Abstract:In order to solve the problems of serious grain breakage and high unstripping rate in the direct harvest of corn in doublecropping area, a longitudinal axial flexible hammerclaw corn threshing device was designed. The threshing device adopted the longitudinal axial flow threshing drum, and the threshing hammerclaw was installed on the threshing drum. Different types of threshing hammerclaw can be replaced in the front and back sections of threshing, and the threshing hammerclaw can be flexibly connected with the threshing drum to reduce the grain crushing rate and realize the flexible and lowdamage threshing of corn. The threshing concave plate adopted a segmented combination type, which was convenient for the adjustment of the threshing section and the separation section. The concave plate cylindrical steel was designed with a semispherical protrusion to increase the rubbing force and improve the removed rate. The feeding amount and drum rotational speed, threshing hammerclaw type were taken as test factors, the orthogonal experiment under different moisture contents was confirmed, roller speed and the best parameter combination of threshing hammerclaw results showed that under the condition of moisture content of 25.12%, the best parameter combination for the drum rotating speed was 500r/min, feeding amount was 8kg/s, the takeoff section was a flat head threshing hammer, and the flat and strong release sections were round head threshing hammerclaw, the grain crushing rate was 3.73%, unstripping rate was 0.69%. Under the condition of water content of 32.83%, the optimal parameter combination was the drum speed of 450r/min, the feeding amount of 8kg/s, the takeoff section, the flat and strong release sections were all round head threshing hammerclaws, and the grain crushing rate and unstripping rate were 4.36% and 0.70%, respectively.