Abstract:
Rotary accelerating apparatus for a vertical crop residue spreader of an agricultural combine capable of receiving, combining and accelerating a relatively high velocity of voluminous flow of relatively heavy, bulky crop residue including straw and the like deflected downwardly from the thresher of the combine, and a weaker, less voluminous flow of chaff and air from the cleaning system of the combine located forwardly of the spreader, by generating a negative pressure or suction condition in the vicinity of the chaff flow for overcoming any undesirable back pressure condition that interferes with induction of the crop residue flow from the cleaning system and which facilitates air flow through the chassis region of the combine to reduce conditions leading to undesirable dust buildup and other problems.

Description:
TECHNICAL FIELD  
       [0001]     This invention relates generally to a vertical straw and chaff spreader for an agricultural combine, and more particularly, to rotary crop residue accelerating apparatus for a vertical spreader including blades having features for improving induction of chaff and air into the spreader from a cleaning system of the combine and improving air flow through the combine chassis, for mixing with a flow of heavier straw from above and accelerating and discharging the mixture sidewardly from the spreader.  
       BACKGROUND ART  
       [0002]     Rotary crop residue spreaders for agricultural combines are well known in the art. Commonly, such spreaders are of the horizontal type, that is, they include one or more horizontal disks supported for rotation about an axis oriented vertically or at a small acute angle to vertical, and a plurality of radially extending blades attached to an upper surface of the disk for receiving straw from the threshing system of the combine and/or chaff from the cleaning system and directing a flow of the residue sidewardly and/or rearwardly from the spreader. Reference in this regard, the spreaders shown in U.S. Pat. Nos. 6,406,368; 6,343,986; and 6,209,808. Reference also U.S. Pat. No. 4,591,102 which discloses a horizontal chaff spreader including blades rotatable in a horizontal plane above a base plate for receiving crop residue blown and/or dropped from above and accelerating and discharging the residue through sidewardly directed chutes. An advantage of the known horizontal crop residue spreaders is that the crop residue, be it straw and/or chaff, essentially falls from above into the spreader such that induction and mixing of the crop residue for acceleration and discharge from the spreader is not problematic. However, a disadvantage of the known horizontal type crop residue spreaders such as those disclosed above, include that they have a relatively large forward to rearward horizontal extent, and must be located beneath an outlet or other pathway of crop residue from the spreader, for instance, a rear opening to a cleaning system of the combine, so as to make access to the cleaning system and other components in the rear of the combine inconvenient and more difficult than is desirable.  
         [0003]     To overcome the above referenced disadvantages, it is desired to utilize a vertical spreader, that is, one including accelerating apparatus or elements that rotate in a vertical plane, or a plane oriented at only a small acute angle to vertical, about a rotational axis oriented horizontally or at a small acute angle to horizontal generally less than about  45  degrees, and located in a rear opening of a combine. It is also desired for the spreader to be to movable away from the opening to allow access to the cleaning system and other components in the rear of the combine. However, by using the vertical orientation, the spreader must have the capability for simultaneously receiving or inducting both the heavier, bulkier crop residue discharged from the threshing mechanism of the combine, which heavier residue typically includes straw, husks, cobs, stems, and the like and is typically propelled rearwardly by a rapidly rotating and powerful beater or straw walker and is deflected downwardly toward the rear opening of the combine, and the lighter, fluffier, and less bulky chaff which includes pod fragments and the like which are separated by the cleaning system from the grain or other crop and blown much more gently rearwardly toward the rear opening.  
