The wheel is considered to be humankind’s first and most significant innovation, but improvements to this most basic of devices have continued into the 21st century.
“There’s still a lot to do for agriculture wheel development to reduce our carbon footprint while improving performance in terms of reduction of work hours, soil compaction and fuel consumption,” the R&D director for agriculture and forestry tyres at Trelleborg Wheel Systems, Piero Mancinelli, said. “More and more, tyres need to go both out on the fields and also on the roads, so they need to be versatile to accommodate different working conditions.”
Typically, agricultural end users are looking for tyres that can offer improved traction, low soil compaction, flotation on soft terrain and a wider footprint, combined with better driver comfort, handling stability, low fuel consumption and high wear resistance.
Trelleborg Wheel Systems Progressive Traction fits neatly into its Blue Tire philosophy. Blue Tire Technology is a Trelleborg concept that aims to increase the value for the end user through better performance and functionality, while also reducing the environmental impact through a lower carbon footprint and better sustainability.
Progressive Traction technology has had to overcome some practical limitations, Mr Mancinelli said. “The way to increase the traction in a tractor is normally to exchange it with a bigger, more powerful one with bigger tyres,” he says. But there are limits. During the past 15 years, tractors in the 100hp to 240hp range have been optimised in terms of torque and efficiency, while tire designs have not changed significantly.
Progressive Traction provides an opportunity to be more efficient in terms of fuel consumption and traction through a technical solution that introduces a double-edged lug design to the tyre to better distribute the forces onto the front surface. Thus it enhances the self-cleaning performance generated by the inter-lug terraces and gives an additional terrace on the vertical face of the lug that provides more power to the ground and ensures a better grip.
The traction grip has been increased thanks to the edge of the lug working as an anchor. Numerical analysis has confirmed how pressure on the contact surface increases locally with the additional rib. Forces transmitted to the soil by a standard lug are much more concentrated and stronger, while with Progressive Traction it is better distributed and consequently results in lower soil compaction. Mancinelli says that even in a very humid and muddy terrain the footprint depth can be reduced by as much as 10 per cent, while traction increases by up to 10 per cent. Better self-cleaning and a wider footprint automatically generate an important increase in traction.
“This is why this tire can ensure more traction and lower fuel consumption on both field and road as well as reduced soil compaction,” Mr Mancinelli said.
Agricultural machinery inevitably has to travel on roads. With Progressive Traction the second edge acts as a reinforcement rib for the lug, thus reducing the brushing on the road surface. This means a reduction in tire wear as well as improved driving safety and stability, especially with heavy trailers.
This technology can be translated into measurable improvements for the farmers in terms of reduced working time and costs. This saving can easily reach between five and 10 per cent (a saving of £500 to £700 on a 300ha unit).
Progressive Traction is an important milestone, potentially applicable to a range of heavy-duty applications suitable for both existing and future tire designs. Commenting on the future direction of research, Mr Mancinelli said there’s a need to focus on the integration of performance between rim and tire, and features such as continuous pressure adjustment in relation to actual working conditions could contribute to lower costs and greater yields.
As the tyre becomes more and more optimised for real working conditions, R&D collaboration between tyre manufacturers, original equipment manufacturers and end users will be increasingly important.
For more information visit: www.trelleborg.com/en/wheels/.
