Tandem wheel assembly and tandem wheel kit

Abstract

A tandem wheel assembly or kit has a housing including a center chain case, a first wheel end housing, and a second wheel end housing. The center chain case has an interior volume extending between a first case end and a second case end, an integral pivot portion having a case opening disposed about a pivot axis, a first case flange having a first case flange face, and a second case flange having a second case flange face. The first wheel end housing has a first wheel end flange having a first wheel end flange face mateable with the first case flange face, a first wheel end opening, and defines a first length. The second wheel end housing has a second wheel end flange having a second wheel end flange face mateable with the second case flange face, a second wheel end opening, and defines a second length.

Description

Technical Field

[0001] This disclosure generally relates to tandem wheel assemblies for use in work vehicles. Background Technology

[0002] Work vehicles used in industries such as construction, agriculture, forestry, mining, and others can utilize tandem wheel assemblies (also known as bogie axles) to support large loads on four or more ground-engaging wheels or tracks using a single axle. This single axle allows the wheels to pivot together to maintain ground contact over changing terrain without significantly displacing other areas of the work vehicle, including the cab and work implements (e.g., shovels). Such tandem wheel assemblies can also be driven (e.g., from the work vehicle's powertrain via a transmission, or they can be powered themselves). One type of work vehicle that frequently uses tandem wheel assemblies is the motorized grader. Applications may require the motorized grader to provide high torque, low-speed power to the ground-engaging wheels or tracks, achieved through high-ratio gear reduction of the wheels. Different applications may suit different motorized graders with varying load-carrying capacities. Various machines may have different overall dimensions and use different wheel sizes and tandem wheel assemblies of different sizes and wheelbases. Summary of the Invention

[0003] This disclosure provides an improved tandem wheel assembly and tandem wheel kit for work vehicles.

[0004] In one aspect, this disclosure provides a tandem wheel assembly for a work vehicle. The tandem wheel assembly has a housing including a central chain box, a first wheel end shell, and a second wheel end shell. The central chain box has an inner wall and an outer wall defining an internal volume and extending between a first box end and a second box end. The inner wall defines a pivot portion as a single part of the central chain box, the pivot portion having a box opening disposed about a pivot axis and communicating with the internal volume. The central chain box has a first box flange with a first box flange face at the first box end and a second box flange with a second box flange face at the second box end. The first wheel end shell has a first wheel end flange having a first wheel end flange face that mates with the first box flange face. The first wheel end shell has a first wheel end opening disposed about a first wheel end axis substantially parallel to the pivot axis and communicating with the internal volume of the central chain box when the first wheel end shell is mounted to the first box end. The first wheel end shell defines a first length from the first wheel end flange face to the first wheel end axis. The second wheel end housing has a second wheel end flange having a second wheel end flange surface that mates with a second housing flange surface. The second wheel end housing has a second wheel end opening that communicates with the internal volume of the central chain box and is disposed around a second wheel end axis substantially parallel to the pivot axis. When the second wheel end housing is mounted to the end of the second housing, it communicates with the internal volume of the central chain box. The second wheel end housing defines a second length from the second wheel end flange surface to the second wheel end axis.

[0005] On the other hand, this disclosure provides a tandem wheel assembly for a work vehicle. The tandem wheel housing includes a center chain box, a first wheel end housing, a second wheel end housing, and a third wheel end housing. The center chain box has an inner wall and an outer wall defining an internal volume and extending between a first box end and a second box end. The inner wall defines a pivot portion that is a single part of the center chain box, the pivot portion having a box opening disposed about a pivot axis and communicating with the internal volume. The center chain box has a first box flange with a first box flange face at the first box end and a second box flange with a second box flange face at the second box end. The first wheel end housing has a first wheel end flange having a first wheel end flange surface that mates with a first housing flange surface. The first wheel end housing defines a first wheel mount as a single part of the first wheel end housing. The first wheel mount extends from the outer wall of the first wheel end housing and defines a first wheel end opening. The first wheel end opening is arranged about a first wheel end axis that is substantially parallel to the pivot axis and communicates with the internal volume of the center chain box when the first wheel end housing is mounted to the end of the first housing. The first wheel end housing defines a first length from the first wheel end flange surface to the first wheel end axis. The second wheel end housing has a second wheel end flange having a second wheel end flange surface that mates with a second housing flange surface. The second wheel end housing defines a second wheel mount as a single part of the second wheel end housing. The second wheel mount extends from the outer wall of the second wheel end housing and defines a second wheel end opening that communicates with the internal volume of the center chain box and is disposed about a second wheel end axis that is substantially parallel to the pivot axis. When the second wheel end housing is mounted to the end of the second housing, it communicates with the internal volume of the center chain box. The second wheel end housing defines a second length from the second wheel end flange surface to the second wheel end axis. The third wheel end housing has a third wheel end flange with a third wheel end flange surface that mates with the flange surface of the first housing. The third wheel end housing has a third wheel end opening that communicates with the internal volume of the center chain box and is positioned about a third wheel end axis substantially parallel to the pivot axis. When the third wheel end housing is mounted to the end of the first housing, it communicates with the internal volume of the center chain box. The third wheel end housing defines a third length from the third wheel end flange surface to the third wheel end axis, wherein the third length differs from the first length. The configurable tandem wheelbase is defined by selectively mounting either the first wheel end housing or the third wheel end housing to the first housing end of the center chain box.

[0006] Details of one or more embodiments are set forth in the accompanying drawings and the following description. Other features and advantages will become apparent from the specification, drawings, and claims. Attached Figure Description

[0007] Figure 1This is a simplified perspective view of an example work vehicle in the form of a motorized grader according to the present disclosure, in which a tandem wheel assembly can be used;

[0008] Figure 2 It is used for Figure 1 An isometric view of an example train wheel assembly for an example motorized grader;

[0009] Figure 3 It is along Figure 2 A top sectional view of the train wheel assembly taken from plane 3-3;

[0010] Figure 4 yes Figure 2 An isometric view of one side of an example train wheel assembly;

[0011] Figure 5 It is an isometric view of its inner side;

[0012] Figure 6 yes Figure 2 An isometric view of the central chain box of the train wheel assembly; and

[0013] Figure 7 This is an exploded partial isometric view of the train wheel assembly, showing the center chain box and two wheel end pairs of different sizes.

[0014] The same reference numerals in different figures indicate the same elements. Detailed Implementation

[0015] The following describes one or more exemplary embodiments of the disclosed tandem train wheel assembly, as illustrated in the figures in the accompanying drawings briefly described above. Various modifications to the exemplary embodiments will be conceived by those skilled in the art.

[0016] As used herein, unless otherwise limited or modified, a list of elements separated by connecting terms (e.g., “and”) and preceded by the phrase “one or more” or “at least one” indicates a construction or arrangement that potentially includes the individual elements of the list or any combination thereof. For example, “at least one of A, B and C” or “one or more of A, B and C” indicates the possibility of only A, only B, only C, or any combination of two or more of A, B and C (e.g., A and B, A and C, B and C, or A, B and C).

