OF COMBINE-HARVESTERS

Combine-harvesters are used to harvest various crops. The combine cuts the crop, threshes it, and separates the grain from the straw and chaff.

The mechanism of a combine can be divided into three sections: cutting, threshing and separating the grain from the straw and chaff. The main parts of the cutting unit are a reel, a divider, a cutting bar and an auger.

To cut the crop a reciprocating type cutter bar is used. There is a divider at each side¹ of the cutter bar. It separates the crop to be cut from that, which will be left for the next round². After the crop is cut, the reel directs it to the cutter bar platform. The reel is one of the main parts of the combine. It has tines, which can be angled³ to provide better cutting of the crops. A large auger moves the crop to the centre of the platform.

By means of tines the auger directs the crop to the main elevator. The main elevator lifts the crop to the threshing mechanism.

The threshing mechanism consists of front and rear beaters, a heavy rotating drum and a concave. The main elevator is used to lift the crop to the front beater. It delivers the crop to the drum and concave. The front beater increases the speed of the crop as it moves to the drum.

Threshing takes place between the drum and concave. There are spaces between the concave bars for the threshed grain to fall through to the grain pan. To reduce the speed of the crop as it leaves the cylinder is the task of the rear beater. The rear beater both reduces the speed of the crop and directs it to the separating mechanism. The separating mechanism consists of 2 parts: the straw walkers and the grain sieves. There the grain is separated from the straw. The cleaned grain falls into the grain pan, located under the concave. Then it is directed to the grain tank. Its capacity varies with the type of a combine.

NOTES

¹at each side - на каждой боковине

²for the next round - для следующего хода

³which can be angled - которые могут быть наклонены