Roller height adjustment in undercarriage systems using flowing material displacement

Abstract

An undercarriage system (18) for a track-type machine (10) includes an idler height adjustment system (32) having piston assemblies (34, 38) supported relative to each other in a frame (12) to contact upper and lower sides (75, 77) of an idler support member (44) or block. A conduit (46) connects the piston assemblies (34, 38) and has a fluid exchange valve (48) therein adjustable to an open position in which a flowable material such as grease is exchanged between the piston assemblies (34, 38) through the conduit (46) and a closed position in which the fluid connection between the piston assemblies (34, 38) is blocked and the idler height is fixed.

Description

Technical Field

[0001] The present disclosure relates generally to adjusting roller height in an undercarriage system of a track-type machine, and more particularly to an idler height adjustment system in which a conduit fluidly connects a piston assembly adjustable to set the roller height by exchanging a flowable material. Background Art

[0002] Tracked machines are used throughout the world in many applications, such as construction, forestry, landfills, mining, demolition, and various other environments. In a typical design, an annular ring of coupled track links is located on each side of the machine and extends around a plurality of rotatable track engagement elements. Tracked machines, and particularly the undercarriage system including the tracks, may be subjected to extremely harsh conditions. Side loads, bending loads on components, torsional loads, shocks, and various other phenomena may cause strain, wear, and degradation of the tracks. Materials at the job site, including hard rock materials, sand, clay, landfill waste, and various other materials, may intrude between the components of the track. The movement of the components in the undercarriage system in contact with one another tends to wear away the materials from which the undercarriage components are made, and the worksite materials may accelerate or exacerbate said wear. Therefore, machine tracks and related components are typically constructed with a specific service life in mind, utilizing expected wear patterns and wear rates in the basic design of the components.

[0003] However, it is often necessary to service the undercarriage system, tighten or otherwise adjust the tracks, inspect and replace seals, and perform other basic maintenance during the life of the undercarriage in the field. One phenomenon that may require machine downtime is related to addressing changes in idler height in response to wear on undercarriage system components. Idler rollers are rotatable track engaging elements that passively rotate and guide the tracks as they are driven by a drive sprocket. As material wears off the idlers, tracks, and potentially other components, the position of the idlers relative to the other components may change. Too much idler height can cause the tracks advancing around the idlers to contact the underlying substrate at a position that is rearward of the desired position, while too little idler height can cause the tracks to contact the substrate further forward than desired. In either case, the ride quality and performance of the machine can be adversely affected.

[0004] Various techniques have been proposed over the years to enable adjustment of idler height. Sometimes a set of shims or the like is provided and carried on the machine, and individual shims may be moved from a position above the idler to a position below the idler as the idler height slowly decreases over time due to wear of the undercarriage components. Still other techniques involve idler support blocks having an eccentric hole for the idler shaft. As the idler height changes, the support block may be repositioned to support the idler shaft at different heights. These and other idler height adjustment strategies can be labor intensive and require disruption of the track, requiring machine downtime. One known idler height adjustment strategy is set forth in U.S. Patent No. 7,237,631 to Livesay et al. Summary of the invention

[0005] In one aspect, a roller height adjustment system for rollers in an undercarriage system of a track-type machine includes: a first piston assembly having a first piston movable between an advanced position and a retracted position; a second piston assembly including a second piston movable between an advanced position and a retracted position; and a frame supporting the first and second piston assemblies relative to each other for positioning above and below roller support elements in the undercarriage, respectively. The system also includes: a conduit connecting the first piston assembly to the second piston assembly; and a fluid exchange valve within the conduit and adjustable from a closed position to an open position to exchange flowable material between the first and second piston assemblies through the conduit.

[0006] In another aspect, an undercarriage system for a track-type machine includes a roller yoke and a roller support member coupled to the roller yoke. The system also includes a first piston assembly and a second piston assembly supported at an upper position and a lower position relative to the roller support member and opposite to each other, respectively. The system also includes a conduit connecting the first piston assembly to the second piston assembly, and a fluid exchange valve within the conduit and adjustable from a closed position to an open position to fluidly connect the first piston assembly and the second piston assembly.

