A combine harvester has a driving shoe arrangement. The driving shoe includes a preparation pan and one or more sieves, coupled to a drive mechanism for driving a reciprocating movement of the pan and sieves. The stroke of the reciprocating movement of the pan and/or sieves is adjustable, through the application of a drive mechanism including one or more pivotably mounted support arms for supporting the pan or sieve, and a drive arm connected to one of the support arms through an adjustable connection link. The adjustable connection link can be a variable length actuator whose length determines the stroke of the pan or sieve. The stroke of the pan or sieve can be adjusted during a harvesting run, thereby allowing a fast adjustment to changing external conditions such as the slope of the terrain.

A combine harvester has a driving shoe arrangement. The driving shoe includes a preparation pan and one or more sieves, coupled to a drive mechanism for driving a reciprocating movement of the pan and sieves. The stroke of the reciprocating movement of the pan and/or sieves is adjustable, through the application of a drive mechanism including one or more pivotably mounted support arms for supporting the pan or sieve, and a drive arm connected to one of the support arms through an adjustable connection link. The adjustable connection link can be a variable length actuator whose length determines the stroke of the pan or sieve. The stroke of the pan or sieve can be adjusted during a harvesting run, thereby allowing a fast adjustment to changing external conditions such as the slope of the terrain.

An agricultural harvester includes a straw walker arrangement positioned downstream from a threshing and separating system. The straw walker arrangement includes a first straw walker positioned to receive crop material from the threshing and separating system, a second straw walker positioned downstream from the first straw walker, and a rotatable drum positioned between the first straw walker and the second straw walker. The rotatable drum is operable to convey crop material from the first straw walker to the second straw walker.

A cleaning system for a harvester has a sieve that is moveable by a drive assembly that includes a rotary drive, an eccentric device, a transmission connected to the eccentric device and to the sieve, which transmission cyclically varies the distance between the driving point of the eccentric device and the sieve coupling during each full rotation of the rotatable output shaft of the rotary drive, wherein, due to the cyclic variation of the distance between the driving point of the eccentric device and the sieve coupling, during each reciprocating sieve movement at least one of the accelerating portion of the throw stroke, the decelerating portion of the throw stroke, the accelerating portion of the return stroke and the decelerating portion of the return stroke has a duration that is different from the duration of at least one other of the portions of the reciprocating sieve movement.

A cleaning shoe for an agricultural machine includes a chaffer supported for movement relative to a chassis, a sieve positioned below the chaffer and supported for movement relative to the chassis. The cleaning shoe also includes a first link, a second link, and a drive shaft. The first link includes a first end and a second end coupled to the chaffer. The second link includes a first end and a second end coupled to the sieve. The drive shaft rotates about a shaft axis and includes a first cam and a second cam. The first cam is coupled to the first end of the first link, and the second cam is coupled to the first end of the second link. Rotation of the drive shaft drives the first link to reciprocate the chaffer and drives the second link to reciprocate the sieve. The second cam is angularly offset relative to the first cam by a phase angle less than 180 degrees about the shaft axis.

A concave extends circumferentially about a portion of a rotor of a rotary processing unit of an agricultural combine. The concave has threshing beds forming openings therebetween for grain to pass through from a path of crop material between the concave and the rotor. The path of crop material has a flow direction relative to the concave in response to rotation of the rotor in a threshing direction. Each threshing bed includes a first extremity defining a threshing edge, a second extremity, and a separating grate extending across one of the openings between the first extremity and the second extremity, the first extremity overlapping the second extremity of an adjacent one of the threshing beds, locating the threshing edge in the path of crop material facing opposite to the flow direction. Each threshing bed extends from its threshing edge to its second extremity in the flow direction.

A concave extends circumferentially about a portion of a rotor of a rotary processing unit of an agricultural combine. The concave has threshing beds forming openings therebetween for grain to pass through from a path of crop material between the concave and the rotor. The path of crop material has a flow direction relative to the concave in response to rotation of the rotor in a threshing direction. Each threshing bed includes a first extremity defining a threshing edge, a second extremity, and a separating grate extending across one of the openings between the first extremity and the second extremity, the first extremity overlapping the second extremity of an adjacent one of the threshing beds, locating the threshing edge in the path of crop material facing opposite to the flow direction. Each threshing bed extends from its threshing edge to its second extremity in the flow direction.

A concave for an agricultural combine includes threshing beds carried by a base frame and forming openings therebetween for grain to pass through. Each threshing bed includes a first end, a second end, a length from the first end to the second end, an inner extremity, an outer extremity, and a separating grate extending across one of the openings for separating grain from threshed crop material. The separating grate extends along the length between the first end and the second end, is between the inner extremity and the outer extremity and includes grate openings and spaced-apart bars. The bars are between adjacent grate openings and include struts each connecting two adjacent parts of the separating grate between adjacent grate openings and severed bars each including bar segments extending inwardly toward one another to respective free ends on either side of a gap between adjacent grate openings.

A concave for an agricultural combine includes threshing beds carried by a base frame and forming openings therebetween for grain to pass through. Each threshing bed includes a first end, a second end, a length from the first end to the second end, an inner extremity, an outer extremity, and a separating grate extending across one of the openings for separating grain from threshed crop material. The separating grate extends along the length between the first end and the second end, is between the inner extremity and the outer extremity and includes grate openings and spaced-apart bars. The bars are between adjacent grate openings and include struts each connecting two adjacent parts of the separating grate between adjacent grate openings and severed bars each including bar segments extending inwardly toward one another to respective free ends on either side of a gap between adjacent grate openings.