Abstract:
A shroud for the infeed section impeller in a rotary combine. The shroud includes a rear converging wall cone and a front diverging wall cone. A feed plate extends transversely across the front of the shroud and a sump is formed in the shroud behind the feed plate. The front diverging wall cone comprises top and bottom, rearwardly diverging walls. Transitions castings separate the top and bottom walls on left and right sides and have rearwardly converging front faces.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates generally to agricultural combines. It relates particularly to rotary combines and, more particularly, to the rotor assembly in a rotary combine.  
         BACKGROUND OF THE INVENTION  
         [0002]    A well-known form of harvesting machine is a rotary combine. A typical combine includes a crop harvesting header assembly which reaps grain stalks and feeds the grain stalks to a rotary threshing assembly. The grain stalks or other crop materials harvested in the field are moved rearwardly from the crop harvesting header assembly by a crop feeder assembly and introduced for threshing to the rotary threshing and separating assembly.  
           [0003]    In a rotary combine, the rotary threshing and separating assembly includes a generally tubular rotor housing mounted in the combine body. A driven rotor is coaxially mounted within the housing. The rotor comprises a frusto-conical infeed section and a cylindrical threshing and separating section, and is supported at opposite ends by front and rear bearings.  
           [0004]    The cylindrical threshing and separating section of the rotor, and its surrounding rotor housing, mount cooperating threshing elements which thresh grain from other material in a threshing zone. The crop material is threshed and separated as it spirals around the rotor threshing section, and separated grain passes through openings in the surrounding rotor housing.  
           [0005]    As discussed in Tanis, U.S. Pat. No. 5,387,153, and Tanis et al., U.S. patent application Ser. No. 09/412,468, assigned to the same assignee as the present invention, the ability to transfer crop materials from the feeder assembly to the threshing zone of the rotor assembly is critical to efficient combine operations. Most rotary combine rotors include an infeed section impeller comprised of a series of impeller blades arranged at a forward end of the rotor. The impeller blades rotate within a shroud which is a forward part of the rotor housing. During harvesting operations, the generally linear movement of the crop materials received from the feeder assembly is converted by the rotating impeller blades into a rotating, circulatory movement, in a rearward and outward direction.  
           [0006]    In the Tanis et al. application, a new and improved impeller blade construction and arrangement is disclosed. The present application relates specifically to the construction and arrangement of the shroud which encloses the impeller. In that sense, the shroud of the present invention finds particularly advantageous application with the impeller disclosed in the aforementioned Tanis et al. application.  
         SUMMARY OF THE INVENTION  
         [0007]    It is an object of the invention to provide a new and improved shroud for the infeed section impeller of the rotor in a rotary combine.  
           [0008]    It is another object to provide a shroud whose geometry results in a crop delivery pattern which substantially eliminates localized areas of intensive crop pressure against the working surfaces of the rotor and rotor housing.  
           [0009]    It is still another object to provide an infeed section shroud which enhances throughput capacity of the combine.  
           [0010]    It is a further object to provide an infeed section shroud which controls crop flow in a manner which improves the energy efficiency of the rotor operation.  
           [0011]    It is yet another object to provide an infeed section shroud which controls crop flow in a manner which improves component wear life.  
           [0012]    The foregoing and other objects are realized in an infeed section shroud which combines a rear converging wall cone and a front diverging wall cone. The diverging wall cone or “reverse” cone diverges from a crop inlet opening at the front end of the shroud to its junction with the converging cone. The opposed cones or, more precisely, frustums of cones, enclose the impeller blades on the infeed section impeller of the rotor. The reverse cone is interrupted on one side by a transition member and a reverse transition member which, together, extend angularly around the axis of the impeller from about the 2:30 o&#39;clock position, to about the 5:30 o&#39;clock position as viewed from the front of the combine.  
