Recent developments have focused on both power transmission and conveyor chains, often targeting applications in extreme environments - where elevated temperatures and corrosive substances are encountered - as well as those where cleanliness is important, such as in the food and beverage industries.
For the majority of applications, however, the main drawback with roller chain is wear in the chain and sprockets, which leads to the chain lengthening (often misleadingly referred to as 'stretching') and, eventually, the need to replace the chain and maybe the sprockets too. To combat this problem, companies such as Eriks have been investigating ways to improve the wear characteristics of roller chains.
Shot-peened plates help further in extending the chain's life, as this process relieves the stresses built up during manufacture and reduces the likelihood of fatigue failures. In addition, since the chain plates are punched progressively, hole concentricity and the accuracy of both the diameter and pitch are maintained along the entire length of the chain. This ensures quiet and accurate meshing with the sprockets and eases pin extraction when splitting the chain.
A lubrication-free version of Fenner Plus chain is also available with sintered bushes that retain lubricant, thereby negating the need for external lubrication and avoiding the problems associated with maintenance teams failing to adhere to relubrication regimes. An added benefit of using sintered bushes is that the chain can operate at linear speeds of up to 2.5m/s - which is more than twice the speed of a composite bush chain.
To complement the Fenner Plus chain, Fenner Plus sprockets are manufactured from C45, a 0.45 per cent plain carbon steel that is suitable for through-hardening. The teeth are flame-hardened to just below the tooth root, helping to improve the chain and sprocket life by up to 50 per cent.