Undercarriage system for a tracked work vehicle

An undercarriage system for a tracked work vehicle is provided that includes a tensioning system configured to provide tension to a continuous track. Additionally, the undercarriage system includes an undercarriage beam having a first opening and a second opening. The first opening is located on an upper face of the undercarriage beam and is configured to enable insertion of the tensioning system inside a cavity of the undercarriage beam. The second opening is located at one longitudinal end of the undercarriage beam and is configured to enable a portion of the tensioning system to extend through the second opening. Furthermore, the tensioning system pivotably couples to an idler wheel via a pivot assembly, and the idler wheel is configured to engage the continuous track.

BACKGROUND

The present disclosure relates generally to tracked work vehicles, and more particularly, to an undercarriage for a tracked work vehicle.

Certain work vehicles are driven by a track system having continuous tracks and an undercarriage system. Certain track systems include an undercarriage beam and a tensioning system located within the undercarriage beam. The tensioning system provides tension to a respective continuous track. Under some conditions, such as traveling over an uneven surface, the undercarriage beam may be subjected to torsional loads. Some undercarriage beams may enable the insertion of the tensioning system through an opening at a longitudinal end of the beam. However, by placing an opening at the longitudinal end of the beam. Large enough to receive the tensioning system, the undercarriage beam may be less resistant to torsional loads. Accordingly, additional material (e.g., iron) may be disposed around the opening to enhance torsional rigidity. However, by disposing additional material around the opening, the cost and weight of the undercarriage beam may be increased.

BRIEF DESCRIPTION

In one embodiment, an undercarriage system for a tracked work vehicle includes a tensioning system configured to provide tension to a continuous track. Additionally, the undercarriage system includes an undercarriage beam. The undercarriage beam includes a first opening located on an upper face of the undercarriage beam. The first opening is configured to enable insertion of the tensioning system into a cavity of the undercarriage beam. Furthermore, the undercarriage beam includes a second opening located at one longitudinal end of the undercarriage beam. Moreover, the second opening is configured to enable a portion of the tensioning system to extend through the second opening to enable the tensioning system to pivotably couple to an idler wheel via a pivot assembly, and wherein the idler wheel is configured to engage the continuous track

In another embodiment, a method for manufacturing an undercarriage system for a tracked work vehicle includes inserting a tensioning system in to a cavity of an undercarriage beam through a first opening in an upper face of the undercarriage beam. Additionally, the method includes extending a portion of the tensioning system through a second opening in a longitudinal end of the undercarriage beam. Furthermore, the method includes tensioning a continuous track using the extended portion of the tensioning system.

In another embodiment, an undercarriage system for a tracked work vehicle includes a continuous track, a pair of idler wheels each configured to engage the continuous track, and a tensioning system configured to tension the continuous track by biasing each idler wheel longitudinally outward. Moreover, the tensioning system includes an extension arm, an actuator, and overload protection system. Additionally, the undercarriage system includes an undercarriage beam disposed about the tensioning system. Furthermore, the undercarriage beam includes a first opening located on an upper face of the undercarriage beam and a second opening located at a longitudinal end of the undercarriage beam. The first opening is configured to enable insertion of the tensioning system into a cavity of the undercarriage beam, and the second opening is configured to enable the extension arm to protrude through the opening to rotatably couple with a respective idler wheel via a pivot assembly.

DETAILED DESCRIPTION

Various embodiments of the present disclosure include an undercarriage system configured to damp vibrations between a track and a work vehicle. The undercarriage system uses an undercarriage beam to suspend the vehicle over load bearing wheels. In certain embodiments, the undercarriage beam also houses a tensioning system that provides tension to a continuous track. It is often desirable to locate the tensioning system within the undercarriage beam to protect the tensioning system from contaminants that may interfere with operation of the tensioning system. In some embodiments, the tensioning system may be placed within the undercarriage beam through an opening located at a longitudinal end of the beam. In such embodiments, the opening is large enough for the entire tensioning system to be inserted into the undercarriage beam through the opening. However, the large opening may reduce the torsional rigidity of the undercarriage beam. Accordingly, the beam may be reinforced with additional material (e.g., iron) around the opening. Instead of a large opening on one longitudinal end, the embodiments disclosed herein include an undercarriage beam that enables insertion of the tensioning system through an opening in an upper face of the undercarriage beam. Accordingly smaller opening may be located at each longitudinal end of the beam, thereby providing the desired torsional rigidity without adding additional material the openings. As a result, manufacturing costs and vehicle weight may be reduced without decreasing the ability of the undercarriage beam to withstand torsional loads.

