Authors

Abstract

Searching for and identifying methods to reduce grain cleaning loss, grain impurity, and improve cleaning efficiency is crucial for processing threshed rapeseed outputs in uneven conditions. Leveling a single-degree-of-freedom cleaning sieve becomes particularly challenging under terrain undulations and limited cleaning space. Based on spiral theory and mechanical design principles, this study explores a multi-degree-of-freedom cleaning sieve capable of vertical movement along the horizontal plane and rotation around its center. This design allows the sieve to adjust its relative angle, enabling a more uniform distribution of threshed outputs. A CFD-DEM coupling method was used to simulate the movement of these outputs. The cleaning sieve inclined forward and to the right served as the experimental group, while a horizontal cleaning sieve functioned as the control group. Compared to the control, the experimental group showed a 14.6% reduction in grain loss and a 2.3% decrease in impurities. Furthermore, the centroid motion of the rapeseed was enhanced prior to sieving, facilitating more effective separation, while the movement speed of impurities outside the cleaning shoe increased, aiding impurity removal.

Abstract in Chinese

针对丘陵地区地形起伏，小型收获机清选空间有限的难题，多自由度的清选装置开发是相当具有挑战性的。文章基于螺旋理论和机械设计方法，探索了一种可以在水平方向上垂直移动并绕其中心旋转的多自由度清选筛。该清选筛通过调整筛面角度实现脱出物均布，实现清选性能和清选效率的提升。基于CFD-DEM 耦合方法模拟脱出物运动，将清选筛前倾和向右倾斜状态设置为实验组，清选筛水平状态设置为对照组。结果表明，对比对照组，试验组籽粒损失和含杂分别减少了 14.6% 和 2.3%。同时，在筛分前，油菜籽、杂质的质心运动速度明显增强，这有利于去除含杂和提高筛分效率。该研究方法对于收获装备转型升级具有重要的实际意义。