Gavrilchenko O. Substantiation of Parameters and Designs of Cultivator Shares with Curvilinear Blades

The thesis provides substantiation of design parameters and surfaces of curvilinear blades in cultivator shares. The work presents the results of theoretical investigations and field tests for different designs of curvilinear blades in cultivator shares capable of self-cleaning from sticking soil and weeds. The author describes the action of a side-contiguity effect, which causes the formation of a zone with congested soil at the end of a share wing and the hanging of weeds. To avoid this phenomenon, the author suggests a blade design having a curvilinear shape, in the form of logarithmic spiral in particular, which enhances soil motion along the blade proportionally to the speed of a share. The author has developed a design algorithm and surface parameters for cultivator shares of different standard sizes. Agrotechnical tests of curvilinear blades as compared to straight-line blades prove the advantage of the first. The principal results of this thesis have already been implemented in designing cultivator shares 250 mm, 270 mm and 330 mm wide. Key words: soil tillage machinery, cultivators, cultivator shares, soil sticking, weed hanging, friction ratio, agrotechnical indexes.