Abstract:
A forage harvester includes a post-accelerator disposed in an interior of said forage harvester and comprising a conveying fan that rotates about a rotary axle. The post-accelerator is partially enclosed by a housing that is open in sections and that extends in sections into a crop-conveyance path. An extent of the extension into the crop-conveying path is adjusted by displacing the post-accelerator relative to the housing. The forage harvester also includes a wall disposed opposite an open section. The rotary axle includes ends that are mounted in bearing supports disposed on the housing via one end so as to be pivotable about a pivot axle. Each of the bearing supports are connected to an actuator at a free end opposing the one end disposed on the housing.

Description:
CROSS-REFERENCE TO A RELATED APPLICATION 
       [0001]    The invention described and claimed hereinbelow is also described in German Patent Application DE 10 2014 106 696.0, filed on May 13, 2014. The German Patent Application, the subject matter of which is incorporated herein by reference, provides the basis for a claim of priority of invention under 35 U.S.C. 119(a)-(d). 
       BACKGROUND OF THE INVENTION 
       [0002]    The present invention relates to a forage harvester with a post-accelerator designed as a conveying fan rotating about a rotary axle and partially enclosed by a housing designed to be open in sections, where the post-accelerator adjustably extends in sections into a crop-conveyance path. 
         [0003]    Partially enclosed post accelerators are known. EP 1 961 288 A1 describes a post-accelerator designed in the form of a conveying fan of a self-propelled forage harvester that is partially encased in a housing. The post-accelerator is driven by a pulley, which is disposed on an axle of the post-accelerator, which extends beyond the width of the housing. The post-accelerator is disposed so as to be displaceable relative to the housing. To this end, the housing is assigned a displacement mechanism, which acts on sliding devices disposed at both ends of the axle. The displacement mechanism comprises two coupling rods, each one of which acts on the respective sliding device and connects this to an eccentric shaft. The eccentric shaft is pivoted by a telescopic adjusting element, which acts on the eccentric shaft in the center. The pivoting motion of the eccentric shaft is converted into a translational motion of the sliding devices, in order to displace the post-accelerator. 
         [0004]    The disadvantage of such a conventional device is the complex design of the displacement mechanism, which has increased play due to the plurality of connection points, making it difficult, at the least, to fine-tune the adjustment of the position. 
       SUMMARY OF THE INVENTION 
       [0005]    The present invention overcomes the shortcomings of known arts, such as those mentioned above. 
         [0006]    To that end, the present invention provides a partially enclosed post accelerator configured such that a fine-tuned and exact adjustment of the position of the post-accelerator is ensured and a method for the adjustment according thereto. 
         [0007]    In an embodiment, the invention provides a forage harvester includes a post-accelerator disposed in an interior of said forage harvester and comprising a conveying fan that rotates about a rotary axle. The post-accelerator is partially enclosed by a housing that is open in sections and that extends in sections into a crop-conveyance path. An extent of the extension into the crop-conveying path is adjusted by displacing the post-accelerator relative to the housing. A wall is disposed opposite an open section. The rotary axle is rotatably mounted in bearing supports, which are arranged at the ends of the rotary axle and are disposed on the housing, via one end thereof, so as to be pivotable about a pivot axle and which are each connected to an actuator at the opposing, free end thereof. 
         [0008]    This arrangement has the advantage that only two connection or engagement points are required on the housing in order to induce a movement for displacing the post-accelerator, which is supported by the bearing supports. The actuation of the actuators immediately results in a movement of the respective bearing support. A displacement that is direct and exact is achieved by reduction of the parts involved in the displacement of the post-accelerator. Preferably, the bearing supports are designed as cast parts. 
         [0009]    The rotary axle is accommodated at each of the ends thereof in a bearing housing that is a component of the respective bearing support. The single-pieced design of the bearing support and the bearing housing as a cast part simplifies the manufacture and is a low-cost option. 
