Specification of the absolute speed of the soil displaced by the spherical disc of the ridge seeder roller
Heuristic and technical analysis of various designs of tillage rollers of row-crop seeders has led to the conclusion that they are mainly intended for destruction of lumps and soil compaction before and after sowing on a flat field surface. When studying the available methods for assessing the impact on improvement criteria of the design parameters and surface features of individual working elements of the ridge-forming rollers, it was revealed that, currently there are unresolved issues, in particular, the method for specification of the absolute speed of the soil displaced by the spherical discs of the ridge seeder roller. Thus, it is necessary to substantiate theoretically this parameter of the tillage roller, which directly affects the distance between the spherical discs of the roller of the ridge seeder. For the finishing operation of formation of the soil ridge of the required parameters and density simultaneously with sowing, a roller was developed, the novelty of which is confirmed by the patents of the Russian Federation № 194330, № 194348, № 196712. The design of the roller includes regulation of the angles of attack of the spherical discs and the degree of compression of the spring, because these parameters have a significant effect on the geometric dimensions of the formed ridge and the density of the soil inside it. The proposed roller is mounted on the rear beam holder of the sowing section of the ridge seeder. Moving on the surface of the field, the ridge seeder colters sow seeds on a wet compacted bed, the ridge formers form a loose soil hill above the sown seeds and the rollers compact the soil hill. The speeds and forces acting on the spherical disc of the roller have been determined. It was theoretically revealed that the absolute speed of soil particles thrown by the edge of the spherical disc towards the symmetry longitudinal axis of the soil ridge is maximum and depends on the angular velocity of the spherical disc, its radius and angle of attack, as well as the frictional properties of the soil. As moving to the center of the spherical disc, the absolute speed of soil particles thrown from a specific point of the studied roller working body decreases.