[0017] Additionally, in describing this disclosure in detail, terms of orientation and direction, such as “longitudinal,” “internal,” “external,” “radial,” “axial,” “circumferential,” “lateral,” and “transverse,” may be used. These terms are defined at least in part relative to wheel axles, pivot axes, and / or the work vehicle. As used herein, the term “longitudinal” indicates an orientation along the length of the equipment; the term “lateral” indicates an orientation along the width of the equipment and perpendicular to the longitudinal orientation; and the term “transverse” indicates an orientation along the height of the equipment and orthogonal to both the longitudinal and lateral orientations. These orientations may be determined relative to the work vehicle or the direction of travel of the work vehicle, to which components may be attached. In other examples, according to this disclosure, the components referenced by those terms may be reversed.

[0018] Overview

[0019] Work vehicles (such as motorized graders) typically comprise components for performing tasks across a variety of terrains and conditions, such as chassis, powertrain (e.g., engine and drivetrain), suspension, and work implements (e.g., blades). Typically, work vehicles may perform tasks requiring consistent work implement positioning (e.g., a blade scrapes a work area at a desired height to create a flat surface). The wheel axle area can bear significant static weight loads from onboard components (e.g., engine, transmission, axles, work implements, etc.) and encounters significant operational loads (e.g., impacts / loads from attached work implements and through the wheels and suspension). Therefore, work vehicles must adapt to varying terrain, static loads, and operational loads generated by the work task while maintaining desired implement positioning. Tandem wheel assemblies can accommodate such variations in load or gradient by mounting the wheel assemblies (typically the rear wheel assemblies) together to pivot relative to the work vehicle, providing ground contact to the wheels without significantly hindering work implement placement.

[0020] Especially in the case of motorized graders, the work implement is a large flat shovel that cuts and moves large amounts of soil in the initial phase of site preparation. In the final phase, even with the rear wheels following behind the shovel, the final base surface must be level and precisely sloped over a large area and / or distance (e.g., several miles of road). Motorized graders must operate at sufficient speeds to be productive while preventing unwanted bouncing and swaying; for example, motorized graders can operate at speeds ranging from approximately a slow "crawling" 0.3 miles per hour (mph) to approximately 7 mph. In other applications (e.g., rough preliminary cutting or plowing), higher speeds of up to approximately 40 mph can be used. During use, the shovel is subjected to resistance such as friction from the ground, the weight of previously loosened soil and debris as it flows along the shovel, and impact loads from obstacles. For example, with shovel dimensions ranging from 8 to 24 feet in length and 1 to 3 feet in height, the weight of soil or other material carried by the shovel is substantial. These operational loads are transferred to the vehicle wheels, which then distribute the load to the prepared surface. Therefore, the wheels can improve site preparation performance by maintaining contact with the ground to achieve consistent traction, while also distributing the load evenly across the surface to minimize stress on the scraped work surface.

[0021] Additionally, this disclosure provides a tandem wheel that can have modular wheel ends adapted to different wheelbase requirements of the machine. Work vehicle manufacturers can offer a range of different models or categories of vehicle platforms, where multiple similar work vehicles differ in some aspects, such as chassis size, engine size, or various other features. For example, motorized graders can be offered as different models with different shovel sizes and different expected operating loads, which may require different wheel sizes, engine sizes, wheelbases, etc. In some examples, the relevant models may have tandem wheelbases varying from approximately 60 to 160 mm (e.g., wheelbases of 1480 mm, 1540 mm, and 1640 mm). However, these different models also share many common characteristics and components (e.g., drivetrain components, engine size, etc.). The tandem wheel assembly of different work vehicle models may have variations (e.g., tandem wheel housing dimensions, chain size, sprocket size, wheel diameter), which require significant redesign and component separation along the entire platform line. Such a tandem wheel assembly may have a complex multi-part housing, where the dimensions of several key components are redefined for each different model. This disclosure provides modularity in terms of wheel end housings of different lengths, while sharing other parts such as the center chain box and drive components. This disclosure can also be adapted to modularity in terms of some drive components (e.g., one or more sprockets and / or chains) that are easily assembled with the shared parts. Therefore, the disclosed tandem wheel assembly can provide relatively fewer parts and a lighter weight compared to conventional arrangements.

[0022] The present invention also provides a tandem wheel assembly having multiple wheel end shells that can be selectively mounted to a center chain box. The wheel end shells have different lengths; thus, multiple wheelbases can be achieved using a single center chain box and at least some shared internal components. The selected wheel end shells mounted to each end of the center chain box can have substantially equal lengths. The tandem wheel assembly can therefore be assembled to provide a wheelbase for a specific work vehicle model.

[0023] This disclosure provides a tandem wheel assembly that facilitates manufacturing, assembly, and repair. Many components assembled in the tandem wheel assembly are large, formed metal parts, castings, and / or specialized parts that can have high material and production costs. The aforementioned shared components, integrated with modular components, reduce costs by reducing or eliminating separate processes and assembly lines. For example, a single center chain box can be designed and manufactured to serve multiple tandem wheel sizes. Various access panels and gripping surfaces allow for maintenance and repair without obstruction from wheels, drivetrain, or other components. This accessibility simplifies assembly and, for maintenance, saves costs and reduces downtime for the work vehicle.

[0024] Furthermore, this disclosure provides a pivot joint for a tandem wheel assembly of a work vehicle, wherein a portion of the pivot joint is integrated as a single part of the housing. This integrated arrangement reduces the number of parts in the housing, thereby saving manufacturing costs. The pivot joint is a structural link between the work vehicle and the tandem wheel assembly; thus, various static and dynamic loads supported by the tandem wheels are transmitted through the pivot joint. Additionally, the disclosed tandem wheels are driven by the work vehicle's powertrain, which may induce torque loads in the surrounding housing structure. Therefore, the pivot joint must be appropriately robust to support the various loads and the resulting torques, while providing the necessary pivoting movement to maintain ground contact. The integrated pivot portion, together with the central chain box, is formed from a heavy-duty material (e.g., cast metal) to accommodate these loads and perform these functions.

[0025] The following describes one or more exemplary embodiments of the disclosed tandem wheels and housings. While the discussion herein may sometimes focus on exemplary applications of tandem wheels with cast housings in motorized graders, the disclosed tandem wheels can also be applied to bogie axles or tandem axles in other types of work vehicles, including self-propelled or tractor-trailer work vehicles, as well as various other agricultural machinery (e.g., articulated tractors, multi-purpose tractors, front-end loaders, harvesters, etc.), various construction and forestry machinery (e.g., harvesters, lumber mills, etc.), and transport vehicles (e.g., semi-trailers).

