Abstract:
A wheel and final drive assembly for a work machine, such as a mining truck, having a driven rotatable wheel having inboard and outboard rims mounted thereto. The final drive assembly including a first and a second reduction gear assembly. A carrier output adapter having an inboard end, an outboard end, a cover attached to the outboard end and a mounting surface. The carrier adapter being attached at the inboard mounting surface to a outboard rim mounting ring and at the cover to a carrier assembly of the second reduction gear assembly.

Description:
TECHNICAL FIELD 
     This invention relates to a wheel and final drive assembly having a carrier output adapter, for use with a ground-driven work machine, such as an off-highway truck. 
     BACKGROUND 
     Large earth working machines, such as large mining trucks, typically have at least one pair of driven wheels that are rotatably mounted on corresponding axles or spindles. Each wheel may be driven through a final drive gear assembly, which is typically a double reduction planetary gear arrangement. Typical planetary gear arrangements include a sun gear coupled to and input shaft, a set of planetary gears disposed about the sun gear and held by a carrier and a ring gear disposed about the planetary set. The double reduction gear arrangements typically have an input shaft to a first reduction sun gear and an output through a second reduction carrier or ring gear. Power transfer from the first reduction planetary assembly to the second reduction gear assembly is typically through the first carrier to the second sun gear. A final drive adapter is used to transmit the final output to the rotatably mounted wheel. The final drive adapter couples the second reduction gear assembly to the wheel via a second carrier output adapter or a ring gear adapter. 
     As the size and capacity of machines increases, greater amounts of gear reduction are required to move the machines across the ground. Because the final drive must be confined within the wheel and rim, the structural design and geometric configuration of the final drive adapter can impact the amount of gear reduction. Another problem incurred when designing final drive assemblies with greater gear reduction is the ability to perform routine maintenance on the final drive assembly. It is preferable, although not always possible, to provide a wheel and final drive assembly that permits maintenance and service of the gear reduction portion of the final drive assembly without having to remove the outboard tire and rim. 
     In U.S. Pat. No. 4,799,564, a wheel assembly for a large mining truck is described. The output of the second reduction gear assembly is accomplished through a ring gear provided on the inboard portion of the wheel. The first reduction gear assembly is disposed outboard of the second gear assembly. 
     SUMMARY OF THE INVENTION 
     In one aspect of the present invention is a wheel and final drive assembly for a work machine. The wheel has an inboard rim mounting flange, and outboard flange and an intermediate portion. An outboard rim mounting ring includes an inboard surface and an outboard surface, the outboard rim mounting ring is removably attached to the outboard mounting flange of the wheel. The final drive assembly includes a double planetary gear arrangement. A carrier output adapter having an inboard end and an outboard end connects the double planetary gear arrangement to the outboard rim mounting ring and wheel. 
     In another aspect of the present invention a work machine having a wheel and final drive assembly is provided. The wheel includes and inboard rim mounting flange, an outboard mounting flange and an intermediate portion. An outboard rim mounting ring includes an inboard surface and an outboard surface and is removably attached to the outboard mounting flange of the wheel. The final drive assembly includes a double planetary gear arrangement. A carrier adapter having an inboard end and an outboard end connects the double planetary gear arrangement to the outboard rim mounting ring and the wheel. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side elevational view of mining dump truck with which this invention may be used. 
     FIG. 2 is a cross-sectional view showing a wheel drive assembly in accordance with the present invention. 
     FIG. 2 a  is an enlarged view of FIG. 2 taken along line  2 B illustrating one embodiment of the present invention. 
     FIG. 2 b  is an enlarged view of FIG. 2 taken along line  2 B of another embodiment of the present invention. 
