Patent Publication Number: US-2023157210-A1

Title: Threshing system and chopper for combine harvester

Description:
FIELD OF THE INVENTION 
     The present invention relates to a threshing system and chopper for a combine harvester. 
     BACKGROUND OF THE INVENTION 
     As is described in U.S. Pat. No. 8,092,286 to CNH America LLC (the &#39;286 Patent), which is incorporated by reference in its entirety and for all purposes, in the operation of a typical agricultural combine that employs a threshing rotor, the flow of crop residue remaining after threshing, sometimes referred to as material other than grain (MOG), is typically discharged into a crop residue treatment and distribution system for treatment thereby and for ultimate distribution onto or over a field. Straw and residue chopper assemblies and residue spreader assemblies of various types and constructions have long been in use in or with such residue treatment and distribution systems. Such assemblies chop or pulverize the crop residue resulting from a harvesting operation into finer pieces and/or to spread the resulting crop residue, whether chopped into finer pieces by operation of a chopper assembly or passed to the spreader assembly as larger pieces of residue, onto and over the field. Operators seek to vary the cut length and chop quality of the MOG based upon the crop being harvested and the desired residue management practice. Described herein is a threshing system and chopper that enables operators to vary the cut length and chop quality. 
     SUMMARY OF THE INVENTION 
     According to one aspect of the invention, a combine harvester comprises a cage at least partially surrounding a rotor for threshing crops in a space between the cage and the rotor; an auger at least partially positioned within the cage and connected to said rotor for rotating therewith, said auger comprising vanes for transporting crop in a transport direction from the rotor and towards an outlet of the cage; and a chopper positioned either at or adjacent the outlet of the cage, wherein a rotational axis of the chopper is substantially aligned with an axis of rotation of the auger and the rotor. 
     According to another aspect of the invention, a combine harvester comprises a cage at least partially surrounding a rotor for threshing crops in a space between the cage and the rotor; an auger at least partially positioned within the cage and connected to said rotor for rotating therewith, said auger comprising vanes for transporting crop in a transport direction from the rotor and towards an outlet of the cage, wherein the auger has a body and vanes extending from an exterior surface of the body, and wherein a height of the vanes decreases in the transport direction, a pitch of the vanes increases in the transport direction, and a volume space disposed between adjacent convolutions of the vanes is substantially constant in the transport direction; and a chopper positioned either at or adjacent the outlet of the cage. 
     According to yet another aspect of the invention, a combine harvester comprises: a cage at least partially surrounding a rotor for threshing crops in a space between the cage and the rotor; a chopper positioned either at or adjacent an outlet of the cage, wherein a rotational axis of the chopper is substantially aligned with an axis of rotation of the rotor; and means for driving the chopper at a different rate of rotation than a rate of rotation of the rotor. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of an embodiment of the invention taken in conjunction with the accompanying drawings, wherein: 
         FIG.  1    is a simplified side plan view of an agricultural combine, illustrating, in dotted outline, an axially arranged threshing system of the combine and an integral chopper assembly of the residue treatment and distribution system of the combine. 
         FIG.  2    is a simplified side plan view of the threshing system and a portion of the crop residue treatment and distribution system of the combine of  FIG.  1   , further illustrating the flow of crop residue to and through the integral chopper assembly. 
         FIG.  3    is a schematic block diagram of a threshing system and a portion of a crop residue treatment and distribution system according to an exemplary embodiment. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Corresponding reference characters indicate corresponding parts throughout the several views. The exemplification set out herein illustrates an embodiment of the invention, in one form, and such exemplification is not to be construed as limiting the scope of the invention in any manner. 
     For convenience of reference and understanding in the following discussions, and with respect to the various drawings and their descriptions, the point of reference for the use of various terms that are hereafter employed, including “left”, “right”, “forward”, “rearward”, “front”, “back”, “top”, and “bottom”, should generally be considered to be taken from a point at the rear of the combine harvester machine facing in its normal direction of travel, unless it is clear from the discussion and context that a different point of reference is appropriate. Any use of such terms should therefore be considered exemplary and should not be construed as limiting or introducing limitations. 