[0026] Example embodiment of a train wheel assembly

[0027] refer to Figure 1In some embodiments, the disclosed work vehicle 10 may be a motorized grader; however, as described herein, the tandem wheels are applicable to a variety of machinery, such as other construction vehicles, agricultural vehicles including articulated frame tractors, forestry vehicles (e.g., harvesters), and transport vehicles (such as semi-trailers). As shown, the work vehicle 10 may be considered to include a chassis 12 consisting of a rear frame 14 and a front frame 16 for carrying a flat shovel 18 selectively positioned by a implement drive system 20. The work vehicle 10 may also be considered to include a powertrain 24, a cab 26, a control system 28, and a hydraulic system 30. The work vehicle 10 may be lifted off the ground by ground-engaging wheels or tracks. In the example shown, the work vehicle 10 includes a tandem wheel assembly 32 on the rear frame 14, which mounts four wheels, including a pair of left wheels 34 defined by a first left wheel 36 and a second left wheel 38, and a pair of right wheels 40 defined by a first right wheel 42 and a second right wheel 44 (also collectively referred to as the "four tandem wheels 36, 38, 42, 44"). A third set of wheels 46 is mounted on the front axle (not shown) on the front frame 16, which may be configured to be automatically steerable or steerable by operator control. It should be noted that any left / right wheel pair (first left wheel 36 and first right wheel 42, second left wheel 38 and second right wheel 44, or third set of wheels 46) may be arranged for each left / right side of the work vehicle 10 (e.g., Figure 1 The double wheels are shown on the side in the x-direction.

[0028] Generally, the powertrain 24 includes a propulsion source (such as engine 50) that supplies power to the work vehicle 10 either as direct mechanical power or after conversion to electrical (e.g., via battery) or hydraulic power. In one example, engine 50 is an internal combustion engine (such as a diesel engine) controlled by an engine control module (not shown) of control system 28. It should be noted that the use of an internal combustion engine is merely an example, as the propulsion source can be a fuel cell, an electric motor, a hybrid gas motor, or other power-generating device. Transmission 52 transmits power from engine 50 to one or more of the wheels (e.g., the four tandem wheels 36, 38, 42, 44 of tandem wheel assembly 32). Additionally, the powertrain 24 has a wheel steering component 54 that includes various devices (e.g., power steering pumps and lines, steering mechanisms, etc.) that connect manual (e.g., operator steering controllers or wheels) and / or automatic (via control system 28) steering inputs to one or more of the wheel sets (e.g., a third set of wheels 48). The powertrain 24 may additionally or alternatively include various devices (e.g., steering mechanisms, hydraulic actuators, etc.) that connect manual and / or automatic steering inputs to the articulated joint 22.

[0029] In addition to providing traction power to propel the work vehicle 10, engine 50 can also power various onboard subsystems, including various electrical and hydraulic components of the work vehicle, and provide off-boarding power to other subsystems located away from the work vehicle 10. For example, engine 50 can provide mechanical power converted to electrical form to operate the electronics of control system 28 and one or more electric drive units of the work vehicle 10. Thus, powertrain 24 may have mechanical-to-electric conversion components 56, one or more batteries 58, and associated electronics, including various alternators, generators, voltage regulators, rectifiers, inverters, etc. Engine 50 can also provide mechanical power converted to hydraulic form to power various pumps and compressors that pressurize fluids to drive various actuators of hydraulic system 30 to power wheel steering and braking on the work vehicle 10 and various work implements. Hydraulic system 30 may include other components (e.g., valves, flow lines, pistons / cylinders, seals / gaskets, etc.) so that control of various devices can be utilized and based on hydraulic, mechanical, or other signals and movements.

[0030] The control system 28 can be configured as a computing device with associated processor and memory architecture, configured as a hardwired computing circuit (or multiple circuits), configured as a programmable circuit, or configured as a hydraulic, electrical, or electro-hydraulic controller. The control system 28 can be configured to perform various computational and control functions relating to the work vehicle 10, which includes various devices associated with the work vehicle 10's powertrain 24, hydraulic system 30, implement drive system 20, and various additional components. In some embodiments, the control system 28 can be configured to receive input signals in various formats (e.g., as hydraulic signals, voltage signals, current signals, etc.) and output command signals in various formats (e.g., as hydraulic signals, voltage signals, current signals, mechanical motion, etc.).

[0031] As described above, the hydraulic system 30 can be controlled by the control system 28 (automatically, via operator input, or both). The hydraulic system 30 can be powered by the engine 50 and configured in various arrangements to provide a variety of hydraulic functions (e.g., powering the tool drive system 20). Therefore, the hydraulic system 30 can have components (not shown) including a pump for supplying pressurized hydraulic fluid, a reservoir for storing the hydraulic fluid, and various valves (e.g., control valves) associated with each function.

[0032] In the example shown, when the work vehicle 10 is driving in the forward direction ( Figure 1As shown in the diagram, the tandem wheel assembly 32 follows behind the shovel 18 and supports most of the weight on the rear frame 14. The tandem wheel assembly 32 is pivotable about a pivot axis 60. Specifically, each of the left wheel pair 34 and the right wheel pair 40 can pivot independently relative to the work vehicle 10 about the pivot axis 60. During use, if the work vehicle 10 encounters obstacles or uneven surfaces, the tandem wheel assembly 32 adapts to this situation by pivoting. As a result, the transmission of bumps or terrain changes is reduced or eliminated, thereby keeping the shovel 18 and the cab 26 in a relatively stable position that maintains traction and weight distribution. Similarly, the four tandem wheels 36, 38, 42, and 44 maintain ground contact while pivoting.

[0033] Also refer to Figure 2 and Figure 3 The tandem wheel assembly 32 mounts four tandem wheels 36, 38, 42, and 44 under the rear frame 14. An example tandem wheel assembly 32 may include a differential housing 62, a first mounting arm 64, a second mounting arm 66, a first pivot joint 68, a second pivot joint 70, a first tandem wheel housing 72, and a second tandem wheel housing 74. The first tandem wheel housing 72 includes a center chain box 80 having a pivot portion 82 extending laterally inward toward the differential housing 62, a first wheel end housing 84 for mounting the first left wheel 36, and a second wheel end housing 86 for mounting the second left wheel 38. It should be understood that the center chain box 80 with separable first and second wheel end housings 84 provides a robust and aesthetically pleasing design that advantageously accommodates modular attachment of different wheel end housings and internal drive components, as detailed below. The tandem wheel assembly 32 may have a substantially similar mirror structure on each lateral side of the differential housing 62 (e.g., the first pivot joint 68 and the second pivot joint 70, as well as the first tandem wheel housing 72 and the second tandem wheel housing 74, are substantially similar in the example shown). Therefore, the details discussed below for one structure (e.g., the first pivot joint 68 or the first tandem wheel housing 72) apply to the corresponding opposite side structures.

[0034] The tandem wheel assembly 32 also allows the four tandem wheels 36, 38, 42, 44 to pivot relative to the work vehicle 10 about a pivot axis 60. The differential housing 62 is rigidly attached to a first mounting arm 64 and a second mounting arm 66, which are fixed to the chassis 12 of the work vehicle 10 (e.g., by bolts through arm holes 88). Thus, the differential housing 62 is relatively fixed in place, and one or both of the first tandem wheel housing 72 and the second tandem wheel housing 74 can pivot independently relative to the differential housing 62 via a first pivot joint 68 and a second pivot joint 70. Specifically, the pivot portion 82 of the center chain box 80 is rotatably journal-supported on a fixed pivot portion 90, which is non-rotatably mounted relative to the differential housing 62 (and therefore fixed relative to the chassis 12 of the work vehicle 10). One or more rotation limiters 92 may be provided on the central chain box 80 to define the maximum pivoting travel of the first train wheel housing 72 and the second train wheel housing 74 (e.g., by contacting the lower portion of the chassis 12).