         [0010]    In an embodiment, a respective actuator is designed as a threaded spindle held by an attaching module to be movable relative to the housing. The design of the actuator as a mechanical adjusting device is a variant that is low-cost and is implemented using a simple design. This actuator is manually actuated by an operator. 
         [0011]    To this end, the attaching module comprises a base plate having an adjusting element disposed thereon as well as an internal thread section for accommodating the threaded rod. The base plate is clamped between a retainer plate and the bearing bracket by the retainer plate. Given that the base plate is clamped between the bearing bracket and the retainer plate, it is ensured that pressure and tensile forces applied by the conveyed crop and by the drive belt onto the post-accelerator are always absorbed. The base plate, with the adjusting element located thereon, permits a linear displacement of the post-accelerator. 
         [0012]    According to an embodiment, the respective actuator is designed as a hydraulic lifting cylinder, permitting an automated adjustment of the post-accelerator. The two lifting cylinders are activated independently of one another. Instead of a hydraulic lifting cylinder, it also is possible to use another type of actuator, which is designed as a linear drive, e.g., an electric motor. 
         [0013]    Advantageously, the lifting cylinders are connected to at least one pressure relief valve. The pressure relief valve is used as an overload protection unit, which responds to an overload in the crop-conveyance path caused by an excessive quantity of crop, in order to enable the post-accelerator to undergo a compensating movement by increasing the separation from the wall. 
         [0014]    Preferably, the lifting cylinders are hydraulically coupled according to the master-slave principle. A configuration as a master-slave hydraulic cylinder pair has the advantage that a synchronous displacement of the two lifting cylinders is ensured. 
         [0015]    In addition, an angular sensor is assigned to the respective bearing support. The advantage of this is that redundant protection is ensured. In addition, after the post-accelerator has executed a compensating movement due to an overload that occurred, the post-accelerator is returned to the previous position. is Also, a section of the housing that is open in the circumferential direction of the post-accelerator is closed by a wall disposed to be spaced apart from the post-accelerator. At least one acoustic sensor is disposed on the wall. 
         [0016]    The invention also includes a method for adjusting a separation between a post-accelerator, which is partially enclosed by a housing designed to be open in sections, disposed in a forage harvester and arranged to extend in sections into a crop-conveyance path, and a wall, which borders an open section of the housing and is disposed to be spaced apart from the post-accelerator, and wherein the extent of the extension is adjusted by displacing the post-accelerator relative to the housing using an actuator. The method includes steps of moving the post-accelerator toward the wall, by use of the actuator, until the wall is touched by the post-accelerator; detecting the contact with the wall by an acoustic sensor disposed on the wall; and moving the post-accelerator, by the actuator, back into a position in which a defined minimum separation from the wall is assumed. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0017]    Further features and advantages of the invention will become apparent from the description of embodiments that follows, with reference to the attached figures, wherein: 
           [0018]      FIG. 1  depicts a side view of a self-propelled forage harvester configured according to the inventive principles; 
           [0019]      FIG. 2  depicts a partial view of a housing, which encloses a post-accelerator of the forage harvester in sections, according to one embedment of the invention; and 
           [0020]      FIG. 3  depicts a partial view of a housing, which encloses a post-accelerator of the forage harvester in sections, according to one embodiment of the invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0021]    The following is a detailed description of example embodiments of the invention depicted in the accompanying drawings. The example embodiments are presented in such detail as to clearly communicate the invention and are designed to make such embodiments obvious to a person of ordinary skill in the art. However, the amount of detail offered is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present invention, as defined by the appended claims. 
