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 Drive Chain alternate with the next type, the outer links, comprising two external plates held with each other by pins moving through the bushings of the internal links. The “bushingless” roller chain is comparable in procedure though not in construction; instead of separate bushings or sleeves keeping the inner plates jointly, the plate has a tube stamped involved with it protruding from the hole which serves the same purpose. This has the benefit of removing one step in assembly of the chain.
The roller chain design reduces friction in comparison to simpler designs, leading to higher efficiency and less wear. The initial power transmission chain varieties lacked rollers and bushings, with both the inner and external plates kept by pins which directly contacted the sprocket the teeth; however this configuration exhibited extremely rapid wear of both the sprocket tooth, 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 linking the inner plates. This distributed the use over a greater area; however the the teeth of the sprockets still wore quicker than is desired, from the sliding friction against the bushings. The addition of rollers encircling the bushing sleeves of the chain and provided rolling contact with one’s teeth of the sprockets leading to excellent resistance to use of both sprockets and chain aswell. There is even suprisingly low friction, so long as the chain is definitely sufficiently lubricated. Constant, clean, lubrication of roller chains is of major importance for efficient operation along with correct tensioning.