Abstract:
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.

Description:
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 claim  1  herein, 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. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Three embodiments of the invention are explained on the basis of the figures. 
         FIG. 1  shows a partial section in side view of a combine with a straw chopper and a first embodiment of an impeller blower. 
         FIG. 2  shows an enlarged side view of the straw chopper and the impeller blower of  FIG. 1 . 
         FIG. 3  shows a side view of a second embodiment of a straw chopper and an impeller blower. 
         FIG. 4  shows a side view of a third embodiment of a straw chopper and an impeller blower. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       FIG. 1  shows an agricultural combine  10  with a chassis  12  with wheels  14  in contact with the ground that are fastened to the chassis  12  and are used for the propulsion of the combine  10  in the forward operating direction that extends to the left in  FIG. 1 . The operation of the combine  10  is controlled from the operator&#39;s cab  16 . A cutter head  18  is used in order to harvest crop containing corn and to conduct it to a slope conveyor  20 . The harvested crop is conducted to the guide drum  22  by a slope conveyor  20  disposed within the feederhouse. The guide drum  22  guides the harvested crop through an inlet transition section  24  to an axial harvested crop processing arrangement  26 . In the following, directions such as “front”, “forward”, and “forwardly” refer to the forward operation direction of the combine  10  that extends to the left in  FIG. 1 . Directions such as “rear”, “rearward”, and “rearwardly” referred to a direction opposite to the forward operation direction of the combine  10 . 
     The harvested crop processing arrangement  26  includes a rotor housing  34  with a rotor  36  arranged within it. The rotor  36  includes a hollow drum  38  to which crop processing elements are fastened for a charging section  40 , a threshing section  42 , and a separating section  44 . The charging section  40  is arranged on the front side of the harvested crop processing arrangement  26 . The threshing section  42  and the separating section  44  are located in the longitudinal direction downstream and to the rear of the charging section  40 . In the charging section  40  the drum  38  is in the form of a truncated cone. The threshing section  42  includes a forward section in the form of a truncated cone and a cylindrical rear section. The cylindrical separating section  44  of the drum  38  is located at the end of the axial harvested crop processing arrangement  26 . In place of an axial harvested crop processing arrangement  26  a 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 section  42  and a separating grate associated with the separating section  44  are conducted to a cleaning system  28  with a blower  46 , and sieves  48 ,  50  with louvers, that can be oscillated in a fore-and-aft direction. The cleaning system  28  removes the chaff and guides the clean corn over a screw conveyor  52  to an elevator for clean corn (not shown). The elevator for clean corn deposits the clean corn in a corn tank  30 . The clean corn in the corn tank  30  can be unloaded by an unloading screw conveyor  32  to a corn wagon, trailer, or truck. Harvested crop remaining at the lower end of the lower sieve  50  is again conducted to the harvested crop processing arrangement  26  by means of a screw conveyor  54  and 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 conveyor  56  rearwardly and into a lower inlet  58  of a straw chopper  60 . 
     Threshed out straw that leaves the separating section  44  is ejected through an outlet  62  from the harvested crop processing arrangement  26  and conducted to an ejection drum  64 . The ejection drum  64  interacts with the sheet  66  located underneath it and ejects the straw to the rear. There is a wall  68  located to the rear of the ejection drum  64  that guides the straw into an upper inlet  70  of the straw chopper  60 . 
     The straw chopper  60  is composed of a housing  72  and a rotor  74  arranged within it that can rotate about an axis extending horizontally and transversely to the direction of operation together with chopper knives  76 , pendulously suspended in pairs and distributed about the circumference of the rotor  74 , that interact with opposing knives  78 , fixed to the housing. Downstream of an outlet  80  of the straw chopper  60 , two impeller blowers  82  are provided that are arranged side-by-side alongside each other (of which only one can be seen in  FIG. 1 ). The impeller blowers  82  include a number of impeller blades  84 , each of which is connected rigidly to an upper circular disk  86 , that can rotate about a central axis of rotation  88  that extends generally vertically, but with a slight rearward inclination. The disks  86  with the impeller blades  84  that extend radially can be brought into rotation by a hydraulic motor  90  that is fastened above a bottom sheet  92  that is connected to the housing  72  of the straw chopper  60 . 
     It should be noted that an adjustable flap could be arranged between the ejection drum  64  and the upper inlet  70  of the straw chopper  60 , with which the straw could be selectively guided past the rear of the straw chopper  60  and deposited on the field in a swath in a long straw operating mode. 
     As can be seen in  FIG. 2 , the outer edges  94  of the impeller blades  84  are provided with a radius over their entire height that is complementary to the envelope  96  defined by the rotating chopper knives  76 , so that the distance between the envelope  96  of the chopper knives  76  and the edge  94  of the impeller blades  84  is constant over the entire height of the impeller blades  84  so that the impeller blades  84  conform to the envelope  96  of the chopper knives  76 . The diameter of the impeller blades  84  as measured in the radial direction is larger at its lower end that at its upper end. If the impeller blades  84  had maintained the diameter of the lower end over their entire height then they would have collided with the chopper knives  76  at their upper ends as indicated by the dashed lines. In other words, a recessed area  100  is created by the conical form of the impeller blades  84 , that otherwise would intrude into the envelope  96  of the chopper knives  76 . Due to the reduced spacing between the straw chopper  60  and the impeller blower  82  the 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 in  FIG. 3 , components identical to those of the first embodiment are identified with the same part number call outs. Essential differences between  FIG. 2  and  FIG. 3  that should be noted are that the disk  86 , the bottom sheet  92 , and the hydraulic motor  90  are arranged underneath the impeller blower  82  in the second embodiment. Furthermore, in the embodiment according to  FIG. 3 , the outer edges  94  of the impeller blades  84  are slanted in a straight line inward complementary to the envelope  96  in the upper partial region  102 , in order to create a recessed area  100 , without which the impeller blades  84  would collide with the chopper knives  76  as indicated by the dashed lines. The spacing between the envelope  96  of the chopper knives  76  and the edge  94  is nearly constant over the length of the partial region  102 . The outer edges  94  of the partial region  102  extend parallel to the axis of rotation  88  that is also oriented at an angle to the rear and upward. The housing  72  of the straw chopper  60  and the housing of the impeller blower  82  formed by the bottom sheet  92  and an upper sheet metal housing  104  are one-piece components. 
     In the third embodiment, shown in  FIG. 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 chopper  60  delivers 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 blower  82 . Accordingly, the axis of rotation  88  of the impeller blower  82  is located underneath the envelope  96  of the chopper knives  76  of the straw chopper  60 . Furthermore, in the embodiment according to  FIG. 4 , the outer edges  94  of the impeller blades  84  are provided with a radius conforming to the envelope  96  of the chopper knives  76  only in their upper partial region  102  and complementary to the envelope  96  in order to create a recessed area  100 , without which the impeller blades  84  would otherwise collide with the chopper knives  76  as indicated by the dashed lines. The spacing between the envelope  96  of the chopper knives  76  and the edge  94  is nearly constant over the length of the partial region  102 . Underneath the curved partial region  102  the outer edges  94  extend parallel to the axis of rotation  88  which extends exactly vertically. The housing  72  of the straw chopper  60  and the housing of the impeller blower  82  formed by the sheet metal bottom  92  and an upper sheet metal housing  104  are also configured as one piece components.