There are two types of links alternating in the bush roller chain. The 1st type is inner links, Auto Chain having two internal plates held jointly by two sleeves or bushings upon which rotate two rollers. Internal links alternate with the next type, the outer links, consisting of two external plates held together by pins moving through the bushings of the internal links. The “bushingless” roller chain is similar in operation though not in building; instead of individual bushings or sleeves keeping the inner plates jointly, the plate includes a tube stamped involved with it protruding from the hole which serves the same purpose. This has the benefit of removing one part of 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 directly contacted the sprocket tooth; nevertheless this configuration exhibited extremely rapid put on of both the sprocket tooth, and the plates where they pivoted on the pins. This issue was partially solved by the advancement of bushed chains, with the pins holding the outer plates passing through bushings or sleeves connecting the inner plates. This distributed the put on over a larger area; however the tooth of the sprockets still wore more rapidly than is desired, from the sliding friction against the bushings. The addition of rollers surrounding the bushing sleeves of the chain and provided rolling contact with the teeth of the sprockets leading to excellent resistance to use of both sprockets and chain as well. There is even suprisingly low friction, provided that the chain is certainly sufficiently lubricated. Continuous, clean, lubrication of roller chains is usually of main importance for efficient operation along with correct tensioning.