         [0022]      FIG. 1  presents a side view and sectional illustration of an agricultural harvesting machine  2  designed as a self-propelled forage harvester  1 . The harvesting machine  2  is built on a frame  3  that is carried by front and rear wheels  4 ,  5 , respectively. The forage harvester  1  is operated by an operator  6  by an input/output unit  37  from within the driver&#39;s cab  7 , from which it is possible to see the front attachment  8 . The front attachment  8  is attached to the front of the forage harvester  1  such that in the working mode of the forage harvester  1 , the front attachment picks up crop  9 , cuts it and feeds it to downstream intake and compression rollers  10 ,  11 . The intake and compression rollers  10 ,  11  guide the crop  9  to a downstream, rotating chopper drum  13 , which equipped with blades  12  and which chops the crop  9  on a shear bar  14 . The chopped crop  9  is transferred to a rechopper  15 , before it is drawn into a post-accelerator  16 . The task of the rechopper  15  is to pound the corn kernels, when corn is the crop being harvested. The rechopper  15  may therefore be eliminated entirely if it is not necessary to pound the crop  9 , e.g., when the crop is grass. The chopped crop  9  is accelerated by the post-accelerator  16 , thereby ensuring that it emerges from the transfer device  17  located downstream of the post-accelerator  16  and lands in a hauling vehicle, which is not shown. 
         [0023]    The crop flows in the interior of the forage harvester  1  along a crop-conveyance path, which is bounded by a chute  18 . Disposed above the rechopper  15  is a housing  19 , which accommodates the post-accelerator  16  and is mounted on the chute  18 . The housing  19  partially encloses the post-accelerator  16  in the circumferential direction and is designed so as to be open toward the chute  18 , thereby allowing the post-accelerator  16  to extend into the crop-conveyance path in sections. A wall  20 , which is designed as a wearing part, is disposed opposite the open section of the housing  19 . This wall  20 , together with the post-accelerator  16 , borders a passage gap  21 . The width of the passage gap  21  is adjusted by moving the post-accelerator  16  relative to the wall  20 . A sensor  22  ( FIG. 2 ), which is preferably designed as a knock sensor, is disposed on the side of the wall  20  facing away from the post-accelerator  16 . 
         [0024]      FIG. 2  shows a partial view of the housing  19 , which encloses the post-accelerator  16 . The layout of the housing  19  and the components disposed thereon is symmetrical, i.e., in particular those components described in the following, which are provided for adjusting the post-accelerator  16 , are disposed on the housing  19  in a mirror-image arrangement. 
         [0025]      FIG. 2  depicts the housing  19  having a sidewall  29  and an inlet opening  23 , which is disposed adjacent to the wall  20  and through which the crop  9  fed from the rechopper  15  enters. A rotary axle  24 , on which the post-accelerator  16  is rotatably mounted, extends through the housing  19 . The rotary axle  24  is supported by a bearing housing  25  so as to be rotatable relative to the housing  19 . The bearing housing  25  is disposed on a bearing support  26 , which is preferably designed as a cast part. In an alternative embodiment, the bearing support  26  and the bearing housing  25  are designed as a single-piece cast part. 
         [0026]    The bearing support  26  extends in the radial direction toward the rotary axle  24 . The bearing support  26  is mounted via one end thereof so as to be pivotable about a pivot axle  27 . The pivot axle  27  is attached to the housing  19  in a rotationally locked manner. A bolt  28 , which extends in the direction of the sidewall  29  of the housing  19 , is located at the opposite end of the bearing support  26 . An actuator  30  acts at one end of the bearing support  26 , by which the rotary axle  24  and, therewith, the post-accelerator  16  are displaced relative to the wall  20 . A non-illustrated recess is provided in the respective sidewall  29 , which allows the post-accelerator  16  to move relative to the housing  19 . This recess is closed by a cover  35  in order to prevent material from entering or exiting through open sections of the recess. 
         [0027]    As shown in  FIG. 2 , the actuator  30  is designed as a hydraulic cylinder  31 . A connecting rod eye  32  is located on the end of the connecting rod and is connected to the bolt  28  in an articulated manner. A cylinder eye  33  is located on the hydraulic cylinder  31 , by which the hydraulic cylinder  31  is attached to the housing  19  by a bearing bracket  34  so as to be pivotable about an axle. As mentioned above, the configuration has a mirror-image design, i.e., another hydraulic cylinder  31 , among other things, is located on the opposite side. This design makes it possible to activate the two hydraulic cylinders  31  independently of one another. 
