The present disclosure relates to heel shrouds that are used to protect the work implements such as the buckets of heavy equipment such as hydraulic mining shovels, and the like. Specifically, the present disclosure relates to such heel shrouds that may have stress concentration reduction geometry and/or enhanced durability features.
In various mining applications, the curved shell of a bucket or other work implement used by heavy equipment such as hydraulic mining shovels, and the like are subjected to heavy loads and/or abrasive environments. Accordingly, heel shrouds may be provided that are intended to extend the life of the bucket. However, the amount of material needed to create such heel shrouds may increase the cost and may necessitate sections that act as stress risers or the like. This may lead to unwanted maintenance of the heel shroud or its work implement early on its useful life at a higher cost than desired.
U.S. Pat. No. 10,562,257 B2 (the '257 patent) discloses a track slider used on heavy equipment such as electric roper shovels or the like. The slider includes an elongated base portion that is coupled to a frame, and a sliding portion extending from the elongated base portion. The sliding portion includes an outer surface that is configured to slidably engage with a track link of the track assembly. The sliding portion includes a set of wear indicators that are defined in the outer surface. The set of wear indicators includes a first wear indicator, and a second wear indicator. The first and the second wear indicators are located at a first predefined thickness, and a second predefined thickness respectively, measured along a central axis of the sliding portion. Further, the first wear indicator indicates partial wear of the sliding portion, and the second wear indicator indicates substantial wear of the sliding portion. However, the '257 patent is silent about possible stress reduction geometry for heel shrouds.
On the other hand, U.S. Pat. No. 4,052,802 A (the '802 patent) discloses ground engaging tools with a plurality of wear-resistant inserts. According to the '802 patent, the wear-resistant inserts are secured in between ribs which minimize the spalling of the inserts in use. However, the '802 patent is silent how to add durability to the heel shrouds having a right angled configuration for protecting the curved shell of a bucket or the like.
Accordingly, heel shrouds that may have features for increasing their useful life are still needed.
A heel shroud according to an embodiment of the present disclosure may include a bottom leg, and a side leg extending orthogonally from the bottom leg, forming an interior corner with the bottom leg. The heel shroud may define a first lateral surface, a second lateral surface, and the bottom leg may include a curved interior surface extending from the first lateral surface to the second lateral surface, at least partially forming the interior corner. The first lateral surface may define a first wear indicator or a stress reduction geometry that is disposed at the interior corner.
A heel shroud according to another embodiment of the present disclosure may comprise a bottom leg, and a side leg extending orthogonally from the bottom leg, forming an interior corner with the bottom leg. The heel shroud may define a first lateral surface, a second lateral surface, and the bottom leg may include a curved interior surface extending from the first lateral surface to the second lateral surface at least partially forming the interior corner, and the first lateral surface defines a first wear indicator that is disposed at the interior corner.
A heel shroud according to yet another embodiment of the present disclosure may comprise a bottom leg, and a side leg extending orthogonally from the bottom leg, forming an interior corner with the bottom leg. The heel shroud may define a first lateral surface, a second lateral surface, and the bottom leg may include a curved interior surface extending from the first lateral surface to the second lateral surface, at least partially forming the interior corner. The first lateral surface may define a stress concentration reducing geometry at the interior corner including a concave arcuate surface.
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate several embodiments of the disclosure and together with the description, serve to explain the principles of the disclosure. In the drawings:
Reference will now be made in detail to embodiments of the disclosure, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. In some cases, a reference number will be indicated in this specification and the drawings will show the reference number followed by a letter for example, 100a, 100b etc. It is to be understood that the use of letters immediately after a reference number indicates that these features are similarly shaped and have similar function as is often the case when geometry is mirrored about a plane of symmetry. For ease of explanation in this specification, letters will often not be included herein but may be shown in the drawings to indicate duplications of features discussed within this written specification.
While the arrangement is illustrated in connection with a hydraulic mining shovel, the arrangement disclosed herein has universal applicability in various other types of machines commonly employ track systems, as opposed to wheels. The term “machine” may refer to any machine that performs some type of operation associated with an industry such as mining, earthmoving, or construction, or any other industry known in the art. For example, the machine may be an excavator, wheel loader, cable shovel, or dragline or the like. Moreover, one or more implements may be connected to the machine. Such implements may be utilized for a variety of tasks, including, for example, lifting and loading. Among other uses, a hydraulic mining shovel can be used to load overburden and ore into haul trucks during the mining process in various surface mine applications.
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The body 104 may be supported on a main frame 112 supported on an undercarriage structure 114. The undercarriage structure 114 includes a supporting structure 118 that supports a track system 102 utilized for movement of the machine 100. The track system 102 may include first and second track roller frame assemblies 116, which are spaced from and adjacent respective first and second sides of the undercarriage structure 114. It will be appreciated that only one of the track roller frame assemblies 116 is visible in
Each of the track roller frame assemblies 116 carries an idler wheel 120, a drive sprocket wheel 122, and a plurality of track guiding rollers 124. The drive sprocket wheel 122 is powered in forward and reverse directions by the machine 100 (via a motor such as an internal combustion engine). An endless track chain assembly 126 encircles each drive sprocket wheel 122, the idler wheel 120, and the track guiding rollers 124. The track chain assembly 126 includes a plurality of interconnected track pads 128. The track guiding rollers 124 guide the track pads 128 as the track chain assembly 126 is driven by the drive sprocket wheel 122.
