Bearings eliminate failures in the field

Edited by the Engineeringtalk editorial team Nov 3, 2006

When a manufacturer of equipment for loading and unloading at docks discovered that bronze bushings used in its gangways were cracking and breaking it called Spyraflow.

A manufacturer of equipment for loading and unloading at docks, such as gangways, crossover walkways and towers, discovered that bronze bushings used in its gangways were cracking and breaking.

Spyraflo solved the problem with its Delrin AF material and its Permaglide Teflon Bronze self-clenching and self-aligning bearings.

The company discovered that bearings in some of its gangways, including their pivot points, were wearing down considerably faster than expected under certain conditions.

These pivot points are critical because they enable the gangway treads to remain horizontal, regardless of the frame's angle.

The problem centred on companies that used the gangways to load and transport dry powdered cement, the main reason being their usage rate for the gangways was anywhere from 20 to 60 times greater than most companies.

Another was the work environment as the cement dust quickly dissipated the oil from the bearing's bronze bushings, causing the bushings to function very poorly under the extremely heavy loads.

In the field this was far from a simple repair, as the problem/solution would impact three major products: articulating tread gangways, which provide safe access from a fixed platform height to vehicles such as transport trucks, barges and other platforms; V-groove wheel track rollers, used to roll gangways along a fixed track; and B-1 stand treads, a variable platform with self-levelling treads designed for use by aircraft ground services.

Repairing the gangway alone would require replacing four bearings in each tread side plate and four in the main pivot axis, a total of 20 or more bearings per gangway.

Combined with the V-groove wheel track roller and B-1 stand tread, the manufacturer might have had to replace a significant number of bearings on an ongoing basis.

This process would be prohibitively expensive and clearly a better and more cost-efficient solution was needed.

After conducting in-house research reviewing the products and catalogues several alternatives were identified, such as bronze press-fit bushings and expensive bolt-on bearings using ball-bearing assemblies.

The Spyraflo option offering the patent pending bearing assembly meant the search was over.

The product met all their needs from the beginning using two stock products, the 18mm diameter Permaglide Teflon Bronze and 16mm diameter Delrin AF self-clinching/self-aligning bearings.

These were chosen because the Permaglide bearing wears well and is designed for a wide variety of environments, including cement dust.

The bearings completely eliminated failures in the field, leading to significant cost savings.

Installation time is less and the performance is better than the bronze bushing assembly they replaced and the clinching feature provides a secure mount so that the bearings help enhance product quality.

Although the bearing's self-aligning feature enables it to adapt to variances, working with engineers drove the company to be even more precise in manufacturing to improve quality still further.

The self-aligning feature of these bearings allows a +/-5 degrees self-alignment with a pivoting capability in any direction.

This provides customers with a number of important benefits, including: enhanced equipment/machine performance; extended service life; reduced costs; and easier OEM equipment/machine assembly.

The permanent and secure installation of self-clinching bearings also gives these further benefits: fast and easy assembly; no precision diameter mounting holes required; no mounting blocks, bolts or screws; reduced panel thickness; minimum footprint; and significant cost savings The switch to these bearings not only solved an expensive repair problem but a potentially seriously damaged reputation.

In addition there were substantial manufacturing cost savings making the gangways a highly profitable key product for the company.

Micromech is the UK and Ireland distributor for these clever bearings.