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HISTORY OF TECHNOLOGY, TECHNOLOGY, OBJECTS AROUND US
Combine harvester. History of invention and production
Directory / The history of technology, technology, objects around us A grain harvester is a complex grain harvester (reaper-thresher) that performs sequentially in a continuous stream and simultaneously: cutting bread (that is, plants), feeding it to the threshing apparatus, threshing grain from ears, separating it from a heap and other impurities, transporting clean grain to bunker and mechanical unloading from it. One of the most important agricultural machines, capable of performing several different operations at once. For example, a combine harvester cuts the ears, knocks out the grains from the spikelets and cleans the grains with a jet of air. A complex machine performs the functions of three simple ones - a harvester, a threshing machine and a winnowing machine. Additional attachments are available for combine harvesters that allow you to harvest different crops.
The time when bread was harvested by hand is long gone: they harvested it with sickles, tied it into sheaves, threshed it with flails, separated grain from straw and chaff on manual winnowing machines. Thirty reapers were required to manually harvest bread on one hectare of land in a day, and forty more people were required to thresh grain from ears and separate it from straw. To facilitate these heavy and time-consuming work, machines were created: reapers that mow bread; threshers that thresh grain; sorting, separating high-grade grain from unusable seeds and weed seeds, cleaning grain from impurities. And then the harvester, thresher and sorting were combined into one machine, put on wheels - and a combine harvester appeared. The first such machine was developed in 1868 by the Russian inventor A.R. Vlasenko. At first, such machines were driven by a tractor, and later they became self-propelled. The combiner is now working in much more comfortable conditions than before. The cab is equipped with air conditioning, a heater, a ventilation unit that purifies the supplied air, an electric wiper, tinted windows, sun visors, headlights for night work, a rear-view mirror, and a thermos for drinking water. For the first time in our country, contactless electronic devices were used on combines of the Don brand to control all the main assembly units and assemblies. The system of automatic control of the technological process and the state of the most important aggregates of the combine harvester "Don" provides a measurement of the frequency of rotation of the main working bodies of the combine and the speed of its movement. It also detects deviations from the nominal speed of the shafts or modes of the engine, hydraulic system, threshing apparatus and other units from the norm and warns the combine operator about this using a light display and sound alarm. The light panel is installed in the cab on the front wall of the air conditioning and ventilation compartment, here is also the block of switches for the combine's electrical equipment. On the latest generation combines, computer devices are widely used to control the main operational parameters and control the technological process.
And here is how a modern harvester works. First, a strip of stalks of the harvested crop is captured by the reel blades and brought to the cutting unit. The cut stems are fed by a reel to the harvester auger. The auger, having spirals of the right and left directions, moves the cut stems from the edges to the center of the harvester, where the finger mechanism is located. The finger mechanism of the auger captures them, as well as the stalks directly entering it, and directs them to the header window, from which the mass is taken by the spacer beater and transferred to the feeder house conveyor, which directs it to the threshing chamber. Three types of threshing devices are used in combines: beater, pin and axial-rotor. The main purpose of the threshing apparatus is to extract all the grains from the ear, if possible without damaging them. At the same time, they strive for minimal damage to the stems so as not to impede the separation of grain on the cleaning sieves and the straw walker. In his book "Grain harvesters" A.F. Morozov notes that in the process of threshing, the natural connection between seeds, films and spikelet scales should be destroyed. Threshing in the threshing device occurs as a result of repeated blows to the stems and the ear when the mass is dragged through the threshing gap between the drum and the concave (deck). The drum, rotating, captures the mass with whips, while striking it, and advances it along the threshing gap. The speed of movement of the mass depends on both the speed of rotation of the drum and the size of the threshing gap. The upper layer of stems moves much faster than the lower one, which is in contact with the fixed deck. Threshing in a pin threshing device occurs as a result of repeated blows to the stems and spike when the mass is dragged between the concave pins. In the axial-rotary threshing and separating device, the grain mass is also threshed due to the impact of whips on it, but in the process of threshing, it makes a helical movement. Threshers of domestic harvesters "Don" and "Niva" are made according to the classical scheme, the most common in foreign combines. It includes a threshing device with one beater drum and a sieve concave, an active breaker beater, a keyboard straw heap separator, and a two-station sieve cleaning. The grain mass comes out of the threshing machine in the form of two fractions - straw and grain heap. The straw heap, containing mainly coarse straw and part of the grain, falls on the straw walker, on which the remaining grain and small straw particles are separated, and the straw goes to the stacker through the straw walker. Depending on the design of the threshing device and harvesting conditions, the straw entering the straw walker contains from 5 to 30 percent of the total amount of grain passing through the combine. In domestic combines, only keyboard-type straw walkers are used. The principle of operation of such a straw walker is based on the separation of grain from a layer of straw as a result of counter blows applied by the keys on the mass falling on them. When leaving the straw walker, the straw is captured by the rakes of the straw-roller and is directed to the stacker chamber. As the stacker is filled, the straw pre-pressing force increases, which acts on the emergency filling valve and turns on the signal of the full stacker filling. If for some reason the machine operator did not notice this signal and did not drop the shock, then the shock reset automatic turns on. The grain heap, separated through the concave, as well as grain and small straw particles, separated on the straw walker, enter the transport board, which delivers this heap for cleaning. On cleaning sieves, blown by a fan, the grain is finally separated from straw impurities. The clean grain that has passed through both sieves enters the grain auger along the sieve board and is transported by the elevator to the bunker. “Unthreshed spikelets descending from the lower sieve and from the extension of the upper sieve, together with an admixture of free grain and chaff,” writes A.F. Morozov, “fall into the return auger and are moved by the auger and elevator to an autonomous re-threshing device, where the grain remaining in the spikelets is released . The heap formed after final threshing enters the neck of the distribution auger, which drops it to the end of the transport board (due to the special design of the distribution auger casing, the heap is evenly distributed over the width of the thresher). At the same time, spikelets that are difficult to thresh can circulate several times along the “finishing-cleaning” circuit until they are completely threshed. The small straw part of the heap is transported by air flow and sieves to the chaff feeder, which feeds it into the stacker chamber or into the auger of the chopper chaff box. When using a mounted chopper, the straw from the straw walker goes directly to the chopper and, after chopping with hammer knives, is thrown through the deflector into the cart or onto the field. At the same time, it passes through the lower hatch and spreader blades, which can be set in one of two positions: for spreading across the field or laying in a swath. Additional attachments are available for combine harvesters that allow you to harvest different crops. So, a corn harvester cuts off a tall corn stalk, separates the cob from it and crushes the stalk into small pieces (after additional processing, livestock feed is prepared from this mass - silage). The flax harvester first carefully pulls the delicate flax stalks out of the ground, combs the seed pods and leaves from them with steel combs, and then ties the stalks into sheaves. There is also a special harvester for harvesting sugar beets. With steel fingers, he grabs the tops, pulls the plant out of the garden, cuts off the greens with a knife and shakes off the stuck earth. The potato harvester first digs up a large layer of earth and crushes it carefully so as not to damage the tubers. Then, moving and shaking at the same time, it sifts the earth on a bar conveyor, frees the potatoes and feeds them into the back of a truck. In addition to the listed combines, engineers have created and continue to improve machines for harvesting other types of grains and vegetables. Author: Musskiy S.A.
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