STAR-TOOTH SPHERICAL DISC CLOSING WHEELS FOR A ROW CROP PLANTER: EXPERIMENT AND DISCRETE ELEMENT METHOD MODELING.

Traditional row crop planter closing wheel systems are sometimes unreliable, causing inadequate seed-soil contact, thereby reducing seed germination and emergence. To solve this problem, a star-tooth spherical disc closing wheel system is proposed. To further explore the operational mechanism of the closing wheels, a discrete element interaction model between the furrow soil and the closing wheels was established, and the operation process of the closing wheels was analyzed. A single factor test was designed with forward speed, disc tilt angle, disc lateral distance, and disc penetration depth as the test factors. Based on simulation tests and soil bin tests, the effects of the velocity and displacement of soil aggregates, closing wheel draft, and operational quality under different test conditions were explored. The test results showed that properly increasing the forward speed, disc tilt angle, and disc penetration depth, and selecting the appropriate lateral distance between the rotation centers of the two discs can increase the trend of soil aggregates moving towards the furrow, increase the weight of the covering soil, improve the uniformity of soil covering, facilitate the closure of the seed furrow, and improve the quality of operation. The Discrete Element Method (DEM) can accurately simulate operational quality in the soil covering process. The operational quality of the closing wheels can be explained by the movement of the soil aggregates. These results provide theoretical support for the performance of closing wheel systems. [ABSTRACT FROM AUTHOR]