The structure of the roller chain

The roller chain is composed of ‌inner plate, outer plate, pin,‌ sleeve and rollers. ‌ ‌

The inner plate linked with sleeve with interference structure, and the outer plate linked with pin in the same way.

This design makes the outer plate and pin constitute a outer chain section, meanwhile, the inner plate and sleeve constitute a inner chain section.

There is a clearance fit between roller‌ and‌ sleeve, and sleeve between‌ pin. When the inner and outer chain joints are bent relative, the sleeve can be rotated freely around the pin shaft. When the chain is engaged with‌ sprocket, the roller on the sleeve running along the sprocket tooth profile, which can reduce the wear of the chain and sprocket teeth.

The roller chain structure also includes ‌double row roller chain, the plate is made of "8" shape, designed to make each cross section of the chain plate tend to equal strength, but also reduce the weight of the chain and the inertia force during movement. The distance between the center of the two adjacent pins on the chain is called‌ pitch. The larger the pitch, the larger the size of each part of the chain, and the greater the power that can be transferred. When the number of sprocket teeth is certain, the greater the pitch, the sprocket diameter will increase. In order to reduce the diameter of the sprocket, when the load is large, double or multiple rows of chains with smaller pitch can be used, but due to the influence of manufacturing and installation accuracy, the load distribution of each row is not easy to be uniform, so the number of rows should not be too much.