US20150013197A1

US20150013197A1 - Wear collar for tool retention system

Info

Publication number: US20150013197A1
Application number: US13/941,241
Authority: US
Inventors: Patrick Simon Campomanes
Original assignee: Caterpillar Inc
Current assignee: Caterpillar Inc
Priority date: 2013-07-12
Filing date: 2013-07-12
Publication date: 2015-01-15
Also published as: CN203977489U; AU2014203302A1

Abstract

A wear collar is provided for use with a tool retention system having a locating member with a wedge portion. The wear collar may have a hollow body at least partially forming an inner surface configured to mate against an external surface of the locating member at the wedge portion, and an outer surface offset from the inner surface. The outer surface may have a profile generally matching a profile of the inner surface. The hollow body may be configured to receive and annularly surround the locating member.

Description

TECHNICAL FIELD

The present disclosure relates generally to a tool retention system and, more particularly, to a wear collar for a tool retention system.

BACKGROUND

Earth-working machines, such as cable shovels, excavators, wheel loaders, draglines, and front shovels, include implements generally used for digging into, ripping, or otherwise moving earthen material. These implements are subjected to extreme abrasion and impacts that causes them to wear. To prolong the useful life of the implements, various ground engaging tools can be connected to the earth-working implements at areas experiencing the most wear. These ground engaging tools are replaceably connected to the implements using a retention system.
An exemplary system for retaining a ground engaging tool connected to an implement is disclosed in U.S. Pat. No. 8,468,724 of Leslie et al. that issued on Jun. 25, 2013 (“the '724 patent”). Specifically, the '724 patent discloses a retaining pin assembly having opposable locating members, each with a shank portion able to be slidably inserted into opposing sides of a wear member and into a mounting nose of an excavator bucket. Each locating member also has an enlarged wedge portion adjacent a normally-outer end. A bolt extends between the locating members from one side of the retaining pin assembly. When tension is applied to the bolt, relative contraction of the locating members occurs. This contraction urges the wear member into engagement with the mounting nose by engagement of each of the wedge portions with a rear wall of respective retaining pin apertures.
Although acceptable for some applications, the retaining pin assembly of the '724 patent may be less than optimal. In particular, over time, the retaining pin apertures and/or the wedge portions can wear, resulting in loosening of the wear member from the mounting nose. Although additional tensioning of the bolt may re-tighten this engagement, eventually enough wear may occur such that additional tensioning is not possible. When this occurs, the retaining pin assembly and/or the wear member or mounting nose must be replaced. This replacement can be time consuming and costly.
The disclosed wear collar and tool retention system are directed to overcoming one or more of the problems set forth above.

SUMMARY

According to one exemplary aspect, the present disclosure is directed to a wear collar for a tool retention system having a locating member with a wedge portion. The wear collar may include a hollow body at least partially forming an inner surface configured to mate against an external surface of the locating member at the wedge portion, and an outer surface offset from the inner surface. The outer surface may have a profile generally matching a profile of the inner surface. The hollow body may be configured to receive and annularly surround the locating member.
According to another exemplary aspect, the present disclosure is directed to a wear collar kit for a tool retention system having a locating member with a wedge portion. The wear collar kit may include at least a first wear collar connectable to the wedge portion of the locating member and being configured to limit relative movement between a tool adapter and a mounting nose of a work implement by a first amount. The wear collar kit may also include at least a second wear collar connectable to the wedge portion of the locating member and being configured to limit relative movement between a tool adapter and the mounting nose of the work implement by a second amount greater than the first amount.
According to another exemplary aspect, the present disclosure is directed to a tool retention system. The tool retention system may include at least one locating member having a wedge portion and a shank portion extending from the wedge portion. The shank portion may be configured to be slidably inserted into a side of an adapter and into a mounting nose of a work implement. The tool retention system may also include a bolt configured to engage an end of the shank portion opposite the wedge portion. Tension of the bolt may cause the wedge portion to urge the adapter into further engagement with the mounting nose. The tool retention system may further include at least one wear collar having a first axial end, an opposing second axial end, and an inner surface extending from the first axial end to the second axial end. The inner surface may be configured to mate against an external surface of the at least one locating member at the wedge portion. The tool retention system may additionally include an outer surface offset from the inner surface and having a profile generally matching a profile of the inner surface. The inner surface of the wear collar may receive and annularly surround the at least one locating member, and the wear collar may extend in an axial direction a majority length of the wedge portion. The inner surface at the first axial end may be generally elliptical, and the inner surface at the second axial end may be generally circular.
According to another exemplary aspect, the present disclosure is directed to a method of servicing a tool retention system. The method may include removing tension from a bolt to release a locating member connecting an adapter to a mounting nose of a work implement, and removing the locating member from corresponding apertures in the adapter and the mounting nose of the work implement. The method may also include installing a wear collar over a wedge portion of the locating member, and inserting the locating member and the wear collar back through the corresponding apertures. The method may further include re-tensioning the bolt to increase engagement of the adapter to the mounting nose of the work implement.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side-view illustration of an exemplary disclosed machine;