         [0004]     More particularly, typically, the straw and other heavier, bulkier crop residue is blown or propelled rearwardly from the threshing region with considerable force, and then is deflected downwardly toward the rear opening. In contrast, the chaff and other crop residue from the cleaning system is propelled much less forcefully, using air flow from a fan, as it is not desired for the grain or other crop, which is relatively lightweight, to be blown out of the rear opening and lost. It is typical to desire for the crop residue to be spread relatively evenly over the swath of the combine as it moves along a field, it being possible for a swath to have an extent of 40 feet or more for some large farming operations. Therefore, for a vertical spreader including two counter-rotating crop accelerating elements, it would be expected for each element to be capable of propelling crop residue a distance equal to about one-half of the combine swath, or up to as much as 20 feet or so, in the instance of the larger combines. To achieve such a propulsion requirement, it is necessary for the rotary accelerating apparatus to be rotated at a relatively high rotational speed. It is also desirable for blades or other impellers of the rotary accelerating apparatus to be sufficiently large for handling anticipated volumes of crop residue, particularly the bulkier material from the thresher. However, vertical crop residue spreaders including rapidly rotating rotary accelerating apparatus having such relatively large blades have been found to generate an undesirable back pressure condition forwardly of the blades in the region for receiving and inducting the chaff from the cleaning system, which results in a build-up of crop residue in that region and even blow back of crop residue into the cleaning system area. Also, a less than desirable degree or level of rearward flow of air through the rear opening of the combine may be achieved, which can cause an undesirable dust buildup in the more forward chassis region of the combine.  
         [0005]     Still another variable to be factored when using a vertical spreader which is not as problematic for a horizontal spreader is the size and rearward extent of the rear wheels of the combine. That is, some combines have driven rear wheels and/or may be larger machines so as to require larger rear wheels that extend rearwardly to beside the rear opening of the combine. As a result, for the sideward discharge of the spreader to pass the larger rear wheels it may be required to tilt the spreader rearwardly to an orientation at an angle to vertical. This can result in at least the lower portion of the spreader being located farther rearwardly of or in the rear opening, such that desired air and chaff flow characteristics into the spreader are more difficult to achieve.  
         [0006]     Thus, what is sought is apparatus that overcomes the problems, shortcomings and disadvantages set forth above.  
       SUMMARY OF THE INVENTION  
       [0007]     What is disclosed is rotary accelerating apparatus for a vertical crop residue spreader of an agricultural combine, that is capable of receiving, combining and accelerating a relatively high velocity of voluminous flow of relatively heavy, bulky crop residue including straw and the like deflected downwardly from the thresher of the combine, and a weaker, less voluminous flow of chaff and air from the cleaning system of the combine located forwardly of the spreader, by generating a negative pressure or suction condition in the vicinity of the chaff flow for overcoming any undesirable back pressure condition that interferes with induction of the crop residue flow from the cleaning system and which facilitates air flow through the chassis region of the combine to reduce conditions leading to undesirable dust buildup and other problems.  
         [0008]     According to one aspect of the invention, the rotary crop residue accelerating apparatus includes a rotatable member mountable in an upwardly and forwardly open housing of the spreader for rotation therein in a predetermined rotational direction about a forwardly and rearwardly extending rotational axis oriented generally horizontally or at a small acute angle to horizontal and extending through a center of the rotatable member. The apparatus includes a plurality of blades connected to and supported by the rotatable member at angularly spaced locations around the rotational axis, respectively, for rotation with the rotatable member within the housing adjacent to a forwardly and upwardly facing opening thereof through which a downwardly directed first flow of crop residue is to be received, each of the blades having a surface oriented to face in the rotational direction for propelling and accelerating the crop material flow through and from the housing, and each of the blades including a forward surface portion disposed to rotate adjacent to a forwardly facing portion of the opening through which a second flow of crop material is to be received, the first surface portion including a radial outer tip portion that extends radially outwardly and forwardly from the blade and has a shape and orientation which during the rotation will generate a negative pressure condition in a region forwardly of the forwardly facing opening of the housing for inducting the second flow into the housing therethrough.  