         [0028]    The hydraulic cylinders also can be hydraulically connected to one another as a master-slave hydraulic cylinder pair, however. When the connecting rods are extended, the pressure of the cylinder pair is controlled via a connecting line on the face end of the master cylinder. This master cylinder activates the slave cylinder on the face end by the outflowing hydraulic oil of the rod end, and therefore the two hydraulic cylinders  31  extend synchronously. The volume of hydraulic oil of the rod end of the master cylinder is therefore exactly matched to that of the face end of the slave cylinder. In the end positions, the volume of hydraulic oil is compensated for every time by a valve in the piston of the master cylinder, in order to ensure that the movement remains synchronous. 
         [0029]    Due to the extension and retraction of the hydraulic cylinder  31 , the bearing support  26  pivots about the pivot axle  27  in the direction of the wall  19  or away therefrom. The synchronous motion sequence of the hydraulic cylinders  31  makes it possible to set and adjust the post-accelerator  16  directly and exactly, relative to the wall  19 . The enclosing circle of the post-accelerator  16  assumes a defined minimum separation from the wall  20 . This minimum separation defines a width of the passage gap  21 , by which the greatest possible acceleration of the crop  9  is achieved. Preferably, this minimum separation is stored as a data set in a control device  36  of the forage harvester  1 , which is indicated in  FIG. 1 . 
         [0030]    If the post-acceleration must be reduced due to the crop properties, the post-accelerator  16  is moved away from the wall  20  by the actuator  30 , which results in an enlargement of the passage gap  21 . The pivoting of the post-accelerator  16  about the pivot axle  27  is detected on both sides by angular sensors  37 , which are independent of one another and which are connected to the control device  36 . The control device  36  evaluates the signals of the angular sensors  37  and stores the corresponding values for the width of the passage gap  21  in a memory of the control device  36 . It is therefore possible to determine and call up the width of the passage gap  21  at any point in time during operation. 
         [0031]    The respective angular sensor  37  is connected to the end of the bearing support  26  facing away from the pivot axle  27  by a coupling rod  38 . The substantially linear movement, which is executed during the displacement of the post-accelerator  16 , is transferred by the coupling rod  38  to the angular sensor  37 , which is connected to the control device  36  via a signal line. A signal representing the movement is forwarded to the control device  36  for evaluation. 
         [0032]    Providing a pressure relief control valve having an integrated relief valve results in the advantage that the pressure relief valve can be used in conjunction with the hydraulic cylinders  31  as overload protection. The pressure relief valve senses the hydraulic pressure that is applied by the hydraulic cylinders  31 , in order to counteract the force applied by the crop  9  that is flowing past, which induces a deflection of the post-accelerator  16  away from the wall  20 . If a defined threshold value for this pressure is passed, the pressure relief valve switches such that the post-accelerator  16  executes an evasive motion, which increases the separation from the wall  20 . This makes it possible to prevent damage to the post-accelerator  16 . As soon as the pressure at the pressure relief valve passes the threshold value once more, the post-accelerator  16  is automatically returned, by the hydraulic cylinders  31 , into the originally set position thereof, which was detected by the angular sensors. 
         [0033]    The sensor  22 , which is preferably designed as a knock sensor, has the task of simplifying the adjustment of the post-accelerator  16  for an operator of the forage harvester  1  such that the minimum separation between the wall  19  and the enclosing circle of the rotating post-accelerator  16  is automatically set. The post-accelerator  16  is designed as a rotating conveying fan, which is equipped with guide vanes that extend in the radial direction and are distributed around the circumference of the conveying fan. The guide vanes are subject to increased wear due to the contact thereof with the crop, wherein this increased wear changes the minimum separation between the enclosing circle and the wall  20 . 
