PARAMETERS AND OPERATION MODES OF ROTARY TILLAGE WITH SERRATED KNIVES

The authors have studied some ways of improving the technology of pre-planting tillage of lumpy soils using milling cutters with serrated profi les of the knife surface. This technology is certain to improve the cultivation quality and increase the agrotechnical indicators of soil cultivation. The study focused on the infl uence of the soil cultivation depth, the number of knives, the speed of the tiller rotor and the unit travel speed on the operation quality of a rotary tiller. The unit travel speed is characterized by the specifi c energy consumption of rotary tillage, the average size of lumps left on the fi eld after rotary tillage and the degree of soil crushing. The study applied the theory of experimental design. Taking into account the shape and size of a tuber bunch as applied to the actual conditions of potato cultivation, the authors have proposed methodological principles for optimizing the parameters of formed ridges. When two cutters with a serrated blade are installed on the tiller rotor, an increase in the travel speed from 2.1 to 3.2 m/s results in a 2.5% increase in specifi c traction resistance, while that in the range between 3.2 and 4.3 m/s ensures a 3.0% increase. At an angular speed of the tiller rotor of 30 rad/s, when the depth of soil layer tillage increases from 100 to 120 mm, specifi c traction resistance increases by 2.0%, in case of an increase from 120 to 140 mm – by 2.5%. The study has proved the feasibility of using knives with serrated curved blades, as it ensures a reduction in the energy intensity of soil tillage and an increase in potato productivity by 20% as compared to the soil cultivation with the ФН-1.2 serial rotary tiller.