OPTIMISATION AND TESTING OF STRUCTURAL PARAMETERS OF INTERNAL TANGENT CIRCLE EXTERNAL GROOVED WHEELE FERTILISER DISCHARGER

Aiming at the problem of traditional external grooved wheel type fertilizer discharger, which discharges fertilizer unevenly, an internal tangent circle external grooved wheel type granular fertilizer discharger is designed. Firstly, the 19-19-19 NPK compound fertilizer produced by Stanley Company in China is selected, and the pulsatility of the straight groove wheel, external tangent circle groove wheel, and internal tangent circle groove wheel is compared and analyzed using the Hertz-Mindlin (no-slip) model in the EDM2020 simulation, then the structural parameters are optimized for the better type of groove wheel. Finally, the Field Oriented Control (FOC) algorithm is used to control the brushless motor to further optimize the coefficient of uniform volatility. The four factors and three levels response surface simulation test was conducted with the groove tooth inclination angle, number of grooves, diameter of the inner tangent circle and angular velocity of groove wheel as test factors. Simulation results showed that when the groove tooth inclination angle was 38.341°, the number of grooves was 9.999, the diameter of the inner tangent circle was 13.154 mm, and the angular velocity of groove wheel was 5.998 rad/s, the coefficient of uniformity of fluctuation of the discharged fertilizer was 4.11%. Based on practical considerations, the groove tooth inclination angle was set to 38°, the number of grooves to 10, the diameter of the inner tangent circle to 13 mm, and the groove wheel angular velocity to 6 rad/s for a bench validation test. The bench test results showed that the optimized internal tangent circle groove wheel fertilizer applicator achieved a uniform fluctuation coefficient of 6.32%, while incorporating FOC algorithm motor control further reduced the coefficient to 4.62%, meeting the design requirements for the fertilizer applicator.