FIG. 2 is an exploded view illustration of an exemplary disclosed tool retention system that may be used in conjunction with the machine of FIG. 1;

FIGS. 3 and 4 are isometric view illustrations of an exemplary disclosed wear collar that forms a portion of the tool retention system of FIG. 2;

FIG. 5 is an exploded view illustration of an alternative tool retention system that may be used in conjunction with the machine of FIG. 1; and

FIGS. 6 and 7 are isometric view illustrations of an exemplary disclosed wear collar that forms a portion of the tool retention system of FIG. 4.

DETAILED DESCRIPTION

FIG. 1 illustrates a mobile machine 10 having a work implement 12 operatively connected at a leading end. In the disclosed embodiment, machine 10 is a rope shovel. It is contemplated, however, that machine 10 may embody any other type of mobile or stationary machine known in the art, for example a wheel loader, an excavator, a motor grader, a dredge, a dragline, or another similar machine. Machine 10 may be configured to use work implement 12 to move material, such as earthen overburden and ore, during completion of an assigned task. Although shown as being located at the leading end of machine 10, it is contemplated that work implement 12 could alternatively or additionally be located at a midpoint or trailing end of machine 10, if desired.
Work implement 12 may embody any device used to perform a particular task such as, for example, a bucket (shown in FIG. 1), a blade, a shovel, a crusher, a grapple, a ripper, or any other material moving device known in the art. In addition, although connected in the embodiment of FIG. 1 to lift, curl, and dump relative to machine 10, work implement 12 may alternatively or additionally rotate, swing, pivot, slide, extend, open/close, or move in another manner known in the art.
Work implement 12 may be equipped with one or more ground engaging tools (GET) 14 located at a cutting edge 16. For example, the disclosed bucket could be provided with multiple similar tooth assemblies that are spaced apart along a length of cutting edge 16. While shown as single-point, sharpened tooth assemblies, it is contemplated that GET 14 could take any other form known in the art, for example a fork (i.e., multi-point) configuration, a chisel configuration, or a blunt-end configuration.
GET 14 may be a conventional multi-piece component that is removably connected to work implement 12. In the embodiment shown in FIG. 2, GET 14 is a two-piece component having a tip 18 and an adapter 20 that are connected to a mounting nose 22 at cutting edge 16 of work implement 12 via a retention system 24. Tip 18 may be joined to a nose end 26 of adapter 20 in any manner known in the art, for example via welding, threaded fastening, integral posts and clips, etc. Thereafter, retention system 24 may be used to removably connect GET 14 to work implement 12.
Adapter 20 may be a generally hollow structural member having a base end 28 located opposite nose end 26. Base end 28 may be configured to receive mounting nose 22 of work implement 12, while nose end 26 may be received within tip 18. A pair of aligned apertures 30 (only one shown in FIG. 2) may be formed at base end 28 within opposing side walls 32. Apertures 30 may be generally elliptically shaped, each having a length extending in a direction between base end 28 and nose end 26. When base end 28 of adapter 20 is placed over mounting nose 22, apertures 30 (only one shown in FIG. 2) may align at least partially with corresponding apertures 34 located within side walls 36 of mounting nose 22. That is, when base end 28 of adapter 20 is placed over mounting nose 22, apertures 30, 34 may align in a transverse direction and at least partially overlap in the length direction.
Retention system 24 may include components that interact to clamp an associated GET 14 in a removable manner to mounting nose 22 at cutting edge 16 of work implement 12. Specifically, retention system 24 may include one or more locating members 37, a bolt 38, and a wear collar 40. In the embodiment of FIG. 2, retention system 24 includes two locating members 37 and two wear collars 40; one wear collar 40 associated with each locating member 37. It is contemplated, however, that retention system 24 could have different numbers of locating members 37 and wear collars 40, if desired. For example, retention system 24 could have two locating members 37, and a single wear collar 40 associated with only one of the two locating members 37. Locating members 37 may be inserted