TRACK ADJUSTING SYSTEM

A track adjustment system for adjusting a track of an undercarriage system of a machine is provided. The undercarriage system includes a drive sprocket and an idler. The track adjustment system includes a sensor module provided proximate to a portion of the track. The sensor module generates a signal indicative of a sag in the portion of the track. An adjuster assembly is coupled to the idler, and adjusts a position of the idler with respect to the drive sprocket. A controller is coupled to the sensor module and the adjuster assembly. The controller receives the signal indicative of the sag in the portion of the track. The controller compares the sag with a pre-defined range. The controller alters a tension, through the adjuster assembly, in the portion of the track, if the sag in the portion of the track lies outside the pre-defined range.

TECHNICAL FIELD

The present disclosure relates to an undercarriage system of a machine, and more specifically, to adjusting a track of the undercarriage system of the machine.

BACKGROUND

Machines, such as track-type tractors etc. are used for performing various operations. Typically, the machines include an undercarriage assembly to propel the machine on a variety of different terrains, such as sand surfaces, mud surfaces, or any other uneven surfaces. The undercarriage assembly includes various components, such as tracks, drive sprockets, idlers, load rollers, and a track roller frame spring. During the operation of the machine, a portion of the track between the drive sprocket and the idler may sag. The sag may be defined as an under-tension condition or an over-tension condition in the tracks which results in reduced power transmission efficiency to propel the machine. Further, during the operation of the machine, track tension may vary due to an ingestion of soil/debris within the track (leading to tightening) and wear and tear of various components of the undercarriage assembly (leading to loosening). In case of tightening within the track, excessive loading of internal joints in the track may exist, and which in turn may lead to extra wear and tear to the track itself. On the other hand, in the case of loosening of the track, the track may easily de-rail from load rollers (causing excessive stresses in the track and frame, and leading to wear and tear in the track). Alternatively, the track may also jump the drive sprocket, leading to loud impact loads of joints that subsequently engage with the drive sprocket, which may lead to wear and tear of a drive sprocket tooth and/or a track joint.

Currently, a number of techniques are available to prevent the sag between the drive sprocket and the idler. For example, adjustments may be made to the tracks by adding grease to a track spring adjustment mechanism. Typically the undercarriage assembly is cleaned out on a periodic basis. This technique accounts for necessary adjustments due to wear, but effect on the track tension from the wear tends to be slow. Also, the adjustments may be required only on a weekly or a daily basis. Thus, such technique may not be effective at controlling tension as the track ingests material, which may require adjustments to be made very quickly (i.e., within minutes or less). In another example, adjustments may be made to the tracks by using a real-time pressure adjustment mechanism. The real-time pressure adjustment mechanism requires detecting small differences of large pressure measurements, and requires accurate and well-calibrated/filtered systems. As a result, such techniques may be expensive and may not provide a timely adjustment of the sag in the tracks.

U.S. Pat. No. 9,169,623 describes a wear monitoring system for a track type machine. The wear monitoring system includes at least a first radius sensor which is configured to generate a first signal indicative of a change in radius of at least one idler wheel. The wear monitoring system includes a displacement sensor which is configured to generate a second signal indicative of a change in displacement of a track tensioning actuator. The wear monitoring system includes a controller in communication with the first radius sensor and the displacement sensor. The controller is configured to determine wear of a track link guided by the at least one idler wheel and tensioned by the track tensioning actuator based on the first and second signals. Further, the wear monitoring system may make adjustments due to wear, but the effect on the track tension from the wear tends to be slow. Also, the adjustments may be required only on a weekly or a daily basis. However, such type of the wear monitoring system may not be effective at controlling tension as the track ingests material, which may require adjustments to be made very quickly (i.e., within minutes or less).

However, known solutions may not be efficient and cost effective in controlling the sag in the tracks of the machine. Therefore, there is a need for an improved track adjusting system provided in association with the machine.

SUMMARY OF THE DISCLOSURE

in one aspect of the present disclosure, a track adjustment system for adjusting a track of an undercarriage system of a machine is provided. The undercarriage system includes a drive sprocket and an idler. The track adjustment system includes a sensor module provided proximate to a portion of the track. The sensor module is configured to generate a signal indicative of a sag in the portion of the track. An adjuster assembly is coupled to the idler. The adjuster assembly is configured to adjust a position of the idler with respect to the drive sprocket. A controller is coupled to the sensor module and the adjuster assembly. The controller is configured to receive the signal indicative of the sag in the portion of the track. The controller is configured to compare the sag in the portion of the track with a pre-defined range. The controller is configured to alter a tension, through the adjuster assembly, in the portion of the track, if the sag in the portion of the track lies outside the pre-defined range.

