Kinematic and Energy Optimization of Blade Arrangement and Rotor Phasing in Vertical-Axis Rotary Tillers

Abstract

Abstract

This study presents a compact analytical methodology for selecting the number of blades, rotor spacing, phase shift, and kinematic indicator of a multi-rotor vertical-axis rotary tillage tool. The trajectory of the blade tip is represented by a trochoid, the feed per blade is directly related to the kinematic indicator, and the total power spent on soil cultivation is divided into components related to soil cutting and discarding. The overlap of rotor working zones is further linked to the number of knives by the condition that only one knife is located simultaneously in the overlap zone of adjacent rotors rotating in opposite directions. For the calculated variant of a four-rotor structure with a width of 1.8 m at R = 0.25 m, p = 0.46 m, and a 40 mm overlap, the model allows for the installation of three knives on each rotor with a permissible phase deviation of ±13.9°. With equal feed to one blade, the three-blade variant ensures a reduction in specific energy consumption from 99.7 to 77.6 kJ/m3 compared to the two-blade scheme. In the calculated mode, at n = 350 rpm and vm = 1.39 m/s, the required power at the VOM is 26.5 kW. The results obtained show that the number of knives and the phase shift should be selected together with the kinematic indicator, rather than being considered as independent structural-kinematic parameters.