through apertures 30 and 34 of adapter 20 and mounting nose 22, respectively. Bolt 38 may be used to join locating members 37 to each other in an end-to-end configuration. Wear collars 40, as will be described in more detail below, may enhance engagement of adapter 20 to mounting nose 22 after other components of retention system 24 (locating members 37) and/or GET 14 (e.g., apertures 30, 34) have worn. It is contemplated that retention system 24 may include additional components, if desired, such as one or more intermediate body members that inhibit rotation of locating members 37, one or more pins that inhibit rotation of bolt 38, one or more seals that inhibit ingress of dirt and debris, spacers, etc.
As shown in FIGS. 3 and 4, locating member 37 may include a generally cylindrical shank portion 42, and a wedge portion 44 that protrudes radially outward from one side of shank portion 42 at an external end 46 thereof External end 46 may be generally flat and perpendicular to an axis 48 of shank portion 42, and have an elliptical shape conforming to a combined perimeter of shank portion 42 and wedge portion 44. Wedge portion 44 may join shank portion 42 at an axial transition 50, and have an outer surface 52 that is inclined by an angle a outwardly away from axis 48 between transition 50 and a chamfered edge 54 that joins end 46 with wedge portion 44. When locating member 37 is inserted into apertures 30, 34 (referring to FIG. 2), surface 52 of wedge portion 44 may be oriented rearward (i.e., toward work implement 12 and base end 28 of adapter 20), such that surface 52 of wedge portion 44 engages a rearward edge 56 of aperture 30. In this manner, as wedge portion 44 is forced further into apertures 30, 34 by tensioning of bolt 38, the inclination at surface 52 of wedge portion 44 acting on rearward edge 56 of aperture 30 may urge adapter 20 into further engagement with mounting nose 22.
Wedge portion 44 may have a single axially-oriented plane of symmetry 58, which passes through a center of outer surface 52. This configuration of locating member 37 may allow for insertion within apertures 30, 34 in only a single orientation, and help to inhibit rotation of locating member 37 after assembly and during operation.
As can also be seen in FIGS. 3 and 4, wear collar 40 may have a generally hollow body 60 that at least partially forms smooth and continuous inner and outer surfaces 62, 64. Inner surface 62 may be configured to substantially match and mate against outer surface 52 of locating member 37 at wedge portion 44. Accordingly, inner surface 62 may be configured to receive a worn wedge portion 44 via a tight fit (e.g., an interference fit), and body 60 may extend in an axial direction of locating member 37 a majority length of wedge portion 44 (i.e., more than ½ of the length of wedge portion 44). In one embodiment, body 60 may extend in the axial direction from transition 50 to chamfered edge 54. Outer surface 64 may be offset from inner surface 62 by a thickness t and have a profile that generally matches a profile of inner surface 62.
Like locating member 37, wear collar 40 may have a single plane of symmetry configured to align with plane 58 once assembled, such that once locating member 37 is inserted into wear collar 40, the singular-symmetry of these components may help to resist relative rotation therebetween. Plane 58 may pass through inner surface 62 at two spaced apart locations. At a first of these locations (lower-left location shown in FIG. 3), inner surface 62 may be generally aligned with an axial direction of locating member 37. At a second of these locations (at the upper-right location shown in FIG. 3) inner surface 62 may be tilted at angle a relative to the axial direction.
Body 60 of wear collar 40 may also include a first or outer axial end 66 located at chamfered edge 54, and an opposing second or inner axial end 68 located at transition 50. In the disclosed embodiment, inner surface 62 at first axial end 66 has a shape that is generally elliptical, while inner surface 62 at second axial end 68 has a shape that is generally circular. It is contemplated, however, that inner surface 62 at both of first and second ends 66, 68 could alternatively be elliptically shaped, if desired. In either configuration, inner surface 62 at first axial end 66 may have a small diameter D₁that is about equal to a small diameter d₁of inner surface 62 at second axial end 68, and a large diameter D₂that is about 10-30% larger than a large diameter d₂of inner surface 62 at second axial