Field performance of Trelleborg PneuTrac tyres

Tractors have become heavier and more powerful, so bigger tyres are necessary to the exert adequate traction forces and to limit the soil compaction. Nevertheless, in the last 50 years, wheel load has increased more than twice the tyre-soil contact area, consequently, soil compaction caused by tractors has been increased as well. A tractor equipped with Trelleborg PneuTrac tyres could be an exception to this trend, because these tyres can attain large tyre flexibility, so that they allow a larger tyre footprint and lower inflating pressure than any standard tyre. The aim of this paper was the drawbar performance comparison between a set of PneuTrac tyres and a set of equivalent radial tyres with the same external drawing. Both of these tyres were mounted in two 115 kW tractors with the same mass configuration. On each tractor, a load cell was installed in order to measure the drawbar pull and a CAN-Bus data logger was fitted to measure the vehicle operating parameters. Drawbar tests were carried out with the two tractors in the same soil at different water contents. From the acquired data, the drawbar pull and the efficiency were calculated. The obtained results demonstrate that Trelleborg PneuTrac permits to increase the drawbar pull up to 5.7% and to reduce the slip. Moreover, its performance was slightly less affected by the soil conditions.