     Moreover, inasmuch as various components and features of harvesters and fan assemblies are of well-known design, construction, and operation to those skilled in the art, the details of such components and their operations will not generally be discussed in significant detail unless considered of pertinence to the present invention or desirable for purposes of better understanding. 
     In the drawings, like numerals refer to like items, certain elements and features may be labeled or marked on a representative basis without each like element or feature necessarily being individually shown, labeled, or marked, and certain elements are labeled and marked in only some, but not all, of the drawing figures. 
       FIGS.  1  and  2    depict a representative agricultural combine  20  that includes a longitudinally axially arranged threshing system  22  and a crop residue treatment and distribution system  24  with a crop residue spreader  26 , all of which, are of well-known construction and operation. Threshing system  22  is axially arranged in that it includes a cylindrical threshing rotor  28  that is conventionally supported and rotatable in a predetermined, typically clockwise direction, about a rotational axis  30  therethrough and within a concave  32  ( FIG.  2   ), for conveying a flow of crop material in a helical flow path through a space  34  extending circumferentially around an outer cylindrical surface  35  of rotor  28  and an inner circumferential surface  38  of concave  32 . Rotor  28  has a set of helical vanes  31  on its exterior surface, as shown. As the crop material is moved through space  34 , the crop, such as grain, legumes, or the like, will be loosened and separated from crop residue such as husk and pods, and carried away therefrom in the well-known conventional manner. 
     As may be best illustrated by  FIG.  2   , the crop residue will continue along a helical path through space  34 , and will be expelled therefrom, as denoted by arrows B, into and through a discharge opening and passage  36 , which essentially comprises an extension of space  34  at the downstream end of threshing rotor  28 . The consistency of the flow of crop residue, volume thereof, and extent or pattern thereof, will typically vary, and be a function of a variety of conditions, including, but not limited to, the speed of rotation of rotor  28 , crop type, plant maturity, moisture content, and weather conditions. As an example, rotor speeds can vary between just a few hundred RPM and over 1000 RPM. Wheat and other small grains will typically have relatively small crop residue components, whereas other grains, such as corn, will typically have larger components, such as thick stalk segments, cob fragments, and large leaves. 
     Crop residue treatment and distribution system  24  includes a transport and chopping assembly, such as integral chopper assembly  46 , sometimes hereinafter referred to as rotary assembly  46  having a rotary chopper element  47  rotatable in a direction E above a concave pan assembly such as chopper grate assembly  48 . Rotary chopper element  47  typically rotates at a rapid speed, so as to be capable of accelerating and propelling a flow of crop residue rearwardly within the confines of the rear end of combine  20 , as generally denoted by arrows F. Such rearward flow is typically guided and directed by internal panels or shields, generally denoted by shields  50  ( FIG.  1   ), so as to either flow through a rear opening so as to be deposited directly onto a field, such as in a windrow, or flow into a secondary crop residue chopper and/or spreader, such as chopper/spreader  26 , for spreading thereby in a swath on the field. Further details of combine  20  are described in the &#39;286 Patent. 
     Turning now to  FIG.  3   , that figure depicts a schematic block diagram of a threshing system and a portion of a crop residue treatment and distribution system according to an exemplary embodiment. The threshing system and crop residue treatment and distribution system are referred to generally herein as “systems  300 .” It is noted at the outset that the systems  300  of  FIG.  3    differ from those systems of  FIGS.  1  and  2   , however, the systems  300  of  FIG.  3    may be incorporated into the combine  20  of  FIGS.  1  and  2   . 
     More particularly, systems  300  includes an extended cylindrical cage  32 ′ (the prime designation indicating that the cage  32 ′ corresponds to the concave  32  of  FIG.  1   ) defining a hollow interior region in which a rotor  28 ′ and an auger  302  are positioned. Cage  32 ′ may be one continuous cylinder, as shown, or, alternatively, cage  32 ′ may represent multiple parts that are fixedly mounted together along axis  30 ′. Cage  32 ′ comprises a concave, and the concave includes a series of openings  303  that are disposed beneath rotor  28 ′ and (optionally) auger  302 . In operation, threshed grain falls through openings  303  and onto sieves (not shown). 
