Combine harvesters - full technical data
A combine harvester (also in English: combine harvester) is an agricultural harvesting machine for mowing, threshing out grains or seeds, separating straw and grains or seeds, cleaning grains and seeds from the dump and depositing the Straw in swaths for later salvage as litter or flat distribution of the chopped straw for natural fertilization on the field.
The items to be cleaned, consisting of grains and NKB (non-grain components = chaff and straw parts), are cleaned by the threshing mechanism and other separation elements (shakers or separation rotors). This mixture is usually cleaned using two sieves arranged one above the other, the upper and lower sieves. The items to be cleaned are fed to the sieves differently depending on the manufacturer:
a) Via a step floor (stepped profiled sheet), which is responsible for both the conveyance and for an even distribution in the longitudinal and transverse direction and a certain amount of pre-segregation. b) Active conveyance by means of several adjacent screws, the main task of which is to gain height within the cleaning process and to feed the items to be cleaned evenly to the sieves. c) One or more, with the help of a fan, ventilated fall steps, which blow out a large proportion of the light chaff fractions from the items to be cleaned before they reach the sieves. Above all, this ensures that the grains hit the sieve surface under the NKB and are quickly separated.
Both screens are ventilated from below by an air stream (wind). This ensures that the items to be cleaned are loosened, whereby in the best case a so-called fluidized bed phase is created. Light components such as the chaff and short straw "float" and allow the much heavier grains to reach the sieve surface.
The items to be cleaned first pass from the feeder onto the top sieve. This essentially has the task of separating grains and unthrown ear parts (tailings) to the lower sieve and conveying the NKB out of the combine through the sieve end. The lower sieve represents the last cleaning stage, whereby in the ideal case a grain purity of over 99.6% is achieved. The pure grain is transported via a screw to one side of the machine (usually on the right in the direction of travel) and from there by means of an elevator into the grain tank. The sieve transition of the lower sieve (tailings) consists of non-threshed ear parts, grains and chaff. These returns are conveyed to one or both sides of the combine with a screw and from there returned to the threshing unit or the conveyor elements for cleaning with the help of another screw or an elevator. Manufacturers who bring the returns back for cleaning install an additional small threshing device on the way there.
Since large quantities of weed seeds get out of the combine with the NKB, the chaff and the straw (if chopped) are distributed over the entire working width if possible with cutting widths of more than 3 meters, for example by means of a disc-shaped chaff spreader. The cleaning can be adjusted to the type of grain to be threshed by changing the upper and lower sieve designs as well as by varying the wind speeds. Both the frequency and the amplitude of the sieve oscillation are usually specified by the manufacturer and can only be changed with great effort.
Combine harvesters brands:
AGCO Belarus Carraro CaseIH Claas David Brown Deutz Deutz-Fahr Fendt Ferguson Fiat Ford Ford-New-Holland Fortschtitt International Case JCB John Deere Kubota Lamborghini Landini Lanz Leyland Manitou Massey Ferguson McCormick Mercedes-Benz Merlo MTZ New Holland Renault SAME Steyr Ursus Weidemann Valmet Valtra Volvo Zetor
View more combine harvesters specifications at: https://www.farmtractorspecs.com/combine-harvesters-specs/