Experimental investigations in draft resistance of spherical working tool of disk harrow

Spherical working tools find wide application in soil tillage, particularly in various designs of harrows. Despite the many advantages and many years' practical use, there is a need for a detailed assessment of the power characteristics of spherical disks when interacting with different types of soil in order to improve labour efficiency and reduce the specific energy costs. Experimental investigations were carried out under the field conditions using an experimental installation and specimens of tillage tools. In order to study the draft resistance of the working tool, the tensometry method was used. The obtained data were processed by the methods of mathematical statistics, as well as the dispersion and regression analysis using a PC and the corresponding software. According to the results of the research a special methodology was proposed for the determination of the power characteristics of a spherical disk working tool depending on the conditions of its operation, provided that the technological process is ensured. Using the results of the experimental studies, regression equations were obtained and the dependences of energy consumption upon the operating conditions of the spherical disk working tool were constructed. The tractive force of the spherical disk varies within the range from 88.2 N (at the depth of 6 cm) to 1985.0 N (at the depth of h = 18 cm).