DESIGN AND EXPERIMENT OF A DOUBLE LONGITUDINAL AXIAL-FLOW CORN THRESHING DEVICE FOR LARGE FEEDING CAPACITY

Traditional corn threshing devices face issues of high unthreshed grain rate and high breakage rate under conditions of high feeding rates. To address this, a high-throughput double longitudinal axial flow corn threshing device was designed in this study. Based on a stress analysis of the interaction between threshing components and corn ears, an arc-shaped plate tooth structure was developed to progressively increase the squeezing force between the plate teeth and the ears. A combined threshing element, integrating arc-shaped plate teeth and round-headed nail teeth, was designed to improve threshing cleanliness and minimize grain breakage under high feed capacity conditions. The crucial parameters of the threshing cylinder were determined by theoretical analysis. Threshing bench experiments were conducted to investigate the effects of feed rate, threshing cylinder speed, and guide plate angle on the device's grain breakage rate and unthreshed grain rate. Based on the findings, the optimal parameter ranges were identified. An orthogonal test involving three factors at three levels each was conducted to determine the optimal working parameters of the device. The results indicated that the ideal conditions were a feed rate of 16 kg/s, a threshing cylinder speed of 400 r/min, and a guide plate angle of 26°. Under these parameters, the grain breakage rate was 5.02%, and the unthreshed grain rate was 0.171%. The operational performance met the actual harvesting requirements. This research could offer a reference for the design of large-feed-rate threshing devices and related harvesters.