         [0009]     According to a preferred aspect of the invention the radial outer tip portion of each of the blades is curved or bent so as to extend forwardly in the rotational direction and terminates at an edge portion spaced in the rotational direction from the surface of the blade. According to another preferred aspect the radial outer tip portion of each of the blades includes a radially inner edge portion which tapers forwardly and radially outwardly to a forwardmost edge portion of the outer tip portion. According to another aspect the radial outer tip portion adjacent to the edge portion or the edge portion itself is oriented at an acute angle relative to the rotational direction greater than zero and less than about 40 degrees and more preferably at an angle from about 30 to about 40 degrees relative to the rotational direction. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]      FIG. 1  is a fragmentary, simplified representation of a rear end of an agricultural combine, including a vertical straw and chaff spreader including rotary accelerating apparatus according to the present invention;  
         [0011]      FIG. 2  is an enlarged fragmentary perspective view of the spreader and rotary accelerating apparatus of  FIG. 1 , illustrating crop residue flow into and out of the spreader;  
         [0012]      FIG. 3  is a front view of the spreader and rotary accelerating apparatus of  FIG. 1 , showing crop residue flow;  
         [0013]      FIG. 4  is an enlarged fragmentary side representation of the rear end of the combine and the spreader of  FIG. 1 , illustrating crop residue flow into the spreader;  
         [0014]      FIG. 5A  is a perspective view of rotary accelerating apparatus of  FIG. 1 ;  
         [0015]      FIG. 5B  is a perspective view of an alternative rotary accelerating apparatus of the invention;  
         [0016]      FIG. 6  is an enlarged side view of the accelerating apparatus of  FIG. 5B ;  
         [0017]      FIG. 7  is a rear perspective view of the accelerating apparatus of  FIG. 5B ; and  
         [0018]      FIG. 8  is an enlarged perspective representation of another rotary accelerating apparatus of the invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0019]     Referring now to the drawings, wherein preferred embodiments of the present invention are shown, in  FIG. 1 , a rear end  10  of a typical self-propelled agricultural combine  12  is shown, including a rotary crop residue spreader  14  including rotary crop residue accelerating apparatus  16  constructed and operable according to the teachings of the present invention. Briefly, combine  12  includes a threshing mechanism  18  which separates straw, including stalks, cobs, stems, weeds and other larger plant matter, from the harvested crop, and feeds that material to a rotating straw walker or beater mechanism  20  which carries or propels a flow  22  of the straw rearwardly, denoted by arrows A through an internal duct of combine  12  and against a deflector plate  24 , which helps deflect the flow  22  downwardly, denoted by arrows B, into spreader  14 . At the same time, cleaning apparatus  26  of combine  12  separates chaff, such as seed pods and husks, from the threshed grain, using a rearwardly and upwardly directed flow of air from a forwardly located fan (not shown) and blows and directs a flow of the air and chaff, denoted by arrows C, rearwardly toward spreader  14 .  
         [0020]     Referring also to  FIGS. 2 and 3 , wherein only spreader  14  is shown, spreader  14  includes a housing  28  having a rear wall  30  and side walls  32  and  34 , defining and partially enclosing a pair of side-by-side spaces  36 , each including a crop residue accelerating apparatus  16  for rotation therein in a predetermined rotational direction, as denoted by arrows D. Housing  28  defines an upwardly and forwardly open inlet region  38  positioned to receive the generally downwardly extending flow of straw, denoted by arrows B, and a forwardly and upwardly open region  40  positioned for receiving the forward to rearward flow of chaff, denoted by arrows C, such that rotation of crop residue accelerating apparatus  16  in the rotational directions D will accelerate and discharge the flows through opposite sidewardly facing openings  42 , as denoted by arrows E. Each crop residue accelerating apparatus  16  is mounted on a rotatable shaft  44  for rotation therewith, each shaft  44  extending through an opening in rear wall  30  and being drivingly connected to a motor  46 , which can be, for instance, an electric motor, fluid motor, or the like ( FIG. 1 ), operable for rotating shaft  44  and crop residue accelerating apparatus  16  for accelerating and propelling or discharging the crop residue, as denoted by arrows E, a desired distance from spreader  14 .  
