WEAR MEMBER

Abstract

A wear member comprising: a housing defining a passageway therethrough and having a longitudinal axis, the housing comprising a housing cavity formed therein, fully recessed from an inner surface of the housing, and opening into the passageway; an insert slidably located within the passageway and defining a longitudinal clearance between the inner surface of the housing and the insert, the insert comprising an insert cavity formed therein, fully recessed from an outer surface of the insert and opening into the passageway; brazing material filling the longitudinal clearance and extending transversely to the longitudinal axis into the housing cavity and insert cavity to provide an axially resistive force against axial movement of the insert relative to the housing in addition to any bonding of the brazing material to the insert and the housing.

Description

FIELD OF THE INVENTION

The present invention relates to a wear member including a hardened insert.

The invention has been developed primarily for use along the digging edge of an excavating machine and will be described hereinafter with reference to this application. However, it will be appreciated that the invention is not limited to this particular field of use.

BACKGROUND OF THE INVENTION

Any discussion of the prior art throughout the specification should in no way be considered as an admission that such prior art is widely known or forms part of the common general knowledge in the field.

Excavating equipment of all kinds and sizes include various wear members to protect the front digging edge from damage and wear. Wear members include points (or tips), adapters, shrouds, runners, and the like. These wear members are commonly subjected to highly abrasive materials and are used under arduous conditions. To withstand the rigors of digging, the wear members may be made from abrasion resistant materials, overlays, or layers.

One type of material having high abrasion resistance is a carbide, such as tungsten carbide or silicon carbide. However, such materials are very expensive, so it is known to use inserts of such material that are located in a housing comprising less expensive material, such as steel. It is also known to use a hardened outer later, such as a layer created using infiltration hardening. The two approaches may be combined so that an insert (such as a tungsten carbide or silicon carbide insert) is mounted in a housing passageway in the wear member, and the space between the insert and the housing is filled with brazing material that provides a hardened infiltrated layer. Improvements in the use of such inserts is desired.

SUMMARY OF THE INVENTION

According to a first aspect there is provided a wear member comprising: a housing defining a passageway therethrough and having a longitudinal axis, the housing comprising a housing cavity formed therein, fully recessed from an inner surface of the housing, and opening into the passageway; an insert slidably located within the passageway and defining a longitudinal clearance between the inner surface of the housing and the insert, the insert comprising an insert cavity formed therein, fully recessed from an outer surface of the insert and opening into the passageway; brazing material filling the longitudinal clearance and extending transversely to the longitudinal axis into the housing cavity and insert cavity to provide an axially resistive force against axial movement of the insert relative to the housing in addition to any bonding of the brazing material to the insert and the housing.

The brazing material may also provide a resistive force transverse to the longitudinal axis.

In some embodiments, the housing further comprises a support cavity defining a support cavity axis therethrough, where the support cavity axis is transverse to the insert cavity thereby providing additional longitudinal axially resistive force.

In some embodiments, the support cavity extends from the housing inner surface of the housing to a housing outer surface of the housing, and is closed by a cap on the outer surface of the housing.

In some embodiments, the insert may be substantially enclosed within the passageway.

In some embodiments, the housing cavity is spaced from the passageway entrance and an inner rear wall of the housing at an end of the passageway.

In some embodiments, the insert is insertable to the inner rear wall unobstructed by protrusions into the passageway from either the housing or the insert.

In some embodiments, the housing cavity is longitudinally offset from the insert cavity.

In some embodiments, the insert comprises a plurality of insert cavities.

In some embodiments, each insert cavity has an arcuate concave shape.

In some embodiments, the housing comprises a plurality of housing cavities.

In some embodiments, each housing cavity comprises a wedge shape, a narrow end of the wedge being closer to the passageway entrance than a wider portion of the wedge.

In some embodiments, each housing cavity has a general wedge shape (optionally with concave walls in a vertical direction), a narrow end of the wedge being further from the passageway entrance than a wider portion of the wedge.

