Design and testing of seed maize ear peeling roller based on Hertz theory

Seed maize Zea mays (corn in the USA) have a very high value and thus it is crucial to avoid problems of high grain damage and low removal rates that can occur during the peeling of ears to remove the bracts. A mechanical model of the dynamic process of seed maize ear peeling was established using a finite element explicit dynamics simulation of the peeling process based on the Hertz theory and a mechanical analysis of the collisions and friction between the ears and the rollers during the peeling process was carried out. The main factors that affect the magnitude of the collision force and friction force were obtained. Based on the results of the modelling, peeling rollers consisting of four rubber-cast iron mixed rollers with different patterns were designed. The rationality of the mechanical model was verified and, based on the designed peeling roller; a test rig was built to carry out high-speed video tests. The whole peeling process of seed maize ear using the rollers was observed, and the test results showed that the redesigned roller had a peeling rate of 93% and a grain damage rate of 1.87%. The performance of the peeling device designed in this study was significantly better than that of the standard peeling device. This research provides a theoretical basis for various types of seed maize peeling operations.