         [0021]     In  FIG. 4 , rear end  10  of combine  12  is shown, to better illustrate crop residue flow to spreader  14 . Here, the downward direction of flow  22 , denoted by arrows B is better shown, as is the rearward flow, denoted by arrows C of the chaff. The more rearward of arrows C adjacent to spreader  14  are shown as enlarged relative to the more forwardly located arrows C. This is to represent the improved induction of the chaff flow into spreader  14 , as achieved by the improved design of rotary accelerating apparatus  16  according to the present invention, as will be explained.  
         [0022]     Referring also to  FIG. 5A , which shows the crop residue accelerating apparatus  16  of  FIGS. 1-4 , and  FIGS. 5B, 6  and  7 , which show an alternative embodiment of the crop residue accelerating apparatus  16 , each apparatus  16  includes a central hub  48  which mounts on shaft  44  for rotation therewith in the rotational direction D ( FIGS. 2 and 3 ), about a rotational axis  50  of shaft  44 . Hub  48  is preferably a tubular or hollow cylindrical or similar shape member including a first axial end portion  52 , a second axial end portion  54  axially spaced from and opposite axial end portion  52 , and an axial hole  56  at least partially through hub  48  for receiving shaft  54 . First axial end portion  52  preferably includes a radially outwardly extending annular flange  58  therearound, supported by a plurality of axially extending ribs  60  connected to flange  58  and hub  48  at angularly spaced locations therearound. A blade support member  62 , preferably of sheet metal construction, is mounted to flange  58  of first axial end portion  52  of hub  48  in a suitable manner such as by a plurality of bolts  64  which pass through holes in flange  58  and member  62 , and which are secured by nuts  66 , for rotation with hub  48  about rotational axis  50 . Member  62  preferably extends at least substantially around hub  48  and includes a plurality of arms  68  located at angularly spaced locations around axis  50  and extending radially outwardly relative to hub  48 . In the embodiment shown in  FIG. 5A  there is a pair of arms  68  at each angularly spaced location, one arm  68  being oriented so as to extend at a forwardly directed angle relative to axis  50 , and one arm  68  being oriented to extend at a rearwardly directed angle. In the embodiment shown in  FIGS. 5B, 6  and  7 ; in contrast, only a single arm  68  is utilized at each location. Each arm  68  preferably has a generally radially outwardly extending leading edge portion  70 , and a trailing edge portion  72  which is angularly related to leading edge portion  70 . In the embodiment of  FIGS. 5B, 6  and  7 , each leading edge portion  70  includes an elongate tab  74  oriented so as to have a surface facing the rotational direction.  
         [0023]     A blade  76  is suitably mounted to the arm or arms  68  at each location around hub  48  so as to extend radially outwardly and forwardly relative to hub  48 . In the embodiment of  FIG. 5A , blades  76  are shown welded to arms  68 , whereas in the embodiment of  FIGS. 5B, 6  and  7 , blades  76  are attached by a plurality of bolts  64  which pass through holes in tabs  74  and are secured by nuts  66 . In both embodiments, either bolts or welds can be used for attachment. Each blade  76  has a surface  78  oriented to face in the rotational direction (arrows D) and including a first axial edge  80 , and a second axial edge  82  opposite edge  80 , edges  80  and  82  extending generally radially outwardly relative to rotational axis  50 , and-each blade  76  including an intermediate or mounting portion  84  preferably located intermediate or in spaced relation between edges  80  and  82 .  
         [0024]     Surface  78  of each blade  76  is relatively large and includes a first surface portion  86  extending from first axial edge  80  generally or about to mounting portion  84 , and a second surface portion  88  extending generally or about from mounting portion  84  to second axial edge  82 . First surface portion  86  is positioned to be in the downward path of the flow of straw denoted by arrows B ( FIGS. 1-4 ) and also in or just rearwardly of region  40  ( FIGS. 2-4 ) so as to be in or adjacent to the rearward flow of chaff denoted by arrows C. Second surface portion  88  is positioned to be directly in the downward path of the flow of straw denoted by arrows B.  