According to a second aspect there is provided a wear member comprising a housing defining a passageway therethrough and having a longitudinal axis, the housing comprising a housing cavity formed therein, fully recessed from an inner surface of the housing, and opening into the passageway; an insert slidably located and substantially enclosed within the passageway and defining a longitudinal clearance between the inner surface of the housing and the insert, the insert comprising an insert cavity formed therein, fully recessed from an outer surface of the insert and opening into the passageway; the insert and housing being configured such that there is no projection from the insert into the housing cavity, and no projection from the housing into the insert cavity.

According to a third aspect there is provided a wear member comprising a housing defining a passageway extending axially therein from a front end, a support cavity in communication with and extending transverse to the passageway, a wear-resistant insert received in the passageway, and a brazing material filling the passageway and support cavity to secure the insert in the passageway.

According to a fourth aspect there is provided a wear member comprising a housing defining a passageway extending axially therein from a front end, an insert received in the passageway along its longitudinal axis, and a housing cavity opening in the passageway having a wedge shape, wherein a narrow end of the wedge being closer to the passageway entrance than a wider portion of the wedge.

According to a fifth aspect there is provided an excavating equipment component comprising the wear member according to the first aspect.

According to a sixth aspect there is provided a wear assembly comprising: (i) a wear member according to any of the first through fourth aspects; (ii) a base on which the wear member is mounted, and (iii) a lock securing the wear member to the base.

In some embodiments, the excavating equipment component is selected from a group consisting of: a point (or tip or tooth); an adapter; a shroud; a runner; or a bucket.

In alternative embodiments, the wear member of the invention may be utilized in other industrial equipment, for example within a pump in an impeller or a throatbush (suction liner, side liner, etc.), or the like.

These and other aspects, features, and advantages will become apparent from the following Detailed Description when taken in conjunction with the accompanying drawings, which are a part of this disclosure and which illustrate, by way of example, principles of the various embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1 is a pictorial perspective view of a wear member according to an embodiment of the invention;

FIG. 2 is a simplified cross-sectional side view of a front portion of the wear member of FIG. 1 along line 2-2 in FIG. 1, prior to a brazing process;

FIG. 3 is a simplified cross-sectional top plan view of a front portion of the wear member of FIG. 1 along line 3-3 in FIG. 1, prior to the brazing process;

FIG. 4 is a simplified cross-sectional front view of a central front portion of part of the wear member of FIGS. 1 and 2 (the portion shown by broken line 4′ in FIG. 1), prior to the brazing process.

FIG. 5 is a perspective view of an insert used in the wear member of FIGS. 1 to 4;

FIG. 6 is a top plan view of the insert of FIG. 5;

FIG. 7 is a side view of the insert of FIGS. 5 and 6;

FIG. 8 is a simplified cross-sectional side view similar to that of FIG. 2, but subsequent to the brazing process;

FIG. 9 is a simplified cross-sectional top plan view similar to that of FIG. 3, but subsequent to the brazing process; and

FIG. 10 is a simplified cross-sectional front view similar to that of FIG. 4, but subsequent to the brazing process.

DETAILED DESCRIPTION OF EMBODIMENTS

The following embodiments are described by way of example only to provide a more detailed understanding of certain aspects of the invention. It is to be understood that other embodiments are contemplated.

Reference is first made to the FIGS. 1 to 4, which illustrate various views of a wear member 10 in the form of a tip (or point), which is used as part of a ground engaging tool. FIGS. 2 to 4 are simplified in that they are cross-sections that do not show any shading, and they only show a front portion of the wear member 10.

The wear member 10 comprises: a housing 12 defining a passageway 14 therethrough and a longitudinal axis 16. The passageway 14 is defined, in part, by an inner surface of the housing 12 including a rear wall 18, an upper surface 20a, an opposite lower surface 20b, a left side surface 22a and a right side surface 22b. The upper and lower surfaces 20 are generally flat (e.g. planar), and the left and right side surfaces 22 preferably include protrusions thereon (24a,b respectively) near an entrance 26 of the passageway 14 and near the rear wall 18 to better position an insert 40 in the passageway (not all are shown in the drawings). The optional arrangement of the protrusions can be varied. Protrusions could also be omitted (or provided) on some or all the top, bottom, side and rear surfaces of the inner surface of the housing.

