Combine harvester threshing cylinder constructive parameters

Abstract

For the purpose of finding the optimal shape of filler plates, laboratory trials were performed that involved threshing of corn ears. Total 8 sets of threshing cylinder filler plates (each containing 8 plates) were produced for the purpose of investigation. Research was done with fixed tangential threshing cylinder which was 0.6 m in diameter and 1.2 m in width, and had eight rasp bars. It was surrounded in concave by angle of 146º. Threshing process was recorded using high-speed video recording camera Photron 1024 PCI (at the speed of 2000 frames per second). Threshing of individual corn ears showed that corn ears tend to move faster during the process of threshing when linear speed of rasp bars is increased. Moreover, corn ear travel speed was found to be higher in first part of the concave when compared to its part two. Increasing linear speed of rasp bars was found to result in increased number of impacts suffered by each corn ear. Threshing studies showed that grain separation through the concave is affected by design of threshing cylinder filler plates. Grain separation through the concave is most intensive when cylinder filler plates are made with working plane angle of 36° to radius of the cylinder. Laboratory tests of individual corn ear threshing suggest that further research of rational filler plates design should be carried out with filler plates with passive plane angle to the cylinder radius should change from 51° to 67°, while working plane angle should be kept 36°