Turning now to the drawings,FIG. 1is a perspective view of an embodiment of a tracked work vehicle10. The vehicle10includes an undercarriage system12used to damp vibrations between a continuous track14and the work vehicle10. The undercarriage system12includes an undercarriage beam16, which may be formed using casting, machining, and/or other suitable methods. Moreover, the undercarriage beam16may be formed from steel, iron (e.g., ductile iron), and/or other materials suitable for formation of an undercarriage beam capable of supporting the vehicle10. Additionally, the undercarriage system12supports the work vehicle above the continuous track14and may damp rotation and movement of various components of the undercarriage system during operation of the work vehicle10. Additionally, the tracked work vehicle10has a body18. In certain embodiments, the body18may enclose various components used to operate the vehicle10. For example, in some embodiments, the body18may enclose an engine, a transmission, a drive train, an exhaust system, and/or other vehicle components. The vehicle10further includes a driver compartment20. In some embodiments, the driver compartment20may be fully enclosed (e.g., having glass windows all around the drive compartment20), as illustrated. Other embodiments may include a driver compartment20that is open to the environment with or without a compartment roof. Furthermore, in certain embodiments, the driver compartment20may include steering controls, a seat apparatus, temperature controls, and/or other suitable driver controls.

FIG. 2is a perspective view of an embodiment of the undercarriage system12. The undercarriage system12includes a drive wheel22having multiple drive spokes24extending from a center to a perimeter of the drive wheel22. Additionally, the continuous track14has multiple track protrusions26disposed along the length of the continuous track14. Moreover, the drive wheel22is drivably coupled to the engine of the vehicle10so that the engine drives the drive wheel22in rotation (e.g., through a drive train, transmission, and/or another suitable drive system). As the drive wheel22rotates, the drive spokes24engage respective track protrusions26, thereby driving the continuous track14.

The illustrated undercarriage system12further includes four idler wheels28(e.g., a first pair of idler wheels at the front of the track, and a second pair of idler wheels at the back of the track). As discussed below, the idler wheels28provide tension to the continuous track14to maintain contact between the track protrusions26and the respective drive spokes24. Furthermore, by spacing the idler wheels28of each pair at a lateral distance approximately equal to the width of the track protrusions28, the idler wheels28provide guidance to the continuous track14to block the continuous track14from laterally moving away from the undercarriage system12. Furthermore, although the illustrated track undercarriage12includes four idler wheels28, other embodiments may include 2, 3, 4, 5, 6, or more idler wheels28.

As discussed below, a roller wheel beam30supports the undercarriage system12by coupling with the undercarriage beam16. The roller wheel beam30also couples with multiple roller wheels32arranged in two rows. The rows are spaced at a distance greater than equal to the width of the roller wheel beam30and width of the protrusions26. The roller wheels32provide support to the undercarriage system and roll along the continuous track14when the continuous track14is propelled around the undercarriage system12by the drive wheel22. As will be appreciated, it is desirable to distribute the weight of the work vehicle among the roller wheels32to reduce loads on the continuous track12and/or the undercarriage system12. For example, if one row of the roller wheels32receives an excessive portion of the vehicle load, the continuous track14may overheat, thereby reducing the longevity of the continuous track14. As illustrated, certain embodiments of the undercarriage system12may include 6 roller wheels32arranged in two rows. Other embodiments of the undercarriage system12may include 2, 4, 6, 8, or more roller wheels arranged in one or more rows.

FIG. 3is a cross-sectional view of an embodiment of the undercarriage system12shown inFIG. 2. As illustrated, the undercarriage system12includes a tensioning system34disposed within the undercarriage beam16. The tensioning system34includes an actuator36, an overload protection system38, and an extension arm40. The actuator36includes a piston42and an actuator body44. The extension arm40couples to a pivot assembly46. The pivot assembly46includes a static pivot joint48and an extendable pivot joint50each coupled to an idler wheel axle52via a pivot plate54. As discussed below, each pivot joint enables the idler wheel axle52to move in a substantially longitudinal direction in response to movement of the extension arm40along a longitudinal axis56of the tensioning system34. Furthermore, the undercarriage system12includes a protection plate58coupled to the undercarriage beam16to protect the tensioning system34from dirt and other contaminants that may otherwise interfere with operation of the actuator36, the overload protection system38, or the extension arm40.

In certain embodiments, the actuator may be a hydraulic cylinder. In such embodiments, the actuator body44may be filled with a hydraulic fluid, thereby urging the piston42out of the actuator body44. The piston42pushes against the overload protection system38. In the illustrated embodiment, the overload protection system38includes a coil spring configured to reduce pressure on the actuator36. However, other embodiments may include other suitable overload protection systems, such as a hydraulic accumulator, which may employ raised weight, compressed gas, or metal bellows. Tension in the overload protection system38from the actuator36exerts pressure against the extension arm40, thereby urging the arm40away from the actuator36. As the extension arm40, exerts a load along the longitudinal axis56, the extendable pivot joint52is urged longitudinal outward, thereby urging the idler wheel axle52longitudinally outward. As will be appreciated, by urging the extension arm40outward at a desired pressure, the continuous track14may be loaded with a desired tension to block lateral movement/rotation of the continuous track14during operation of the vehicle10.

