Grain cleaning system for a combine harvester

1 . A grain cleaning apparatus for a combine harvester, comprising:

a grain pan or sieve;

a linkage system for moving the grain pan or sieve with an oscillatory movement;

a driver for inducing the oscillatory movement to the grain pan or sieve;

an actuator for setting a configuration of the linkage system in dependence on a lateral inclination of the combine harvester;

wherein the linkage system comprises:

a first fixed point;

a first arm between the first fixed point and a first adjustable point;

a second fixed point;

a second arm between the second fixed point and a second adjustable point;

three linkages in series between the first adjustable point and the second adjustable point, wherein the motion of the grain pan or sieve is constrained by the movement of a middle one of the three linkages,

and wherein the first and second adjustable points have a position which is adjusted by the actuator, with the first and second adjustable points stationary for a constant angle of inclination, and wherein the first and second adjustable points have a position which is adjusted by the actuator in dependence on the angle of inclination.

2 . The grain cleaning apparatus of claim 1 , comprising an inclination sensor for sensing an angle of lateral inclination of the combine harvester.

3 . The grain cleaning system of claim 1 , comprising:

a return pan;

a stratification pan for receiving the harvested crop material from a front end of the return pan;

a fan; and

a sieve arrangement for receiving the harvested crop material from a rear end of the stratification pan, wherein the grain pan or sieve comprises a sieve of the sieve arrangement.

4 . The grain cleaning system of claim 3 , wherein the sieve arrangement comprises:

a chaffer sieve for conveying harvested crop material in a generally rearward direction; and

a lower sieve,

wherein the grain cleaning system comprises a clean grain chute below the lower sieve.

5 . The grain cleaning system of claim 3 , comprising a second chute for directing tailings to a tailings collection trough.

6 . A grain cleaning apparatus for a combine harvester, comprising:

a grain pan or sieve;

a linkage system for moving the grain pan or sieve with an oscillatory movement;

an actuator for setting a configuration of the linkage system in dependence on a lateral inclination of the combine harvester;

wherein the linkage system comprises:

a first fixed point;

a first arm between the first fixed point and a first adjustable point;

a second fixed point;

a second arm between the second fixed point and a second adjustable point;

three linkages in series between the first adjustable point and the second adjustable point, wherein the motion of the grain pan or sieve is constrained by the movement of a middle one of the three linkages,

wherein the first and second adjustable points have a position which is adjusted by the actuator, and wherein the first and second adjustable points have a position which is adjusted by the actuator in dependence on the angle of inclination; and

wherein the second arm has a control end at an opposite side of the second fixed point to the second adjustable point, wherein the linkage system comprises a control arm between the first adjustable point and the control end, wherein the actuator comprises a position controller for setting a position of the control arm in dependence on the angle of inclination, thereby to set the positions of the first and second adjustable points.

7 . A combine harvester comprising:

a crop cutting head;

a threshing system; and

the grain cleaning system of claim 3 for receiving the cut and threshed crop material.

8 . The grain cleaning system of claim 6 , comprising:

a return pan;

a stratification pan for receiving the harvested crop material from a front end of the return pan;

a fan; and

a sieve arrangement for receiving the harvested crop material from a rear end of the stratification pan, wherein the grain pan or sieve comprises a sieve of the sieve arrangement.

9 . The grain cleaning system of claim 8 , wherein the sieve arrangement comprises:

a chaffer sieve for conveying harvested crop material in a generally rearward direction; and

a lower sieve,

wherein the grain cleaning system comprises a clean grain chute below the lower sieve.

10 . The grain cleaning system of claim 8 , comprising a second chute for directing tailings to a tailings collection trough.

11 . A combine harvester comprising:

a crop cutting head;

a threshing system; and

the grain cleaning system of claim 8 for receiving the cut and threshed crop material.

12 . A grain cleaning apparatus for a combine harvester, comprising:

a grain pan or sieve;

a linkage system for moving the grain pan or sieve with an oscillatory movement;

an actuator for setting a configuration of the linkage system in dependence on a lateral inclination of the combine harvester;

wherein the linkage system comprises:

a first fixed point;

a first arm between the first fixed point and a first adjustable point;

a second fixed point;

a second arm between the second fixed point and a second adjustable point;

three linkages in series between the first adjustable point and the second adjustable point, wherein the motion of the grain pan or sieve is constrained by the movement of a middle one of the three linkages,

wherein the first and second adjustable points have a position which is adjusted by the actuator, and wherein the first and second adjustable points have a position which is adjusted by the actuator in dependence on the angle of inclination; and

wherein the first and second adjustable points ( 104 , 204 ) are adjustable between first and second end positions, wherein the first end position is for inclination in one lateral direction and the second end position is for inclination in an opposite lateral direction.

13 . The grain cleaning apparatus of claim 12 wherein in the first or second positions, the grain pan or sieve is driven with an oscillatory motion in a diagonal fore/aft and lateral direction.

14 . The grain cleaning apparatus of claim 12 , wherein a mid-position between the first and second end positions is for zero lateral inclination.

15 . The grain cleaning apparatus of claim 14 , wherein in the mid position, the grain pan or sieve is driven with an oscillatory motion in a fore/aft direction.

16 . The grain cleaning system of claim 12 , comprising:

a return pan;

a stratification pan for receiving the harvested crop material from a front end of the return pan;

a fan; and

a sieve arrangement for receiving the harvested crop material from a rear end of the stratification pan, wherein the grain pan or sieve comprises a sieve of the sieve arrangement.

17 . The grain cleaning system of claim 16 , wherein the sieve arrangement comprises:

a chaffer sieve for conveying harvested crop material in a generally rearward direction; and

a lower sieve,

wherein the grain cleaning system comprises a clean grain chute below the lower sieve.

18 . The grain cleaning system of claim 16 , comprising a second chute for directing tailings to a tailings collection trough.

19 . A combine harvester comprising:

a crop cutting head;

a threshing system; and

the grain cleaning system of claim 16 for receiving the cut and threshed crop material.