Disc seeders.
Holes are cut in the bottom of the fertilizer box of such a seeder, under which the plates are placed. Part of their surface, the discs protrude outside the box. During work, the discs filled with fertilizer rotate around their axis. They receive their drive via a gear transmission from road wheels or from the tractor power take-off shaft. The degree of filling of the discs is regulated by shifting (with a latch) the size of the seed slot. Wings rotate over the part of each plate that protrudes beyond the bottom of the box, the so-called. projector blades, removing the fertilizer from the plate. The amount of fertilizer sown per unit area is regulated by changing the width of the working gap or by changing the rotational speed of the discs. For this purpose, a toothed gear that acts as an intermediary in transmitting the drive to the discs is used.
Regulation of the sowing amount by means of the shutter is a stepless regulation, only to a small extent. A step change of the sowing amount within wider limits can be obtained by replacing two gear wheels in the transmission. With the first gear arrangement, as shown in the picture 3.2, we get less seed, while in the second system - larger.
Replacing the gears does not present any major difficulties, because: tenons, on which the wheels are mounted, are equipped with elastic clasps.. After removing these fasteners, the gears can be easily removed from the pins.