Abstract:
An agricultural work machine having a chassis with an operating direction and a transport system coupled to the chassis. The transport system includes a plurality of wheels including a first wheel and a wheel repositioning system. The wheel repositioning system is operatively connected to the first wheel. The wheel repositioning system is configured to adjust a position of the first wheel in a direction substantially normal to the operating direction while the chassis is moving in the operating direction.

Description:
FIELD OF THE INVENTION 
     The present invention relates to an apparatus and method for reducing tire wear on an agricultural work machine, and, more particularly to the adjustment of wheels to reduce tire wear on an agricultural vehicle. 
     DESCRIPTION OF THE RELATED ART 
     Agricultural machines, in particular combines, have headers that harvest crop leaving cut stubble after the harvesting head removes a portion of the agricultural crop. Combines are known to have contour adjusting capability so that the chassis of the combine remains substantially vertical while the wheels traverse a slope and the header is adjusted to conform to the slope for the harvesting of the crop. As the crop is cut, the cut stubble that is left behind the header can cause significant damage to tires of the combine. This problem may be made worse by the large wheels that are currently used on large combines because they are not able to fit between the rows due to the small row spacing that is commonly used in today&#39;s agricultural planting systems. As the tire is running continuously on a row in one place the tire may be prematurely worn out due to the cutting action of the sharp stubble on the same area of the tire in a circumferential direction as the tire impacts the row of the cut stubble thereby intensifying the effect on the tire. This is particularly true on modern combines since the cutting action of the header results in stubble that is sharp due to the increasingly efficient cutting systems utilized on current headers. 
     What is needed in the art is a method and apparatus to reduce the wear on expensive tires, particularly the wear that leads to premature failure of the tires. 
     SUMMARY OF THE INVENTION 
     The present invention repositions the wheels of an agricultural work vehicle and reduces tire wear thereon. 
     The invention in one form is directed to an agricultural work machine having a chassis with an operating direction and a transport system coupled to the chassis. The transport system includes a plurality of wheels including a first wheel and a wheel repositioning system. The wheel repositioning system is operatively connected to the first wheel. The wheel repositioning system is configured to adjust a position of the first wheel in a direction substantially normal to the operating direction while the chassis is moving in the operating direction. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a view of a ground engaging vehicle, in the form of an agricultural vehicle that utilizes an embodiment of the wheel repositioning system of the present invention; 
         FIG. 2  is another view of the agricultural vehicle of  FIG. 1 ; and 
         FIG. 3  is a schematized diagram illustrating more than one embodiment of the present invention utilized on the agricultural vehicle of  FIGS. 1 and 2 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to the drawings, and more particularly to  FIGS. 1 and 2 , there is shown a work machine  10 , also illustrated as a harvesting machine  10 , known as a combine  10  that is utilized to harvest row crops in an agricultural field. Work machine  10  includes a chassis  12  coupled to a transport system  14 . Chassis  12  may include grain processing, grain cleaning, grain storage and grain transport systems. Additionally chassis  12  includes an operator cab having operator controls therein. Transport system  14  transports chassis  12  across the field so that work machine  10  can perform its intended function. 
     Now, additionally referring to  FIG. 3  transport system  14  is schematically illustrated as moving in a direction  16 . Transport system  14  includes wheels  18  and wheel repositioning system  20 . Wheel repositioning system  20  includes a controller  22 , a wheel wear detector  24 , a row spacing detector  26 , an input device  28 , a steering angle detector  30  and an actuator  42 . For purposes of clarity repositioning system  20  will be discussed as applying to the rear axle of combine  10 , but the invention can apply to either axle or both axles. 
     The view in  FIG. 3  is schematically shown as a top view with transport system  14  moving in a direction  16  encountering rows  40  of cut crop stubble. Repositioning system  20  includes actuators  42  that can be utilized by controller  22  to move wheels  18  in directions  32  through  38  as illustrated on one set of wheels  18 . Actuator  42  may extend wheels  18  by repositioning axles upon which wheels  18  rotate or may function to reposition wheels  18  along an axis schematically illustrated as the connecting line between actuator  42  and wheels  18 . Alternatively, wheels  18  may be on separate axles that are generally axially aligned with each other having actuator  42  configured to reposition the position of wheel  18  as it encounters cut crop stubble. 
