Combine harvester

A combine harvester with a threshing and separating mechanism for threshing and separating crop material, and a cleaning device for cleaning threshed and separated grain;

• the cleaning device comprising:
• a cleaning fan structure with a fan housing and a fan therein;
• the fan housing comprising a generally cylindrical body extending transversely of the cleaning device with a pair of opposite end walls and an air inlet provided in each end wall and a further air inlet and an air outlet provided in the cylindrical body and extending transversely of the cleaning device;
• the further air inlet extends substantially across the full width of the fan housing and has a generally rectangular shape;
• the outlet generally extends substantially across the full width of the fan housing and wherein the further inlet and the outlet are provided the one closely adjacent the other in the circumference of the fan housing;
• the further air inlet and the outlet together extend over a section in the range of 180.degree. of the cylindrical body of the fan housing;
• the further air inlet is provided substantially in the upper portion of the fan housing;
• the further air inlet is covered by a perforated shielding;
• the outlet communicates with a main and with an additional outlet duct which face different locations in the cleaning device;
• an angularly adjustable baffle is provided generally between the main and additional outlet ducts and which is capable of more or less throttling the one outlet duct in favour of the other;
• the fan comprises a plurality of generally concavely shaped fan blades, with the concave shape facing in the direction of rotation of the fan;
• and
• the fan blades comprise three generally flat sections;
• a first central section disposed at a sharp angle in advance of the fan radius and angled inner and outer sections defining with said first section said generally concave shape.