         [0034]    In order to permit this minimum separation to be adjusted in accordance with the wear-induced reduction in the enclosing circle, the actuator  30  designed as a hydraulic cylinder  31  is activated by the control device  36  such that the post-accelerator  16  is moved toward the wall  20  until said actuator touches this wall. The sensor  22  detects the contact of the post-accelerator  16  with the wall  19  and transmits a corresponding signal to the control device  36 . The control device  36  evaluates the signal and activates the hydraulic cylinders  31  accordingly, in order to interrupt the movement in the direction of the wall  20 . In a subsequent step, the control device  36  activates the hydraulic cylinders  31  such that the defined minimum separation between the wall  20  and the enclosing circle of the post-accelerator  16 , which is stored in the control device  36 , is set. 
         [0035]    This process of setting the minimum separation can be carried during assembly in the process of manufacturing a forage harvester, and at any subsequent point in time during active use of the forage harvester in a harvesting operation. In the first case, the minimum separation is set precisely, with consideration for any production tolerances. The wear of the guide vanes is accounted for at a later point in time. This process can be initiated, as needed, by an operator of the forage harvester  1 , for example, by a corresponding entry on an input/output unit  37 , such as a touchscreen, a terminal having a keyboard, or the like, in the driver&#39;s cab of the forage harvester  1 . 
         [0036]      FIG. 3  depicts an embodiment of the actuator  30 , which is used to displace the post-accelerator  16 . According to the embodiment depicted in  FIG. 3 , the actuator  30 , which is disposed on the housing  19  in a mirror-image configuration in accordance with the previously described embodiment, is designed as a threaded rod  40 . The threaded rod  40  is guided in the bearing bracket  34 , to which the threaded rod  40  is connected by means of an attaching module  41 . The attaching module  41  comprises a base plate  42  having the shape of a circular disk, on which an adjusting element  43 , which has an internal thread section, is disposed and which accommodates and guides the threaded rod  40 . 
         [0037]    The base plate  42  is attached to the bearing bracket  34  by means of a retainer plate  44 . The retainer plate  44  is preferably designed as a substantially isosceles triangle and has a recess  45  in the center thereof, through which the threaded rod  40  extends, in sections. The retainer plate  44  encloses the base plate  42 . The retainer plate  44  is attached by being screwed to the bearing bracket  34 . The screws used to attach the retainer plate  44  to the bearing bracket  34  are loosened in order to adjust the post-accelerator  16 . The position of the post-accelerator  16  is changed by actuating the adjusting element  43 , i.e., by moving or rotating this relative to the threaded rod  40 . It is thereby possible to achieve a linear adjustment of the post-accelerator  16  without having actuated the threaded rod  40 . Given that the base plate  42  is clamped between the retainer plate  44  and the bearing bracket  34 , it is possible to absorb tensile and pressure forces that act on the actuator  30  during operation of the post-accelerator  16 . 
       LIST OF REFERENCE SIGNS 
       [0000]    
       
           1  forage harvester 
           2  harvesting machine 
           3  frame 
           4  wheels 
           5  wheels 
           6  operator 
           7  input/output unit 
           8  front attachment 
           9  crop 
           10  compression roller 
           11  compression roller 
           12  knife 
           13  chopper drum 
           14  shear bar 
           15  rechopper 
           16  post-accelerator 
           17  transfer device 
           18  chute 
           19  housing 
           20  wall 
           21  passage gap 
           22  sensor 
           23  inlet opening 
           24  rotary axle 
           25  bearing housing 
           26  bearing support 
           27  pivot axle 
           28  bolt 
           29  sidewall 
           30  actuator 
           31  hydraulic cylinder 
           32  connecting rod eye 
           33  cylinder eye 
           34  bearing bracket 
           35  cover 
           36  control device 
           37  angular sensor 
           38  coupling rod 
           40  threaded rod 
           41  attaching module 
           42  base plate 
           43  adjusting element 
           44  retaining plate 
           45  recess 
       
     
         [0082]    As will be evident to persons skilled in the art, the foregoing detailed description and figures are presented as examples of the invention, and that variations are contemplated that do not depart from the fair scope of the teachings and descriptions set forth in this disclosure. The foregoing is not intended to limit what has been invented, except to the extent that the following claims so limit that.