Spyraflo bearings improve gangway performance

Edited by the Engineeringtalk editorial team Sep 25, 2009

A manufacturer of equipment for loading and unloading at docks recently contacted Spyraflo to come up with a suitable replacement for its failing bronze bushings.

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

A manufacturer of equipment for loading and unloading at docks recently contacted Spyraflo to come up with a suitable replacement for its failing bronze bushings.

The manufacturing company discovered that bearings in some of its gangways, including its 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.

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

After conducting in-house research that involved reviewing 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 met all of the company's needs 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 variety of environments, including cement dust.

The bearings completely eliminated failures in the field, leading to 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 +/-5deg self-alignment with a pivoting capability in any direction.

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

The permanent and secure installation of self-clinching bearings offers further benefits such as: fast and easy assembly; no precision diameter mounting holes required; no mounting blocks, bolts or screws; reduced panel thickness; and minimum footprint.

The switch to these bearings not only solved an expensive repair problem but a potential seriously damaged reputation.

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