Fig. 3
Contact mechanics analysis of rice collision process. (a) The impact of the drum on the seeds when it rotates. (b) Collision between the top of the threshing element and the seeds. (c) The collision between the threshing element and the kernel from the tangential perspective.Where O1 and O2 are the centers of the threshing drum and the threshing element bearing rod, respectively; ω is the drum speed, rmp; V is the linear speed of the top of the threshing element teeth, m/s; Vn is the normal linear speed of threshing element, m/s;Vt is the tangential linear speed of threshing element, m/s; θ is the angle between the linear velocity of the top of the threshing element teeth and the horizontal direction, °; α is the angle between the normal linear velocity of the threshing element and the horizontal direction, °; β is the angle between the linear velocity of the top of the threshing element teeth and the normal linear velocity of the threshing element, °; R1 is the radius of the threshing disc, m; R2 is the drum body curve radius, m; R3 is the radius of the threshing element bearing bar, m; r is the top radius, m; H is the height of the threshing element, m; h is the distance from the top of the threshing element to the largest drum of the threshing element, m; δ is the embedding distance between the threshing element and the rice grain, m; m1 and m2 are the mass of threshing element and rice grain, respectively, kg.
