Patent Publication Number: US-2020296895-A1

Title: Removable insert for a threshing rotor cage

Description:
FIELD OF THE INVENTION 
     The present invention pertains to an agricultural harvester and, more specifically, to a rotor cage of an agricultural harvester. 
     BACKGROUND OF THE INVENTION 
     An agricultural harvester known as a “combine” is historically termed such because it combines multiple harvesting functions with a single harvesting unit, such as picking, threshing, separating, and cleaning. A combine includes a header which removes the crop from a field, and a feeder housing which transports the crop matter into a threshing rotor. The threshing rotor rotates within a perforated housing, which may be in the form of adjustable concaves, and performs a threshing operation on the crop to remove the grain. Once the grain is threshed it falls through perforations in the concaves onto a grain pan. From the grain pan the grain is cleaned using a cleaning system, and is then transported to a grain tank onboard the combine. A cleaning fan blows air through the sieves to discharge chaff and other debris toward the rear of the combine. Non-grain crop material such as straw from the threshing section proceeds through a residue handling system, which may utilize a straw chopper to process the non-grain material and direct it out the rear of the combine. When the grain tank becomes full, the combine is positioned adjacent a vehicle into which the grain is to be unloaded, such as a semi-trailer, gravity box, straight truck, or the like, and an unloading system on the combine is actuated to transfer the grain into the vehicle. 
     More particularly, a rotary threshing or separating system includes one or more rotors that can extend axially (front to rear) or transversely (side to side) within the body of the combine, and which are partially or fully surrounded by perforated concaves. The crop material is threshed and separated by the rotation of the rotor within the concaves. Coarser non-grain crop material such as stalks and leaves pass through a straw beater to remove any remaining grains, and then are transported to the rear of the combine and discharged back to the field. The separated grain, together with some finer non-grain crop material such as chaff, dust, straw, and other crop residue are discharged through the concaves and fall onto a grain pan where they are transported to a cleaning system. Alternatively, the grain and finer non-grain crop material may also fall directly onto the cleaning system itself. 
     A cleaning system further separates the grain from non-grain crop material, and typically includes a fan directing an airflow stream upwardly and rearwardly through vertically arranged sieves which oscillate in a fore and aft manner. The airflow stream lifts and carries the lighter non-grain crop material towards the rear end of the combine for discharge to the field. Clean grain, being heavier, and larger pieces of non-grain crop material, which are not carried away by the airflow stream, fall onto a surface of an upper sieve (also known as a chaffer sieve), where some or all of the clean grain passes through to a lower sieve (also known as a cleaning sieve). Grain and non-grain crop material remaining on the upper and lower sieves are physically separated by the reciprocating action of the sieves as the material moves rearwardly. Any grain and/or non-grain crop material which passes through the upper sieve, but does not pass through the lower sieve, is directed to a tailings pan. Grain falling through the lower sieve lands on a bottom pan of the cleaning system, where it is conveyed forwardly toward a clean grain auger. The clean grain auger conveys the grain to a grain elevator, which transports the grain upwards to a grain tank for temporary storage. The grain accumulates to the point where the grain tank is full and is discharged to an adjacent vehicle such as a semi trailer, gravity box, straight truck or the like by an unloading system on the combine that is actuated to transfer grain into the vehicle. 
     Certain crops are difficult to fully thresh and separate. When harvesting such crops, the risk of unthreshed crop material reaching the grain tank increases. Unthreshed crop material in the grain tank must be further processed after delivery or, more often, is discarded, which increases cost and/or lowers crop yield. 
     What is needed in the art is a way to decrease the risk of unthreshed crop material reaching the grain tank. 
     SUMMARY OF THE INVENTION 
     Exemplary embodiments provided in accordance with the present disclosure provide a threshing insert removably coupled to a rotor cage of a threshing and separating system such that material entering the rotor cage from a tailings return inlet travels past the threshing insert before reaching a concave coupled to the rotor cage. 
     In some exemplary embodiments provided in accordance with the present disclosure, a threshing and separating system for an agricultural harvester includes a rotor configured to rotate about a rotor axis, a rotor cage at least partially enclosing the rotor and including a tailings return inlet formed therein and configured to couple to a tailings return elevator and an insert opening formed therein that is at least partially circumferentially aligned with the tailings return inlet relative to the rotor axis, at least one concave coupled to the rotor cage and defining a plurality of concave perforations, and a threshing insert removably coupled to the rotor cage and including at least one mounting opening. The threshing insert at least partially covers the insert opening and is positioned such that material from the tailings return inlet travels past the threshing insert before reaching the concave. 
