Development and experiments on reel with improved tine trajectory for harvesting oilseed rape

Crops with branching characteristics, such as rapeseed, are difficult to harvest owing to their specific plant geometry. To solve this problem, an harvesting reel with improved tine trajectory, considering the reel working process and a function suitable for oilseed rape, is proposed in this study. The improved tine, of which angle can be continuously adjusted to adapt to the plant structure and meet the operating requirements of the reel in the stages of pushing the reel into the crops, feeding plants into the auger, and releasing the reel. The kinematics of the tine trajectory between the new and standard reels were calculated and a simulation comparative analysis was performed, which proved that the new reel satisfies the theoretical requirements. Single-factor field experiments were conducted for the two types of reels. The test results demonstrated that the proposed reel has a lower header loss rate and is significantly affected by the reel speed than the reel height or machine forward speed. According to the multivariate orthogonal results, the combination of optimal pa-rameters with minimum loss rate yielded a reel rotational speed of 1.88 rad s(-1), machine speed of 0.6 m s(-1), and reel vertical height of 1100 mm. The actual loss rate was found to authentically decrease to 1.04% in the supplementary field test under this condition, which verified that the parameters are reasonable. This study combines experiments and trajectory analysis to explain the advantages of the improved reel and provide a new study direction of reducing rapeseed harvesting losses. (C) 2021 IAgrE. Published by Elsevier Ltd. All rights reserved.