Vortex Airflow Coupled with Flexible Collision: An Optimized Low-Damage Threshing Approach for High-Moisture Maize

To solve the problems of high kernel breakage and low threshing efficiency in the threshing operation of high-moisture maize, this study designs an adaptive threshing device based on the coupled working principle of vortex airflow driving and flexible collision. The adaptive threshing mode enables maize ears to move spirally upward under vortex airflow and make compliant contact with flexible components. By adopting repeated mild collisions instead of the rigid violent impact used in traditional devices, low-damage maize threshing is achieved. Preliminary experiments verify that the layout density of flexible threshing units, tangential airflow velocity, and feeding speed are the key factors affecting threshing performance. A regression orthogonal rotational combination test is conducted to systematically explore the single-factor and interactive effects on threshing efficiency, and the optimal parameter configuration is obtained. The test results show that, under the conditions of circumferential angular spacing of 21.5°, tangential velocity of 45.9 m/s and feed rate of 0.65 kg/s, the maize threshing rate reaches 96.1% while the grain breakage rate is controlled below 0.1%, which is significantly superior to conventional rigid threshing methods. This research provides a new technical scheme and experimental data reference for the low-damage threshing study of high-moisture maize.