     In some exemplary embodiments provided in accordance with the present disclosure, an agricultural harvester includes a chassis, a cleaning system carried by the chassis and including at least one sieve and a tailings return elevator with an inlet located below the at least one sieve; and a threshing and separating system carried by the chassis. The threshing and separating system includes a rotor configured to rotate about a rotor axis; a rotor cage at least partially enclosing the rotor and including a tailings return inlet formed therein that is coupled to the tailings return elevator and an insert opening formed therein that is at least partially circumferentially aligned with the tailings return inlet relative to the rotor axis, at least one concave coupled to the rotor cage and defining a plurality of concave perforations; and a threshing insert removably coupled to the rotor cage and including at least one mounting opening. The threshing insert at least partially covers the insert opening and is positioned such that material from the tailings return inlet travels past the threshing insert before reaching the concave. 
     In some exemplary embodiments, a method for adjusting threshing performance of a threshing and separating system of an agricultural harvester is provided. The threshing and separating system includes a rotor defining a rotor axis and a rotor cage at least partially enclosing the rotor and having a tailings return inlet and an insert opening at least partially covered by a threshing insert and at least partially circumferentially aligned with the tailings return inlet relative to the rotor axis. The method includes removing the threshing insert to uncover the insert opening and mounting a replacement threshing insert to at least partially cover the insert opening. Threshing performance of the threshing and separating system is altered by mounting the replacement threshing insert. 
     One possible advantage that may be realized by exemplary embodiments disclosed herein is that the threshing insert can be equipped with threshing bars and positioned under the tailings return inlet, where threshing and separation does not normally occur, to provide additional threshing for crops that are difficult to thresh. 
     Another possible advantage that may be realized by exemplary embodiments disclosed herein is that the threshing insert can be equipped with bushings that are flush with an interior surface of the rotor cage when additional threshing is not needed. 
     Yet another possible advantage that may be realized by exemplary embodiments disclosed herein is that different threshing inserts can be used to conveniently adjust threshing performance of the threshing and separating system. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For the purpose of illustration, there are shown in the drawings certain embodiments of the present invention. It should be understood, however, that the invention is not limited to the precise arrangements, dimensions, and instruments shown. Like numerals indicate like elements throughout the drawings. In the drawings: 
         FIG. 1  illustrates a side view of an exemplary embodiment of an agricultural vehicle, the agricultural vehicle comprising a threshing and separating system that is provided in accordance with an exemplary embodiment of the present disclosure; 
         FIG. 2  illustrates an interior sectional view of a rotor cage of the threshing and separating system of  FIG. 1  with a threshing insert mounted thereto, in accordance with an exemplary embodiment of the present disclosure; 
         FIG. 3  illustrates another interior sectional view of the rotor cage illustrated in  FIGS. 1-2  without a concave coupled thereto; 
         FIG. 4  illustrates an exterior sectional view of the rotor cage illustrated in  FIGS. 1-3 ; 
         FIG. 5  illustrates a front sectional view of the threshing and separating system of  FIG. 1 ; 
         FIG. 6  illustrates the threshing and separating system of  FIGS. 1-5  with another exemplary embodiment of a threshing insert mounted to the rotor cage; and 
         FIG. 7  is a flow chart illustrating an exemplary embodiment of a method for adjusting threshing performance of a threshing and separating system, which is provided in accordance with the present disclosure. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The terms “grain”, “straw” and “tailings” are used principally throughout this specification for convenience but it is to be understood that these terms are not intended to be limiting. Thus “grain” refers to that part of the crop material which is threshed and separated from the discardable part of the crop material, which is referred to as non-grain crop material, MOG or straw. Incompletely threshed crop material is referred to as “tailings”. Also, the terms “forward”, “rearward”, “left” and “right”, when used in connection with the agricultural harvester and/or components thereof are usually determined with reference to the direction of forward operative travel of the harvester, but again, they should not be construed as limiting. The terms “longitudinal” and “transverse” are determined with reference to the fore-and-aft direction of the agricultural harvester and are equally not to be construed as limiting. The terms “downstream” and “upstream” are determined with reference to the intended direction of crop material flow during operation, with “downstream” being analogous to “rearward” and “upstream” being analogous to “forward.” 
