AXIAL FAN Russian patent published in 1997 - IPC

FIELD: agricultural engineering, in particular, grain combine cleaning system. SUBSTANCE: fan has housing 1 with two inlet windows 2,3 and discharge window 4, working wheel with shaft 5, impellers 6 and 7 secured on shaft and rotated in right and left directions. Impellers are fixed along housing edges. Wall 8 is positioned centrally of housing 1 perpendicular to working wheel axis of rotation. Screen 9 is mounted in discharge window 2 and screen 10 is positioned in discharge window 3. Both screens have perforated and nonperforated portions and are made curved, with curvature extent being similar to that of housing. Screen 9 and 10 are movable relative to discharge window 4 and are arranged symmetrically on levers 13, which are rigidly connected with pin 11 having predetermined angle of rotation. Levers are positioned adjacent to impellers 6 and 7. EFFECT: increased efficiency, simplified construction and enhanced reliability in operation. 6 dwg