The inner surface of the housing 12 also preferably defines one or more housing cavities therein (28a,b respectively) (best seen in FIG. 3). Each housing cavity 28a,b is fully recessed from the surrounding portions of the side surface 22a,b that define that cavity 28a,b, and opens into the passageway 14. Each housing cavity 28a,b has a general wedge shape (with concave walls in a vertical direction), where the larger portion of the wedge is closer to the inner rear wall 18 than the smaller portion of the wedge. The wedge shape simplifies cleaning out the housing cavities prior to casting for improved quality. While a housing cavity is illustrated as being on opposite side surfaces, other variations are possible. As examples, a plurality of housing cavities can be provided on one or both side surfaces, housing cavities can be provided on the top and bottom surfaces with or without such housing cavities on the side surfaces, the housing cavities can be mirror images of the housing cavities on opposite surfaces or offset from the housing cavities on opposite surfaces, there may be more housing cavities on certain surfaces than others, etc.

An insert 40 is slidably located and optionally substantially enclosed within the passageway 14. While the illustrated embodiment includes one passageway 14 with an insert 40, a plurality of passageways, each with an insert, could be provided depending on the size and/or shape of the wear member. The insert 40 will now be described in more detail with reference to FIGS. 5 to 7. The insert 40 is manufactured of a hardened, abrasion-resistant material to increase the overall wear resistance of the wear member 10. In this embodiment, the insert 40 comprises a tungsten carbide or an alloy thereof; however, the insert 40 may also, e.g., be manufactured of any alternative hardened materials, for example selected from the group consisting of silicon, titanium, vanadium, chromium, zirconium, niobium, molybdenum, hafnium, tantalum, or tungsten carbides and/or nitrides and/or borides, or alloys thereof.

The insert 40 includes a body 42 of generally cuboid shape that tapers to a front edge 44 to conform to the shape of a forward part of the wear member 10 and to provide a wear-facing edge for the forward part of the wear member 10. Other shapes of insert are possible.

In the illustrated embodiment, the insert body 42 includes opposing sidewalls 46a,b, each optionally defining a front insert cavity 50a,b respectively, and a rear insert cavity 52a,b respectively. The insert cavities 50, 52 are generally arcuate and concave in shape, when viewed from above (best seen in FIGS. 5 and 6) and the insert cavities on each sidewall 46a,b are fully recessed from the other portions of that sidewall 46a,b (such that opposing outer surfaces on the sidewall on each side of each cavity are preferably planar, or at least linear—though other shapes are possible). The insert body 42 further defines a generally planar rear wall 54. Other arrangements of insert cavities are possible. For example, one or more than two insert cavities may be provided on each sidewall, they may be formed with different sizes, they may be placed in offset positions from each other, they may have different shapes, etc. The insert cavities are preferably broad and extend along substantial portions of the insert sidewalls. In the illustrated embodiment, the insert cavities may define about 30-50% of the insert sidewalls rearward of the tapered front, though other percentages (higher or lower) are possible.

As described in more detail below, the insert cavities 50,52 provide additional surface area to braze or otherwise secure the insert 40 within the housing 12 of the wear member 10.

Referring again to FIGS. 1 to 3, the insert 40 is located within the passageway 14 of the housing 12 and a longitudinal clearance 60 is defined between the inner surfaces of the housing 12 (i.e. upper surface 20a, lower surface 20b, left side surface 22a and right side surface 22b) and the insert 40, prior to insertion of the brazing or other matrix material.