     Wheel wear detector  24  detects the wear of the tire rubber along the face of wheel  18  so that information therefrom is used by controller  22  to decide when to reposition wheels  18 . Controller  22  sends control commands to actuator  42  to reposition at least one wheel  18  to change the position of the wear that is inflicted upon the tire by the cut crop stubble, thereby distributing the wear across the face of wheel  18 . Additionally or alternatively, the positioning of the rows is detected by a row spacing detector  26  to determine where the rows of the cut crop stubble are positioned, so that it can be anticipated where the wear will occur on the tire, as the tires encounter rows  40 . Additionally, input device  28 , positioned in the operator cab, can be utilized by an operator to command a certain position of tires  18  to adjust for row spacing. If practical, the wheels can be adjusted to run between rows  40 , or wheels  18  can simply be positioned based on an input from the operator. 
     Controller  22  commands actuator  42  to adjust wheels  18  in directions  32  and  34  substantially the same distances in opposite directions or may adjust one wheel  18  in a direction  32  one distance and the opposite wheel  18  in direction  34  a different distance, which may be the case if the wheel spacings need to be different to accommodate row spacings or tire wear. Controller  22  is additionally connected with steering angle detector  30  so that the automatic spacing of tires  18  can be temporarily suspended while combine  10  is being turned, which would have significant impact on the information from row spacing detector  26 . Alternatively, the information from row spacing detector  26  may be utilized if it is consistent over a certain period of time and disregarded when inconsistencies occur, for example as a result of traversing rows or at the ends of a field where rows running in different directions may be encountered. 
     Steering angle detector  30  may be associated with a ground engaging wheel as illustrated or the steering angle may be obtained from input commands from the operator in the cab of combine  10 . Additionally, if steering angle detector  30  detects an extreme angle turn, at least one of wheels  18  may be extended to the widest possible extent to provide additional stability to work machine  10  as it turns. 
     The adjustable axle can be adjusted on the go, while combine  10  is moving in direction  16 , from the operator&#39;s station by manually entering the information in input device  28 , or wheel repositioning system  20  can function automatically with input from such devices as a tire wear detector  24  or row spacing detector  26 . The tire wear can be dramatically reduced, thereby extending the tire life substantially by adjusting the position of wheels  18  in the direction that is substantially perpendicular to direction  16 . The same portions of the tires are then not always running on the cut stubble of the row. This allows the wear to be more evenly distributed across the full width of the tire and not just in one location. Repositioning system  20  adjusts for row spacing at specific intervals so that the tire wear becomes very uniform. For example, row spacing between rows  40  may be encountered at two positions along a tire  18 . Those positions can be varied over time to reduce the wear that is being encountered along any one annular ring of the tire. If work machine  10  is running in rows that are spaced such that the tires can fit between the rows, then the wheel spacing can be set to run between the rows to improve the tire life even further. This can be tied in to selections on operator input device  28  based upon crop row spacing. 
     The repositioning of the wheels by repositioning system  20  can be done on a time duration method, where the position of wheels  18  can be moved after the passage of a selected duration of time. For example, after the passage of a predetermined time of two hours wheels  18  may be moved a predetermined distance of two inches. This can be repeated until the wheels have been moved to one extreme, then the method moves wheels  18  in the opposite direction, in two hour increments, until the other extreme of movement is met. 
     By moving the axle in and out at uniform intervals to distribute the wear over the full width of the tire, the tire wear can be dramatically reduced, significantly extending the life of expensive agricultural tires, reducing the overall cost of repairs and downtime for the machine. By making the axle adjustable, the axle extension can be easily adjusted causing the wheels to operate between the rows in crops where the tires are small enough to fit between the rows. In the automatic mode the spacing and selection of tire/wheel positioning relative to row spacing is done automatically so that the operator does not have to determine where to set the wheel spacing. 
     Having described the preferred embodiment, it will become apparent that various modifications can be made without departing from the scope of the invention as defined in the accompanying claims.