[0035] As described above, the tandem wheel assembly 32 includes multiple components of the powertrain 24 to transmit prime mover power to each of the four tandem wheels 36, 38, 42, and 44. A differential 100 is mounted in a differential housing 62 and connected to a drive shaft 102 driven by the transmission 52. The differential 100 includes a gear assembly to disengage and translate the rotational lateral of the drive shaft 102 toward the first tandem wheel housing 72 and the second tandem wheel housing 74. A pinion 104 at the end of the drive shaft 102 meshes with a differential ring gear 106 mounted on a differential housing 108, which is coupled to a first inner shaft 110 and a second inner shaft 112 (via a side gear 114). The differential 100 may be a limited-slip differential with a clutch assembly 115 for anti-slip. The first inner shaft 110 is coupled to a first outer shaft 116 after gear reduction provided by a planetary gear set 118. Specifically, the planetary gear set 118 includes a sun gear 120 formed on (or mounted on) a first inner shaft 112, a plurality of planetary gears 122 within a fixed ring gear 124, and a carrier 126 that rotates together with the plurality of planetary gears 122. The carrier 126 is non-rotatably attached to a first outer shaft 116 extending into the first train wheel housing 72. The planetary gear set 118 is selectively activated by a clutch assembly 128.

[0036] Components of the powertrain 24 in the tandem wheel assembly 32 may include additional support components, such as bearings for any rotating parts. For example, drive shaft 102 is supported in differential housing 62 by first bearing 130a and second bearing 130b, which may be tapered roller bearings mounted in opposite tapered directions to accommodate axial loads other than rotation. First inner shaft 110 may be supported by one or more rotating bearings, as shown, with tapered roller bearing 132 supporting the first inner shaft 110 between differential 100 and planetary gear set 118. Outer shaft 116 may be supported in fixed pivot portion 90 by first bearing 134a and second bearing 134b, which may also be opposing tapered roller bearings. It should be understood that fixed pivot portion 90 is fixed relative to work vehicle 10 while supporting pivot portion 82 for rotational support at the outer journal of fixed pivot portion 90, and also supporting outer shaft 116 for power transmission rotation. Although not shown in detail, the differential housing 62 can accommodate additional components of the differential 100, including brakes, multiple U-joints, ring gears, multiple pinion shafts, multiple pinions, multiple planetary gears, side gears, clutch plates, bearings, etc. Any type of differential can be implemented within the tandem wheel assembly 32, including open differentials, limited-slip differentials, etc. The differential housing 62 also mounts various parts of the drive shaft 102. Figure 3 ) and the various parts of the first inner shaft 110 and the second inner shaft 112.

[0037] Power transmission continues within the first train wheel housing 72, which has a central sprocket 140 non-rotatably attached to a first outer axle 116. The central sprocket 140 is a double-ring sprocket, mounting a first chain 142 extending to a first wheel-end sprocket 144 and a second chain 146 extending to a second wheel-end sprocket 148. The first chain 142 and the second chain 146 can be a plate chain, a roller chain, or other suitable drive chains for heavy-duty construction applications. The first wheel-end sprocket 144 and the second wheel-end sprocket 148 are each aligned with one of the double rings of the central sprocket 140. Thus, when the central sprocket 140 rotates, the first chain 142 and the second chain 146 provide co-rotation for the first wheel-end sprocket 144 and the second wheel-end sprocket 148. The first wheel-end sprocket 144 mounts a first wheel axle 150 supporting a first left wheel 36. Similarly, the second wheel-end sprocket 148 mounts a second wheel axle 152 supporting a left rear wheel 38. The first wheel-end sprocket 144 and the second wheel-end sprocket 148 will have equal dimensions (e.g., equal number of teeth) to drive the corresponding first left wheel 36 and second left wheel 38 at substantially equal speeds. Although the first chain 142 is shown mounted inside relative to the second chain 146, these relative positions can be reversed.

[0038] To propel the work vehicle 10, the engine 50 powers the transmission 52, which drives the differential 100, the first inner shaft 110, and the first outer shaft 116. The first outer shaft, in turn, drives the center sprocket 140 in the center sprocket box 80. The center sprocket 140 drives the first chain 142 and the second chain 146, which respectively rotate the first wheel-end sprocket 144 and the second wheel-end sprocket 148, and similarly rotate the first wheel axle 150 and the second wheel axle 152 to ultimately rotate a pair of left wheels 34. The transmission 52 typically includes one or more gear arrangements and / or clutches (not shown) to change the speed of the input from the engine 50 to one or more speeds suitable for the tandem wheel assembly 32. Further gear reduction can be achieved via a planetary gear set 118 between the first inner shaft 110 and the first outer shaft 116. If necessary, gear reduction via a planetary gear set (not shown) can be provided between the first wheel end sprocket 144 and the first left wheel 36, and similarly between the second wheel end sprocket 148 and the second wheel 38.

[0039] Still referencing Figures 4 to 6The center chain box 80 may be a generally hollow portion having an inner wall 160 and an outer wall 162 that define an internal volume 164 extending from a first box end 166 to a second box end 168 and between an upper wall 170 and a bottom wall 172. The center chain box 80 may be formed of cast metal or other suitable robust material. The inner wall 160 has a pivot portion 82 as a single part of the center chain box 80 (e.g., integrally formed simultaneously from the same material using the same process), although in other examples the pivot portion 82 may be a separate component. The integral construction of the pivot portion 82 with the center chain box 80 can advantageously reduce parts and assembly time, thereby reducing manufacturing costs, and also provides suitable strength and stiffness to accommodate internal and external loads on the tandem train wheel housing 72. The pivot portion 82 defines a box opening 173 disposed around a pivot axis 60 and communicating with the internal volume 164. A first flange 174 having a first flange face 176 is formed at the first end 166 of the housing for mounting a first wheel end housing 84. A second flange 178 having a second flange face 180 is formed at the second end 168 of the housing for mounting a second wheel end housing 86. An internal volume 164 accommodates the components of the aforementioned powertrain 24, provides an elongated channel 181 for the first chain 142 and the second chain 146 extending from the first end 166 of the housing to the second end 168 of the housing, and the internal volume 164 is at least partially filled with lubricant for the accommodated components. The first flange 174 and the second flange 178 each include mounting holes 182 around their peripheries for attaching the first wheel end housing 84 and the second wheel end housing 86, respectively, by fasteners such as a first set of bolts 184 and a second set of bolts 185. The first box end 166 and the second box end 168 are substantially open within the first box flange 174 and the second box flange 178 to extend the internal volume 164 to the first wheel end housing 84 and the second wheel end housing 86.