[0007] In yet another aspect, a method for adjusting the height of an idler in an undercarriage system of a track-type machine includes opening a fluid exchange valve in a conduit extending between a first piston assembly supported on an upper side of an idler support element in the undercarriage system and a second piston assembly supported on a lower side of the idler support element. The method also includes repositioning the idler support element relative to a track roller frame in the undercarriage system when the fluid exchange valve is opened, and co-changing the positions of pistons in the first piston assembly and the second piston assembly based on the repositioning of the idler support element. The method also includes displacing a flowable material through the conduit based on the co-changing positions of the pistons, and closing the fluid exchange valve to set the height of the idler after the displacement of the flowable material. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 is a partially opened schematic diagram of a track-type machine having an undercarriage system according to one embodiment;

[0009] Figure 2 is a perspective schematic diagram of a roller height adjustment system according to one embodiment;

[0010] Figure 3 is a partially cut-away side view of the undercarriage system with the idler positioned at a first height;

[0011] Figure 4 yes Figure 3 A partial cross-sectional side view of the undercarriage system of FIG. 1 , wherein the support rollers are positioned at a second height; and

[0012] Figure 5 is a schematic diagram of an undercarriage system as it would appear positioned for roller height adjustment in accordance with the present disclosure. DETAILED DESCRIPTION

[0013] refer to Figure 1, shows a track-type machine according to one embodiment and including a machine frame 12 having a cab 14 mounted thereon. An implement system 16 is supported by the frame 12 and provides an undercarriage system 18 for machine propulsion. The machine 10 is shown in the context of a track-type tractor, however, in other embodiments, the machine 10 may include a track loader, an excavator, or even a semi-track machine. The undercarriage system 18 includes a track 20 located on a first side of the machine 10, and will typically include an identical track located on an opposite side of the machine 10. The track 20 includes an annular ring of track links coupled together, with track shoes attached to the track links, extending around a plurality of rotatable track engaging elements including a drive sprocket 24, idlers 30, load rollers 26, and a plurality of track rollers 28 configured to carry the majority of the weight of the machine 10. The track 20 is shown as an oval track configuration, however, in other embodiments, the track 20 may be configured with the undercarriage system 18 in a so-called high drive configuration. The undercarriage system 18 also includes an idler height adjustment system 32 for the idlers 30 in the undercarriage system 18. The idler height adjustment system 32 (hereinafter referred to as "system 32") includes a first piston assembly 34 and a second piston assembly 38, and a conduit 46 connecting the first piston assembly 34 to the second piston assembly 38. As will be further apparent from the following description, the system 32 is uniquely configured for idler height adjustment, such as in response to wear of components in the undercarriage system 18, in a quick and efficient manner that does not require damage to the track 20.

[0014] Now also refer to Figure 2 and Figure 3 , the first piston assembly 34 includes a first piston 36 that is movable between an advanced position and a retracted position, and the second piston assembly 38 includes a second piston 40 that is movable between an advanced position and a retracted position. The system 32 also includes a frame 42 that supports the first piston assembly 34 and the second piston assembly 36 in an upper position and a lower position relative to the roller support element 44, respectively. As configured in the system 32, the first piston assembly 34 and the second piston assembly 38 are positioned relative to each other and are located above and below the roller support element 44 in the chassis system 18. The roller support element 44 may include an idler support block. An idler yoke 50 is provided, and the roller support element 44 is coupled to the idler yoke 50 in a generally conventional manner.

[0015] In the illustrated embodiment, the frame 42 includes a support frame having an upper arm 56 that contacts the first piston assembly 44, a lower arm 58 that contacts the second piston assembly 38, and a U-shaped bend 60 connecting the upper arm 56 and the lower arm 58. The U-shaped bend 60 can have a generally U-shaped configuration, and various shapes that do not strictly follow the "U" can be functionally and structurally similar to the configuration shown in the figure. The frame 42 has a plurality of bolt holes 62 formed therein, each of which receives a bolt for bolting the frame 42 to the track roller frame 22 in the undercarriage system 18. It can also be noted that the upper arm 56 forms a first receiving portion 64 and the lower arm 58 forms a second receiving portion 66, the first receiving portion 64 and the second receiving portion 66 receiving the first piston assembly 34 and the second piston assembly 38 respectively. The roller shaft 54 ​​extends into the roller support member 44, and the roller yoke 50 generally supports the roller 30 for rotation. In some embodiments, the idler yoke 50 can be coupled to an idler recoil system (not shown), such as one or more mechanical or gas springs. It should be appreciated that the system 32 includes substantially identical but possibly mirrored components on each side of the idler 30. In particular, the first piston assembly 34 and the second piston assembly 38 can be positioned on a first side of the track roller frame 22, and the third piston assembly, the fourth piston assembly, and the second conduit connecting the third piston assembly to the fourth piston assembly can be positioned on a second side of the track roller frame 22. Figure 3 and 4 The description and discussion of the components depicted in the side view of the track roller frame 22 should be understood to refer to the components on the second side of the track roller frame 22 by analogy. In some cases, the components on either side of the track roller frame 22 that form the system 32 can be understood as separate and independent systems. In still other embodiments, the components can be integrated into a single system or even a single assembly.