           [0013]    From the aforementioned (about) 5:30 o&#39;clock position to about the 7:30 o&#39;clock position the reverse cone continues and forms a sump behind a horizontal feed plate assembly of the shroud. From this 7:30 o&#39;clock position to about the 9:00 o&#39;clock position the reverse cone is again interrupted. At the 9:00 o&#39;clock position the reverse cone is restored in the form of a reverse cone support member which supports and mounts a reverse cone rotor door extending over the top of the shroud to the aforementioned 2:30 o&#39;clock position.  
           [0014]    The rear, converging wall cone is mounted on a cylindrical housing member which mates with the cylindrical housing for the threshing rotor. The trailing edges of the impeller blades and the rear of the impeller itself extend into this cylindrical housing member. Arranged in helical paths extending circumferentially within the converging wall cone is a series of at least three crop directing vanes.  
           [0015]    Similarly, arranged in helical paths extending circumferentially within the cylindrical housing member is another series of at least three crop directing vanes. The vanes extend radially inwardly to inner edges which are spaced only a short distance from the traces defined by the outer edges of the impeller blades as they rotate.  
           [0016]    Crop material is fed into the shroud through a horizontal feed opening in the front face of the front diverging wall cone. A mat of crop material is fed up over an inlet ramp by the feed conveyor. This mat falls into the shroud&#39;s sump where it is picked up by the rotating impeller blades and carried in a counter-clockwise direction (viewed from the front) onto the rear, converging wall cone. The vanes lead and separate the crop mat into three continuous rows of crop material which are moved rearwardly in helical patterns into the threshing section of the rotor assembly.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0017]    The invention, including its construction and method of operation, is illustrated more or less diagrammatically in the drawings, in which:  
         [0018]    [0018]FIG. 1 is a side elevational view of a portion of a rotary combine showing, in partial section, a crop feeder assembly and a rotor assembly including a rotor housing with an impeller shroud embodying features of the invention; and  
         [0019]    [0019]FIG. 2 is an enlarged sectional view of the impeller and impeller shroud seen in FIG. 1; and  
         [0020]    [0020]FIG. 3 is a front elevational view of the impeller and impeller shroud seen in FIGS. 1 and 2, with parts removed;  
         [0021]    [0021]FIG. 4 is a front perspective view of the impeller and impeller shroud seen in FIG. 3; and  
         [0022]    [0022]FIG. 5 is a perspective view of the impeller shroud embodying features of the invention, with the impeller removed. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0023]    Referring now to the drawings, and particularly to FIG. 1, a self-propelled rotary combine is seen generally at  10 . The combine  10  includes a body  14  supported by front wheels  12  (the rear wheels are not shown). The combine  10  also includes an operator&#39;s cab  16 .  
         [0024]    The combine  10  is powered by an engine (not shown), suitably supported within the body  14 . The transfer of power from the engine to various driven components of the combine is effected conventionally.  
         [0025]    The combine  10  is provided with a crop harvesting header assembly  18  for cutting and gathering crop materials. The header assembly  18  cuts and directs crop materials into a crop feeder assembly  20 , including a conveyor  21 . The conveyor  21  carries crop materials in a layer or mat toward a rotor assembly  22 , which receives and threshes the grain from materials other than grain (MOG).  
         [0026]    The rotor assembly  22  is supported in a conventional manner inside the body  14 . The rotor assembly  22  includes a cylindrical rotor housing  24  mounted in a fore-and-aft direction in the body  14 . A rotor  26  is mounted coaxially within the rotor housing  24 , for rotation on the axis A.  
         [0027]    Referring also to FIG. 2, the rotor  26  is a hollow drum rigidly affixed to a shaft  42  extending coaxially through it. The rotor  26  includes an infeed section  62  and a threshing section  64 . The infeed section  62  comprises an impeller  30  including a cone-shaped impeller body  31  having two impeller blades  32  extending outwardly therefrom.  
         [0028]    At its forward end, the rotor housing  24  includes an impeller shroud  25  embodying features of the present invention. The shroud  25  partially encloses the impeller  30  and cooperates with it in feeding the crop material radially and circumferentially into the threshing section  64  in the manner hereinafter described.  
