Oil-free chains get put to work

The increasing need for reduced maintenance has meant lubrication free chains are finding increasing applications in industry. Justin Cunningham reports.

Design engineers are increasingly being asked to improve in-use efficiency as well improve reliability and reduce maintenance costs. Sourcing the best components for a particular project or application is essential and can provide a lot of inherent benefit. Reducing the need for lubrication in bearings has been a frequent subject of interest in our editorial pages, but lubrication-free chains are another technology that has the potential to deliver improvements. Lubricant-free chains are not exactly new, and have been around for the last couple of decades. However, the uptake has been limited to a certain number of industries and specific applications due to problems with operating conditions and temperatures. However, Tsubakimoto Europe say its latest lubricant-free chain is the best yet and should allow it to be used for a number of new applications. With demands for increased cleanliness spreading to industries such as paper, packaging and electronics, chains that require no additional lubrication are becoming ever more popular. Tsubakimoto's Lambda drive chain uses internal lubrication that combats wear just as well as a normally lubricanted chain, without risking contamination to the conveyed product or surrounding machinery area. The chains' link plates undergo shot peening, a process that improves the surface hardness. The process expands the surface of the cold metal, thereby inducing compressive stresses or relieving tensile stresses already present. These are then combined with oil-impregnated steel bushes to give the chains the properties necessary for long life without lubrication. In many cases, this type of roller chain will directly retrofit with standard BS/DIN or ANSI chain sizes and wear tends to be minimal since the key bearing areas of the chain are always lubricated, reducing the friction normally created. Industries and applications that have traditionally used expensive lubricants are now finding they can operate without the need for additional chain lubrication, even in some arduous washdown environments. The Lambda chain is the culmination of more than two decades of development and the company boasts that it will comfortably outlast both traditional externally lubricated chains and other 'lube-free' chains that it claims have not received the same depth of design input or product development. Lambda chains can operate over a wide operating temperature range from -10°C through to 230°C without compromising lubrication performance. This helps to create an environment where less frequent chain replacement results in less consumption of resources and ultimately contributes to reducing CO2 emissions. The chain provides a direct replacement for standard size roller chains and only requires standard dimension sprockets. Unlike normally lubricated chains Lambda is dry to handle and available in the size range 06B-24B in both single strand and 'duplex' form. Many standard attachment variants are available for BS/DIN in addition to an equally wide range of ANSI sizes. Special corrosion protective N.E.P Lambda and ultra-long life X-Lambda versions are also available for specific applications. With such a strong development history Lambda is available not just as a oil-free chain but also in a number of variants within the ANSI series. The Lambda heavy series, which has the advantage of higher shock load resistance than standard ANSI Lambda, is particularly suitable for harsh environments where the chain will be subject to heavy impact. Equally, it can be used for compact drives and equipment that must operate in tight spaces; or where higher transmission power, allowable load or tensile strength is required. Specifically for food industry applications, Tsubaki offers the Lambda FG series with a special food grade lubricant impregnated in the bush (NSF-H3 certified) and anti-corrosive oil (NSF-H1 certified) to prevent chain corrosion.