Harvested crop residue chopper and distribution arrangement for a combine with an impeller blower whose shape conforms to the contour of the straw chopper

The invention concerns a harvested crop residue chopper and distribution arrangement for a combine (10) with a straw chopper (60) with a rotor (74) that can be brought into rotation about a horizontal axis (98) with chopper blades (76) fastened thereto that define an outer envelope (96), and with at least one impeller blower (82) arranged downstream of the straw chopper (60) with impeller blades (84) that can rotate about an axis of rotation (88) that extends vertically, in which the impeller blades (84) are provided with outer edges (94) that conform to the envelope (96) of the chopper knives (76) and follow it very closely and are not in contact with it.

FIELD OF THE INVENTION

The invention relates generally to agricultural combines. More particularly it relates to crop processing elements for agricultural combine. Even more particularly it relates to a harvested crop residue chopper and distribution arrangement with a straw chopper with a rotor that can be brought into rotation about a horizontal axis and with chopper knives fastened to it that define an outer envelope, and at least one impeller blower arranged downstream of the straw chopper with impeller blades that can rotate about an axis of rotation extending vertically.

BACKGROUND OF THE INVENTION

Agricultural combines are large machines that harvest, thresh, separate, and clean agricultural planted harvested crops such as corn. The cleaned corn, so obtained, is stored in a corn tank on the combine. As a rule, the threshed out straw is either chopped and distributed on the fields across the width of the cutter head or conducted around the straw chopper and deposited in a swath on the field without being chopped, in order to be able pick it up subsequently with a baler. The harvested crop residue remaining at the rear outlet of the cleaning arrangement, such as chaff and small straw particles, is distributed across the field by a chaff spreader or is conducted through the straw chopper and distributed across the field.

DE 199 08 111 C describes a combine with a straw chopper and two impeller blowers, arranged side by side alongside each other, that follow the straw chopper for the widely distributed ejection of straw across the field. The outlet of the straw chopper and the inlet of the impeller blowers are arranged in a housing, that includes impeller blades rotating about an approximately vertical axis and are arranged in a single plane for the purpose of transfer of the harvested crop without changing direction. The impeller blades are fastened below the cover plate to a central, circular cylindrical shaft that is brought into rotation by means of a drive element arranged above the cover plate. The impeller blades are configured as rectangles so that their outer edges are oriented parallel to the axis of rotation and define a circular cylindrical envelope when rotated.

US 2007/0015556 A describes an impeller blower in which the straw in chopped form is thrown against the impeller blowers by means of a straw chopper at an angle from below, the impeller blowers are built up of impeller blades on an upper circular disk and extend downward radially and vertically to the surface of the disk. The impeller blades are wedge shaped, where the outer ends of the impeller blades extend to a greater distance vertically than the inner ends. The outer edges of the impeller blades (except for rather short, upper corner regions that inclined inwards) are oriented parallel to the axis of rotation, so that they define a circular, cylindrical envelope when rotated.

In the case of the known arrangement of straw choppers and following impeller blades, it is seen as detrimental on the basis of the outer edges of the impeller blades that are parallel to the axis of rotation that a certain distance must be maintained in order to avoid a collision between the straw chopper and the following impeller blade. However, problems may result in view of the distance that must be maintained in the transfer of harvested crop.

SUMMARY OF THE INVENTION

The problem underlying the invention is seen in the need for preparing a harvested crop residue chopper- and distribution arrangement of the kind cited initially for a combine that makes possible an improved flow of the harvested crop residue.

This problem is solved according to the invention by the teaching of claim1herein, where the further claims cite characteristics that further develop the solution to great advantage.

A harvested crop residue chopper and distribution arrangement for a combine includes a straw chopper with a rotor rotating about the horizontal axis of rotation with chopper knives attached to it that chop and eject the chopped straw and/or the chaff conducted to it. An impeller blower (or two or more impeller blowers arranged to the side alongside each other) is arranged downstream of the straw chopper that includes impeller blades that can be brought into rotation about an axis of rotation by an appropriate drive. The axis of rotation of the impeller blades extends vertically that means that it is sufficient when the axis of rotation includes a vertical component so that it need not extend exactly vertically but may be inclined slightly to the front or to the rear or to the side. The outer edges of the impeller blades are provided with at least partial regions that do not extend parallel to the axis of rotation of the impeller blower, but extend in a straight line or in a complementary curve that conforms to the envelope of the chopper knives and define partly or completely non cylindrical but conical enveloping surface of the impeller blower. Therefore the outer edges of the impeller blades conform to the envelope of the chopper knives with a relatively narrow gap, so that the spacing between the straw chopper and the impeller blower can be reduced as compared to the state of the art, and the transfer of the crop from the straw chopper to the impeller blades can be improved.

In a preferred embodiment of the invention the straw chopper and the impeller blades are located within a common housing that permits a saving of material and a compact configuration. This characteristic represents an independent invention that deserves an independent rank.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1shows an agricultural combine10with a chassis12with wheels14in contact with the ground that are fastened to the chassis12and are used for the propulsion of the combine10in the forward operating direction that extends to the left inFIG. 1. The operation of the combine10is controlled from the operator's cab16. A cutter head18is used in order to harvest crop containing corn and to conduct it to a slope conveyor20. The harvested crop is conducted to the guide drum22by a slope conveyor20disposed within the feederhouse. The guide drum22guides the harvested crop through an inlet transition section24to an axial harvested crop processing arrangement26. In the following, directions such as “front”, “forward”, and “forwardly” refer to the forward operation direction of the combine10that extends to the left inFIG. 1. Directions such as “rear”, “rearward”, and “rearwardly” referred to a direction opposite to the forward operation direction of the combine10.

