There are actually two types of links alternating in the bush roller chain. The first type is inner links, having two internal plates held jointly by two sleeves or bushings upon which rotate two rollers. Inner links alternate with the next type, the outer links, consisting of two external plates held with each other by pins passing through the bushings of the internal links. The “bushingless” roller chain is comparable in procedure though not in construction; instead of individual 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. It has the advantage of removing one part of assembly of the chain.
The roller chain design reduces friction in comparison to simpler designs, leading to 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; however this configuration exhibited incredibly rapid wear of both the sprocket teeth, and the plates where they pivoted on the pins. This problem was partially solved by the advancement of bushed chains, with the pins keeping the outer plates passing through bushings or sleeves connecting the internal plates. This distributed the wear over a larger area; however the teeth of the sprockets still wore quicker than is desirable, from the sliding friction against the bushings. The addition of rollers surrounding the bushing sleeves of the chain and provided rolling contact with one’s teeth of the sprockets leading to Drive Chain excellent resistance to wear of both sprockets and chain as well. There is even suprisingly low friction, as long as the chain is definitely sufficiently lubricated. Constant, clean, lubrication of roller chains is definitely of major importance for efficient operation as well as correct tensioning