Corn stalk roll arrangement

A corn harvester includes a first stalk roll having a plurality of first blades circumferentially spaced apart by a first angle. A second stalk roll has a plurality of second blades circumferentially spaced apart by a second angle. The first and second stalk rolls are rotatable about parallel first and second axes that are separated by a centerline therebetween. In an operational state when a tip of one first blade is aligned with the centerline, a tip of one second blade is angularly offset from the centerline by a third angle. The third angle is less than 45% of the second angle. The one first blade forms a cross section perpendicular to the first axis having an altitude extending from the tip toward the first axis along a first blade altitude. The cross section of the one first blade is asymmetric about the first blade altitude.

BACKGROUND

The present disclosure relates to corn stalk rolls for a corn harvester.

SUMMARY

In one embodiment, the disclosure provides a stalk roll assembly for a corn harvester that includes a first stalk roll having a first elongate cylinder and a plurality of first blades, in which each first blade of the plurality of first blades is circumferentially spaced around a perimeter of the first elongate cylinder from an adjacent first blade by a first angle, and the first stalk roll is rotatable about a first axis by a power source. A second stalk roll has a second elongate cylinder and a plurality of second blades, in which each second blade of the plurality of second blades is circumferentially spaced around a perimeter of the second elongate cylinder from an adjacent second blade by a second angle, and the second stalk roll is rotatable about a second axis parallel to the first axis by the power source. A first plate is positioned above the first stalk roll, and a second plate is positioned above the second stalk roll. The first and second stalk rolls are spaced apart to separate corn ears from corn stalks. The first and second axes are separated by a centerline therebetween. In an operational state when a tip of one first blade of the plurality of first blades is aligned with the centerline, a tip of one second blade of the plurality of second blades is angularly offset from the centerline by a third angle. The third angle is less than 45% of the second angle. The one first blade forms a triangle with a cross section perpendicular to the first axis and has an altitude extending from the tip and forming a first base angle and a second base angle. The first base angle is at least 3° greater than the second base angle.

In another embodiment, the disclosure provides a corn harvester that includes a work vehicle configured to move along a ground surface and a crop divider configured to separate adjacent rows of corn stalks. A first stalk roll has a first elongate cylinder and a plurality of first blades, in which each first blade of the plurality of first blades is circumferentially spaced around a perimeter of the first elongate cylinder from an adjacent first blade by a first angle. The first stalk roll is rotatable about a first axis by a power source. A second stalk roll has a second elongate cylinder and a plurality of second blades, in which each second blade of the plurality of second blades is circumferentially spaced around a perimeter of the second elongate cylinder from an adjacent second blade by a second angle. The second stalk roll is rotatable about a second axis parallel to the first axis by the power source. A first plate is positioned above the first stalk roll and a second plate is positioned above the second stalk roll. The first and second stalk rolls are spaced apart to permit corn stalks to move between the first and second plates and to separate corn ears from corn stalks. A hopper is configured to store harvested corn ears. A conveyor is configured to move separated corn ears toward the hopper. The first and second axes are separated by a centerline therebetween, and in an operational state when a tip of one first blade of the plurality of first blades is aligned with the centerline, a tip of one second blade of the plurality of second blades is angularly offset from the centerline by a third angle. The third angle is less than 45% of the second angle. The one first blade forms a triangle with a cross section perpendicular to the first axis and having an altitude extending from the tip and dividing the cross-sectional angle thereof unequally.

In another embodiment, the disclosure provides a stalk roll assembly for a corn harvester that includes a first stalk roll having a first elongate cylinder and a plurality of first blades, in which each first blade of the plurality of first blades is circumferentially spaced around a perimeter of the first elongate cylinder from an adjacent first blade by a first angle. The first stalk roll is rotatable about a first axis by a power source. A second stalk roll has a second elongate cylinder and a plurality of second blades, in which each second blade of the plurality of blades is circumferentially spaced around a perimeter of the second elongate cylinder from an adjacent second blade by a second angle. The second stalk roll is rotatable about a second axis parallel to the first axis by the power source. A first plate is positioned above the first stalk roll, and a second plate is positioned above the second stalk roll. The first and second stalk rolls are spaced apart to permit corn stalks to move between the first and second plates and to separate corn ears from corn stalks. The first and second axes are separated by a centerline therebetween. In an operational state when a tip of one first blade of the plurality of first blades is aligned with the centerline, a tip of one second blade of the plurality of second blades is angularly offset from the centerline by a third angle. The third angle is less than 45% of the second angle. The one first blade forms a cross section perpendicular to the first axis having an altitude extending from the tip toward the first axis along a first blade altitude. The cross section of the one first blade is asymmetric about the first blade altitude.