     Referring now to the drawings, and more particularly to  FIG. 1 , there is shown an embodiment of an agricultural harvester  100  in the form of a combine which generally includes a chassis  101 , ground engaging wheels  102  and  103 , header  110 , feeder housing  120 , operator cab  104 , threshing and separating system  130 , cleaning system  140 , grain tank  150 , and unloading conveyance  160 . Front wheels  102  are larger flotation type wheels, and rear wheels  103  are smaller steerable wheels. Motive force is selectively applied to front wheels  102  through a power plant in the form of a diesel engine  105  and a transmission (not shown). Although combine  100  is shown as including wheels, is also to be understood that combine  100  may include tracks, such as full tracks or half tracks. 
     Header  110  is mounted to the front of combine  100  and includes a cutter bar  111  for severing crops from a field during forward motion of combine  100 . A rotatable reel  112  feeds the crop into header  110 , and a double auger  113  feeds the severed crop laterally inwardly from each side toward feeder housing  120 . Feeder housing  120  conveys the cut crop to threshing and separating system  130 , and is selectively vertically movable using appropriate actuators, such as hydraulic cylinders (not shown). 
     Threshing and separating system  130  is of the axial-flow type, and generally includes a threshing rotor  131  at least partially enclosed by a rotor cage  210  and rotatable within a corresponding perforated concave  132 . The cut crops are threshed and separated by the rotation of rotor  131  within concave  132 , and larger elements, such as stalks, leaves and the like are discharged from the rear of combine  100 . Smaller elements of crop material including grain and non-grain crop material, including particles lighter than grain, such as chaff, dust and straw, are discharged through perforations of concave  132 . Threshing and separating system  130  can also be a different type of system, such as a system with a transverse rotor rather than an axial rotor, etc. 
     Grain which has been separated by the threshing and separating assembly  130  falls onto a grain pan  133  and is conveyed toward cleaning system  140 . Cleaning system  140  may include an optional pre-cleaning sieve  141 , an upper sieve  142  (also known as a chaffer sieve or sieve assembly), a lower sieve  143  (also known as a cleaning sieve), and a cleaning fan  144 . Grain on sieves  141 ,  142  and  143  is subjected to a cleaning action by fan  144  which provides an air flow through the sieves to remove chaff and other impurities such as dust from the grain by making this material airborne for discharge from a straw hood  171  of a residue management system  170  of combine  100 . Optionally, the chaff and/or straw can proceed through a chopper  180  to be further processed into even smaller particles before discharge out of the combine  100  by a spreader assembly  200 . It should be appreciated that the “chopper”  180  referenced herein, which may include knives, may also be what is typically referred to as a “beater”, which may include flails, or other construction and that the term “chopper” as used herein refers to any construction which can reduce the particle size of entering crop material by various actions including chopping, flailing, etc. Grain pan  133  and pre-cleaning sieve  141  oscillate in a fore-to-aft manner to transport the grain and finer non-grain crop material to the upper surface of upper sieve  142 . Upper sieve  142  and lower sieve  143  are vertically arranged relative to each other, and likewise oscillate in a fore-to-aft manner to spread the grain across sieves  142 ,  143 , while permitting the passage of cleaned grain by gravity through the openings of sieves  142 ,  143 . 
     Clean grain falls to a clean grain auger  145  positioned crosswise below and toward the front of lower sieve  143 . Clean grain auger  145  receives clean grain from each sieve  142 ,  143  and from a bottom pan  146  of cleaning system  140 . Clean grain auger  145  conveys the clean grain laterally to a generally vertically arranged grain elevator  151  for transport to grain tank  150 . Tailings from cleaning system  140  fall to a tailings auger trough  147 . The tailings are transported via tailings auger  147  and tailings return elevator  148 , which has an inlet below the sieves  141 ,  142 ,  143 , to the threshing and separating system  130  for repeated cleaning action, as described further herein. A pair of grain tank augers  152  at the bottom of grain tank  150  convey the clean grain laterally within grain tank  150  to unloader  160  for discharge from combine  100 . 
