Design and testing of key components for air-blown wheat precision seed-metering device

To address high miss-seeding rate and re-seeding rate during high-speed wheat seeding, a novel staggered-cell scoop-hole seed-metering device suitable for wheat was developed．Structural design and working principle has been systematically elaborated．Research has determined that seed-metering wheel diameter was 80 mm, with seed hole design parameters of length 7.82 to 8.32 mm, width 4.16 to 4.46 mm, and depth 2.87 to 2.97 mm, providing a theoretical basis for structural optimization．Correlation among seed-metering wheel rotational speed, seed hole depth, and seeding performance was elucidated using EDEM discrete element method simulation．Results have indicated that seed-metering wheel rotational speed was primary factor influencing seed filling quality, while seed hole depth regulated seeding uniformity by affecting seed retention and release processes．Optimal overall performance was achieved at a seed-metering wheel speed of 25 r/min and seed hole depth of 3.0 mm．Field experiments have confirmed that seed-metering wheel rotational speed, seed filling height, and seed hole depth all exert varying degrees of influence on metrics such as miss-seeding rate and re-seeding rate．Among factors, seed-metering wheel rotational speed has the most significant impact on improving qualification rate．In conclusion, staggered-cell scoop-hole seed-metering device has been demonstrated clear advantages in optimizing structural parameters and enhancing operational performance, effectively increasing seed filling rate while simultaneously reducing both seed-missing and re-seeding rates．