APPLIED ENGINEERING IN AGRICULTURE, cilt.24, sa.4, ss.409-413, 2008 (SCI-Expanded)
The blades of a rotary tiller trace a trochoidal path in the soil during tillage. This path is affected by both rotational and forward speeds. The successive trochoidal paths of two blades cut the soil into slices. The size and shape of soil slices depends on the number of blades on one side of a flange, rotor radius., tractor forward speed, rotor rotational speed and blade geometry. Therefore, a better understanding of the factors affecting soil slice size will help its to appropriately operate rotary tillers. In the present study, rotary tiller blade paths were used to simulate distribution of the soil slice size. A program was written in the Lisp language for AutoCAD to draw blade paths based on the number of blades on one side of a flange, the rotor radius, tractor forward speed, and rotor rotational speed. Slice area on the drawn paths was calculated using the AREA command of AutoCAD. Data show that soil slice size increased as rotor radius and tractor forward speed increased and the number of blades on one side of a flange decreased. As the rotor rotational speed increased to 190 min(-1), the volume of soil slice increased to a maximum. Then, as the speed increased further; the volume decreased. The number of cuts of a soil slice increased as the number of blades on one side of a flange, the rotor radius, and the rotor rotational speed increased. As the number of cuts of a slice increased, the size of each part decreased and soil fragmentation increased.