     FIG. 2 c  is an enlarged section view of the carrier output adapter of yet another embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION 
     FIG. 1 illustrates an off-highway truck, generally designated as  10 , on which this invention may be used. The illustrated truck  10  may be of any suitable construction. The truck comprises a frame  12 , a material carrying dump body  14  pivotally mounted to the frame  12 . An operator cab  16  is mounted on the front of the frame  12  above an engine enclosure  18 . The truck  10  is supported on the ground by a plurality of tire and rim assemblies  19  (two shown). At the rear of the truck  10 , a pair of tire and rim assemblies  19  (two shown in FIG. 2) is mounted on one of a pair of wheels  20  (one shown). As well known in the art, one or more engines (not shown) are housed within the engine enclosure  18 . The engine is used to provide power to the wheel  20  and final drive assembly  21 , via a mechanical or electric drive train. 
     Referring now to FIG. 2, a wheel  20  and final drive assembly  21  is defined about a horizontal central axis  22 . The final drive assembly  21  includes a first reduction gear assembly  23  and second reduction gear assembly  25 . A substantially cylindrical spindle  24  is defined about the central axis  22 . The spindle  24  is adapted on a first end (inboard end)  26  to attach to a differential housing (not shown), or alternatively, an electric drive motor housing. The spindle  24  further defines a hole  28  about the central axis  22 , the hole  28  extends from the inboard end  26  to a second end (outboard end)  30 . An input shaft or drive shaft  27  typically extends through the hole  28  to transmit power to the first and second planetary gear assembly  23  and  25 . A pair of bearing mounting surfaces  32  are defined about an outer surface  34  of the spindle  24 . 
     In one embodiment of the invention, a wheel  20  is rotatably mounted on the spindle  24  via a pair of wheel bearings  36 . The wheel  20  defines an inboard end  38 , an outboard end  40  and an outer surface  42 . The inboard end  38  of the wheel  20  includes a radially outwardly extending inboard rim mounting flange  44  defined about the central axis  22 . An inboard rim assembly  48  is attached to the inboard rim mounting flange  44  in a conventional manner. The outboard end  40  of the wheel  20  includes an outboard mounting flange  48 , also disposed about the central axis  22 . The outboard mounting flange  48  may define a radially outwardly extending member having an inboard surface  50 , an outboard surface  52  and an outside edge  54  that adjoins the inboard and outboard surfaces  50 ,  52 . Alternatively, the outboard mounting flange  48  may provide a single machined surface disposed about the outboard end  40  of the wheel  20 . An alignment ring  60  is further defined about the outboard end  30  of the wheel  20 . The alignment ring  60  extends axially outward from the outboard surface  52  of the mounting flange  48  and is preferably integral of the rotatable wheel  20 . A plurality of threaded holes  56  disposed in a circular pattern on the inboard surface  50  and are centered about the central axis  22 . The plurality of threaded holes  56  extend toward the inboard surface  52  of the outboard mounting flange  48 . An outboard annular portion  58  is defined about the central axis  22  near the outboard end  30  of the wheel  20 . The outboard annular portion  58  defines an inner surface  60 . The first reduction gear assembly  23  and a second reduction gear assembly  25  is adapted to fit within the outboard annular portion  58 . 
     A carrier output adapter  62  defines a substantially cylindrical member disposed about the central axis  22 . The carrier output adapter  62  has an inboard end  64 , an outboard end  66 , an inner surface  68  and an outer surface  70 . The inboard end  64  of the carrier output adapter  62  includes a radially outwardly extending mounting flange  72  disposed thereabout. The mounting flange  72  includes an inboard surface  74 , an outboard surface  76  and an outside edge  78  extending from the inboard surface  74  to the outboard surface  76 . A first plurality of through holes  80  are disposed in a circular pattern about the central axis  22  the and extend from the inboard surface  74  of the mounting flange  70  toward the outboard surface  76  of the carrier output adapter  62 . The carrier output adapter  62  defines a closed end portion or cover  84  at the outboard end  66 . The cover  84  connects to the carrier of the second reduction gear assembly  25  in a conventional manner, typically through bolts  67 . 
