bending strength, and above all wear resistance.
Roller: when the chain engages the sprocket the roller rolls into the tooth, smoothly changing the direction in which the chain bends and protecting the chain from the impact of the sprocket teeth. It must have good shock resistance and wear resistance.
Bushing: keeps the pin from taking the impact of chain and sprocket engagement directly. It too must have good shock resistance and wear resistance.