DETAILED DESCRIPTION

Referring toFIG. 1, an exemplary machine10is illustrated. The machine10includes a ripper tool12which is disposed at a first end14of the machine10. The ripper tool12is utilized for ripping operations such as, but not limited to, to loosen hardened ground or break up rock formations. The ripper tool12is coupled to a ripper frame assembly16. Further, the machine10includes a first hydraulic cylinder18which is coupled to the ripper frame assembly16, and a second hydraulic cylinder20which is coupled to the ripper tool12.

The machine10further includes an operator cab22and an engine assembly24. The engine assembly24is disposed at a second end26of the machine10and includes an engine (not shown) which is configured to provide power to the machine10. Further, the machine10includes an undercarriage system28. The undercarriage system28includes a track30that is driven by the engine via a drive sprocket32. The track30includes a number of links34connected end-to-end via pins36. The track30is wrapped around the drive sprocket32and an idler38. In the accompanying figures, only the single track30and the single drive sprocket32have been illustrated for exemplary purposes, without departing from the scope of the present disclosure. The design of the undercarriage system28may vary and is not limited to that described herein. The machine10may further include various other components that are not labeled inFIG. 1for the purpose of simplicity. It will be apparent to one skilled in the art that the machine10shown inFIG. 1is a track-type tractor. However, the machine10may be any other tracked machine such as, but not limited to, a track-type loader, tanks, pipelayers, pavers, underground mining equipment, electric rope shovels, hydraulic mining shovels and an excavator, without departing from the scope of the disclosure. It should be noted that an adjustable track system is valuable to the excavators and the hydraulic mining shovels, given that while digging, a tighter track30provides a more stable platform for the machine10. Therefore, the adjustable track system may loosen the track30while travelling to reduce wear of the track30, and thereafter tighten the track30once the machine10stops to increase stability of the machine10.

Referring toFIG. 2, a track adjustment system40includes a sensor module42which is provided proximate to a portion of the track30. In an embodiment, the track adjustment system40may also include a number of sensor modules42which are positioned at corresponding locations proximate to the track30. The sensor module42is configured to generate a signal indicative of a sag in the portion of the track30. When the drive sprocket32drives the track30, torque applied by the drive sprocket32causes the sag in the portion of the track30, especially in a condition when thrust resistance increases. This portion of the track30may include the links34of the track30that lie between the drive sprocket32and the idler38such that the portion of the track30is not in contact with a work surface of the machine10. The term “sag” used herein refers to an under-tension condition or an over-tension condition in the portion of the track30. The sag may be quantified in terms of a value or a number which may indicate any one of the under-tension condition in the portion of the track30, the over-tension condition in the portion of the track30, or an acceptable tension condition in the portion of the track30.

The sensor module42includes a number of sensors44such that the sensor module42is configured to generate a signal indicative of a presence of the portion of the track30in front of the respective sensor44. It should be noted that the sensor module42includes a linear arrangement of the number of sensors44, such as, but are not limited to, proximity sensors, sag sensors, displacement sensors, eddy current sensors, and paramagnetic sensors positioned such that the sensor module42is positioned perpendicular to a horizontal frame member46of the undercarriage system28. Alternatively, the sensor module42includes a single sensor configured to generate a signal indicative of a distance of the portion of the track30from the sensor module42. The sensor module42may be the single sensor which is disposed vertically along a direction X and perpendicular to the horizontal frame member46. It should be noted that in another embodiment, the sensor module42may be disposed parallel along a length of the portion of the track30either above the track30or below the track30, without departing from the scope of the disclosure.

If the sensor module42detects deviation in the portion of the track30from a pre-defined position of the track30between the drive sprocket32and the idler38, then the sensor module42generates the signal indicative of the sag in the portion of the track30. The pre-defined path may be a theoretical straight line path that the track30traverses while the machine10is moving, or a curved path that allows for an acceptable sag in the track30. It should be noted that more than one sensor module42may be provided at different locations between the drive sprocket32and the idler38. It will be apparent to one skilled in the art that the sensors44in the sensor module42mentioned above have been provided only for explanation purposes, without departing from the scope of the disclosure.

The track adjustment system40further includes an adjuster assembly48which is coupled to the idler38. The adjuster assembly48is configured to adjust a position of the idler38with respect to the drive sprocket32. The detailed description of the adjuster assembly48is described later in this section. Further, the track adjustment system40includes a controller50which is coupled to the sensor module42and the adjuster assembly48. The controller50is configured to receive the signal indicative of the sag in the portion of the track30, from the sensor module42. After receiving the signal indicative of the sag in the portion of the track30, the controller50is configured to compare the sag in the portion of the track30with a pre-defined range. In an embodiment, the pre-defined range may be indicative of an acceptable value of the sag in the portion of the track30. The pre-defined range may be determined based on a historical data, may be obtained from reports, external source or repository associated with the machine10, without departing from the scope of the disclosure.

