Economia de combustível de tratores agrícolas utilizando diferentes transmissões e estratégia de condução

Abstract

Due to Diesel oil s mineral origin and marketing price, the consumption of this fuel by a tractor becomes one of the most important aspects at the time of its acquisition and use. Knowledge of the appropriate strategies in driving combined with correct selection of modern power transmissions can help farmers to reduce production costs. When driving the tractor of different ways with different types of power transmissions, more efficiently and cost-effectively, the fuel consumption changes. The following research aimed to evaluate the effects of different types of power transmission and driving strategies on fuel consumption of agricultural tractors. For this, two experiments were conducted at the Agricultural Mechanics Station, Madrid, Spain, using two tractors, one equipped with Powershift transmission and the other with Continuously Variable Transmission (CVT). Standard procedure has been applied considering six load levels (30; 40; 50; 60; 70 and 80%) by means of breaking with a dynamometer car instrumented in a concrete test track, at three travel speeds (5.16; 7.29 and 10.48 km.h-1). Furthermore, the tractor equipped with Powershift transmission was conducted in two ways: Full throttle; Gear up - throttle down. Already the tractor equipped with Continuously Variable Transmission was conducted using the automatic mode. The responses evaluated variables were speed and thermal efficiency of the engine and hourly and specific fuel consumption. Analysis of variance was performed and that presented difference the data were subjected to the Tukey s test (≤0.05) for comparison of averages. The results indicate that the Gear up - throttle down mode (Powershift transmission) can be recommended as a strategy of agricultural tractor driving, since savings may be obtained up to 29.39% of fuel in relation to the Full throttle, typically recommended by manufacturers. The specific fuel consumption of tractor equipped with Continuously Variable Transmission decreases as the load levels and travel speeds are incremented.