end 68. This geometrical relationship may provide a thickness to inner diameter ratio of about 1:3-4 at second axial end 68 and a thickness to axial length ratio of about 1:2.5-3.5, which may help ensure adequate strength and proper fit within worn apertures 30, 34. Wear collar 40 may be made from a material that is substantially identical to a material from which locating member 37 is fabricated, such that wear collar 40 may wear and provide support in a substantially identical manner as locating member 37. In other embodiments, wear collar 40 may be made from a material that is different than the material from which locating member 37 is fabricated, so that the wear collar 40 provides improved wear resistance as compared to the locating member 37 absent a wear collar.
After a period of operation, different components of work implement 12, GET 14, and/or retention system 24 may wear. As will be described in more detail below, wear collars 40 may be selectively assembled around worn locating members 37 to accommodate this wear and help ensure the appropriate engagement conditions between GET 14 and work implement 12. It may be possible, however, for the wear to be more severe in some applications than in others, and/or for the wear to be dependent on an age or usage period of machine 10. To accommodate the different applications and/or worksite conditions, a wear collar kit may be created having multiple different wear collars 40. This kit may include multiple sets of two wear collars 40 each, each set having a different thickness t configured to limit relative movement between adapter 20 and mounting nose 22 by different amounts (e.g., a first collar for initial wear and a second collar that is about 10% thicker for accommodating more severe wear). In addition, the kit may include instructions for removing locating members 37 and/or existing wear collars 40, and for assembling replacement wear collars 40 having a different thickness. The kit may have a single part number, meaning that the kit can be ordered and distributed as a single sales item to consumers. In some embodiments, a replacement bolt 38 and/or seals (not shown) may also be included in the kit, if desired.
An alternative retention system 70 is shown in FIG. 5. In this embodiment, retention system 70 includes a single locating member 72, a bolt 74, a retention member 76, and a wear collar 78. Locating member 72 may be inserted through apertures 30 and 34 of adapter 20 and mounting nose 22, respectively, from only one side of GET 14. Bolt 74 may be inserted into retention member 76, and then retention member 76 may be inserted through aperture 34 of mounting nose 22 from the opposing side of GET 14 to engage an internal end of locating member 72. Tensioning of bolt 74 may then function to draw locating member 72 further into apertures 30, 34, thereby tightening the connection of adapter 20 to mounting nose 22. Wear collar 78, as will be described in more detail below, may enhance engagement of adapter 20 to mounting nose 22 after other components of retention system 70 (locating member 72) and/or GET 14 (e.g., apertures 30, 34) have worn. It is contemplated that retention system 24 may include additional components, if desired, such as one or more intermediate body members that inhibit rotation of locating member 72, one or more pins that inhibit rotation of bolt 74, one or more seals that inhibit ingress of dirt and debris, spacers, etc.
As shown in FIGS. 6 and 7, locating member 72 may have a similar shape and provide similar functionality as locating member 37 shown in FIGS. 3 and 4. In contrast to locating member 37, however, locating member 72 may be faceted. That is, locating member 72 may include a shank portion 80 and a wedge portion 82, both formed by a plurality of generally planar adjoining surfaces. These generally planar surfaces may be configured to engage corresponding generally planar surfaces of adapter 20, mounting nose 22, and/or retention member 76, thereby inhibiting undesired rotation of locating member 72.
Wear collar 78 of FIGS. 6 and 7, like wear collar 40 of FIGS. 3 and 4, may be configured to internally receive a worn locating member 72. However, because of the geometry differences between locating members 37 and 72, wear collar 78 may be shaped differently than wear collar 40. In particular, internal and external surfaces 84, 86 of wear collar 78 may be faceted to match the outer profile of locating member 72 and the inner profiles of adapter 20, mounting nose 22, and/or retention member 76.

