Abstract:Aiming at the problems of unstable operation of the forward speed compensation mechanism of existing direct insertion planter in the northwest dry zone and large size of the running space, a non-circular gear-driven forward speed compensation mechanism was proposed, based on which a type of maize hole seeder with vertical insertion was developed. The structural composition, working principle and technical parameters of the whole machine were described; the forward speed compensation mechanism and the hole seeder were analyzed in depth theoretically. When the hole spacing was 330 mm, the forward speed was 0.5 m/s and the sowing depth was 45 mm, the transmission ratio and the center distance of the forward speed compensation mechanism were optimized, based on which the non-circular gear-driven forward speed compensation mechanism was generated. Combined with the size of maize seeds to determine the size range of the shaped eye structure on the seed picker wheel, and the optimized result showed that when the width of the shaped eye was 11.79 mm, the height of the shaped eye was 7.23 mm, and the opening angle of the shaped eye was 15°, the effect of seed discharge was better. From the field validation experiment, it can be seen that the hole seeder empty hole rate, hole number qualified rate, sowing depth qualified rate average value were 2.0%, 90.1% and 92.3%, respectively; the membrane holes the device broke were smaller, the membrane holes misalignment rate was 4.3%;the device disturbed average amount of soil disturbance in the horizontal direction and the vertical direction was 15 g and 25 g, respectively. The results can meet the actual requirements of maize direct sowing in dry region of Northwest China.