Additionally, the undercarriage system12includes a front bushing mount60and a rear bushing mount62used to couple the roller wheel beam30to the undercarriage beam16, as discussed below. Further, the undercarriage system12includes multiple vertical mounts64. The vertical mounts64enable the undercarriage beam16to support a vertical load (e.g., weight of the vehicle10), and to damp vertical movement of the roller wheel beam30during operation of the vehicle10. Additionally, the illustrated embodiment of the undercarriage system12includes two vertical mounts, but other embodiments may include 0, 1, 2, 3, or more vertical mounts.

FIG. 4is a partially exploded perspective view of the undercarriage system12shown inFIG. 2. As illustrated, the undercarriage system12includes the undercarriage beam16, the roller wheel beam30, the front bushing mount60, rear bushing mount62, and the vertical mounts64. For the purposes of the discussion, reference may be made to a longitudinal direction66, a lateral direction68, and a vertical direction70with respect to the undercarriage system12. Reference may also be made to a pitch direction71, a roll direction72, and a yaw direction73for the undercarriage system12.

In the illustrated embodiment, the front bushing mount60is coupled to the undercarriage beam16via front mount bolts74, and the front bushing mount60is coupled to the roller wheel beam30via a front pin assembly76. The rear bushing mount62is coupled to the undercarriage beam16via rear mount bolts75, and the rear bushing mount62is coupled to the roller wheel beam30via a rear pin assembly78. Other embodiments may couple the front bushing mount60and/or the rear bushing mount62to the undercarriage beam16using welding connection, brackets, braces, or other suitable connections.

Each vertical mount64includes a lower pad80, a resilient pad82, and an upper pad84. In certain embodiments, the width of the lower pad80and the upper pad84in the lateral direction68is equal to a width of the undercarriage beam16in the lateral direction68. In other embodiments, the width of the lower pad80and the upper pad84may be greater than or equal to the width of the roller wheel beam30in the lateral direction68. Moreover, the lower pad80has two lower flanges86that extend downwardly in the vertical direction70. The lower flanges86are positions on opposite lateral ends of each lower pad80. The lower flanges86have a length in the longitudinal direction66that is less than or substantially equal to a length of a roller wheel beam notch88in the longitudinal direction66. The roller wheel beam notch88is formed into the roller wheel beam30such that the notch88may receive the lower pad80, and the lower pad80is planar with the lateral and upper faces of the roller wheel beam30. In other words, the roller wheel beam notch88may be substantially the same size and shape as the lower pad80.

As will be appreciated, the wheel beam notch88blocks the vertical mount64from moving in the longitudinal direction66, and the lower flanges86block movement of the vertical mount64in the lateral direction68. Similar to the lower pad80, the upper pad84has two upper flanges90located on opposite lateral ends of the upper pad84. The upper flanges90extend upwardly in the vertical direction70and have a length in the longitudinal direction66that is less than or substantially equal to the length of a notch in the undercarriage beam16. The undercarriage beam notch secures the upper pad84to the undercarriage beam16, and blocks movement of each respective vertical mount64in the longitudinal and/or lateral directions. The vertical mounts64also include a resilient pad82. The resilient pad82provides support for the undercarriage beam16and enables the roller wheel beam30to move in the vertical direction70. The resilient pad82also damps movement of the roller wheel beam30in the vertical direction70, thereby reducing vibrations transmitted to the undercarriage beam16, and ultimately the remainder of the vehicle10(e.g. driver compartment).

As will be appreciated, movement of the roller wheel beam30in the roll direction72may apply a torsional force92to the undercarriage beam16. In addition, as the undercarriage beam16undergoes the torsional force92, the torsional force92induces rotation in the undercarriage beam, thereby applying a shear force to the surface of the undercarriage beam16along its longitudinal axis94. As described below, the undercarriage system12is designed to resist torsional and sheer loads.