         [0029]    The two identical impeller blades  32  are equally spaced from each other around, and extend radially outwardly from, the impeller body  31 . The impeller  30  may comprise more than two blades  32 . Preferably, the configuration and arrangement of the blades  32  is that described in the aforementioned Tanis et al. application.  
         [0030]    As best seen in FIG. 2, each impeller blade  32  has a leading edge  35  and an outer edge  36 . The trace generated by the outer edge  36  of each of the two impeller blades  32  during rotation of the impeller  30  approximates the frustum of a cone having a cone angle which is substantially equal to that of the adjacent shroud  25 . Accordingly, a narrow, annular space  52  is defined between the outer edges  36  of the impeller blades  32  and the inner surface of the adjacent shroud  25 . As the impeller  30  rotates it moves crop material rearwardly toward the threshing section  64  through this space  52  in a manner hereinafter discussed.  
         [0031]    As previously pointed out, the rotor  26  is fixed to the shaft  42 , which supports the rotor  26  for rotation with the shaft on the axis A. The shaft  42  is rotatably supported in the combine body  14  at its front end in a bearing assembly  46 .  
         [0032]    Referring now also to FIGS. 3 and 4, the shroud  25  and the impeller  30  are shown independently of the rest of the rotor assembly  22 . The shroud  25  encloses the impeller  30  circumferentially and over a portion of its front end. The shroud  25  is welded or bolted to the cylindrical rotor housing  24 , at the rear of the shroud.  
         [0033]    Referring additionally to FIG. 5, the shroud  25  is seen with the impeller  30  removed. The shroud  25  includes a cylindrical segment  55  immediately adjacent the cylindrical rotor housing  24 . Welded to the front end of the cylindrical segment  55  is the rear frusto-conical segment  56  of the shroud  25 , i.e., the converging wall cone of the shroud. The rear frusto-conical segment  56  diverges as it extends forwardly to the point where the trace of each of the impeller blades  32  abruptly turns inwardly (as seen in FIG. 2).  
         [0034]    Two rows  61  and  62  of transport vanes  63  are mounted inside the rear, frusto-conical segment  56  and the cylindrical segment  55  of the shroud  25 , respectively. Three vanes  63  are evenly spaced around the inside of the segment  56 . Three vanes  63  are evenly spaced around the inside of the segment  55 .  
         [0035]    Each of the vanes  63  in the rows  61  and  62  comprises a right angle (cross section) element curved in a helical path to follow the surface of the segment  56 . Each vane  63  element includes a base  65  fastened to the inside of the corresponding shroud segment and a right angle wall  66  extending inwardly of that base. As seen in FIG. 2, the free inner end of the wall  66  of each vane  63  is spaced only a slight distance from the trace of each blade  32 .  
         [0036]    The rear, frusto-conical segment  56  of the shroud  25  has a circular leading edge  69 . Fastened to this circular leading edge  69 , by welding or bolts, is the inlet assembly  71  of the shroud  25 .  
         [0037]    The inlet assembly  71  of the shroud  25  includes a feed plate sub-assembly  74 , left and right (facing forwardly of the combine  10 ) transition castings  76  and  77 , left and right reverse transition castings  78  and  79 , and a door  80  including a reverse frusto-conical door segment  81  and a front closure panel  82 . A horizontally elongated crop inlet  83  is defined between the feed plate sub-assembly  74  and a lateral beam (not shown) which supports the rotor front bearing and which abuts the lower edge of the door segment&#39;s front closure panel  82 .  
         [0038]    The feed plate sub-assembly  74  comprises an inlet ramp  85 . The inlet ramp  85  is inclined upwardly and rearwardly from its lower leading edge  86  to its trailing upper edge  87 . Vertical end plates  88  and  89  support the ramp  85  and are bolted to the bearing support structure for the rotor assembly  22  in a manner not shown.  