     Referring now to  FIGS. 2-3 , the rotor cage  210  of the threshing and separating system  130  is illustrated in further detail. As previously described, the rotor cage  210  at least partially surrounds the threshing rotor  131 , as illustrated in  FIG. 1 . The rotor cage  210  may have a generally cylindrical shape that extends in parallel to a rotor axis RA (illustrated in  FIGS. 1 and 5 ), which the threshing rotor  131  is configured to rotate about during operation. A plurality of helical vanes  220  may be disposed on an interior surface  211  of the rotor cage  210  to direct crop material during rotation of the threshing rotor  131 , as is known. In some embodiments, the vanes  220  are shaped so crop material travels in a travel direction, illustrated as an arrow T in  FIG. 2 , during rotation of the threshing rotor  131 . 
     The concave  132 , which may be formed of one or more concave modules, is coupled to the rotor cage  210  and includes a plurality of concave perforations  233 . As the threshing rotor  131  rotates, crop material is pressed against the concave  132 . Threshed and separated crop material passes through the perforations  233  and travels to the cleaning system  140  for further cleaning. 
     Tailings, which need further cleaning, are returned to the threshing and separating system  130  by the tailings return elevator  148 . The rotor cage  210  has a tailings return inlet  212  formed therein that is coupled to the tailings return elevator  148  and provides an entryway for tailings back into the threshing and separating system  130  for additional threshing. In some embodiments, the tailings return elevator  148  is an auger or similar arrangement. As illustrated in  FIGS. 2-3 , as well as  FIG. 4 , the tailings return inlet  212  may include an angled guide lip  213  that is exterior of the rotor cage  210 . The tailings return elevator  148  may have an outlet that is coupled to the guide lip  213 , with tailings being dumped into the guide lip  213  and through the tailings return inlet  212  into the rotor cage  210 . Once the tailings enter the rotor cage  210 , the tailings may be pressed by the threshing rotor  131  against the concave  132  for additional threshing and separating. 
     It has been found that certain crops and crop conditions require more aggressive threshing and separating conditions to completely thresh and separate the crop material. Harder crops are prone to being unthreshed and/or unseparated after passing through the threshing and separating system  130 , even after multiple passes. This increases the risk of unclean crop material reaching the grain tank  150 , which lowers harvesting efficiency. 
     With further reference to  FIGS. 2-4  as well as  FIG. 5 , an exemplary embodiment of a threshing insert  240  provided in accordance with the present disclosure is illustrated. The threshing insert  240  is removably coupled to the rotor cage  210  and at least partially covers an insert opening  214  formed in the rotor cage  210 , the significance of which is described further herein. In some embodiments, the threshing insert  240  comprises a curved sheet of material, such as a metal or a polymer, that substantially conforms to the shape of the rotor cage  210 . The threshing insert  240  may be removably mounted to the rotor cage  210  by one or more fasteners  241 , such as screws. In some embodiments, the threshing insert  240  is hingedly coupled to the rotor cage  210  and may be pivoted away from the rotor cage  210 . 
     The threshing insert  240  is positioned to be circumferentially aligned with the tailings return inlet  212 , relative to the rotor axis RA, such that material from the tailings return inlet  212 , i.e., previously threshed tailings, travel past the threshing insert  240  before reaching the concave  132 . The material may travel past the threshing insert  240  due to gravity as well as the threshing rotor  131  moving the material against the interior surface  211  of the rotor cage  210  during rotation of the threshing rotor  131  about the rotor axis RA. 
     The threshing insert  240  may include one or more threshing bars  242 , illustrated as four threshing bars  242 , that extend through the insert opening  214  such that material from the tailings return inlet  212  travels past the threshing bars  242  before reaching the concave  132 . In some embodiments, the threshing bars  242  are formed of keystock or a similar material that is welded to the threshing insert  240 . Alternatively, the threshing bars  242  can be removably mounted to the threshing insert  240 . In some embodiments, the threshing bars  242  extend generally parallel to the rotor axis RA so crop material is forced against and into the spaces between the threshing bars  242  as the threshing rotor  131  rotates about the rotor axis RA. A portion of the interior surface  211  of the rotor cage  210  between the insert opening  214  (and the mounted threshing bars  242 ) and the concave  132  may be smooth, i.e., define a generally uninterrupted round surface, so minimal, if any, threshing occurs between the threshing bars  242  and the concave  132 . 