INDUSTRIAL APPLICABILITY

The disclosed wear collar and tool retention system may be applicable to various earth-working machines, such as cable shovels, wheel loaders, excavators, front shovels, dredges, and bulldozers. When used to removably connect ground engaging tools to the work implements of these machines, the work implements may be protected against wear in areas experiencing damaging abrasions and impacts. Accordingly, the disclosed tool retention system may help to prolong the useful life of the implements and the machines. Use of tool retention system 24 to improve connection of GET 14 to work implement 12 after a period of operation and wear will now be described in detail.
After a period of operation, the engagement between work implement 12 and GET 14 may become loose due to abrasive wear. If unaccounted for, continued use under these conditions could result in costly damage of these components. Accordingly, a service technician may periodically check the engagement between work implement 12 and GET 14. When significant movement between work implement 12 and GET 14 is observed (i.e., an amount about a threshold level), the service technician may remove and service retention system 24.
The service technician may remove retention system 24 by releasing tension within bolt 38. In some embodiments, a plug (not shown) may need to be removed to gain access to a head end of bolt 38. Once the tension of bolt 38 is released, one or both of locating members 37 may be removed from (i.e., knocked out of) apertures 30, 34. Depending on the amount of wear that has occurred, the service technician may select for use one or more wear collars 40 (from the kit described above) that have a corresponding thickness. Wear collar(s) 40 may then be installed over the removed and worn locating member(s) 37, and then the locating member(s) 37 and wear collar(s) 40 may be inserted back through the corresponding apertures 30, 34. Bolt 38 may then be re-tensioned to increase the engagement of adapter 20 with mounting nose 22 of work implement 12.
After another period of wear, the previously installed wear collar(s) 40 may need to be replaced with different wear collar(s) 40 from the kit having a greater thickness. This process may be completed in much the same way described above. In particular, tension in bolt 38 may be released, the corresponding locating member(s) 37 removed, the previously installed wear collar(s) 40 removed from locating member(s) 37, the thicker wear collar(s) 40 installed, and everything put back together. It is contemplated, however, that in some embodiments, rather than removing a worn wear collar 40, an additional wear collar 40 may simply be installed over the existing worn wear collar 40, if desired. Servicing of retention system 70 may be performed in the same manner as described above.
The disclosed retention system(s) may be relatively simple and low-cost. Specifically, because worn components may continue to be used, augmented with wear collars 40, the operating cost of machine 10 may be low. In addition, because excessive wear can be absorbed with wear collars 40, damage to more expensive components of machine 10 may be avoided.
It will be apparent to those skilled in the art that various modifications and variations can be made to the disclosed wear collar and retention systems. Other embodiments will be apparent to those skilled in the art from consideration of the specification and practice of the disclosed wear collar and retention systems. For example, although wear collars 40 and 78 are described as being used only after other components of GET 14 and/or retention system 24 have worn, it is contemplated that wear collars 40, 78 could alternatively be used in a new configuration and then replaced as they themselves wear out. In this manner, other components of GET 14 and/or retention system 24 may experience less initial wear. It is further contemplated that wear collars 40, 78 could be made of softer materials, allowing a majority of wear to occur therein as opposed to within other mating components. It is intended that the specification and examples be considered as exemplary only, with a true scope being indicated by the following claims and their equivalents.

Claims

What is claimed is:

1. A wear collar for a tool retention system having a locating member with a wedge portion, the wear collar comprising:

a hollow body at least partially forming:

an inner surface configured to mate against an external surface of the locating member at the wedge portion; and

an outer surface offset from the inner surface and having a profile generally matching a profile of the inner surface,

wherein the hollow body is configured to receive and annularly surround the locating member.

2. The wear collar of claim 1, wherein the hollow body of the wear collar is configured to extend in an axial direction a majority length of the wedge portion.

3. The wear collar of claim 2, wherein:

the locating member has a shank portion extending from the wedge portion, an end surface located opposite the shank portion relative to the wedge portion, and a chamfered edge joining the end surface with the wedge portion; and

the hollow body of the wear collar is configured to extend in an axial direction of the shank portion from the chamfered edge to a transition between the wedge portion and the shank portion.

4. The wear collar of claim 1, wherein the hollow body of the wear collar is fabricated from a material substantially identical to a material from which the locating member is fabricated.

5. The wear collar of claim 1, wherein the hollow body has a single plane of symmetry.

6. The wear collar of claim 5, wherein:

the single plane of symmetry passes through the inner surface at a first location and at an opposing second location;

the inner surface is configured to be generally aligned with an axial direction of the locating member at the first location; and

the inner surface is tilted at an angle relative to the axial direction of the locating member at the second location.

