DEVELOPMENT OF A SINGLE WHEEL TEST RIG FOR MEASURING TRACTION

Abstract

Traction is an important study in the behavior of tractive devices for off road vehicles. Studies in traction are usually conducted with test rig facility under controlled conditions. Such facilities are presently non-existent in Nigeria. A single wheel test rig was developed to enable fundamental research on traction studies with single tires on tropical soils. This available facility consists of a moving carriage with a trolley that moves in either forward or reverse directions on rails well above a soil bin. It was powered by 2.2 kW, three phase induction motor. The present facility set up was able to operate in either towing test mode for tire motion resistance studies or driving test mode for tire net traction and tractive efficiency studies. The narrow wheels that can be used on the developed test rig are pneumatic bicycle wheels of different sizes, rigid bicycle wheel, motorcycle wheel and lugged-rigid wheel for a planting machine. The test tire on the moving carriage was powered to rotate by a motor with additional pull provided by a cablepulley mechanism connected to a tower with hanging dead weights. All controls on the moving carriage were activated from the main control console. The developed facility was successfully tested to determine tractive efficiency for narrow wheels at a particular inflation pressure on clay soil. The effect of varying inflation pressures, wheel loads and soil conditions on the tractive efficiency of the test wheels can be investigated easily using the developed test rig. The single wheel test rig facility worked well and the research indicates that wheel load, wheel slippage, soil moisture content and inflation pressure has great effect on traction efficiency. Traction efficiency decreases as wheel load and wheel slippage increases. The developed single wheel testing facility is able to perform traction tests in controlled soil conditions to study the effect of soil, tire and system parameters on the performance of the tires.