How does a conventional combine work?

The rotary combine uses centrifugal force to drive the grain through the straw. … In a conventional combine, the cylinder had one chance to thresh the material. In a rotary combine the material passes over the concave two or three times before it leaves the threshing area.

Originally designed to harvest wheat, they came to be used to harvest many other crops. Combine funneling harvested wheat into a truck. In design, the combine is essentially a binder-type cutting device that delivers the grain to a threshing machine modified to work as it moves across the field.

Flail, ancient hand tool for threshing grain. It consists of two pieces of wood: the handstaff, or helve, and the beater, joined by a thong. The handstaff is a light rod several feet long, the beater a shorter piece.

Gleaner combines use a two-stage cleaning process. As crop threshes and separates on the rotor, a set of distribution augers and accelerator rolls thins the crop mat and propels it at 4 times the speed of free fall through an air blast above the cleaning shoe.

A threshing machine is used to separate the grain from the straw and other light materials. It is, essentially, a three-step process: … Whatever passed through fell onto a series of progressively smaller shaking screens, removing most of the remaining straw and chaff from the kernels.