The insert rear wall 54 is in contact with, or close proximity to, the housing rear wall 18, and preferably positioned such that the insert 40 is substantially enclosed (for example, at least 80% enclosed, or at least 90% enclosed) within the passageway 12 and the insert cavities 50,52 are located transversely to the longitudinal axis 16 and are offset with respect to the nearest housing cavity 28 (best seen in FIG. 3). The insert 40 could forwardly project from the passageway 14.

The insert 40 is shown relatively centered within the passageway 14; however, in some embodiments the insert 40 may be offset (e.g. from the longitudinal axis 16) in the passageway 14.

The longitudinal clearance 60 allows the insert 40 to be inserted unobstructed by protrusions on the inner surfaces of the housing 12 (i.e. upper surface 20a, lower surface 20b, left side surface 22a and right side surface 22b). The longitudinal clearance 60 and the cavities 28, 50, 52 also provide space that will be filled with powder and/or brazing or other matrix material in a subsequent manufacturing step (described below).

The wear member 10 is preferably formed by sand casting, although other kinds of manufacture are possible (e.g., investment casting or forging). Spacers or cores (not shown) are preferably provided in the mold when casting the wear member 10 to support the rear end of the core forming the passageway 14. When the wear member 10 is cast, these spacers form one or more support apertures or support cavities 70 in the housing 12 through the upper and lower surfaces 20a,b, transverse to the longitudinal axis 16, and extend through an outer surface 72 of the housing 12. The support apertures 70 are sealed at the outer surface 72 by caps 74. The passageway entrance 26, longitudinal clearance 60 through passageway 14, housing cavities 28 and capped support apertures 70 define space for receiving a wear resistant powder (and/or other porous wear-resistant material) and/or a brazing or other matrix material. The caps 74 prevent escape of the received wear resistant powder and/or matrix material during insertion while it is being introduced around the insert 40.

The manufacturing process for the wear member 10 can be summarized as follows. A wear member housing 12 is first cast, e.g., in a sand-casting process. Patterns are used to define the exterior shape of the housing, and cores and/or spacers are used to form the passageway 14, housing cavities 28, and/or support cavities 70. Other cavities such as a mounting cavity (not shown) for receiving a base of the earth working equipment and lock-receiving cavity (not shown) are commonly also formed in a rear portion (not shown) of the wear member housing 12. Molten steel is then poured into the mold to form the cast wear member housing. Other details of the sand casting of such wear members (e.g., quenching, tempering, etc.) are well known and not discussed herein. The support apertures 70 are capped by caps 74 to create support cavities. These are to ensure that powder and/or matrix material does not leak out during the steps for securing the insert 40 in the passageway 14.

A shell funnel 80 (shown in broken line in FIGS. 2 and 3) made of sheet steel is welded to an end of the housing 12 near the passageway entrance 26. This shell funnel 80 is optionally used first to direct a wear-resistant powder or the like (e.g., tungsten carbide or other wear resistant material(s)) to fill the passageway 14 and support cavities 70. Other porous preforms of wear-resistant material could optionally be placed into support cavities 70 prior to capping. Alternatively, the wear-resistant powder and/or preforms could be omitted.

A matrix material is then placed in the funnel 80 and heated (e.g., in a furnace) to infiltrate the powder and/or preform and fill the passageway 14, housing cavities 28, insert cavities 50, 52 and support cavities 70. If powder and/or preforms are not used, the matrix material will still fill the passageway 14, housing cavities 28, insert cavities 50, 52 and support cavities 70. The matrix material is preferably a brazing material or other suitable metal (e.g., ductile iron) for securing the insert in place. The matrix material may comprise a different material (e.g., a resin) to secure the carbide and/or infiltrate the powder and/or preforms. If a resin or the like is used as the matrix material it would generally follow any desired heat treating of the steel. Heat treating may be similar to that used fora brazing material, depending on the temperatures needed for each.

Overlays 82 (e.g., hardfacing) can optionally then be attached to the housing outer surface 72 for additional wear protection near the front of the wear member 10.

One suitable infiltration process is, for example, described in U.S. Pat. No. 9,561,562, which is incorporated herein by reference in its entirety.

