Simulation Research of Broken Gear Counterroll Granulating Machine Based on DEM-FEM Coupling Method

Press roll is a key part of counterroll granulating machine, and shape of its teeth has a direct influence on its performance．Aiming at problems of insufficient material extrusion and poor forming effect of connected gear type of counterroll granulating machine, an improved scheme of broken gear type of press roll structure was proposed．Simulation test of pelletizing process under two kinds of press rollers was carried out by using discrete element software．Results showed that thextrusion effect of broken gear press roller was better than that of continuous gear press roller．The optimal speed range was from 20 rad/s to 25 rad/s through simulation analysis of speed of broken gear counterroll granulating machine．Discrete element was coupled with finite element to analyze stress and deformation of press roller with broken gear under extrusion speed of 25 rad/s, and then nCode software was used to predict stress fatigue of press roller．Results showed that the maximum stress of press roll was 72.279 MPa and the maximum deformation was 0.835 mm, both of which met design requirements of strength and stiffness．The life of die hole was the smallest when gap between two press rolls was the smallest, and fatigue damage was more likely to occur．