[0040] One or more exit regions 186 may be provided in the inner wall 160 and / or outer wall 162 to reduce the volume of the internal volume 164 and reduce the amount of lubricant required within the first train wheel housing 72. As shown, the exit region 186 is an opening extending across the entire width of the central chain box 80. Alternatively, the exit region 186 may be an internal dry cavity, a recess formed in the inner wall 160 and / or outer wall 162, etc. One or more access windows 188 may be provided in the inner wall 160, outer wall 162, upper wall 170, or bottom wall 172 for mounting a removable panel (not shown, by fasteners such as bolts) to allow access to the internal volume 164, for example, for chain maintenance or lubrication. In the example shown, six access windows 188 are provided, two in each of the inner wall 160, outer wall 162, and upper wall 170. Central opening 190 ( Figure 6A mounting position can be formed in the outer wall 162 near the center sprocket 140 to mount a center entry panel 192 that can be mounted by fasteners (such as bolts 194). Figure 4 The central opening 190 allows access during the assembly or repair of the central sprocket 140 and components attached thereto. Additionally, one or more portions of the upper wall 170 may provide gripping surfaces 195, formed as a single part of the upper wall 170 or attached to the wheel surface or ridge of a separate workpiece, to prevent slippage when a user steps on the first train wheel housing 72 to access another area of ​​the work vehicle 10. The pivot portion 82 may be supported by one or more reinforcing ribs 196, which may be formed as a single part of the central chain box 80. It should be understood that the central chain box 80 may include various additional ribs or trusses extending through the internal volume 164 to provide additional structural integrity and / or volumetric displacement without obstructing the first chain 142 and the second chain 146. Additionally, although the mounting holes 182 are shown as a single row evenly spaced around the entire periphery of the first box flange 174 and the second box flange 178, various other arrangements are contemplated, including arranging the mounting holes in multiple rows or only around a portion of the periphery.

[0041] The first wheel end shell is typically hollow, having an inner wall 200, an outer wall 202, a peripheral wall 204, and a first wheel mount 206, which can be formed as a single part of the first wheel end shell 84 (e.g., integrally formed from the same material using the same process). The first wheel end shell 84 can be formed from the same material as the center chain box 80, such as cast metal. The peripheral wall 204 tapers gradually in height from the top to the bottom and forms a semi-circle coaxial with the first wheel mount 206. The first wheel end flange 208 has a first wheel end flange surface 210, which includes mounting holes 212 corresponding to mounting holes 182 of the first housing flange 174, such that the first wheel end flange surface 210 engages with the first housing flange surface 176 via a first set of bolts 184. The first wheel mount 206 extends laterally outward from the outer wall 202 and terminates at a first wheel end opening 214, which supports the first wheel hub 216 of the first left wheel 36. Figure 2 and Figure 3At least a portion of the first wheel end opening 214 is connected to the internal volume 164 of the central chain box 80 during assembly. A first wheel axle 152 is mounted proximal to the first wheel end sprocket 148 for co-rotation and extends through the wheel mount 206. The first wheel axle 152 extends toward the first wheel end opening 214 for mounting the first wheel hub 216 for co-rotation. The first wheel axle 152 and wheel hub 216 are supported in the first wheel mount 206 by a swivel bearing (not shown). Therefore, the first wheel end opening 214 defines a first wheel end axis 218, which is the axis of rotation of the first left wheel 36, the first wheel end sprocket 148, the first wheel axle 152, and the first wheel hub 216. This first wheel end axis 218 is substantially parallel to the pivot axis 60 and substantially perpendicular to the first set of bolts 184. The first wheel end housing 84 and the first wheel mount 206 can be fitted with various additional support components (not shown), such as roller bearings, and as described above, gear components (not shown, such as planetary gear sets) can be fitted to provide additional gear reduction between the first wheel end sprocket 148 and the first wheel hub 216. As discussed below, the first wheel end housing 84 defines a first length 220 from the first wheel end flange surface 210 to the first wheel end axis 218. Figure 3 The first access panel 222 may be disposed in the inner wall 200 to allow assembly / repair of the first wheel end sprocket 144 or other components inside the first wheel end housing.

[0042] The first wheel end shell 84 and the second wheel end shell 86 are basically similar structures that can be copied or mirrored. For example... Figures 3 to 6 As shown, the first wheel end housing 84 and the second wheel end housing 86 are replica structures of the same length and are arranged for mounting together with the first housing flange 174 and the second housing flange 178 of the symmetrical central chain box 80. Therefore, the second wheel end housing 86 includes a substantially similar structure, which will not be described in detail. Specifically, the second wheel end housing 86 includes an inner wall 230, an outer wall 232, a peripheral wall 234, a second wheel mounting member 236, a second wheel end flange 238, a second wheel end flange surface 240 that mates with the second housing flange surface 180, a mounting hole 242, a second wheel end opening 244 communicating with the internal volume 164 of the central chain box 80, a second wheel hub 246, a second wheel end axle 248, a second length 250, and a second access panel 252. As discussed below, in some examples, the second length 250 may differ from the first length 220, although they are shown as equal.

[0043] The arrangement of the first housing flange 174 with a first wheel end flange 208 and the second housing flange 178 with a second wheel end flange 238 advantageously provides a robust connection between the parts of the first train wheel housing 72, while facilitating assembly of the first set of bolts 184 and the second set of bolts 185. As shown, each of the first housing flange face 176 and the second housing flange face 180, as well as the first wheel end flange face 210 and the second wheel end flange face 240, can be substantially flat and planar to provide a consistent mating surface for strength and to enclose the internal volume 164. Other complementary mating surface shapes may also be used. The arrangement of the mating flanges also allows for modular attachment of various sizes (lengths) of the first wheel end housing 84 and / or the second wheel end housing 86, as referenced below. Figure 7 As discussed.

[0044] During assembly, the first train wheel housing 72 will be connected to the first wheelbase 254 ( Figure 3 The first wheel end axle 218 and the second wheel end axle 248 are defined in the generally longitudinal direction of the working vehicle 10 (e.g., Figure 1 and Figure 2 The length in the y-direction shown in the figure. Therefore, the first wheelbase 254 is a function of the first length 220 of the first wheel end housing 84 and the second length 250 of the second wheel end housing 86 (and the fixed length of the center chain box 80).

[0045] Still referencing Figure 7 , Figure 7 A train wheel assembly 260 is shown, having an alternative modular arrangement of a first wheel end housing 84 and a second wheel end housing 86. In this example, the aforementioned first train wheel housing 72 can be implemented using one or more alternative wheel end housings, such as a third wheel end housing 84' and a fourth wheel end housing 86'. Unless otherwise stated, the third wheel end housing 84' and the fourth wheel end housing 86' are similar to those referenced above. Figures 2 to 5 The first wheel end housing 84 and the second wheel end housing 86 are described. Specifically, a third wheel end housing 84' can be mounted to the first housing flange 174 at the first housing end 166 of the center chain case 80. The third wheel end housing 84' has a third wheel end flange surface 210', which is substantially the same size and shape as the first wheel end flange surface 210 to ensure proper mounting with the first housing flange 174. The third wheel end housing 84' has a third length 220', which is different from the first length 220 (in... Figure 7The example shown defines a third wheel end axle 218' (extended to a greater length) with a length 220'. Similarly, a fourth wheel end shell 86', used to replace the second wheel end shell 86, can be configured to be substantially similar to the third wheel end 84', which includes a fourth length 250' different from the second length 250. The fourth length 250' can be substantially equal to the third length 220'. Thus, when the third wheel end shell 84' is mounted to the center chain box 80 at the first box end 166 and the fourth wheel end shell is mounted to the center chain box 80 at the second box end 168, a second wheelbase 254', different from the first wheelbase 254 (e.g., a greater length), is defined between the third wheel end axle 218' and the fourth wheel end axle 250'. The tandem wheel assembly 260 thus selectively provides a tandem wheel shell 72 having either a first wheelbase 254' or a second wheelbase 254'.

