The purpose of research was to determine the optimal design parameters for distributing auger of combine harvester RSM-142 “ACROS-530”. Optimization in fields was carried out by method of experiment planning. From the design parameters of the distributing auger, which influence the distribution of circulation flows over the thresher’s width hasn’t been studied, the following factors were chosen: the distance from the left distribution window to the flange of casing attachment on the threshing panel, the length of the left and the right distribution windows. The values of factors of the distributing auger casing were taken constructively, proceeding from the length of the unloading window and the width of the thresher. The output factors taking into account the influence of the circulation flow on the reduced feed to the thresher and on the grain crushing, that is, the minimum increase in losses and grain crushing by combine from the circulation flow were taken as the optimization criteria. According to the experimental data regression equations of increasing the losses and grain crushing by combine from the circulation streams were obtained in the coded form. Optimal design parameters of the distribution screw casing were determined using two-dimensional cross-sections and solving a compromise problem. As a result of the research it was set up that the minimum losses increase and grain crushing by the combine from the circulation flow are ensured by the following values of factors: distance from the left distribution window to the flange of the casing attachment on the threshing panel – 0 mm; The length of the left distribution window is 440 mm; The length of the right distribution window is 470 mm. Compared with the serial combine harvester RSM-142 “ACROS-530”, the use of an optimal auger design made it possible to reduce grain losses by 6–7 %.
Keywords: combine harvester, distributing auger, design parameters, optimization, grain losses.
