H4-DV-26B coupling Flexible coupling Torsionally rigid cou Helical gearbox H4

Flender/Flender Gear Units/Helical gearbox H4

ing of perforations; and () system pa- rametersrated frequency, amplitude, and direction of oscillation of the sieve() and theircombination. Because of the improper selection of system variables for selected set ofsieves, the seeds are often caught in the openings, thereby reducing the efciency of sieves.Physical properties of the grain, chaff, and straw accordingly play an important role inthe cleaning process by sieves and fan. Feller ( observed that the clogging rates gener- ally increase more for particles that are irregular and undersized than for the oversized ones. In such situation, sieving efciency can be improved if its acceleration is madehigher than that from gravity. MacAulay and Lee ( conducted grain separation studies on oscillating combine sieves at the University of Guelph, Ontario. At low feed rates of wheat, aerodynamic separation of grain from straw occurred over the sieve and the bestseparation was achieved at 3 sieve lip angle and at an oscillation frequency between 5.5 and 6.4 /. Moreover, increase in feed rate caused mat formation on the sieve that decreased the sieving efciency and increased the grain loss. Gorial and OCallaghan ( applied the pneumatic technique to analyze the separa- tion of grain from straw and chaff in vertical air stream. They studied the inuence ofparticle characteristics, air velocity, speed, and the direction of the injection of material onthe separation process. mathematical model describing particle motion was developed tosimulate the paths of grain and straw particles moving in an air stream with view to determining the effectiveness of separation and the level of grain losses. Considering the net force on particle moving vertically in uid as the difference between the drag forceand the gravitational force, and the relative velocities of particle in the xandydirection for air velocity , the following mathematical model ( describing particle motion was developed. 1. The displacement ( Syf) for fall