Tratores de tração em quatro rodas: Estudo preliminar comparativo de tração em duas e quatro rodas.

Abstract

The problem transmitting the high engine power to the tractor drawbar has been of increasingly importance, mainly be cause two factors: a) the present crisis of supplying fuel deri vative from petroleum, and b) the trend to increase the engine advance of the modem enterprise agriculture. The four-wheel - drive tractor has been the mo st employed overall the world. In Brasil, until presently, no work was carried out with the objec tive of evaluating the comparative performance of two and four wheel drive tractors, under out typical soil conditions. In this study, one tried to carry out that evaluation in Red-Iellow prodzolic soil, Laras variation, significantly overs pread in the cultivated areas of the State of São Paulo. In fZ eld trials, a four-wheel drive tractor of 136 hp. at PTO was em ployed. Two test trials were carried out: the first with the tra ction in both axles and the second, with the traction in the re ar axle. The results obtained show a significant advantage for the four-wheel drive tractor.