     Placing the threshing bars  242  between the tailings return inlet  212  and the concave  132  allows for threshing of material from the tailings return inlet  212  against the threshing bars  242  before the threshing rotor  131  moves the material against the concave  132 . In this sense, the threshing bars  242  can provide additional threshing of material that is returned to the threshing and separating system  130  in a location where material is not normally threshed and separated. The additional threshing can decrease the risk of unthreshed and/or unseparated material reaching the cleaning system  140 , and thus the risk of unclean material reaching the grain tank  150 . Further, the location of the threshing bars  242  when the threshing insert  240  is mounted does not block off open area of the concave  132  or reduce separating capacity of the system  130 . Thus, providing the threshing insert  240  in hard thresh crop conditions can improve threshing performance of the threshing and separating system  130  to reduce the amount of unthreshed and unclean crop that makes it to the grain tank  150 . 
     When a hard thresh is not desired, and referring now to  FIG. 6 , the threshing insert  240  illustrated in  FIGS. 2-5  may be removed and replaced by another exemplary embodiment of a threshing insert  640 . The threshing insert  240  may be removed by, for example, untightening the fasteners  241  and the threshing insert  640  may then be coupled to the rotor cage  210  by the fasteners  241 . Alternatively, when the threshing insert  240  is hingedly coupled to the rotor cage  210  and the threshing bars  242  are removable, the threshing insert  240  can be pivoted away from the rotor cage  210  to uncover the insert opening  214  and remove the threshing bars  242 . The threshing insert  640  may be formed as a curved sheet of metal or polymer, similar to the threshing insert  240 , but comprise one or more bushings  641  rather than threshing bars  242 . The bushing(s)  641  may fill the insert opening  214  to be substantially flush with the interior surface  211  of the rotor cage  210  when the threshing insert  640  is mounted. Filling the insert opening  214  with the bushing(s)  641  provides a substantially smooth interior surface between the tailings return inlet  212  and the concave  132  where little, if any, threshing of crop material occurs. Thus, it should be appreciated that providing the rotor cage  210  with the insert opening  214  can allow for different threshing performance by mounting the threshing insert  240  with threshing bars  242  that extend through the insert opening  214  or by mounting the threshing insert  640  with bushing(s)  641  that fill the insert opening  214 . 
     Referring now to  FIG. 7 , a flow chart illustrating an exemplary embodiment of a method  700  for adjusting performance of a threshing and separating system, such as the previously described threshing and separating system  130  of an agricultural harvester  100 , is provided. The method  700  includes removing  701  a threshing insert  240 ,  640  to uncover an insert opening  214  of a rotor cage  210  of the threshing and separating system  130 . Removing the threshing insert  240 ,  640  may include, for example, untightening the fasteners  241  coupling the threshing insert  240 ,  640  to the rotor cage. The removed threshing insert may be, for example, the threshing insert  240  including one or more threshing bars  242  that extend through the insert opening  214  or the threshing insert  640  including one or more bushings  641  that are substantially flush with the insert opening  214 . After removing  701  the threshing insert  240  or  640 , a replacement threshing insert, such as the threshing insert  640  or  240 , may be mounted  702  to at least partially cover the insert opening  214 . As can be appreciated, the different threshing inserts  240 ,  640  have different effects on the threshing that takes place within the threshing and separating system  130  during operation, so mounting  702  the replacement threshing insert alters threshing performance of the threshing and separating system  130 . It should be further appreciated that different kinds of threshing inserts and replacement threshing inserts can be removed and mounted, respectively, to change threshing performance in a desired manner. Therefore, the method  700  provides a relatively easy and convenient way to adjust threshing performance of the threshing and separating system  130  by changing the threshing insert that is mounted to the rotor cage  210 . 
     These and other advantages of the present invention will be apparent to those skilled in the art from the foregoing specification. Accordingly, it is to be recognized by those skilled in the art that changes or modifications may be made to the above-described embodiments without departing from the broad inventive concepts of the invention. It is to be understood that this invention is not limited to the particular embodiments described herein, but is intended to include all changes and modifications that are within the scope and spirit of the invention.