A Theoretical Approach for Determining Irregularities of the Bottom of the Tillage Layer Caused by Horizontal Axis Rotary Tillers

Abstract

Horizontal axis rotary tillers produce irregularities in the tillage depth when they are inappropriately operated and constructed. In such cases, mixing and breaking of soil throughout the tillage layer is not uniform and some untilled ridges will remain at the bottom determining the effect of design and operational characteristics on the height of the resultant ridges at the bottom of the tillage layer. In this study, a method based on the derived geometrical relationships between the rotary tiller operational parameters was developed to determine heights of ridges occurring at the bottom of the tillage layer. The ridge heights can be calculated for various combinations of blade peripheral speed, forward travel speed, rotor radius, and the number of blades on one side of a rotary tiller flange. This method allows for the investigation of effects of rotary tiller operational and constructional properties of horizontal axis rotary tillers on the ridge heights at the bottom of the tillage layers. The results obtained using this method show that the heights of ridges at the bottom of the tillage layer increase with increases in forward travel speed and decrease with increases in blade peripheral speed, rotor radius, and the number of blades on one side of a flange.