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The first wear indicator 214 defines a top angled wall 224 (so called since it extends neither purely horizontally or vertically oriented), a bottom angled wall 226 that is parallel to the top angled wall 226, and a gap distance 228 measured perpendicularly to the top angled wall 224, and the bottom angled wall 226.
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These various curved or arcuate surfaces may help reduce stress concentrations, helping to prolong the useful life of the heel shroud. As will be discussed later herein, the inventor(s) has performed FEA (finite element analysis) showing that this geometry will reduce the stress concentration of the heel shroud in use.
A heel shroud 300 that may have some stress reduction geometry 216 and/or a wear member 400, 500, 600 that is attached to the side leg 304, and/or a wear member 400, 500, 600 that is attached to the bottom leg 302 will now be discussed with reference to
Geometrically speaking, the bottom leg 302 includes a curved interior surface 312 extending from the first lateral surface 308 to the second lateral surface 310 at least partially forming the interior corner 306, and a flat bottom surface 314 that defines a lower wear member receiving pocket 316. Likewise, the side leg 304 may define an exterior planar surface 318 that defines a side wear member receiving pocket 320. As shown, the lower wear member receiving pocket 316, and the side wear member receiving pocket 320 are contiguous, forming a L-shaped cavity 322. They may be separated by a rib or other structure in other embodiments of the present disclosure.
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Also, the side leg 304 may include a tapered portion 364 (i.e., tapers toward the interior surface of the side leg) including an exterior top cavity 366 that is disposed vertically above the side wear member receiving pocket 320, being separated from the side wear member receiving pocket 320 by a laterally extending rib 368. One more of these features may be omitted in other embodiments of the present disclosure.
A laterally extending wear member 400 may be disposed in the side wear member receiving pocket 320. As shown, this wear member 400 may take the form of a chocky bar 400a with four sections 402 that are separated by V-notches 404 to add in the removal of sections to adjust the length of the chocky bar.
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In addition, a pair of transversely extending wear members 500 may be disposed in the lower wear member receiving pocket 316. Similar mounting techniques are used including providing a pair of mounting plates 374 that are interposed between the bottom leg 302, and the pair of transversely extending wear members 500. In this instance, the pair of transversely extending wear members 500 are also chocky bars 500a with seven sections 502, etc. A lifting hook 376 may be disposed laterally between the pair of transversely extending wear members 500. The hook may be located in other positions such as at the top of the side leg in other embodiments of the present disclosure. Another wear member 600 in the form of a wear button 600a is also employed, being disposed laterally between the pair of transversely extending wear members 500. This may not be the case in other embodiments of the present disclosure.
Another embodiment of the heel shroud 300 may be described as follows referring to
For example, the first wear member may be one of chocky bar 500a or a wear button 600a, and the second wear member may be the other of a chocky bar 400a or a wear button. As depicted in
The heel shroud may be a unitary body as shown or be an assembly of different parts including wear members, mounting plates, etc. Often, the heel shroud consists essentially of a metallic material such as cast iron, steel, grey cast iron, etc.
Any of the aforementioned features and their associated dimensions may be altered to be different than what has been shown or mentioned herein in other embodiments of the present disclosure.
In practice, a work implement, a bucket, and a heel or a portion thereof may be sold, manufactured, bought etc. and attached to the machine in the aftermarket or original equipment scenarios according to any of the embodiments discussed herein. That is to say, the machine may be sold with the work implement, or bucket, and/or heel shroud and/or portion thereof according to embodiments described herein or the machine may be retrofitted, repaired, refurbished to use any of the embodiments discussed herein. The various components including, but not limited to the heel shrouds, may be fabricated from any suitable material such as cast iron, grey cast iron, steel, etc.
The inventors have performed design iterations placing the wear indicator/stress reduction geometry at various locations of the heel shroud. For example, the wear indicator/stress reduction geometry (e.g., see cavity 702 of heel shroud 700 in
In various embodiments, a heel shroud is designed with external wear indicators which are present on both left and right sides of the shroud. By placing the indicator's features on the left and right side of the external shroud geometry, the stress concentrations originally created by the internal indicator features have been removed (as shown through virtual heat treatment analysis). This solution provides guidance on when the shroud should be replaced by having visible wear indicators on both sides of the shroud and allows for estimating life left by having the indicators visible throughout the life of the shroud.
In other embodiments, wear protection of Laminated Wear Products (LWP) welds on heel shroud is provided. In general, a heel shroud is designed with designated locations to attach LWP and a protective feature in the form of ribs that surrounds the welds used to attach the LWP. This feature was designed to protrude out above the height of the welds used in this application to protect them from abrasive material and prolong the life of the LWP. This feature also acts as a designator for key locations to add LWP, which will maximize the life of the heel shroud. This feature also allows for the heel shroud to be used without LWP if needed. It can also protect overlays of different types, including Abrasion Resistant Material (ARM) and Plasma Transferred Arc (PTA) welding.
It will be apparent to those skilled in the art that various modifications and variations can be made to the embodiments of the apparatus and methods of assembly as discussed herein without departing from the scope or spirit of the invention(s). Other embodiments of this disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the various embodiments disclosed herein. For example, some of the equipment may be constructed and function differently than what has been described herein and certain steps of any method may be omitted, performed in an order that is different than what has been specifically mentioned or in some cases performed simultaneously or in sub-steps. Furthermore, variations or modifications to certain aspects or features of various embodiments may be made to create further embodiments and features and aspects of various embodiments may be added to or substituted for other features or aspects of other embodiments in order to provide still further embodiments.
Accordingly, it is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention(s) being indicated by the following claims and their equivalents.