[0046] The tandem train wheel kit 260 allows for additional variations. Figures 2 to 4 In the example shown, the lengths of the installed wheel end shells (e.g., the first length 220 and the second length 250) are substantially equal. However, it is feasible for the tandem wheel assembly 260 to provide wheel end shells of different lengths to be installed at the first box end 166 and the second box end 168. For example, a first wheel end shell 84 can be installed along with a fourth wheel end shell 86', where the corresponding fourth length 250' differs from the first length 220. This results in a wheelbase with a length different from the first wheelbase 254 or the second wheelbase 254' (e.g., the wheelbase length between the first wheelbase 254 and the second wheelbase 254'). Various other combinations of wheel end lengths can be considered. In other examples, the tandem wheel assembly 260 can be provided with additional wheel end shells of different lengths to achieve greater modularity; for example, the tandem wheel assembly 260 can be provided with five, six, seven, or eight wheel end shells.

[0047] It should be understood that modularity of the first, second, third, and fourth wheel end housings 84, 86, 84', 86' can be provided to address design variations of the work vehicle 10 (e.g., larger work vehicles or different categories of work vehicles). Changes to the powertrain 24 (e.g., different-sized engines 50 or different transmissions for specific speed / torque requirements) or variations in the dimensions of the four tandem wheels 36, 38, 42, 44 can also be provided. As a result, some components of the tandem wheel assembly 32 may be modified. In the example shown for the first tandem wheel housing 72, these modifications may include different dimensions for the center sprocket 140, the first chain 142 and the second chain 146, and / or the first wheel end sprocket 144 and the second wheel end sprocket 148. Generally, larger wheels and / or larger wheelbases can accommodate heavier machinery with greater operating loads. Therefore, greater tensile strength may be required for the first chain 142 and the second chain 146. In some examples, different sizes of tandem wheel assemblies 32 can utilize the first chain 142 and the second chain 146 as roller chains with standardized American National Standards Institute (ANSI) industrial designation dimensions of 150, 160, 170, or 180. Accordingly, with different sizes of the first chain 142 and the second chain 146, the center sprocket and / or the first wheel end sprocket 144 and the second wheel end sprocket 148 may require sizing substitutions. However, even taking these substitutions into account, the dimensions of the center chain box 80 will remain unchanged.

[0048] The foregoing descriptions have detailed one or more example tandem wheel assemblies and tandem wheel kits. Various other configurations are possible within the scope of this disclosure. For example, the double-ring, double-chain drive in the disclosed tandem wheel housing can be replaced by a gear train, driveshaft, single chain, etc. The aspects of the disclosed examples provide modular and robust tandem wheels for work vehicles. Tandem wheels perform multiple functions in mounting powertrain components, mounting two wheels, distributing loads, and adapting to terrain changes. The center chain box provides a robust, lightweight support for the tandem wheel housing.

[0049] Listed examples

[0050] In addition, the following examples are provided, which have been numbered for easy reference.

[0051] 1. A tandem wheel assembly for a work vehicle is provided. In various embodiments, the tandem wheel assembly includes a central chain box having an inner wall and an outer wall defining an internal volume and extending between a first box end and a second box end, the inner wall defining a pivot portion as a single part of the central chain box, the pivot portion having a box opening disposed about a pivot axis and communicating with the internal volume, the central chain box having a first box flange with a first box flange face at the first box end and a second box flange with a second box flange face at the second box end; a first wheel end shell having a first wheel end flange having a first wheel end flange face mateable with the first box flange face, the first wheel end shell having a first wheel end opening about a distance substantially parallel to the pivot axis. A first wheel end axle is provided and communicates with the internal volume of the central chain box when the first wheel end shell is mounted to the end of the first box, the first wheel end shell defining a first length from the first wheel end flange surface to the first wheel end axle; and a second wheel end shell having a second wheel end flange having a second wheel end flange surface that mates with the flange surface of the second box, the second wheel end shell having a second wheel end opening communicating with the internal volume of the central chain box and being provided about a second wheel end axle substantially parallel to the pivot axis, and communicating with the internal volume of the central chain box when the second wheel end shell is mounted to the end of the second box, the second wheel end shell defining a second length from the second wheel end flange surface to the second wheel end axle.

[0052] 2. The tandem wheel assembly of Example 1, wherein a first housing flange and a first wheel end flange are mounted together by a first set of bolts extending substantially perpendicularly to the pivot axis; and wherein a second housing flange and a second wheel end flange are mounted together by a second set of bolts extending substantially perpendicularly to the pivot axis.

[0053] 3. The tandem wheel assembly of Example 1, wherein a first wheel end housing further defines a first wheel mount as a single part of the first wheel end housing, the first wheel mount extending from an outer wall of the first wheel end housing and defining a first wheel end opening; and wherein a second wheel end housing further defines a second wheel mount as a single part of the second wheel end housing, the second wheel mount extending from an outer wall of the second wheel end housing and defining a second wheel end opening.

[0054] 4. The tandem train wheel assembly of Example 1, wherein the internal volume of the central chain box provides an elongated channel extending from the end of the first box to the end of the second box, the elongated channel being sized to allow one or more drive chains to pass through the elongated channel.

[0055] 5. The tandem train wheel assembly of Example 1, wherein the central chain box has one or more outgoing regions for reducing the internal volume of the central chain box, these outgoing regions being openings in the central chain box or drying chambers within the central chain box that are separated from the internal volume.

[0056] 6. The tandem train wheel assembly of Example 1, wherein the central chain box has an upper wall and one or more gripping surfaces in the upper wall, the upper wall defining one or more gripping surfaces as a single part of the central chain box.

[0057] 7. The tandem train wheel assembly of Example 1 further includes: a central sprocket mounted in the internal volume of a central chain box; a first wheel end sprocket mounted in a first wheel end housing; and a second wheel end sprocket mounted in a second wheel end housing; wherein the central sprocket, the first wheel end sprocket, and the second wheel end sprocket are aligned for mounting one or more chains for common rotation.

[0058] 8. The tandem wheel assembly of Example 7, wherein a first wheel end housing has a first wheel hub and a first wheel axle mounted in a first wheel end opening for rotating together with a first wheel end sprocket; and wherein a second wheel end housing has a second wheel hub and a second wheel axle mounted in a second wheel end opening for rotating together with a second wheel end sprocket.

[0059] 9. The tandem sprocket assembly of Example 7, wherein the central sprocket is a double-ring sprocket.