DETAILED DESCRIPTION

FIG. 1illustrates a corn harvester10including a work vehicle12and a corn harvesting attachment14. The illustrated work vehicle12includes an operator cab16, an engine18, a hopper20, a dispensing chute22, and a plurality of wheels24. Other work vehicles can include tracks in place of the plurality of wheels. The illustrated corn harvesting attachment14includes a plurality of crop dividers26and a cross auger28.

FIG. 2illustrates that each of the crop dividers26includes a cover32positioned behind the crop divider26and between two stalk roll assemblies30The crop divider26directs corn stalks toward one of the stalk roll assemblies30. A stalk roll cover32is removed from some stalk roll assemblies30inFIGS. 2 and 3B.

FIGS. 3A and 3Billustrate a pair of stalk roll assemblies30with a crop divider26and a cover32positioned between the pair of stalk roll assemblies30. The cover32directs any harvested corn to the stalk roll assemblies30and inhibits any harvested corn from falling between the stalk roll assemblies30onto the ground.

FIGS. 4-6more clearly illustrate one such stalk roll assembly30. The illustrated stalk roll assembly30includes a first stalk roll36, a second stalk roll38, a first gathering chain40, a second gathering chain42, a first plate44, a second plate46, and a power source48.

As shown most clearly inFIGS. 7 and 8, the illustrated first stalk roll36includes a frustoconical tip52having a helical blade, and a cylindrical portion54having a plurality of first blades56that extend along a circumference of the cylindrical portion54of the first stalk roll36in the axial direction. The first stalk roll36is configured to rotate about a first longitudinal axis58in response to the power source48. As shown inFIG. 7, the illustrated first stalk roll36is rotated in the direction of arrow A, which is counter clockwise when viewed from the end with the frustoconical tip52.

The illustrated second stalk roll38includes a frustoconical tip62having a helical blade and a cylindrical portion64having a plurality of second blades66that extend along a circumference of the cylindrical portion64of the second stalk roll38in the axial direction. The second stalk roll38is configured to rotate about a longitudinal axis68in response to the power source48. As shown inFIG. 7, the illustrated second stalk roll38is rotated in the direction of arrow B, which is clockwise when viewed from the end with the frustoconical tip62.

As shown most clearly inFIG. 4, the first gathering chain40includes a plurality of lugs70and is moveable in response to rotation of a drive sprocket72. The power source48can cause rotation of the drive sprocket72and thus, movement of the lugs70. The second gathering chain includes a plurality of lugs74and is moveable in response to rotation of a drive sprocket76. The power source48can cause rotation of the drive sprocket76and thus, movement of the lugs74.

With reference toFIGS. 4-7, the first plate44is positioned above the first stalk roll36and below the first gathering chain40. The second plate46is positioned above the second stalk roll38and below the second gathering chain42. The first plate44is spaced from the second plate46a distance that is greater than an average diameter of corn stalks but is less that an average diameter of harvested corn ears.

As shown most clearly inFIG. 7, the first stalk roll36rotates in the direction of arrow A and the second stalk roll38rotates in the direction of arrow B to draw a corn stalk80down and the plurality of first and second blades56and66cut the corn stalk80into pieces and dispense the pieces downward. Harvested corn ears82are retained on the first and second plates44and46and are thus stripped off of the corn stalk80. The spacing between the first and second plates44and46permits the corn stalks to slide between the plates44and46but the first and second plates44and46retain harvested corn ears82on top of the plates44and46.

With reference toFIGS. 2 and 4, the lugs70and74on the respective gathering chains40and42move the harvested corn ears82along the first and second plates44and46and toward the cross auger28. The covers32retain the harvested corn ears82above the ground surface. As shown inFIG. 1, the cross auger28rotates to move harvested corn ears82toward the hopper20. The corn kernels are then stripped off of the harvested corn ears82and are directed out the dispensing chute22. A second work vehicle, such as a wagon, is positioned to receive the corn kernels from the dispensing chute22.

FIG. 9illustrates the first stalk roll36and the second stalk roll38in greater detail. The first stalk roll36is configured to rotate about the first longitudinal axis58. The first blades56are evenly circumferentially spaced around a circumference of the cylindrical portion54. Each of the first blades56is spaced from adjacent first blades56by a first angle84. In the illustrated embodiment, the first angle84is 36°. However, in other embodiments, other quantities of first blades56can be utilized which would alter the first angle84accordingly.

