The development of wear characteristics of the picking spindle hook teeth based on the discrete element method

In this study, samples of worn spindle hook teeth were collected under different field working times to investigate their loss of ability to pick seed cotton owing to wear failure of the geometric structure. The wear characteristics of the surface of the hook teeth were tested and analyzed, and the development process of the wear region and the average value of the wear depth were obtained. This research established a wear process model for the surface of hook teeth. The results show that wear originates from the tip of the hook teeth, and a parallelogram-like wear region is gradually formed along the direction of the teeth edge. The size of the wear region and wear depth gradually decreased in the following order: hook teeth 1, hook teeth 2, and hook teeth 3. The relative errors of the front three hook teeth of simulated wear depth and wear depth were Delta 1 = 2.55%, Delta 2 = 1.43%, and Delta 3 = 4.02%, respectively. Thus, the accuracy of the picking spindle hook teeth wear process model was verified. Accordingly, the failure process of hook teeth wear can be predicted, laying a foundation for the subsequent optimization design of the spindle picking hook teeth geometric structure.