Mechanics of the process of seeds falling or being sucked in the sowing apparatus.

摘要

A theoretical analysis is made of the kinematic conditions and dynamic conditions of the movement of seeds into the discs or drums for delivery. The analysis covers mechanical seed drills and pneumatic seed drills. In mechanical disc drills and drumdrills the seeds fall into the 'cells' as a result of gravitational forces; in pneumatic drum drill the seeds fall as a result of gravitational forces and the air flow; and in pneumatic disc drills the seeds are only sucked in the force field of the airflow. The critical speed of relative movement of the seeds is much greater in pneumatic drills than mechanical drills, which means that sowing accuracy is less dependent on disc or drum speed. Different conditions exist when removing seeds from the seedmass in mechanical and pneumatic drills.