To improve the sowing performance of the spoon wheel maize seeding machinery, in this paper, two varieties of maize seed are selected as examples. The maize spoon precision seed metering device, a core component of the spoon wheel seeding machinery, is used as the research object. The maize seed assembly model is first established based on the maize seed assembly modeling method. Its validity is verified by the sowing experiment and corresponding DEM simulation under the different revolving speeds of the seed metering wheel. Secondly, the performance of the spoon precision seed metering device is optimized by integrating the maize seed assembly model and multivariate nonlinear regression method. Therefore, the number of sub-spheres of the horse tooth, spherical cone, and spheroid maize seed model are 10–14, 18, and 6, respectively. The results show that the performance of the seed metering device improved when the revolving speed of the seed metering wheel, handing angle, and seed spoon radius are 25 r/min, 40°, and 7 mm, respectively. There is good agreement between the expected results and experimental ones with relative errors of less than 5%, and the optimized seed metering device facilitates the process of seed guiding and seed delivery during the sowing process.

The large toothed double-roll crusher, as key crushing equipment for open pit mines, is very necessary to analyse its crushing performance at different feed particle sizes, compressive strengths of coal, and rotation speeds of toothed rollers. Firstly, a toothed double-roll crusher is taken as the research object in this paper; the coupling simulation model of the toothed double-roll crusher based on the DEM-MBD and Ab-T₁₀ breakage model is constructed. The validity of the coupling simulation model is verified through the actual measurement data. On this basis, the crushing performance under variable factors is analysed by integrating comprehensive tests. The results show that the rotation speed of the toothed roller is the main influence factor on the crushing performance of the toothed double-roll crusher when it works at 25~33.3 r/min. With the increase in compressive strength of coal, the productivity decreases, and this phenomenon disappears gradually at 33.3~42 r/min. Further, a 5–20% increase in the large size of the coal particles can improve 10% crushing quality with a discharge size lower than 300 mm and approximately 25% productivity of the toothed double-roll crusher. Finally, the power density is reduced as the mass percentage of large-sized coal particles increases, and this phenomenon is weakened with the increase in the compressive strength of coal.