     An outboard rim mounting ring  86  is defined about the central axis  22 . The outboard rim mounting ring  86  includes a first inboard surface  88 , a second inboard surface  90  and an exterior surface  92 , adjoining the first inboard surface  88  and an outboard surface  94 . An interior edge  96  is defined between the second inboard surface  90  and the outboard surface  94 . A first plurality of through holes  98  are defined in a circular pattern about the central axis  22  on the outboard rim mounting ring  86 . The first plurality of holes  98  correspond to the holes  56 , 80  in the wheel  20  and carrier output adapter  62  and extend from the outboard surface  94  to the second inboard surface  90 . A second plurality of through holes  99  extent from the outboard surface  94  of the rim mounting ring  86  to the first inboard surface  88 . The second plurality of holes  99  are positioned at a location radially outward from the first plurality of holes  98 . The second plurality of holes  99  correspond to a plurality of holes  104  on the outboard rim  106 . A bolt  100  is inserted into each of the first plurality of holes  80  of the carrier output adapter  62  and a corresponding one of the of the first plurality of holes  98  of the rim mounting ring and thread into a corresponding one of the threaded holes  56  of the wheel  20 . A rim stud  108  is inserted from the first inboard surface  88  of the rim mounting ring  86  into each of the plurality of through holes  98 . Each rim stud  108  is further aligned with, and inserted into, one of the holes  102  of the outboard rim  106 . A nut  110  engages each rim stud  108  to attach the rim  106  to the rim mounting ring  86 . 
     FIG. 2 b  illustrates an alternate embodiment of the present invention. A plurality of through holes  112  are defined about the outboard mounting flange  48 . The through holes  112  extend from the outboard surface  52 ′ to the inboard surface  50 ′ and are disposed in a circular pattern at a predetermined distance from the central axis  22  and correspond to the first plurality of holes  98  of the output rim mounting ring  86 . A bolt  100  is inserted from the inboard surface  50 ′ through the corresponding holes  98 ,  112  of the outboard rim mounting ring  86  and carrier output adapter  62 ′. A nut  114  is threaded onto each bolt to secure the carrier output adapter, outboard rim mounting ring  86  and the wheel  20  together. 
     FIG. 2 c  illustrates yet another embodiment of the present invention. The carrier output adapter  62 ″ defines a substantially cylindrical member. The inboard end  64 ″ of the carrier output adapter  62 ″ defines an inboard mounting surface  116  and an outboard mounting surface  118 . A first plurality of threaded holes  120  are defined in the inboard mounting surface  116  of the carrier output adapter  62 ″ and extend toward the outboard end  66 ″. An outboard plurality of threaded holes  122  are defined in the outboard mounting surface  118  and extend toward the inboard end  64 ″. The outboard plurality of holes  122  correspond to a plurality of through holes  124  in an end plate or cover  126 . The end plate  126  is attached to the carrier output adapter  62 ″ via high strength bolts  128 . The end plate  126  is additionally bolted to the carrier of the second reduction gear assembly  25  in a conventional manner. The first plurality of through holes  112  of the outboard mounting flange  48  of the wheel  20  and corresponding plurality of holes  98  in outboard rim mounting ring  86  align with the corresponding inboard plurality of threaded holes  120  defined in the inboard mounting surface  116 . Bolts  130  attach the carrier output adapter  62 ″ to the outboard rim mounting ring  86  and outboard mounting flange  48 ″ of the wheel  20 . 
     Industrial Applicability 
     The wheel  20  and final drive assembly  21  described above provides several advantages over constructions previously known in the art. More particularly, because the carrier output adapter  62  provides an inner surface  68  that is substantially equal, or larger, in diameter to the annular portion of the wheel  20 , the size of the second reduction gear assembly  25  may be maximized, therefore maximizing the amount of gear reduction of the final drive assembly  21 . 
     Service or maintenance of the final drive assembly  21  may be accomplished by removing the outboard tire and rim assembly  19  and removing the bolts  100  that secure the outboard rim mounting ring  86  and carrier output adapter  62  to the wheel  20 . In the case of the embodiment illustrated in FIG. 2 c , the end plate  128  may be removed without removing the tire and rim assembly  19 , providing access to the reduction gear assemblies  23 , 25 . 
     Although the presently preferred embodiments of this invention have been described, it will be understood that within the purview of the invention various changes may be made within the scope of the claims.