[0060] 10. The tandem train wheel assembly of Example 1 further includes a third wheel end housing having a third wheel end flange having a third wheel end flange face that mates with a first housing flange face, the third wheel end housing having a third wheel end opening communicating with the internal volume of the central chain box and being disposed about a third wheel end axis substantially parallel to the pivot axis, and communicating with the internal volume of the central chain box when the third wheel end housing is mounted to the end of the first housing, the third wheel end housing defining a third length from the third wheel end flange face to the third wheel end axis, wherein the third length is different from the first length.

[0061] 11. The tandem train wheel assembly of Example 10 further includes a fourth wheel end housing having a fourth wheel end flange having a fourth wheel end flange face that mates with a second housing flange face, the fourth wheel end housing having a fourth wheel end opening communicating with the internal volume of the central chain box and disposed about a third wheel end axis substantially parallel to the pivot axis, and communicating with the internal volume of the central chain box when the fourth wheel end housing is mounted to the end of the second housing, the fourth wheel end housing defining a fourth length from the fourth wheel end flange face to the fourth wheel end axis, wherein the fourth length is different from the second length.

[0062] 12. The train wheel assembly of Example 11, wherein the first length is substantially equal to the second length; and wherein the third length is substantially equal to the fourth length.

[0063] 13. The tandem train wheel assembly of Example 12, wherein when a first wheel end housing is mounted to a central chain box at a first box end and a second wheel end housing is mounted to a central chain box at a second box end, a first wheelbase is defined between the first wheel end axis and the second wheel end axis; wherein when a third wheel end housing is mounted to a central chain box at a first box end and a fourth wheel end housing is mounted to a central chain box at a second box end, a second wheelbase is defined between the third wheel end axis and the fourth wheel end axis; and wherein the first wheelbase is different from the second wheelbase.

[0064] 14. In another embodiment, a tandem wheel assembly for a work vehicle is provided. The tandem wheel assembly includes a center chain box having an inner wall and an outer wall defining an internal volume and extending between a first box end and a second box end, the inner wall defining a pivot portion as a single part of the center chain box having a box opening disposed about a pivot axis and communicating with the internal volume, the center chain box having a first box flange with a first box flange face at the first box end and a second box flange with a second box flange face at the second box end; a first wheel end shell having a first wheel end flange having a first wheel end flange that mates with the first box flange face. The first wheel end housing defines a first wheel mount as a single part of the first wheel end housing, the first wheel mount extending from the outer wall of the first wheel end housing and defining a first wheel end opening, the first wheel end opening being arranged about a first wheel end axis substantially parallel to the pivot axis and communicating with the internal volume of the center chain box when the first wheel end housing is mounted to the end of the first housing, the first wheel end housing defining a first length from the first wheel end flange face to the first wheel end axis; and a second wheel end housing having a second wheel end flange having a second wheel end that can mate with the second housing flange face. A flange face; a second wheel end housing defines a second wheel mount as a single part of the second wheel end housing, the second wheel mount extending from the outer wall of the second wheel end housing and defining a second wheel end opening communicating with the internal volume of the center chain case and disposed about a second wheel end axis substantially parallel to the pivot axis, and communicating with the internal volume of the center chain case when the second wheel end housing is mounted to the end of the second case; the second wheel end housing defines a second length from the second wheel end flange face to the second wheel end axis; a third wheel end housing having a third wheel end flange, the third wheel end flange having A third wheel end flange surface is provided that mates with the flange surface of the first gearbox. The third wheel end shell has a third wheel end opening that communicates with the internal volume of the central gearbox and is arranged around a third wheel end axis that is substantially parallel to the pivot axis. When the third wheel end shell is mounted to the end of the first gearbox, it communicates with the internal volume of the central gearbox. The third wheel end shell defines a third length from the third wheel end flange surface to the third wheel end axis, wherein the third length is different from the first length. The configurable tandem wheelbase is defined by selectively mounting either the first wheel end shell or the third wheel end shell to the first gearbox end of the central gearbox.

[0065] 15. The tandem train wheel assembly of Example 14 further includes a fourth wheel end housing having a fourth wheel end flange having a fourth wheel end flange face that mates with a second housing flange face, the fourth wheel end housing having a fourth wheel end opening communicating with the internal volume of the central chain box and being disposed about a fourth wheel end axis substantially parallel to the pivot axis, and communicating with the internal volume of the central chain box when the fourth wheel end housing is mounted to the end of the second housing, the fourth wheel end housing defining a fourth length from the fourth wheel end flange face to the fourth wheel end axis, wherein the fourth length is different from the second length.

[0066] in conclusion

[0067] The examples discussed above lead to the various benefits of the disclosed tandem wheels. For example, mating box flanges and wheel end flanges provide modularity in wheel ends of different lengths. Thus, the same center chainring and some internal components can be used for different work vehicle models with different tandem wheelbases, thereby reducing manufacturing costs. With the pivot portion integrated with the center chainring rather than being a separate bolted part, the torque load from the drivetrain is transmitted at the center chainring instead of at the more prone-to-fail bolts. The integrated center chainring design also reduces weight compared to conventional components, which improves work efficiency and performance. The pivotable tandem wheels improve the drive traction, weight distribution, and cut consistency of the motorized grader, resulting in improved performance for construction tasks. The tandem wheels of the work vehicle have appropriate strength and rigidity to support and distribute significant static and dynamic loads.

[0068] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that, when used in this specification, the term “comprises and / or comprising” specifies the presence of stated features, integers, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0069] The description in this disclosure has been presented for purposes of illustration and description, but is not intended to be exhaustive or limited to the disclosure presented in its form. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of this disclosure. The embodiments expressly referenced herein were chosen and described in order to best explain the principles of this disclosure and its practical application, and to enable others skilled in the art to understand the contents of this disclosure and recognize the many alternatives, modifications, and variations of the described examples(s). Therefore, various embodiments and implementations other than those expressly described are within the scope of the following claims.

Claims

1. A tandem wheel assembly for a work vehicle, the tandem wheel assembly comprising: A center chain box having an inner wall and an outer wall defining an internal volume and extending between a first box end and a second box end, the inner wall defining a pivot portion as a single part of the center chain box, the pivot portion extending inwardly in an annular manner and having a box opening disposed about a pivot axis and communicating with the internal volume, the pivot portion being configured to connect the center chain box to a work vehicle for pivoting about the pivot axis, the center chain box having a first box flange with a first box flange face at the first box end and a second box flange with a second box flange face at the second box end, wherein the first box flange face has a first opening at an angle relative to the pivot axis, and the second box flange has a second opening at an angle relative to the pivot axis; A first wheel end housing, the first wheel end housing having a first wheel end flange, the first wheel end flange having a first wheel end flange surface capable of engaging with a first housing flange surface, the first wheel end housing having a first wheel end opening, the first wheel end opening being disposed about a first wheel end axis parallel to the pivot axis and communicating with the internal volume of the central chain box when the first wheel end housing is mounted to the end of the first housing, the first wheel end housing defining a first length from the first wheel end flange surface to the first wheel end axis; and The second wheel end housing has a second wheel end flange, the second wheel end flange having a second wheel end flange surface capable of engaging with the flange surface of the second housing, the second wheel end housing having a second wheel end opening communicating with the internal volume of the central chain box and being disposed around a second wheel end axis parallel to the pivot axis, and communicating with the internal volume of the central chain box when the second wheel end housing is installed at the end of the second housing, the second wheel end housing defining a second length from the second wheel end flange surface to the second wheel end axis.

