Design and Experiment of Spinning Disc Precision Centralized Metering Device for Rapeseed Based on Bezier Curve

Considering the facts that the uniformity of seeding distribution in the existing mechanical centrifugal centralized metering device for rapeseed which led to the lower apiece row consistency, a spinning disc precision centralized metering device for rapeseed based on Bezier curve was developed. The working principle of the distributor device was elaborated. The parameter equation of the guide vane curve of the spinning disc was constructed by using Bezier curve, s tangential vector property and the characteristic of no curvature mutation. The dynamic and kinematic models of seed particles were established, and the key structural parameters and ranges affecting the seed performance were determined. The EDEM discrete element simulation software was used to carry out the quadratic orthogonal combination test in order to establish a mathematical model between the performance of the apiece row consistency variation coefficient and guide vane' s inlet angle, the outlet angle, the wrap angle and the quantity. The results showed that the sequence of factors affecting the apiece row consistency variation coefficient were vane ' s inlet angle, the outlet angle, the quantity and the wrap angle. The optimal parameter combination was established when the guide vane ' s inlet angle was 36°, the outlet angle was 26°, the wrap angle was 55° and the number was 8. Based on the optimal parameter combination, the bench verification test results of the metering performance at different rotational speeds showed that the metering device could adapt to different rotational speeds according to the sowing demand, and when the rotational speed was 60 〜100 r/min, the apiece row consistency variation coefficient was less than 3. 9%, the single row stability variation coefficient was less than 4. 6%, and the damage rate was less than 0. 5%-The field experiment showed that when the planting speed of the seeder was 4. 15 km/h, the apiece row plant distribution consistency variation coefficient of rapeseed was less than 14%. It could meet the seeding performance requirements of rapeseed. © 2022 Chinese Society of Agricultural Machinery. All rights reserved.