[0016] Recall that conduit 46 connects the first piston assembly 34 to the second piston assembly 38. A fluid exchange valve 48 is located within conduit 46 and is adjustable from a closed position to an open position to exchange flowable material between the first piston assembly 34 and the second piston assembly 38 through conduit 46. A second conduit and a second fluid exchange valve constructed in a similar manner may be positioned on a second side of the track roller frame 32. In the illustrated embodiment, conduit 46 extends through each of the upper arm 56 and the lower arm 58 for feeding flowable material to and from the first piston assembly 34 and the second piston assembly 38. Figure 3, the frame 42 is shown as having an aperture 68 formed in the upper arm 56, and another aperture 70 formed in the lower arm 58. In other embodiments, the conduit 46 may extend around the side of the structure of the frame 42, or otherwise be fluidly connected to the piston assemblies 34 and 38. The fluid exchange valve 48 is shown as being positioned approximately in the middle of the conduit 46 between the first piston assembly 34 and the second piston assembly 38. In other embodiments, the fluid exchange valve 48 may be positioned in other locations. Also in the illustrated embodiment, the fluid exchange valve 48 includes a mechanically actuated valve having an external handle 72. The conduit 46 may be a closed conduit, meaning that the conduit 46 is not connected and cannot be connected to other fluid circuits in the machine 10, such as an onboard hydraulic system. It is contemplated that the conduit 46 and other components of the system 32 may still be part of a resident machine hydraulic system.

[0017] As described above, the conduit 46 transports flowable material between the first piston assembly 34 and the second piston assembly 38. The fluid exchange valve 48 can have a closed position to block the fluid connection between the first piston assembly 34 and the second piston assembly 38, and move to an open position to fluidly connect the first piston assembly 34 and the second piston assembly 38, the significance of which will become more apparent in the following description. It should also be understood that the exchange of flowable material between the first piston assembly 34 and the second piston assembly 38 via the conduit 46 should not be understood to mean that the fluid in one piston assembly must always flow to the other piston assembly when the exchange of flowable material occurs. In other words, opening the fluid exchange valve 46 can be understood as fluidly connecting the two sides of the system 32 so that the flowable material is transferred from one side to the other side, even if the material is not actually exchanged between the piston assemblies.

[0018] In a practical implementation strategy, the flowable material includes a grease filled conduit 46. The grease contemplated herein will generally be a semi-solid or semi-fluid composition, such as a composition obtained by mixing oil and a thickener (e.g., soap). Oil can be used alone, however, greases such as mineral grease or vegetable grease provide a practical implementation strategy. The system 32 may include a grease port 86 at a location fluidly located between the first piston 36 and the second piston 40. A closure 88 blocks the grease port 86.

[0019] Also refer to Figure 4, it will be noted that the roller support element 44 is captured between the first piston assembly 34 and the second piston assembly 38. The system 32 also includes a first contact plate 74 adjacent to the first piston 36 and configured to contact an upper side 75 of the roller support element, and a second contact plate 76 in contact with the second piston 40 and configured to contact an underside 77 of the roller support element 44. The first contact plate 74 and the second contact plate 76 can each include a horizontally oriented surface 78 and 80 in a fixed contact mode with a corresponding one of the first piston 36 and the second piston 40, respectively. Each of the first contact plate 74 and the second contact plate 76 can also include a vertically oriented guide surface 82 and 84, respectively, in a sliding contact mode with the frame 42. Figure 3 Idler 30 and system 18 are depicted as they would appear when idler support members 44 and idler 30 are fully raised to nearly the maximum idler height. Figure 4 These components are depicted as if fully lowered almost to the lowest idler height. It can also be seen that the contact plates 74 and 76 are configured to be guided during movement up and down relative to the frame 42. In particular, the first contact plate 74 is shown as being configured with legs 90 that extend generally vertically and are received in slots 92 formed in the frame 42. Pads 94 or the like can be placed vertically between the legs 90 and the frame 42. The pads 94 can provide cushioning, but can also have a thickness that helps set the idler height. Thus, different pads can be replaced to change the relative adjustment of the idler height that can be obtained using the system 18.

