The Effect of Axle Load and Tyre Inflation Pressure on the Tractive Performance of a Two Wheel Drive Tractor on Soft Clay Paddy Field

Abstract

Tests were performed with a two wheel drive light weight tractor (19 kW engine gross power, 990 kg total weight) to evaluate the effect of axle loading and tyre inflation pressure on drawbar power and coefficient of net traction under wetland clay conditions. Bangkok clay soil, having about 60% clay content, was used as the test soil. It was observed that drawbar power, and thus net traction, increased as axle load was increased. The effect of tyre inflation pressure on drawbar power was not significant except at the highest ballasting of 2.2 kN on the drive axle. However, power at 130 kPa tyre pressure was found to be higher than at 100 kPa and 70 kPa. Higher drawbar power and net traction was observed when the tractor was operated in soil with a moisture range of plastic limit to sticky limit. Drawbar power and net traction ratio reduced as the moisture content was increased with field flooding. The paper reviews relevant literature, presents the experimental results and discusses the main findings relative to other published results.