Accordingly, it is desirable to include an undercarriage beam16capable of withstanding torsional loads (e.g., torsional force92) while enabling the insertion of the tensioning system34within the undercarriage beam16. Some embodiments of the undercarriage beam enable the insertion of the tensioning system through an enlarged opening at one longitudinal end of the undercarriage beam. However, such embodiments have reduced torsional rigidity and, consequently, utilize additional material about the opening to reinforce the structure against torsional loads. In contrast, the present embodiment of the undercarriage beam16illustrated inFIG. 5has torsional rigidity even without utilizing additional material.FIG. 5is a partially exploded perspective view of the undercarriage beam16and the tensioning system34. The illustrated embodiment of the undercarriage beam16enables insertion of the tensioning system34through a first opening100in an upper face102of the undercarriage beam16. The undercarriage beam16further includes a smaller second opening104located at a longitudinal end of the undercarriage beam16.

When the tensioning system34is inserted into the undercarriage beam16into a cavity within the undercarriage beam16. Through the first opening100, a portion of the extension arm40extends through the second opening104to facilitate coupling with the pivot assembly46. As will be appreciated, by enabling the insertion of the tensioning system34through the first opening100, the illustrated undercarriage beam16is substantially more resistant to torsional loads than an embodiment including a second opening large enough to enable insertion of the tensioning system34into the undercarriage beam16. Additionally, the coupling of the bushing mounts,60,62with the undercarriage beam16adds additional support to the undercarriage beam16, thereby further increasing the capability of the undercarriage beam16to withstand torsional loads. By locating the first opening100between two arms106, the torsional load may be substantially distributed to the arms106, which couple to the axle structure of the vehicle. Through the arms106and the axle structure connection, the undercarriage beam16transfers the torsional load through the axle structure rather than across the upper face102of the undercarriage beam16. Consequently the first opening100does not substantially reduce the torsional rigidity of undercarriage beam16. Accordingly, by placing the opening at the upper surface102of the undercarriage beam16rather than at the longitudinal end, the cost and weight of the undercarriage system12is reduced without weakening the undercarriage beam16to torsional loads.

Additionally, in certain embodiments, the protection plate58is coupled to the undercarriage beam16by bolts108to block contaminants from entering the undercarriage beam and interfering with operation of the tensioning system34. In other embodiments, the protection plate58may be coupled to the undercarriage beam16using brackets, braces, welded connections, or other suitable methods of sealing the first opening100to block contaminants.

A third opening110is included at an opposite longitudinal of the undercarriage beam16from the second opening104. The third opening110enables the insertion of a core support into the undercarriage beam16during a casting process used to form the undercarriage beam16. For example, in sand casting, a sand core may be used to establish a cavity in the undercarriage beam16. As will be appreciated, sand cores are less dense than molten metal. The lower density encourages flotation of the sand core during the casting process. To block flotation, the sand core may be held in place using a core support that blocks movement of the core during casting. Typical core supports may include chaplets, internal/exterior reinforcements, frames, and/or other suitable core support elements. Specifically, in the undercarriage beam16, the core support may extend through the first opening100, the second opening104, and/or the third opening110to block the core from floating when molten material is poured into the mold.

FIG. 6is a flowchart of an embodiment of a method120for manufacturing an undercarriage system for a tracked work vehicle. The method120includes inserting the tensioning system34into the cavity of the undercarriage beam through the first opening100in the upper surface of the undercarriage beam16(block122). The tensioning system34may be inserted into the undercarriage beam16as individual pieces in any order. For example, certain embodiments may include inserting the pieces individually, with the extension arm40and the actuator36each being installed before the overload protection system38. In other embodiments, the tensioning system34may be inserted into the undercarriage beam16as one or more units with each unit being composed of more than one component (e.g., the actuator36and overload protection system38as a unit). In embodiments including a spring as the overload protection system38, the spring may be pre-loaded (e.g., compressed) to enable the spring to be inserted into the undercarriage beam16. Alternatively or additionally, the actuator36may be pressurized before (e.g., by filling a hydraulic cylinder at least partially with a hydraulic fluid) or after being inserted into the undercarriage beam16. In some embodiments, the extension arm40may protrude at least partially through the second opening104as a result of inserting the tensioning system34into the undercarriage beam16. Other embodiments may include an extension arm40that does not protrude through the second opening104until extended or coupled to an additional extension arm.

In each of the various embodiments, after the tensioning system34is inserted into in the undercarriage beam16, a portion of the tensioning system is extended through the second opening104(block124). Extending a portion may include coupling an extension arm to the tensioning system, decompressing a spring, pressurizing the actuator, or any other suitable method for extending the extension arm40through the second opening104. The portion of the tensioning system34protruding through the second opening104is then coupled to the pivot assembly46. As previously discussed, the tensioning system34may then apply tension to the continuous track14through the pivot assembly46(block126). After inserting the tensioning system34into the first opening100, the first opening100may be sealed by attaching the protection plate58using bolts108, brackets, welded connections, braces, clamps, and/or another connection suitable for protecting the interior of the undercarriage beam16from contaminants that may interfere with operation of the tensioning system34(block128).