The harvested crop processing arrangement26includes a rotor housing34with a rotor36arranged within it. The rotor36includes a hollow drum38to which crop processing elements are fastened for a charging section40, a threshing section42, and a separating section44. The charging section40is arranged on the front side of the harvested crop processing arrangement26. The threshing section42and the separating section44are located in the longitudinal direction downstream and to the rear of the charging section40. In the charging section40the drum38is in the form of a truncated cone. The threshing section42includes a forward section in the form of a truncated cone and a cylindrical rear section. The cylindrical separating section44of the drum38is located at the end of the axial harvested crop processing arrangement26. In place of an axial harvested crop processing arrangement26a tangential threshing drum followed by an axial separating section or a straw chopper could be used.

Corn and chaff that fall through a thresher basket associated with the threshing section42and a separating grate associated with the separating section44are conducted to a cleaning system28with a blower46, and sieves48,50with louvers, that can be oscillated in a fore-and-aft direction. The cleaning system28removes the chaff and guides the clean corn over a screw conveyor52to an elevator for clean corn (not shown). The elevator for clean corn deposits the clean corn in a corn tank30. The clean corn in the corn tank30can be unloaded by an unloading screw conveyor32to a corn wagon, trailer, or truck. Harvested crop remaining at the lower end of the lower sieve50is again conducted to the harvested crop processing arrangement26by means of a screw conveyor54and an overhead conveyor (not shown). The harvested crop residue delivered at the rear end of the upper sieve consists generally of chaff and small straw particles, and it is conveyed by an oscillating sheet conveyor56rearwardly and into a lower inlet58of a straw chopper60.

Threshed out straw that leaves the separating section44is ejected through an outlet62from the harvested crop processing arrangement26and conducted to an ejection drum64. The ejection drum64interacts with the sheet66located underneath it and ejects the straw to the rear. There is a wall68located to the rear of the ejection drum64that guides the straw into an upper inlet70of the straw chopper60.

The straw chopper60is composed of a housing72and a rotor74arranged within it that can rotate about an axis extending horizontally and transversely to the direction of operation together with chopper knives76, pendulously suspended in pairs and distributed about the circumference of the rotor74, that interact with opposing knives78, fixed to the housing. Downstream of an outlet80of the straw chopper60, two impeller blowers82are provided that are arranged side-by-side alongside each other (of which only one can be seen inFIG. 1). The impeller blowers82include a number of impeller blades84, each of which is connected rigidly to an upper circular disk86, that can rotate about a central axis of rotation88that extends generally vertically, but with a slight rearward inclination. The disks86with the impeller blades84that extend radially can be brought into rotation by a hydraulic motor90that is fastened above a bottom sheet92that is connected to the housing72of the straw chopper60.

It should be noted that an adjustable flap could be arranged between the ejection drum64and the upper inlet70of the straw chopper60, with which the straw could be selectively guided past the rear of the straw chopper60and deposited on the field in a swath in a long straw operating mode.

As can be seen inFIG. 2, the outer edges94of the impeller blades84are provided with a radius over their entire height that is complementary to the envelope96defined by the rotating chopper knives76, so that the distance between the envelope96of the chopper knives76and the edge94of the impeller blades84is constant over the entire height of the impeller blades84so that the impeller blades84conform to the envelope96of the chopper knives76. The diameter of the impeller blades84as measured in the radial direction is larger at its lower end that at its upper end. If the impeller blades84had maintained the diameter of the lower end over their entire height then they would have collided with the chopper knives76at their upper ends as indicated by the dashed lines. In other words, a recessed area100is created by the conical form of the impeller blades84, that otherwise would intrude into the envelope96of the chopper knives76. Due to the reduced spacing between the straw chopper60and the impeller blower82the transfer of the harvested crop is improved, so that any blockage of the harvested crop residue can be avoided even while providing greater throughput.

In the second embodiment, shown inFIG. 3, components identical to those of the first embodiment are identified with the same part number call outs. Essential differences betweenFIG. 2andFIG. 3that should be noted are that the disk86, the bottom sheet92, and the hydraulic motor90are arranged underneath the impeller blower82in the second embodiment. Furthermore, in the embodiment according toFIG. 3, the outer edges94of the impeller blades84are slanted in a straight line inward complementary to the envelope96in the upper partial region102, in order to create a recessed area100, without which the impeller blades84would collide with the chopper knives76as indicated by the dashed lines. The spacing between the envelope96of the chopper knives76and the edge94is nearly constant over the length of the partial region102. The outer edges94of the partial region102extend parallel to the axis of rotation88that is also oriented at an angle to the rear and upward. The housing72of the straw chopper60and the housing of the impeller blower82formed by the bottom sheet92and an upper sheet metal housing104are one-piece components.

In the third embodiment, shown inFIG. 4, corresponding elements of the second embodiment are identified by the same part number call-outs. The essential difference is seen in the fact that the straw chopper60delivers the harvested crop residue processed by it not at an angle to the rear and downward, as in the case of the first and second embodiment, but approximately vertically and downward into the impeller blower82. Accordingly, the axis of rotation88of the impeller blower82is located underneath the envelope96of the chopper knives76of the straw chopper60. Furthermore, in the embodiment according toFIG. 4, the outer edges94of the impeller blades84are provided with a radius conforming to the envelope96of the chopper knives76only in their upper partial region102and complementary to the envelope96in order to create a recessed area100, without which the impeller blades84would otherwise collide with the chopper knives76as indicated by the dashed lines. The spacing between the envelope96of the chopper knives76and the edge94is nearly constant over the length of the partial region102. Underneath the curved partial region102the outer edges94extend parallel to the axis of rotation88which extends exactly vertically. The housing72of the straw chopper60and the housing of the impeller blower82formed by the sheet metal bottom92and an upper sheet metal housing104are also configured as one piece components.