2. The tandem train wheel assembly according to claim 1, wherein, The first box flange and the first wheel end flange are mounted together by a first set of bolts, which extend perpendicularly to the pivot axis. as well as The second box flange and the second wheel end flange are mounted together by a second set of bolts, which extend perpendicularly to the pivot axis.

3. The tandem train wheel assembly according to claim 1, wherein, The first wheel end housing further defines a first wheel mount, which is a single part of the first wheel end housing, extending from the outer wall of the first wheel end housing and defining the first wheel end opening; and The second wheel end shell further defines a second wheel mounting member as a single part of the second wheel end shell, the second wheel mounting member extending from the outer wall of the second wheel end shell and defining the second wheel end opening.

4. The tandem train wheel assembly according to claim 1, wherein, The internal volume of the central chain box provides an elongated channel extending from the end of the first box to the end of the second box, the size of which allows one or more drive chains to pass through the elongated channel.

5. The tandem train wheel assembly according to claim 1, wherein, The central chain box has one or more outgoing regions for reducing the internal volume of the central chain box, the outgoing regions being openings in the central chain box or drying cavities within the central chain box that are separate from the internal volume.

6. The tandem train wheel assembly according to claim 1, wherein, The central chain box has an upper wall and one or more gripping surfaces in the upper wall, the upper wall defining the one or more gripping surfaces as a single part of the central chain box.

7. The tandem train wheel assembly according to claim 1, further comprising: A central sprocket, the central sprocket being installed in the internal volume of the central sprocket box; The first wheel end sprocket is installed in the first wheel end housing; as well as The second wheel end sprocket is installed in the second wheel end housing; The central sprocket, the first wheel end sprocket, and the second wheel end sprocket are aligned to mount one or more chains for coordinated rotation.

8. The tandem train wheel assembly according to claim 7, wherein, The first wheel end housing has a first wheel hub and a first wheel axle installed in the first wheel end opening for rotating together with the first wheel end sprocket; as well as The second wheel end housing has a second wheel hub and a second wheel axle installed in the second wheel end opening for rotating together with the second wheel end sprocket.

9. The tandem train wheel assembly according to claim 7, wherein, The central sprocket is a double-ring sprocket.

10. The tandem train wheel assembly of claim 1, further comprising a third wheel end housing having a third wheel end flange having a third wheel end flange surface capable of engaging with a first housing flange surface, the third wheel end housing having a third wheel end opening communicating with the internal volume of the central chain box and disposed about a third wheel end axis parallel to the pivot axis, and communicating with the internal volume of the central chain box when the third wheel end housing is mounted to the end of the first housing, the third wheel end housing defining a third length from the third wheel end flange surface to the third wheel end axis; in, The third length is different from the first length.

11. The tandem train wheel assembly of claim 10, further comprising a fourth wheel end housing having a fourth wheel end flange having a fourth wheel end flange surface capable of engaging with a second housing flange surface, the fourth wheel end housing having a fourth wheel end opening communicating with the internal volume of the central chain box and disposed about a fourth wheel end axis parallel to the pivot axis, and communicating with the internal volume of the central chain box when the fourth wheel end housing is mounted to the end of the second housing, the fourth wheel end housing defining a fourth length from the fourth wheel end flange surface to the fourth wheel end axis; in, The fourth length is different from the second length.

12. The tandem train wheel assembly according to claim 11, wherein, The first length is equal to the second length; and The third length is equal to the fourth length.

13. The tandem train wheel assembly according to claim 12, wherein, When the first wheel end housing is installed at the end of the first housing to the center chain box, and the second wheel end housing is installed at the end of the second housing to the center chain box, the first wheelbase is defined between the first wheel end axis and the second wheel end axis. Wherein, when the third wheel end shell is installed at the end of the first box to the center chain box and the fourth wheel end shell is installed at the end of the second box to the center chain box, the second wheelbase is limited between the axis of the third wheel end and the axis of the fourth wheel end; The first wheelbase is different from the second wheelbase.

14. A tandem wheel assembly for a work vehicle, comprising: A center chain box having an inner wall and an outer wall defining an internal volume and extending between a first box end and a second box end, the inner wall defining a pivot portion as a single part of the center chain box, the pivot portion extending inwardly in an annular manner and having a box opening disposed around a pivot axis and communicating with the internal volume, the pivot portion being configured to connect the center chain box to a work vehicle for pivoting about the pivot axis, the center chain box having a first box flange with a first box flange face at the first box end and a second box flange with a second box flange face at the second box end, wherein the first box flange face has a first opening at an angle relative to the pivot axis, and the second box flange has a second opening at an angle relative to the pivot axis; A first wheel end housing having a first wheel end flange having a first wheel end flange surface capable of engaging with a first housing flange surface, the first wheel end housing defining a first wheel mount as a single part of the first wheel end housing, the first wheel mount extending from the outer wall of the first wheel end housing and defining a first wheel end opening, the first wheel end opening being disposed about a first wheel end axis parallel to the pivot axis and communicating with the internal volume of the central chain box when the first wheel end housing is mounted to the end of the first housing, the first wheel end housing defining a first length from the first wheel end flange surface to the first wheel end axis; and A second wheel end housing having a second wheel end flange having a second wheel end flange surface capable of engaging with a second housing flange surface, the second wheel end housing defining a second wheel mount as a single part of the second wheel end housing, the second wheel mount extending from the outer wall of the second wheel end housing and defining a second wheel end opening communicating with the internal volume of the central chain box and disposed about a second wheel end axis parallel to the pivot axis, and communicating with the internal volume of the central chain box when the second wheel end housing is mounted to the end of the second housing, the second wheel end housing defining a second length from the second wheel end flange surface to the second wheel end axis; A third wheel end housing having a third wheel end flange having a third wheel end flange surface capable of engaging with the flange surface of the first housing, a third wheel end opening communicating with the internal volume of the central chain box and disposed around a third wheel end axis parallel to the pivot axis, and communicating with the internal volume of the central chain box when the third wheel end housing is installed at the end of the first housing, the third wheel end housing defining a third length from the third wheel end flange surface to the third wheel end axis, wherein the third length is different from the first length; The configurable tandem wheelbase is defined by selectively mounting the first wheel end shell or the third wheel end shell to the first end of the central chain box.

15. The tandem wheel assembly of claim 14, further comprising a fourth wheel end housing having a fourth wheel end flange having a fourth wheel end flange surface capable of engaging with the flange surface of the second housing, the fourth wheel end housing having a fourth wheel end opening communicating with the internal volume of the central chain box and disposed about a fourth wheel end axis parallel to the pivot axis, and communicating with the internal volume of the central chain box when the fourth wheel end housing is mounted to the end of the second housing, the fourth wheel end housing defining a fourth length from the fourth wheel end flange surface to the fourth wheel end axis; in, The fourth length is different from the second length.

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