CLEANING UNIT OF GRAIN COMBINE HARVESTER Russian patent published in 1994 - IPC

FIELD: agricultural engineering. SUBSTANCE: cleaning device has a shaking bottom with a grain pan finger rake having an extension. The extension is located under the rake. The unit also has upper and lower sieves and a transporting surface mounted for partial overlapping of the lower sieve. Under the grain pan finger rake and transporting surface there is an axial fan. The fan casing is a shell and it has front and back walls forming its main and additional branch pipes with partitions mounted radially relative to the fan axis. The partitions' upper end-face is located at the beginning of the transporting surface, and the lower end-face is located under the shell in a spaced relation. Inside the main branch pipe there is an air flow distributor, and the additional branch pipe ends with an auxiliary channel formed by the grain pan finger rake and transporting surface. The front strip of the extension is located in the auxiliary channel under the grain pan finger rake to form an opening relative to the rake back end. The strip is stream-lined in shape, and a louver comb is provided under the rake. The upper sieve extension has its separating area at least 1.5 times greater than that of the intermediate sieve, and the lower sieve is mounted to rise in the heap movement direction by means of adjustment holes in the sieve boot. The front holes are displaced downward relative to the back ones at least a distance equal to that between the axes of the holes. EFFECT: higher efficiency. 3 cl, 1 dwg