[0020] Industrial Applicability

[0021] Reference is made generally to the accompanying drawings, but now also to Figure 5, it will be recalled that various known roller height adjustment strategies require disruption of the track to allow for component repositioning, rotation, etc. The present disclosure provides a simplified adjustment system having an unlimited range of roller heights that can be obtained compared to known strategies using shims, rotation of support blocks, or other strategies. Adjusting the height of rollers 30 in undercarriage system 18 according to the present disclosure may include opening a fluid exchange valve 48 in conduit 46 to establish a fluid connection between first piston assembly 34 and second piston assembly 38. With fluid exchange valve 48 open, roller support element 44 may be repositioned relative to track roller frame 22. Repositioning roller support element 44 may cause grease to be displaced between first piston assembly 34 and second piston assembly 38 through conduit 46. Since system 32 is typically a closed system, moving one of pistons 36 or 40 will tend to cause the other of pistons 36 and 40 to move in response to the displacement of grease through conduit 46. The positions of pistons 36 and 40 are best understood to be changed together. For example, as piston 36 advances, second piston 40 will retract the same amount due to the fluid communication of motion between first piston assembly 34 and second piston assembly 38. After grease is displaced with fluid exchange valve 48 open, fluid exchange valve 48 may be closed to set the height of idler 30.

[0022] Continue to refer Figure 5 , roller height adjustment may be performed by positioning machine 10 on a substantially level and generally rigid base with calibration blocks 110 positioned below rollers 30 and resting on the base. Machine 10 may be operated to drive undercarriage system 18, and in particular tracks 20, onto calibration blocks 110. With tracks 20 positioned on or above calibration blocks 110, fluid exchange valves 48 may be opened to enable lowering of roller support elements 44 or lowering of track roller frames 22 in undercarriage system 18 toward calibration blocks 110 under the action of gravity. Figure 5Also shown is a contact point 120 which may be approximately halfway between the rotational axis 100 of the idler 30 located vertically above the calibration block 110 and the first track roller 28 in the undercarriage system 18. It is generally desirable for the grouser of the track 20 to contact the underlying substrate at approximately such point 120. If the idler height is too low, the track 20 may contact the substrate at a location forward of the point 120, and if the idler height is too high, the track 20 may contact the substrate at a location rearward of the point 120. If the idler height is too high as the track 20 is advanced with the machine 10 to be positioned on the calibration support block 110, opening the fluid exchange valve 48 may allow the idler 30 and the idler support element 52 to settle under the downward force of gravity so that the track 20 rests on the calibration block 110. If the idler height is too low in this case, opening the fluid exchange valve 48 may allow the track roller frame 22 to settle under the downward force of gravity and thereby cause the idler 30 and the idler support member 44 to rise relative to the track roller frame 22. In one embodiment, the calibration block 110 may be approximately 10 millimeters thick, however, the present invention is not limited thereto.

[0023] As described above, performance such as grading performance and ride quality of a crawler tractor or certain other machines can depend substantially on the relationship between idler height and roller height. This relationship can change over time due to wear of the components. It should therefore be appreciated that the present disclosure provides a system and repeatable method that is easier to adjust than certain other strategies. In the illustrated embodiment, an operator or technician can manipulate the external handle 72 of the fluid exchange valve 48 to allow grease to flow in the conduit 46. In other cases, rather than manually operating the system, height monitoring or ride quality monitoring, or monitoring and analysis of other parameters can be used in an electronic control system that will selectively electromechanically open and close the fluid exchange valve, typically similar to the manual operation discussed herein.

[0024] This specification is for illustrative purposes only, and should not be interpreted as narrowing the scope of the present disclosure in any way. Therefore, those skilled in the art will recognize that, without departing from the complete and reasonable scope and spirit of the present disclosure, various modifications can be made to the embodiments disclosed currently. By viewing the attached drawings and the attached claims, other aspects, features and advantages will become apparent. As used herein, the articles "a" and "an" are intended to include one or more items, and can be used interchangeably with "one or more". When it is intended to represent only one item, the term "one" or similar language is used. In addition, as used herein, the terms "has", "have", "having" etc. are intended to be open terms. In addition, the phrase "based on" is intended to represent "based at least in part on", unless otherwise explicitly stated.

Claims

1. A roller height adjustment system (32) for a roller (30) in an undercarriage system (18) of a track-type machine (10), comprising: a first piston assembly (34) comprising a first piston (36) movable between an advanced position and a retracted position; a second piston assembly (38) comprising a second piston (40) movable between an advanced position and a retracted position; a frame (12) supporting the first piston assembly (34) and the second piston assembly (38) relative to each other for positioning above and below, respectively, a roller support member (44) in the undercarriage system (18); a fluid conduit (46) connecting the first piston assembly (34) to the second piston assembly (38); as well as A fluid exchange valve (48) is within the fluid conduit (46) and is adjustable from a closed position to an open position to exchange flowable material between the first piston assembly (34) and the second piston assembly (38) through the fluid conduit (46).

