JUSTIFICATION OF THE DESIGN PARAMETERS OF THE SEED QUIET OF THE SOWING SECTION OF THE PNEUMATIC SEEDER

The problem of seed ejection from the furrow during sowing with the John Deere 90 Series planter can be solved by installing a seed firmer. However, factory seed firmers wear out quickly after treating 500–600 hectares. This indicates the need to improve the design and selection of materials for the firmers to ensure their durability. Further research and testing will help find optimal solutions to reduce wear and increase the efficiency of seed firmers. The goal is to conduct numerical modeling and laboratory studies of the oscillations of the seed firmer of the John Deere 90 Series pneumatic planter and to justify its design parameters and material selection. Using the Simcenter STAR-CCM+ software package, a simulation of the seed firmer's oscillation process, which is located between the press wheel and the soil, was carried out. As a result of the simulation, the distribution of the seed firmer's absolute deformation Δyf and stress σf in each cell of the created mesh was determined. The dependencies of the maximum stress value σfmax and the safety factor kf on the firmer's thickness Tf, the heel height Hf, and the distance of its placement relative to the free end of the firmer Lf for different materials (Nylon, ABS, TPU) were obtained. By solving a multi-criteria optimization problem, which reduces to the simultaneous search for optimal values of two criteria, the geometric parameters of the seed firmer were obtained: Tf = 6.5 mm, Hf = 12.4 mm, Lf = 14.6 mm. Based on laboratory studies, it was established that TPU should be chosen as the material for the seed firmer, as the least force (827 N) is required for its bending. This is confirmed by a lower safety factor kf.