The result of the infiltration process in the preferred embodiment is that the matrix area (i.e. the passageway entrance 26, longitudinal clearance 60, housing cavities 28, insert cavities 50,52 and capped support apertures 70) is filled with the hardened material 90. In one embodiment, the brazing material comprises copper and the wear resistant material comprises cemented tungsten carbide powder (a composite of tungsten carbide and a binder metal, such as cobalt). The tungsten carbide powder may be placed in first, then the copper may be placed on the tungsten carbide powder, and the copper is melted and infiltrates into the carbide powder. However, other types of brazing material and wear resistant material may be used.

The matrix material 90 fills the longitudinal clearance 60 and extends transversely to the longitudinal axis into the housing cavities 28 and insert cavities 50,52 to provide an axially resistive force against axial movement of the insert relative to the housing 12 in addition to any bonding of the brazing material 90 to the insert 40 and the housing 12. In particular, the brazing material 90 metallurgically bonds with the inner surfaces 20,22 of the housing 12 and the outer surface of the insert 40 to provide a chemical seal against the dislodgement of the insert 40 from the housing 12. The filling of the housing, insert and support cavities 28, 50, 52, 70 with the matrix material 90 provides enhanced resistance and support to lessen the risk of insert loss during use.

As typical brazing materials usually form stronger bonds to the insert 40 than the housing 12 (which is typically formed of steel/ferrous alloys), the structure of the wear member 10 has been formed such that brazing material 90 in the housing cavities 28 and capped support apertures 70 provide further physical seals to mitigate risks of dislodgement of the insert 40 if the metallurgical bond between the brazing material 90 and the housing 12 is weakened in use.

In particular, the transverse position of the housing cavity 28 and the insert cavities 50,52 further provide a primary physical seal against the dislodgement of insert 40 in that the brazing material 90 must be structurally sheared in these locations to dislodge the insert 40. Moreover, the capped support apertures 70 provide a secondary physical seal in a similar manner—the brazing material 90 must also be sheared in these locations to dislodge the insert 40.

Accordingly, the arrangement of the insert cavities 50,52, the housing cavities 28, and the capped support apertures 70, once sealed with the brazing material 90, physically seal the insert 40 and provide for axial resistance against movements of the insert 40 relative to the housing 12.

The described wear member 10 may be mounted on a base and secured to the base with a lock to form a wear assembly. The shell funnel 80 is preferably cut and/or refolded to close the opening for use.

It will be appreciated that, while the wear member 10 has been illustrated to be wedge shaped, the wear member may also be manufactured in the form of other shapes. Moreover, the wear member 10 may provide advantageous effects when utilized in various wear-facing components, particularly in excavating equipment including a point (tip), an adaptor, an entire tooth, a shroud, a runner, and a bucket.

Throughout this specification and the claims which follow, the singular forms “a”, “an” and “the” include plural referents unless the context clearly dictates otherwise. Furthermore, unless the context clearly requires otherwise, throughout the description and the claims, the words “comprise”, “comprising”, and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in the sense of “including, but not limited to”.

Although the invention has been described with reference to specific embodiments, it will be appreciated by those skilled in the art that the invention may be embodied in many other forms. For example, it will be appreciated that many combinations, alterations, modifications, variations and substitutions will be apparent to those skilled in the art without departing from the scope of the present invention, and it is intended for this application to embrace all such combinations, alterations, modifications, variations and substitutions. Moreover, wherein specific articles are mentioned which have known equivalents in the art to which the invention relates, such known equivalents are deemed to be incorporated herein as if individually set forth.

In other embodiments, the insert cavities may have alternate shapes, e.g. polygonal, ovoid, etc. A greater of fewer number than two insert cavities may be provided on each insert sidewall. The cavities on a sidewall may have different shapes.

In other embodiments, the insert 40 may protrude from the passageway 14. For example, 25% or more of the insert body 42 may protrude beyond the passageway entrance 26.