         [0025]     As a result of the relatively large extent of blades  76 , the relatively fast rotational speed of rotation, and the volume and force of the downward straw flow denoted by arrows B, it has been observed that back pressure can be generated in region  40  ( FIGS. 2-4 ) forwardly of accelerating apparatus  16 , which back pressure can be sufficient to inhibit and significantly reduce the chaff and air flow denoted by arrows C into spreader  14 . As a result, the chaff and other crop residue can build up in the area of the rear opening of the combine, thereby reducing the efficiency of the cleaning system, and the intended spreading function of spreader  14 . Additionally, it is desirable to have a forward to rearward flow of air through the chassis region of the combine for cooling and dust control purposes, which flow is also reduced or inhibited by the back pressure conditions, and can result in dust buildup on surfaces in the chassis.  
         [0026]     To counter this problem, first surface portion  86  of each blade  76  has a forward radial outer tip portion  90  thereof which, importantly, during rotation of the crop residue accelerator  14  counteracts and eliminates the positive pressure or back pressure condition generated by blades  76 , and instead, generates a negative pressure or suction condition in region  40 . As a result, instead of inhibiting or rejecting the chaff flow C, the shape of blades  76  function as a fan or impeller for positively inducting or pulling the chaff and air flow into the path of blades  76 . This is achieved by the shape and orientation of outer tip portion  90 . Tip portion  90  has a gently angled or curved shape which extends forwardly and toward the direction of rotation D from surface portion  86  to a radially extending outermost edge portion  92  spaced from surface portion  86  in the direction of rotation D. Edge portion  92  of tip portion  90  is preferably oriented at a small acute angle to the rotational direction as determined in the vicinity of the respective tip portion  90  so as to generate a rearward air flow during the rotation, which angle can be within a range of from just a few degrees to up to about 40 degrees, depending on the conditions of a particular application.  
         [0027]     As a result, the lighter flow of chaff denoted by arrows C inducted into the path of the rotating blades  76  by the negative pressure condition generated by tip portions  90  is mixed with the flow of the heavier straw. The large axial and radial outward extents of blades  76 , provides a large surface area for receiving the straw and chaff for mixing them and accelerating the mix outwardly from spreader  14  in a relatively wide discharge pattern for distributing it over a desirably large area of a field.  
         [0028]     The construction of blades  76  and the attachment to arm or arms  68  also results in a favorable resultant force loading on blades  76  and distribution or transfer of the force loads to arms  68 . More particularly, blades  76  are shaped and sized, and mounting portions  84  thereof are located, such that the flow of straw denoted by arrows B, which is relatively heavy and powerful, is directed more toward and propelled by the stronger and better supported region of each blade  76  which primarily includes second surface portion  88  and mounting portion  84 . In this regard, it should be observed that the single or pair of arms  68  are generally aligned with about the center of the path of the heavier flow of straw. In the embodiment of FIG.  5 A, the use of a pair of angularly related arms  68 , one of which extends more forwardly, provides better support for the forwardly located first surface portion  86  and tip portion  90  of the blade. In the embodiment of  FIGS. 5B, 6  and  7 , the central region  96  of second surface portion  88  of each blade  76  is backed up and supported by tab  74  of arm  68 . In both mounting arrangements the result is to advantageously strengthen central region  96  and better transfer resulting loads thereon to arm or arms  68 . It should also be noted that rear wall  30  of housing  28  includes an optional deflector plate  98  positioned for deflecting or guiding more rearwardly located portions of the flow of straw B forwardly toward blades  76 .  
         [0029]     Second axial edges  82  of blades  76  are positioned in sufficiently close axially spaced relation to deflector plate  98  ( FIG. 4 ) and rear wall  30  such that apparatus  16  is able to contact and carry the straw into space  36  such that the straw has less of a tendency to build up in the rear regions of spreader  14 . Still further, it should be noted that the extent of blade support members  62  between adjacent ones of blades  76  provides at least a partial barrier to keep longer plant material from wrapping around blades  76  and hub  48 .  
