There are actually two types of links alternating in the bush roller chain. The 1st type is inner links, having two internal plates held with each other by two sleeves or bushings where rotate two rollers. Internal links alternate with the next type, the external links, consisting of two external plates held together by pins moving through the bushings of the internal links. The “bushingless” roller chain is comparable in procedure though not in structure; instead of individual bushings or sleeves keeping the inner plates together, the plate includes a tube stamped involved with it protruding from the hole which serves the same purpose. This has the advantage of removing one part of assembly of the chain.
The roller chain design reduces friction compared to simpler designs, resulting in higher efficiency and less wear. The initial power transmission chain varieties lacked rollers and bushings, with both inner and outer plates held by pins which straight contacted the sprocket the teeth; nevertheless this configuration exhibited incredibly rapid use of both sprocket teeth, and the plates where they pivoted on the pins. This issue was partially solved by the development of bushed chains, with the pins holding the outer plates passing through bushings or sleeves connecting the internal plates. This distributed the use over a greater area; however the teeth of the sprockets still wore more rapidly than is appealing, from the sliding friction against the bushings. The addition of rollers encircling the bushing sleeves of the chain and Conveyor Chain provided rolling contact with the teeth of the sprockets leading to excellent resistance to wear of both sprockets and chain aswell. There is even very low friction, as long as the chain is certainly sufficiently lubricated. Constant, clean, lubrication of roller chains is certainly of principal importance for efficient operation in addition to correct tensioning.