Drives & Controls March 2022

32 n BELTS, BEARINGS AND CHAINS March 2022 www.drivesncontrols.com Choosing chains for tough environments E xposure to challenging environmental conditions is when the ultimate performance and durability of an industrial chain is really tested. From corrosive atmospheres to washdown environments, a chain correctly specified for its application will increase lifespan, reduce the burden of maintenance and minimise downtime. In such applications it often possible to cut the total cost of ownership by installing specialty chains. Chains are integral to operational success in many industrial processes. Chain failures can be extremely costly, and chains can affect the quality of the processes they are its driving. The demands of each application depend on its operating environment, so its is vital to specify a chain that will offer a long operating life and low running costs. Abrasive In harsh industrial environments, such as metal-working, sawmills or cement processing, abrasive particles and dust are hard to avoid. Dust can infiltrate moving parts, accelerating wear and shortening the chain’s lifespan, while grit and abrasive elements can reduce the efficiency and control of power transmission. Specialised chains have been developed to operate in these conditions. For example, their pins can be given a hard-coated, low-friction surface for increased wear and corrosion resistance. Also, by using perfectly cylindrical and seamless bushes, smooth operation can be achieved and wear resistance increased in areas where tight tolerances are crucial. The bushes can incorporate lubrication grooves that hold oil between the pin and the bush – the point of greatest contact – thus maintaining lubrication. Corrosive If water is present, corrosion can occur that will rapidly deteriorate a chain. Corrosion is particularly common in applications that are subject to chemical cleaning, or where the water contains high levels of salt – such as in marine environments. Chains can be coated with materials that repel the effects of corrosion while maintaining strength. For example, Tsubaki’s Neptune chain, designed for use in corrosive environments, has a two-stage coating including an outer resin that provides high corrosion and chemical resistance. Impacts Chain durability and performance can suffer in applications that involve shock loads, or where high power transmission or heavier loads are required. Compact applications – for example where larger double stranded chains cannot be used – also face similar challenges. In such applications, heavy-duty chains can handle the high loads as well as offering high tensile strengths. Typically, such chains achieve longer lives by using thicker plates and through-hardened pins that deliver greater fatigue strength. In clean environments – such as food and beverage or pharmaceutical plants – it is essential that chains do not cause contamination. In such situations, conventional lubrication cannot be used because there is a risk of it escaping and contaminating foods or other sensitive products. For other applications, lubrication might not be easy or possible because of where the chain is located. In such applications, lubrication-free chain ensures long-term use. These chains have sintered bushes which are impregnated with food-grade lubricant, combined with specially coated pins that enhance internal lubrication. Matching a chain to its environment not only optimises its performance and efficiency over long-term use, but can also extend its lifetime. The danger of treating all applications and environments in the same way, and thinking of the chain as being a replaceable commodity, can ultimately increase costs. The right chain for the conditions will not only simplify the lives of maintenance engineers, but will also cut the costs of maintenance and downtime – planned or otherwise. n Chains operating in arduous conditions need to be chosen specifically to cope with their environment, thus maximising their operating lives and minimising running costs and the need for maintenance. Jake Yamamoto, sales and marketing director for Tsubakimoto Europe, explains. Tsubaki’s Neptune chain for use in corrosive environments includes a two-stage coating to provide high corrosion and chemical resistance.