Gyru-Star screening buckets have a hard-earned reputation for reliability and durability and are relied upon by operators on remote jobsites around the world. Paramount to their reliability are the carbon belts, which drive the poly-star rotors.
This is very different from the systems used by other manufacturers, who generally rely on traditional chain-driven systems. In this article, we’re going to compare the two different systems and bust some common misconceptions about carbon belts.
Common Myths About Carbon Belts
Myth #1: Carbon Belts Will Slip Under Load
The idea of belts slipping under load often comes from familiarity with flat rubber belts used in other applications. However, the carbon belts in Gyru-Star screening buckets are different. Equipped with teeth and running on sprockets—just like chains—these belts provide maximum power transfer, eliminating the risk of slipping under heavy loads.
Myth #2: Carbon Belts Can’t Cope with Heavy or Sudden Loads
This misconception stems from outdated assumptions about belt durability. In reality, the carbon belts in Gyru-Star buckets are designed to withstand high pressures and sudden loads. Damage through misuse is rare and comparable to the wear chains might experience under similar conditions.
Myth #3: Carbon Belts Wear Out Faster than Chains
Contrary to popular belief, carbon belts often outlast chains in this application. With fewer moving parts and no metal-on-metal wear, they’re built for longevity. While certain materials or applications may increase strain on the belts, independent testing confirms that their lifespan often exceeds that of chains in equivalent use.
Myth #4: Carbon Belts Require Constant Adjustment Due to Stretching
Both chains and belts are liable to stretch over time. However, thanks to the strands of carbon inside the belts, this is kept to an absolute minimum. Our screening buckets also have a self-tensioning system, meaning that there is never any need for manual adjustment.
Carbon Belts vs Chains: A Side-by-Side Comparison
Durability
Carbon belts are highly durable, with fewer parts exposed to wear and tear compared to chains. They are also less prone to corrosion, seizing, or breakages, especially in demanding environments.
Weight
Unsurprisingly, carbon belts are much lighter than chains. This is especially beneficial on larger screening buckets, where multiple belts or chains are required, as it can dramatically reduce the weight of the attachment.
The reduced weight also helps to ensure that the attachment is balanced, improving overall handling and operation, especially in smaller machines. It has also allowed us to increase the size of the screening area, maximising the output of the bucket.
Operation
Carbon belts operate much quieter than chains, making them ideal for noise-sensitive sites like residential areas. This quieter operation creates a safer working environment for both operators and nearby workers. The lack of lubrication requirements also means fewer delays, keeping downtime to a minimum.
Maintenance
Just like a bicycle chain, chain-driven systems in screening buckets require regular lubrication to ensure that they don’t seize and are free from corrosion. Most manufacturers have taken one of two approaches: installing grease points or an oil bath.
Whilst both are effective methods of lubrication, these features can present their own problems. Not only do lubricants attract dirt and grime (making other maintenance tasks more difficult), but there is also a risk of contaminating the screening material. Furthermore, external grease points are liable to damage, and oil baths have the potential to leak if damaged or incorrectly installed.
In contrast, the carbon belts used in Gyru-Star screening buckets can’t corrode or seize and require zero lubrication as they have no moving parts and don’t wear on metal surfaces. This also makes other maintenance tasks a much cleaner job.
Those unfamiliar with belt-driven screening buckets often raise concerns about the belts losing tension as they stretch. However, the belt drive system in our screening buckets is self-tensioning, meaning that the operator should never have to worry about tensioning for the life of the belt. We should also mention that any stretching is generally minimal, thanks to the unique design of the carbon belts.
Chains are not immune to stretching, and if tensioning is required, then this has to be done manually. This means either adjusting the distance between the sprockets or shortening the chain itself.
Case Study
Last year, we were contacted by a local groundworks contractor in Gloucestershire who needed to replace damaged stars on their Gyru-Star 4-150HDX. The contractor had originally purchased the bucket back in 2020 for screening topsoil.
Despite being in near constant use for the last four years, with zero maintenance during this time, the driveline was in excellent condition. Wear across the components was minimal, meaning that not a single internal component had to be changed.
As the driveline is enclosed, it was protected from the worst of the elements, with minimal build-up of dirt. The sealed bearings meant that in four years of use, there had been no need to grease anything.
A thorough inspection by our engineers revealed only slight cosmetic wear to the belts, which were refitted to the bucket during the rebuild. This is testament to both the innovative design of Gyru-Star screening buckets and the durability of the carbon belts.
Want to Find Out More?
If you want to find out more about our industry-leading range of True Screening® solutions, get in touch with your local Gyru-Star distributor. Alternatively, you can contact us directly using the link below.
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