double pitch roller chain

There are actually two types of links alternating in the bush roller chain. The initial type is inner links, having two inner plates held collectively by two sleeves or bushings upon which rotate two rollers. Internal links alternate with the second type, the outer links, consisting of two outer plates held collectively by pins moving through the bushings of the internal links. The “bushingless” roller chain is similar in procedure Conveyor Chain though not in structure; instead of separate bushings or sleeves holding the inner plates together, the plate has a tube stamped into it protruding from the hole which serves the same purpose. It has the benefit of removing one step in assembly of the chain.

The roller chain design reduces friction in comparison to simpler designs, resulting in higher efficiency and less wear. The original power transmission chain types lacked rollers and bushings, with both the inner and outer plates held by pins which straight contacted the sprocket teeth; nevertheless this configuration exhibited incredibly rapid wear of both the sprocket tooth, and the plates where they pivoted on the pins. This problem was partially solved by the advancement of bushed chains, with the pins holding the outer plates moving through bushings or sleeves linking the inner plates. This distributed the use over a greater area; however the teeth of the sprockets still wore more rapidly than is desirable, from the sliding friction against the bushings. The addition of rollers encircling the bushing sleeves of the chain and provided rolling contact with the teeth of the sprockets leading to excellent resistance to put on of both sprockets and chain aswell. There is even suprisingly low friction, as long as the chain is definitely sufficiently lubricated. Continuous, clean, lubrication of roller chains can be of primary importance for efficient procedure along with correct tensioning.