The preceding description is provided in relation to several embodiments which may share common characteristics and features. It is to be understood that one or more features of any one embodiment, or any aspect described above, may be combined with one or more features of the other embodiments or other aspects of the invention. In addition, any single feature or combination of features in any of the embodiments or aspects of the invention may constitute additional embodiments.

List of Reference Numerals
wear member 10
housing 12
passageway 14
longitudinal axis 16
inner rear wall 18
upper surface 20a
lower surface 20b
left side surface 22a
right side surface 22b
protrusion 24a, b
passageway entrance 26
housing cavity 28a, b
insert 40
insert body 42
insert front edge 44
insert sidewalls 46a, b
front insert cavity 50a, b
rear insert cavity 52a, b
insert rear wall 54.
longitudinal clearance 60
support apertures 70
housing outer surface 72
caps 74
shell funnel 80
overlays 82
brazing material 90

Claims

1. A wear member comprising: a housing defining a passageway therethrough and having a longitudinal axis, the housing comprising a housing cavity formed therein, fully recessed from an inner surface of the housing, and opening into the passageway; an insert slidably located within the passageway and defining a longitudinal clearance between the inner surface of the housing and the insert, the insert comprising an insert cavity formed therein, fully recessed from an outer surface of the insert and opening into the passageway;brazing material filling the longitudinal clearance and extending transversely to the longitudinal axis into the housing cavity and insert cavity to provide an axially resistive force against axial movement of the insert relative to the housing in addition to any bonding of the brazing material to the insert and the housing.

2. A wear member according to claim 1, wherein the housing further comprises a support aperture defining an axis therethrough, where the support aperture axis is transverse to the insert cavity thereby providing additional longitudinal axially resistive force.

3. A wear member according to claim 2, wherein the support aperture extends from the inner surface of the housing to an outer surface of the housing, and is closed by a cap on the outer surface of the housing.

4. A wear member according to claim 1, wherein the housing cavity is spaced from a passageway entrance and an inner rear wall of the housing at an end of the passageway.

5. A wear member according to claim 4, wherein the insert is insertable into the inner rear wall unobstructed by protrusions into the passageway from either the housing or the insert.

6. A wear member according to claim 1, wherein the housing cavity is longitudinally offset from the insert cavity.

7. A wear member according to claim 1, comprising a plurality of insert cavities.

8. A wear member according to claim 7, wherein each insert cavity has an arcuate concave shape.

9. A wear member according to claim 1, comprising a plurality of housing cavities.

10. A wear member according to claim 9, wherein each housing cavity comprises a wedge shape, a narrow portion of the wedge being closer to a passageway entrance than a wider portion of the wedge.

11. A wear member according to claim 9, wherein each housing cavity comprises a wedge shape, a narrow portion of the wedge being further from the passageway entrance than a wider portion of the wedge.

12. A wear member according to claim 1, wherein the insert is located within, and substantially enclosed by, the passageway.

13. A wear member according to claim 1, wherein the insert protrudes from the passageway.

14. A wear member according to claim 13, wherein the insert comprises an insert body, and no more than 25% of the insert body protrudes beyond a passageway entrance.

15. A wear assembly comprising: (i) a wear member according to claim 1,(ii) a base on which the wear member is mounted, and(iii) a lock securing the wear member to the base.

16. A wear member comprising a housing defining a passageway therethrough and having a longitudinal axis, the housing comprising a housing cavity formed therein, fully recessed from an inner surface of the housing, and opening into the passageway; an insert slidably located and substantially enclosed within the passageway and defining a longitudinal clearance between the inner surface of the housing and the insert, the insert comprising an insert cavity formed therein, fully recessed from an outer surface of the insert and opening into the passageway; the insert and housing being configured such that there is no projection from the insert into the housing cavity, and no projection from the housing into the insert cavity.

17. An excavating equipment component comprising the wear member according to claim 1.

18. An excavating equipment component according to claim 17, wherein the excavating equipment component is selected from a group consisting of: a point; an adapter; a shroud; a runner; and a bucket.