2. The roller height adjustment system (32) according to claim 1, wherein: The frame (12) includes an upper arm (56) in contact with the first piston assembly (34), a lower arm (58) in contact with the second piston assembly (38), and a U-shaped bend (60) connecting the upper arm (56) to the lower arm (58); The fluid exchange valve (48) comprises a mechanically actuated valve having an external handle (72); The fluid conduit (46) is a closed conduit; The flowable material includes grease that fills the fluid conduit (46), and wherein the roller height adjustment system (32) further includes a grease port (86) located fluidly between the first piston (36) and the second piston (40), and a closure (88) that blocks the grease port (86); and The roller height adjustment system (32) also includes a first contact plate (74), which is adjacent to the first piston (36) and is configured to contact the upper side (75) of the roller support element (44), and a second contact plate (76), which is in contact with the second piston (40) and is configured to contact the lower side (77) of the roller support element (44).

3. The roller height adjustment system (32) of claim 2, wherein the frame (12) has a plurality of bolt holes (62) formed therein for bolting the frame (12) to a track roller frame (22) in the undercarriage system (18); The upper arm (56) forms a first receiving portion (64) and the lower arm (58) forms a second receiving portion (66), and the first receiving portion (64) and the second receiving portion (66) receive the first piston assembly (34) and the second piston assembly (38), respectively.

4. A roller height adjustment system according to claim 2 or 3, wherein the first contact plate (74) and the second contact plate (76) each include a horizontally oriented surface (78, 80) in a fixed contact mode with a corresponding one of the first piston (36) and the second piston (40), and a vertically oriented guide surface (82, 84) in a sliding contact mode with the frame (12).

5. An undercarriage system (18) for a track-type machine (10), comprising: Roller yoke (50); a roller support element (44) coupled to the roller yoke (50); A first piston assembly (34) and a second piston assembly (38) supported at an upper position and a lower position relative to the roller support element (44) and opposite to each other; a conduit (46) connecting the first piston assembly (34) to the second piston assembly (38); as well as A fluid exchange valve (48) is within the conduit (46) and is adjustable from a closed position to an open position to fluidly connect the first piston assembly (34) and the second piston assembly (38).

6. The undercarriage system (18) of claim 5, wherein the conduit (46) is a closed conduit and further comprising grease filling the conduit; and The undercarriage system (18) also includes a track roller frame (22), and a support frame (42) mounted to the track roller frame (22) and supporting the first piston assembly (34) and the second piston assembly (38) at the upper position and the lower position.

7. The undercarriage system (18) of claim 6, wherein the roller support element (44) comprises a roller support block captured between the first piston assembly (34) and the second piston assembly (38); The support frame (42) includes an upper arm (56) supporting the first piston assembly (34), and a lower arm (58) supporting the second piston assembly (38); The upper arm (56) forms a first receiving portion (64) and the lower arm (58) forms a second receiving portion (66), and the first receiving portion (64) and the second receiving portion (66) receive the first piston assembly (34) and the second piston assembly (38) respectively; and The conduit (46) extends through each of the upper arm (56) and the lower arm (58).

8. A method of adjusting the height of a roller (30) in an undercarriage system (18) of a track-type machine (10), comprising: opening a fluid exchange valve (48) in a conduit (46) extending between a first piston assembly (34) supported on an upper side (75) of a roller support member (44) in the chassis system (18) and a second piston assembly (38) supported on a lower side (77) of the roller support member (44); repositioning the roller support member (44) relative to a track roller frame (22) in the undercarriage system (18) when the fluid exchange valve (48) is open; cooperating to change the position of the pistons (36, 40) in the first piston assembly (34) and the second piston assembly (38) based on the repositioning of the roller support element (44); displacing flowable material through the conduit (46) based on a common change in position of the pistons (36, 40); as well as The fluid exchange valve (48) is closed after displacement of the flowable material to set the height of the support roller (30).

9. The method of claim 8, further comprising positioning the track (20) in the undercarriage system (18) on a calibration block (110) resting on a base plate so that the axis of rotation of the roller (30) is vertically above the calibration block; The conduit (46) is a closed conduit, and the displacement of the flowable material includes displacing grease; and The opening of the fluid exchange valve (48) and the closing of the fluid exchange valve (48) include adjusting the fluid exchange valve (48) using an external handle (72).

10. The method of claim 9, wherein repositioning the roller support element (44) comprises lowering the roller support element (44) toward the calibration block (110) or lowering a track roller frame (22) in the undercarriage system (18) under the action of gravity.

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