         [0030]     Referring to  FIG. 8 , another rotary crop accelerating apparatus  100  constructed and operable according to the teachings of the present invention is shown, like parts of accelerating apparatus  100  and apparatus  16  being identified by like numbers. Crop residue accelerating apparatus  100  includes a central hub  48  which mounts on a shaft of a motor  46  ( FIG. 1 ) which can be, for instance, an electric motor, fluid motor, or the like, operable for rotating the shaft and crop residue accelerating apparatus  100  in a rotational direction, denoted by arrows D ( FIG. 2  and  3 ) for accelerating and propelling or discharging the crop residue a desired distance from spreader  14  as denoted by arrows E ( FIG. 2 ). Hub  48 , again, is preferably a tubular or hollow cylindrical or similar shape member including a first axial end portion  52 , a second axial end portion  54  axially spaced from an opposite axial end portion  52 , and an axial hole (not shown) for receiving the shaft of motor  46 . Also as before, first axial end portion  52  of hub  48  includes a radially outwardly extending annular flange  58  therearound ( FIGS. 6 and 7 ), supported by a plurality of axially extending ribs  60  connected to flange  58  and hub  48  at angularly spaced locations therearound. A generally planar or flat blade support member  62  is mounted to flange  58 , again in a suitable manner, such as by a plurality of bolts for a rotation with hub  48  about a rotational axis  50 . Member  62  preferably extends at least substantially around hub  48 , and includes a plurality of arms  68  located at angularly spaced locations around axis  50  and extending radially outwardly relative to hub  48 . Accelerating apparatus  100  is shown including the arm configuration of  FIG. 5A  wherein only a single arm  68  is utilized at each location around hub  48 , but the dual arm configuration of  FIGS. 5B, 6  and  7  could alternatively be used. Again, each arm  68  preferably has a generally radially outwardly extending leading edge portion  70 , and a trailing edge portion  72  which is angularly related to leading edge portion  70 . Each leading edge portion  70  includes an elongate tab  74  oriented so as to have a surface facing the rotational direction. A blade  116  is mounted to each arm  68  so as to extend radially outwardly relative to hub  48 , preferably by a plurality of bolts  64  secured by nuts or the like. Each blade  116  has a surface  78  oriented to face in the rotational direction (arrows D in  FIG. 2 ) and including a first axial edge  80 , and a second axial edge  82  opposite edge  80 , edges  80  and  82  extending generally radially outwardly relative to rotational axis  50 , and each blade  116  including an intermediate or mounting portion  84  preferably located intermediate or in spaced relation between edges  80  and  82 .  
         [0031]     Surface  78  of each blade  116  includes a first surface portion  86  extending from first axial edge  80  generally or about to mounting portion  84 , and a second surface portion  88  extending generally or about from mounting portion  84  to second axial edge  82 , first surface portion  86  being positioned generally or primarily adjacent to the path of the flow of chaff and air denoted by arrows C ( FIGS. 1-4 ), and a second surface portion  88  being positioned primarily in the path of the flow of straw, denoted by arrows B. First surface portion  86  of each blade  116  has a forward radial outer tip portion  118  thereof which is gradually curved or bent such that a radially extending outermost edge portion  92  thereof is oriented at small acute angle relative to the rotational direction within the above range, which is important for achieving the operational benefits set forth above, namely, the generation of a negative pressure condition or suction in region  40  for drawing or inducting chaff and air-flow C into the path of blades  116 .  
         [0032]     It will be understood that changes in the details, materials, steps, and arrangements of parts which have been described and illustrated to explain the nature of the invention will occur to and may be made by those skilled in the art upon a reading of this disclosure within the principles and scope of the invention. The foregoing description illustrates the preferred embodiment of the invention; however, concepts, as based upon the description, may be employed in other embodiments without departing from the scope of the invention. Accordingly, the following claims are intended to protect the invention broadly as well as in the specific form shown.