V-shaped wing pulley deflects material, minimizes costly downtime and extends conveyor belt life.
When profit margins tighten, nobody wants more downtime or more maintenance labor – which is ultimately what is experienced when adopting the attitude of merely making do. With that said, consider the frequent task of dislodging material from the standard wing pulley. It’s necessary, yet annoying and time consuming – and ignoring the problem means that costly belt damage is likely. But recently, savvy producers are shaping up their pulley systems and eliminating downtime with the use of a new v-shaped pulley design. Unlike the standard wing pulley, this innovative wing pulley literally deflects material from being entrapped while extending conveyor belt life.
Producer perspective
Daryl Schmidt is the plant supervisor for the Milwaukee-based location of Wissota Sand & Gravel, a leading aggregate supplier for more than 85 years. Schmidt coined the term “Wissota-sizing,” which he says means tweaking equipment and systems for greater performance and ease of maintenance. As a part of that initiative, he replaced four of his standard winged tail pulleys with Superior’s patented Chevron® wing pulleys.
“Previously we always ran the standard tail pulley with the straight fins (wings) on it, and we kept getting rocks lodged between the wings. That meant having to shut down, and knock the material out or it would damage the belt,” says Schmidt, adding that a two-man crew would have to deal with this situation up to three times during every shift.
Schmidt installed the new pulleys in strategic locations; two in belts running from the primary crushers and one in each of his surge tunnels where he had fabricated special variable frequency drive belt feeders. “These are the locations where we have up to 5-inch-minus rock, and so these are the areas we always had to worry about. In each installation, the new pulleys are working well. I have yet to see any material lodged in them. The tapered, V-shaped design really shuts out the rock,” he says.
As to wear life, Schmidt says he purchased the mine-duty models of the Chevron wing pulleys, and after more than 18 months, he has detected no wear whatsoever. “We run about a million tons per year through this plant, and I envision these pulleys lasting for at least 15 seasons in the surge tunnels where the feeders are running very slowly and possibly for 5 or more seasons within our primary crushing circuit,” he says.
Tony Traveller is plant supervisor for Gordon Paving/Northwest Sand & Gravel of Twin Falls Idaho. Like Schmidt, he also experienced significant downtime to dislodge material from traditional tail pulleys. “Our downtime is now minimized with the use of the Chevron wing pulleys, which we’ve placed in problematic and abrasive, hard-use application areas,” says Traveller. He installed his first Chevron wing pulley on a 150-foot radial stacker, followed by two more on belts running from a primary impactor, and another two on discharge belts from his screening circuit.
Even with the heaviest-duty traditional wing pulley he could find, Traveller says he continued to have problems. “On the standard wing pulley, the rock would lodge, and then the wing would bend and fold over. Often the wings’ edges would become sharp, which would catch a belt splicing or contribute to the fast wear of the belt. But with the Chevron pulleys, we have had none of those issues. There is nothing to compare with their heavy-duty design, and we can run them 24 hours a day for five or six days a week with absolutely no problems. They are withstanding the test of time and I feel that any extra cost is overshadowed by the elimination of downtime, and their extremely long wear life,” he says.
Engineering perspective
Jarrod Felton is the chief engineer of standard products for Superior Industries. He explains the engineering and design intent behind the new V-shaped Chevron wing pulley. First, what gives it the ability to self clean or shed material, as well as lessen the tendency for bent wings? “On a traditional wing pulley, the impact of the rocks is directly perpendicular to the wing. Material is more easily entrapped between the wings, which over time can cause the wing to bend. On the Chevron wing pulley, the rock does not hit at a direct impact but rather at a glancing blow. The V-shaped wings deflect fugitive material out and away. This prevents rocks being wedged between the wings and the belt, and lessens the possibility of wing tipping and belt damage,” he says.
Next, says Felton, in comparison to the standard wing pulley, the V-shaped Chevron wing pulley provides smooth operation with less vibration, less belt wear, less of an impact and load on the bearings, and less noise. Noting the illustration presented, Felton points to the fact that the Chevron wing pulley has a round end view, so there is continuous belt contact. The belt is essentially rolling around a circle, which significantly reduces any beating action on the belt. On the other hand, the standard wing pulley is “apexed” or is shaped as a many-sided polygon. So the belt is always raising and lowering over one or two wings as the pulley is going around, which causes the belt to flap and results in more belt wear, and much more vibration and noise. As to the latter, Felton says that it’s similar to comparing a jet engine to a vacuum. Tests have shown that the standard wing pulley operates at an average 120 noise decibel level, while a Chevron wing pulley averages only 70 decibels.