         [0039]    Immediately behind the trailing upper edge  87  of the ramp  85 , the inlet assembly  71  contains a sump  92 . The sump  92  is formed by a reverse frusto-conical floor segment  93  below the trailing edge  87  of the ramp  85 . The floor segment is fastened to the leading edge  69  of the shroud assembly segment  56 , where it extends in a circular path below the level of the ramp edge  87 .  
         [0040]    Bracketing the crop inlet opening  83 , immediately above the feed plate sub-assembly  74 , are the transition castings  76  and  77 . These castings  76  and  77  form rearwardly converging sides for the inlet opening  83 .  
         [0041]    The left transition casting  76  includes a face plate  95  which converges toward the axis of the impeller  30  as it extends rearwardly toward the circular leading edge  69  on the shroud segment  56 . The face plate  95  terminates at its lower edge  96  on a shelf  97  which brackets (on one side) the sump  92 . At its upper edge  98  the face plate  95  joins the left reverse transition casting  78 , which bridges the gap between the face plate  95  and the reverse frusto-conical door segment  80 .  
         [0042]    The right transition casting  77  also includes a face plate, in this case at  105 . The face plate  105  also converges toward the axis of the impeller  30  as it extends rearwardly toward the circular leading edge  69 . The face plate  105  terminates at its lower edge  106  on the shelf  107  which brackets (on the other side) the sump  92 . At its upper edge  108 , however, the face plate  105  joins the right reverse transition casting  79  in a manner different from the left side. Here, a horizontal bridge plate  111  connects the edge  108  to the right reverse transition casting  79 .  
         [0043]    The reverse transition casting  79  serves as a support frame for the door  80  at its right end. In this regard, the casting  79  is bolted to the frusto-conical segment  56  of the shroud  25 . The door segment  81  is, in turn, bolted to the casting  79 .  
         [0044]    The door panel  82  has a horizontal, lower edge  116  which abuts a lateral beam (not shown), the lower edge of which defines the top limit of the crop inlet opening  83 . The door  80  also includes a side wall portion which flattens out on its left side, as at  123 .  
         [0045]    Returning now to the left reverse transition casting  78 , and the door  80  where it overlaps the casting  78  at  123 , it will be seen best in FIG. 3 that the casting  78  is also flat where it underlies and supports this left side wall portion  123  of the door segment  81 . As such, the door segment  123 , although inclined inwardly, from back-to-front, extends outwardly of the circumference defined by the leading edge  69  of the shroud segment  56 .  
         [0046]    In operation of the combine  10  incorporating an impeller shroud  25  embodying features of the present invention, the conveyor  21  feeds crop material onto the inlet ramp  85  in a mat. The mat of crop material is forced over the trailing upper edge  87  of the ramp  85  by the conveyor  21  and falls continuously into the sump  92 .  
         [0047]    As the mat of crop material falls into the sump  92 , it moves rearwardly on the frusto-conical floor segment  93  of the sump  92 . At the base of the floor segment  93 , the mat is engaged by the rotating impeller blades  32 . The mat of crop material is driven sideways by the blades  32  and torn into linear segments. These linear segments of crop material engage transport vanes  63  in the first row  61  of vanes and are driven rearwardly in the annular space  52  by interaction of the vane and blades.  
         [0048]    The impeller  30  is rotating in a counterclockwise direction, as viewed from the front. As the crop material rotates in that direction, and is carried out of the sump  92 , it is captured beneath the flat reverse transition casting  78  and its overlying door segment, at  123 . The left transition casting  76  front wall  95  prevents crop material from escaping as it comes out of the sump  92 .  
         [0049]    The vanes  63  are arranged in two rows  61  and  62 . Each row comprises two sets of three vanes  63 . They are placed to direct crop flow in a helical path which passes through the threshing section and over the threshing concaves (which are not shown) at least three times as it passes through.  
         [0050]    While a preferred embodiment of the invention has been described, it should be understood that the invention is not so limited, and modifications may be made without departing from the invention. The scope of the invention is defined by the appended claims, and all devices that come within the meaning of the claims, either literally or by equivalence, are intended to be embraced therein.