*Article* **V-Shaped Toothed Roller Cotton Stalk Puller: Numerical Modeling and Field-Test Validation**

**Zhenwei Wang 1, Weisong Zhao 1, Jingjing Fu 1, Hu Xie 1, Yinping Zhang 2,\* and Mingjiang Chen 1,\***


**Abstract:** The V-shaped toothed roller cotton stalk puller has a low removal ratio and weak pulling effect. Hence, we constructed a simplified mathematical model of the V-shaped tooth roller stalk puller based on elastic collision theory and simple beam theory and conducted a mechanical analysis based on this model to explore the causes of pulling errors and fractures. Specifically, the V-shaped tooth plates of the machine were optimized in an orthogonal experiment with the rotational speed, cogging angle, and ground clearance as the influencing factors, and the removal ratio as the evaluation index. This experiment was designed to enable analysis of the physical characteristics of cotton stalks, and the forces applied during the pulling process. Additionally, a V-shaped toothed roller-type stalk-pulling test bench was constructed. The results revealed that, unlike the cogging angle, the ground clearance significantly affected the removal ratio. Furthermore, the highest removal ratio (i.e., 97%) was achieved when the ground clearance was −20 mm, the rotational speed was 300 rpm, and the cogging angle was 32.5◦. An L9 (34) orthogonal field experiment was also conducted with the rotational speed, cogging angle, and ground clearance as the influencing factors to investigate their respective influences on the stalk removal ratio. The results revealed that the ground clearance most significantly influenced the ratio, followed by the rotational speed, and cogging angle. The ground clearance and rotational speed of the V-shaped toothed roller were each found to significantly influence the ratio. Furthermore, a ground clearance of −20 mm, rotational speed of 300 r/min, and cogging angle of 25◦ yielded an average removal ratio of 98.27%. Through this research, the mechanism of toothed roller stalk pulling is further deepened and the toothed series stalk pulling technology provides theoretical support.

**Keywords:** V-shaped tooth roller; removal ratio; orthogonal experiment; structure design

**Citation:** Wang, Z.; Zhao, W.; Fu, J.; Xie, H.; Zhang, Y.; Chen, M. V-Shaped Toothed Roller Cotton Stalk Puller: Numerical Modeling and Field-Test Validation. *Agriculture* **2023**, *13*, 1157. https://doi.org/10.3390/ agriculture13061157

Academic Editor: Massimo Cecchini

Received: 4 May 2023 Revised: 24 May 2023 Accepted: 25 May 2023 Published: 30 May 2023

**Copyright:** © 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/).