7. The wear collar of claim 1, wherein:

the hollow body includes a first axial end and an opposing second axial end;

the inner surface at the first axial end is generally elliptical; and

the inner surface at the second axial end is generally circular.

8. The wear collar of claim 7, wherein:

the locating member has a shank portion extending from the wedge portion, an end surface located opposite the shank portion relative to the wedge portion, and a chamfered edge joining the end surface with the wedge portion;

the first axial end is configured to be located at the chamfered edge; and

the second axial end is configured to be located at a transition between the wedge portion and the shank portion.

9. The wear collar of claim 7, wherein the hollow body has a thickness to inner diameter ratio of about 1:3-4 at the second axial end.

10. The wear collar of claim 1, wherein:

the hollow body includes a first axial end and an opposing second axial end;

the inner surface at the first axial end is generally elliptical; and

the inner surface at the second axial end is generally elliptical, has a small diameter about equal to a small diameter of the inner surface at the first axial end, and has a large diameter about 10-30% smaller than a large diameter of the inner surface at the first axial end.

11. The wear collar of claim 10, wherein:

the first axial end is configured to be located at the chamfered edge; and

12. The wear collar of claim 1, wherein the hollow body has a thickness to length ratio of about 1:2.5-3.5.

13. The wear collar of claim 1, wherein the inner surface is continuous and generally curved at the wedge portion.

14. The wear collar of claim 1, wherein the inner surface is faceted at the wedge portion.

15. A wear collar kit for a tool retention system having a locating member with a wedge portion, the wear collar kit comprising:

at least a first wear collar connectable to the wedge portion of the locating member and being configured to limit relative movement between a tool adapter and a mounting nose of a work implement by a first amount; and

at least a second wear collar connectable to the wedge portion of the locating member and being configured to limit relative movement between the tool adapter and the mounting nose of the work implement by a second amount greater than the first amount.

16. The wear collar kit of claim 15, wherein:

the at least a first wear collar includes two substantially identical first wear collars each having a first wall thickness; and

the at least a second wear collar includes substantially identical second wear collars having a second wall thickness at least 10% greater than a wall thickness of the first wear collars.

17. A tool retention system, comprising:

at least one locating member having a wedge portion and a shank portion extending from the wedge portion, the shank portion configured to be slidably inserted into a side of an adapter and into a mounting nose of a work implement;

a bolt configured to engage an end of the shank portion opposite the wedge portion, wherein tension of the bolt is configured to cause the wedge portion to urge the adapter into further engagement with the mounting nose; and

at least one wear collar having:

a first axial end;

an opposing second axial end;

an inner surface extending from the first axial end to the second axial end and configured to mate against an external surface of the at least one locating member at the wedge portion; and

wherein:

the inner surface of the wear collar is configured to receive and annularly surround the at least one locating member;

the wear collar is configured to extend in an axial direction a majority length of the wedge portion;

the inner surface at the first axial end is generally elliptical; and

the inner surface at the second axial end is generally circular.

18. The tool retention system of claim 17, wherein:

the at least one locating member includes two locating members configured to be inserted into opposing sides of the adapter and into the mounting nose of the work implement; and

the at least one wear collar includes two wear collars, each configured to receive a corresponding one of the two locating members.

19. A method of servicing a tool retention system, comprising:

removing tension from a bolt to release a locating member connecting an adapter to a mounting nose of a work implement;

removing the locating member from corresponding apertures in the adapter and the mounting nose of the work implement;

installing a wear collar over a wedge portion of the locating member;

inserting the locating member and the wear collar back through the corresponding apertures; and

re-tensioning the bolt to increase engagement of the adapter to the mounting nose of the work implement.

20. The method of claim 19, wherein:

the wear collar is a first wear collar; and

the method further includes:

removing tension from the bolt a subsequent time to release the locating member and the first wear collar;

removing the locating member and the first wear collar from the corresponding apertures in the adapter and the mounting nose of the work implement;

removing the first wear collar from the locating member;

installing a second wear collar having a thickness greater than a thickness of the first wear collar over the wedge portion of the locating member;

inserting the locating member and the second wear collar back through the corresponding apertures; and

re-tensioning the bolt to further increase engagement of the adapter to the mounting nose of the work implement.