Based on the comparison, the controller50determines whether the sag in the portion of the track30lies within the pre-defined range or outside the pre-defined range. It should be noted that if the sag in the portion of the track30lies outside the pre-defined range, then the controller50is configured to alter a tension in the portion of the track30through the adjuster assembly48. If the portion of the track30lies outside the pre-defined range, the portion of the track30may either be subject to the under-tension condition or the over-tension condition. Referring toFIG. 2, during the under-tension condition in the portion of the track30, the sag in the portion of the track30is more than the pre-defined range. Alternatively, the under-tension condition may occur, if the sag in the portion of the track30is less than the pre-defined range, without departing from the scope of the disclosure.

As an example, if the pre-defined range is 2-5 units, and the sag in the portion of the track30has a value of 6 units, then the portion of the track30is identified as undergoing the under-tension condition. If the portion of the track30is experiencing the under-tension condition, the portion of the track30may fall closer towards the horizontal frame member46as compared to an acceptable position thereof. The controller50is configured to provide a notification of the sag in the portion of the track30. An output device, i.e. a display, or a meter may depict the current sag in the track30. In one embodiment, the operator of the machine10may manually control the sag by activating the track adjustment system40in case of a tight/loose track30. The operator may operate a tension increase button or a tension decrease button to incrementally and manually control the sag in the track30. In order to adjust the tension in the portion of the track30, the controller50sends a signal for actuating a valve52. The valve52may be a 1-way electric/hydraulic valve or a 2-way electric/hydraulic valve. The valve52is actuated in a way that allows fluid to pass to a first chamber54of the adjuster assembly48. Further, the adjuster assembly48includes a hydraulic piston56and a track roller frame spring58. The hydraulic piston56may be a 1-way hydraulic piston, or a 2-way hydraulic piston. It should be noted that an increase in pressure of the fluid in the first chamber54of the adjuster assembly48pushes the hydraulic piston56in a first direction Y. The hydraulic piston56then pushes a first piston60which in turn pushes the track roller frame spring58. The track roller frame spring58then pushes a second piston62for pushing the idler38along a second direction Z, thus adjusting the tension in the portion of the track30. The second direction Z is parallel to the first direction Y.

In another scenario, the portion of the track30may experience the over-tension condition. Referring toFIG. 3, the undercarriage system28of the machine10subject to the over-tension condition in the portion of the track30is illustrated. If the portion of the track30is experiencing the over-tension condition, the portion of the track30moves away from the horizontal frame member46as compared to the acceptable position thereof. Accordingly, during the over-tension condition in the portion of the track30, the sag in the portion of the track30may have a value which is less than the pre-defined range. As an example, if the pre-defined range is 2-5 units and the sag in the portion of the track30is 1 unit, then the over-tension condition in the portion of the track30may be identified by the controller50. Alternatively, the over-tension condition may occur, if the sag in the portion of the track30is more than the pre-defined range, without departing from the scope of the disclosure.

Further, in order to adjust the tension in the portion of the track30, the controller50sends a signal for actuating the valve52. The valve52is actuated in away that allows fluid to pass to a second chamber64of the adjuster assembly48. It should be noted that increase in pressure of the fluid in the second chamber64pushes the hydraulic piston56in a third direction Y1. Further, the hydraulic piston56pulls the first piston60which then pulls the track roller frame spring58. The track roller frame spring58then pulls the second piston62for pulling the idler38along a fourth direction Z1, for adjusting, the tension in the portion of the track30. The third direction is parallel to the fourth direction Z1.

It should be noted that the controller50mentioned above may embody a single microprocessor or multiple microprocessors. Numerous commercially available microprocessors can be configured to perform the functions of the controller50. It should be appreciated that the controller50could readily be embodied in a general machine microprocessor capable of controlling numerous machine10functions. The controller50may include a memory, a secondary storage device, a processor, and any other components for running an application. Various other circuits may be associated with the controller50such as power supply circuitry, signal conditioning circuitry, solenoid driver circuitry, and other types of circuitry. It will be apparent to one skilled in the art that controlling movement of the idler38for adjusting the tension in the portion of the track30mentioned above has been provided only for explanation purposes. The components and the methodology through which the tension in the portion of the track30is altered by the adjuster assembly48may vary from that described herein.

INDUSTRIAL APPLICABILITY

The present disclosure provides the track adjustment system40for dynamically adjusting the tension in the portion of the track30of the undercarriage system28of the machine10. The track adjustment system40is a track tensioning adjustment system having a simplified construction. The truck adjustment system40identifies any of the under-tension condition and the over-tension condition in the portion of the track30. Accordingly, the track adjustment system40adjusts the tension in the portion of the track30by controlling movement of the idler38. Thus, the track adjustment system40provides a real-time feedback control for dynamically altering the tension in the portion of the track30.

Further, the track adjustment system40may reduce or prevent abrupt jerks and slowdown of the machine10caused by excess or less tension in the track30. Further, the track adjustment system40prevents wear and tear of various components of the undercarriage system28and the track30. Also, the track adjustment system40is an efficient, a cost-effective, and accurate solution for adjusting the tension in the track30of the undercarriage system28of the machine10.