The second stalk roll38is configured to rotate about the longitudinal axis68. The second blades66are evenly circumferentially spaced around a circumference of the cylindrical portion64. Each of the second blades66is spaced from adjacent second blades66by a second angle86. In the illustrated embodiment, the second angle86is 36°. However, in other embodiments, other quantities of second blades66can be utilized which would alter the second angle86accordingly.

The first longitudinal axis58is parallel to the second longitudinal axis68and is spaced apart from the second longitudinal axis68along a centerline88. When one of the first blades56extends along the centerline88toward the second stalk roll38, one adjacent second blade66is angularly offset from the centerline88by a third angle90. The third angle90is less than 45% of the second angle86. In some embodiments, the third angle90is between 10% and 40% of the second angle86.

In the illustrated embodiment ofFIG. 9, the third angle90is 12°. In contrast, a midline92is positioned halfway between the adjacent second blades66. In the illustrated embodiment, the midline92is spaced 18° from the adjacent second blades66because the midline92is half of the second angle86(which is 36°). Therefore, the first blade56is offset from the midline92by 6°, which is the angle between the midline92and the adjacent second blade66(18°) minus the offset third angle (12°).

In some embodiments that include ten first blades56and ten second blades66, the third angle90can be between 3° and 15°. In some embodiments that include ten first blades56and ten second blades66, the third angle90can be between 5° and 13°. In some embodiments that include ten first blades56and ten second blades66, the third angle90can be between 7° and 11°. In other embodiments, other quantities of first and second blades56,66can be utilized which will alter the third angle accordingly.

FIG. 10is a close up schematic view of one first blade56and one second blade66when the one first blade56and the one second blade66are positioned adjacent and configured to contact a corn stalk to cut said corn stalk into smaller pieces. The one first blade56is rotating in the direction of arrow A, and the one second blade56is rotating in the direction of arrow B (also shown inFIG. 7). Arrow C indicates the direction of the force acting on the first blade56when the first and second blades56,66shear a corn stalk. The force shown by arrow C is acting on the first blade56to a greater extent than on the second blade66because of the offset between the blades56,66and because of the direction of rotation of the first and second blades56,66. Therefore, in the field, the first blades56typically have a shorter operational lifespan than the second blades66.

In order to increase the lifespan of the first blades56, the size of the first blades56is increased. Specifically, the illustrated first blades56are triangular in cross-section and extend perpendicular to the first longitudinal axis58. The illustrated one first blade56has an altitude100extending from the tip and forming a first base angle102and a second base angle104. The first base angle102is at least 3° greater than the second base angle104. In some embodiments, the first base angle102is at least 5° greater than the second base angle104. In the illustrated embodiment, all the first blades56are identical.

The altitude100divides the one first blade56into a first portion106defining a fourth angle108between the altitude100and a first edge110of the first blade56, and a second portion112defining fifth angle114between the altitude and a second edge116of the first blade56. The altitude100divides the cross-sectional angle between the first edge110and the second edge116of the first blade56unequally. Namely, the cross section of the one first blade56is asymmetric about the first blade altitude100.

In the illustrated embodiment, the fourth angle108is 22.5° and the fifth angle114is 17.5°. Other angles and ranges of angles are possible and are within the scope of the present disclosure. For example, the fourth angle108is between 10% and 50% greater than the fifth angle114. In some embodiments, the fourth angle108is between 20% and 40% greater than the fifth angle114.

The illustrated second blades66are triangular in cross-section and extend perpendicular to the second longitudinal axis68. The illustrated one second blade66has an altitude120extending from the tip and forming a third base angle122and a fourth base angle124. The third base angle122is substantially equal to the fourth base angle124. In some embodiments, the third base angle122and the fourth base angle124are substantially equal to the second base angle104. In the illustrated embodiment, all the second blades66are identical.

The altitude120divides the one second blade66into a first portion126defining a sixth angle128between the altitude120and a first edge130of the second blade66, and a second portion132defining a seventh angle134between the altitude120and a second edge136of the second blade66. The sixth angle128is substantially equal to the seventh angle134. The altitude120divides the cross-sectional angle between the first edge130and the second edge136of the second blade66substantially equally. Namely, the cross section of the one second blade56is symmetric about the second blade altitude120.

In the illustrated embodiment, the sixth angle128is 17.5° and the seventh angle134is 17.5°. In the illustrated embodiment, the fifth angle114is substantially equal to the sixth angle128and is substantially equal to the seventh angle134.

Upon rotation of the first stalk roll36and the second stalk roll38, the second edge116of the first blade56is configured to contact the corn stalks and the first edge130of the second blade66is configured to contact the corn stalks. The first blades56are sized and shaped to endure larger forces than the second blades66to increase the lifespan of the first blades56.