     Rotor  28 ′ and auger  302  are non-rotatably connected together by a shaft  304 ; non-rotatably meaning that rotor  28 ′ and auger  302  rotate together in the same rotational direction. Rotor  28 ′ has helical vanes  31 ′ for moving crop material in the direction of arrow X in  FIG.  3   . Arrow X depicts the transport direction of MOG through cage  32 ′. 
     Auger  302  has a frustoconical body  308  in which the small diameter end is positioned adjacent rotor  28 ′ and the large diameter end is positioned at or near the outlet opening  310  of cage  32 ′. Helical vanes  312  extend transversely from the exterior surface of auger  302 . The geometry of vanes  312  differs from that of vanes  31 ′. The auger  302  is configured to gradually compressed and reduces the thickness or depth of MOG as it travels in the direction of arrow X. 
     The height of vanes  312 , as measured from the exterior surface of auger  302 , decreases in the transport direction of arrow X (i.e., in the direction of crop flow through cage  32 ′). The gap ‘G’ between the terminal end of the vanes  312  and the interior surface of cage  32 ′ remains substantially constant along the length of auger  302  that extends along axis  30 ′. The lateral distance (i.e., pitch) separating adjacent convolutions of vanes  312 , in which MOG is carried, increases in the direction of arrow X such that distance H2 is greater than H1 by a predetermined amount. Distances H1 and H2 may be measured from the crests of vanes  312 . Specifically, the lateral distance separating adjacent convolutions of vanes  312  and height of vanes  312  are set such that the volume (V1, V2) of space between adjacent convolutions of vanes  312  remains substantially constant along the length of (direction X) of auger  302 . 
     In lieu of a rotary chopper  57 , systems  300  include a chopper  320  that is rotatably driven about axis  30 ′ by a motor  322 , for example. Unlike chopper  57 , the axis of rotation of chopper  320  is aligned and coextensive with the axis of rotation  30 ′ of rotor  28 ′. Chopper  320  rotates independently of rotor  28 ′ and auger  302 . According to one aspect, the rate of rotation of chopper  320  is greater than that of rotor  28 ′ and auger  302 . Motor  322  may be hydrostatic, hydraulic, chain, belt or gear driven, for example. Motor  322  may be referred to herein as a means for driving the chopper  320 . It should be understood that chopper  320  may be driven by any device that is known to those skilled in the art. Also, in lieu of motor  322 , chopper  320  could be non-rotatably connected to shaft  304  along with rotor  28 ′ and auger  302 . 
     Chopper  320  has a cylindrical body, and a series of paddles or knife blades  326  are mounted about the circumference of body of chopper  320 . A series of mounting points, such as threaded holes, for example, are disposed on the circumference of chopper  320 . Each mounting point is configured to releasably receive a knife blade  326 . The operator of the combine can fasten the knife blades  326  to the chopper  320  at select locations along the circumference of chopper  320  to achieve a desired cut length for the MOG. In other words, adjusting the circumferential spacing of the knife blades  326 , varies the cut length for the MOG. The operator can also adjust the cut length for the MOG by varying the rotational speed of chopper  320 . Thus, in summary, the operator can adjust the cut length for the MOG by varying the rotational speed of chopper  320  and/or the number of knifes blade  326  that are mounted on the chopper  320 . The maximum diameter of the chopper  320  (including knife blades  326 ) is substantially equivalent to the internal diameter of cage  32 ′ or the maximum diameter of auger  302 . 
     Each knife blade  326  includes an angled or curved surface  328  at the downstream end so as to induce suction or vacuum in the direction of arrow X during rotation of chopper  320 , thereby drawing MOG outside of cage  32 ′. A spreader  26 ′ is positioned at the outlet of chopper  326  for directing the MOG outside of combine, as is known in the art. 
     While this invention has been described with respect to at least one embodiment, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.