MRO Magazine

Chain fixes for severe conditions

Self-lubricating chains have been around for more than 20 years, with constant improvements having been made over time in materials, life and strength. For example, Tsubaki's Lambda chain suits any ap...


September 1, 2010
By Mike Welwood

Self-lubricating chains have been around for more than 20 years, with constant improvements having been made over time in materials, life and strength. For example, Tsubaki’s Lambda chain suits any application where regular lubrication is impossible. But what happens when self-lubricating chain cannot handle the speed of your application? There’s a solution designed specifically for high-speed applications.

This chain was designed and tested in the Canadian market for local customers with demanding applications. For example, the forestry industry requires that chains hold up to the extreme speeds of planers, bull-edgers and similar high-speed processes.

Tsubaki’s Speedmaster chain features a hard-chrome plated pin and quad-staked rivets. A hard-chrome plated pin reduces the co-efficient of friction, as well as the wear in this critical pin-bushing area. The quad-staked riveting supports the lateral forces the chain will experithe ence in some of these applications, as well as the resulting vibration from the high speed of the chain.

Why can’t a standard ANSI roller chain work in these applications? Standard off-the-shelf chains use double-staked rivets and standard materials for the pin. The pins will wear quickly from speed and lack of lubrication. Even if the chain is lubricated regularly, the speed will cause the lubricant to exit the chain through the forces of the rotation of the sprocket, and also from the vibration of the chain. The double-staked rivets cannot stand up to the lateral forces or the vibration of the chain at high speeds.

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In one application in a planing mill, Speedmaster chain replaced standard chain to produce a annual savings of almost $3,500, while increasing chain life from 0.87 months to 7.27 months.

Some applications evolve through the years to the point that they can be beyond the capability of the roller chain initially designed for the application. This can cause many headaches if you have to change guide rails, sprockets, shafting, machine position or others pieces of equipment that may interfere with upgrading to a larger chain size. One solution to this problem is Tsubaki’s Super series chain line.

A chain is considered a Super series chain when it uses most of the dimensions and features from the standard ANSI roller chain, but increases the strength capacity through upgrading a few critical dimensions and strengths. Super series chains are ideally suited to severe operating conditions such as heavy shock loads. They are also well-suited to operating conditions that require higher horsepower ratings, and maximum allowable loads and tensile strengths, especially where space is limited.

In a sawmill application, replacing standard chain with Super series chain resulted in annual cost savings of slightly over $64,000, while increasing chain life from 0.83 months to 5.57 months. This operation had a downtime fixed cost of $4,050 every time the chain needed to be replaced. Over the course of only a year, it could require as many as 17 replacement chains.

Corrosion protection

Many industries require roller chains and have to combat corrosion to protect their investment. If you have a washdown, outdoor or extremely humid application, corrosion can prevent you from achieving the maximum life of your chain.

The general solution is to use stainless steel chains and materials. What many people are not aware of is that stainless steel has only 10%-15% of the strength of carbon steel on a similar-sized part. Stainless steel also costs significantly more. To replace a carbon steel chain with a stainless steel chain, in most cases, you will need a much larger chain size, causing the cost to increase exponentially.

The economical solution is a plated chain. Plated chain is not for every application, as the plating will flake as it wears and can contaminate your product. However, it combines the strength of carbon steel with the anti-corrosive properties of the plated material. The most common types of plating are nickel and zinc. Tsubaki’s Neptune brand uses a two-or three-layer zinc-based plating for corrosion protection (see Fig. 1).

In a food processing application, using plated chain resulted in an annual cost saving of $2,745 while increasing chain life from 0.37 months to 6.37 months.

This plating construction is superior to stainless steels but it can affect the strength of the underlying carbon steel chain. Plating chains at high temperatures can cause a reduction in strength due to the extraction of small amounts of carbon material from the chain.

For more information, visit www.tsubaki.ca.


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