DESIGN AND EXPERIMENT OF TRANSVERSE AXIAL FLOW CORN FLEXIBLE THRESHING DEVICE

In order to solve the problem of high broken rate and impurity rate in the direct harvesting of corn kernels in China, a flexible threshing element with variable stiffness consisting of a conical spring and rasp bar was developed on the basis of the existing horizontal axial-flow flow corn threshing cylinder structure to achieve low loss harvesting of corn kernels. Through mechanical analysis of the key components of the threshing element, its structure and operating parameters were determined. Then, orthogonal tests were carried out using the feed amount, threshing clearance and cylinder speed as the test factors, and the broken rate and impurity rate of the corn kernels as the test indicators. The results showed that the feed amount, threshing clearance and cylinder speed had a significant effect on the broken rate and impurity rate of corn kernels; the optimum parameters for the corn variable stiffness flexible threshing device were feed amount 6.1 kg•s−1, threshing clearance 40 mm and cylinder speed 392 r•min−1. The broken rate of corn kernels was 1.67% and impurity rate 1.03%. The test results fully met the requirements of the national standards for corn harvesting operations. This study provides a technical basis for the application of the axial flow corn flexible threshing device in the corn direct harvesting combine.