Abstract: A grain cleaning apparatus for a combine harvester has a linkage system for moving a grain pan or sieve with an oscillatory movement. A configuration of the linkage system is adjusted for example in dependence on a lateral inclination of the combine harvester, in particular by setting the position of a pair of arms of the linkage system, so that some points within the linkage system are fixed and other points are adjustable depending on the angle of inclination (but then remain static for a constant angle of inclination).

Abstract: A combine harvester having a cleaning shoe includes a housing, a chaffer having a frame assembly and a plurality of first louvers rotatably mounted to the frame assembly, and a blower comprising a plurality of second louvers. The first louvers are configured to rotate about lateral axes thereof, the lateral axes perpendicular to a longitudinal axis of the combine harvester. The second louvers are configured to change a lateral direction of air flow from the blower to the chaffer. Another combine harvester has a plurality of second louvers below first louvers of a chaffer. Each of the second louvers are configured to rotate about an axis perpendicular to the lateral axes of the first louvers of the chaffer. A method of operating a combine includes rotating at least one second louver to change a direction of the air flow in the cleaning shoe before the air flow reaches the chaffer.