The Tsubaki 'seventh generation' ANSI standard chain employs a bushing system that greatly improves internal lubrication and extends wear life by 100 per cent in the most popular RS80 to RS140 sizes. A combination of the new 'lube groove' bushing and an exhaustive testing regime also means that the new ANSI standard RS roller chain has a 33 per cent higher kW rating.
Independent testing and field data show that wear in the pin/bushing joint is usually the limiting factor in overall chain life, particularly in externally lubricated chain types such as ANSI standard roller chain. (The chain bushing is located between the solid bearing pin and external roller). Tsubaki has committed a significant amount of its research and development resources to making improvements in this area to reduce wear and effectively prevent chain elongation over a longer period of time. The result is a patented lube groove bushing, the grooves themselves providing an internal reservoir for lubricant where the chain needs it most, which has a dramatic effect on both chain performance and longevity.
The Tsubaki G7 bushings utilise a new production technique to enable a series of grooves to be incorporated on the inner surface of a cold forged, extruded bush. This new process results in a very precise cylindrical profile for better surface contact between the pin and bushing, and improved lubricant retention. The patent design lube groove bush (LG) ensures that the chain is optimally lubricated, particularly in real-world conditions where inconsistent external lubrication is a factor.
The result is a chain that lasts significantly longer in the field. When tested, G7 chain lasted twice as long as Tsubaki's previous generation ANSI chain - and up to four times longer than some comparatively priced alternatives from leading USA and European competitors.
Increased wear life equates to lower maintenance costs, reduced downtime and increased reliability. Overall equipment efficiency (OEE) costs are also reduced since the purchase cost is offset over a longer period of time - the price of G7 chain is unchanged over that of the previous generation. As OEE costs feature more frequently, the evidence is building up to show that the cheapest chain is not always the cheapest solution and that higher quality products can significantly reduce costs.
Rigorous testing has also resulted in a kW rating that is 33 per cent higher for all chain sizes in the range from RS80 to RS240. Only recently have ISO standards for fatigue testing link plates included a cyclic fatigue test, rather than a test for linear tensile strength. ISO requires a 5million-cycle test and Tsubaki tests to 10million cycles, resulting in a higher kW rating for the Tsubaki G7 chain. Customers can now benefit from enhanced power handling capability and an extended service life or, in some circumstances, a more compact and less costly chain installation, the former being of more relevance to maintenance and replacement applications and the latter to OEMs.
A number of other innovations also contribute to this performance improvement. Rollers are heat-treated and shot peened to give added durability and fatigue life in high-speed applications. Link plates have a wider waist for greater fatigue strength, and pins are made from high-quality alloy steel that is then heat treated for greater tensile strength.
Connecting links can also be a point of failure on roller chains, and so this aspect of the chain design has also received the benefit of the Tsubaki R&D investment. The result is a patented ring-coining process that creates plastic deformation of the metal structure around the hole in the connecting link, making up for the added stress on this point due to the fact that the pin is not fixed to the outer link plate. The benefit is increased fatigue strength of the connecting link, equivalent to that of the rest of the chain, something that no other manufacturer offers, hence Tsubaki chain lasts longer and does not have to be de-rated due to the connecting link.
Tsubaki is also conscious of its responsibility to the environment. The outer packaging of G7 uses environmentally friendly recycled paper and natural biodegradable ink at the printing stage. Employees within the Tsubaki environmental division are continuing to collate and evaluate production data on G7 chain, in line with Life Cycle Assessment (LCA), in order to analyse and thus reduce the impact on the environment through CO2 gas output. To ensure maintenance engineers know Tsubaki is fitted to their machines, the Tsubaki name and trademark RS inscription are stamped on the link plates of the chain.
The European chain market combines a number of standards including ANSI, BS, DIN and others. The ANSI standard is commonly adopted in a range of industries from heavy processing of metals and ores to packaging machinery and warehouse sortation systems. The production advancements featured on G7 ANSI will soon also be applied to the heavy-duty range of chains such as RS Super series, where equally impressive levels of performance improvement are envisaged.
Tsubaki G7 chain is available to order across Europe, direct from Tsubaki and from leading power transmission distributors. For more information and to find your nearest stockist contact Tsubaki at .