Patent Application
20220227436
The present disclosure relates to track pads that are used to support heavy equipment such as hydraulic mining shovels, and the like. Specifically, the present disclosure relates to such track pads that allow debris or other contaminants to migrate away from seals used in a pinned joint that joins a pair of such track pads.
In various mining applications, the track pad is subject to heavy loads, requiring that the track pad be robust. Also, dirt, rocks, debris, and other contaminants may infiltrate various components of a track chain using such track pads. More specifically, the track chain using such track pads may have a pinned joint with seals for preventing the unwanted loss of lubrication. Contaminants may infiltrate these seals, which can eventually damage the seal or otherwise interfere with the seal's function, allowing lubrication to leak out of the joint. Eventually, the lack of lubrication may cause galling, seizing, or other mechanical problems with the track chain, necessitating maintenance of the track chain and downtime for the machine. This is unwanted since it adversely affects the profitability of an economic endeavor using the machine.
Chinese patent no. CN2702902Y discloses a track driven machine including a track chain with two chain links that form a pinned joint. More particularly, a pin and a bushing with a seal are provided. The bushing has chamfers on its outer circumferential surface at the axial ends of the bushing. Similar chamfers are provided on the interior circumferential surface at the axial ends of the bushing. The inner chamfers extend further axially than the outer chamfers. The purpose of these chamfers is to ease assembly of the pinned joint, provide for a long service life, and reduce the amount of noise created by the pinned joint as the track chain moves.
However, this prior art fails to disclose a track pad or a track chain that helps reduce the likelihood of contaminants infiltrating a seal assembly of the pinned joints of the track chain, etc.
A track pad according to an embodiment of the present disclosure may comprise a shoe member including a ground engaging surface, and defining a track chain traveling direction, a lateral direction perpendicular to the track chain traveling direction, and a vertical direction perpendicular to both the lateral direction, and the track chain traveling direction. The shoe member may further define a first lateral end, a second lateral end, a front end along the track chain traveling direction, and a rear end along the track chain traveling direction, a lateral distance from the first lateral end to the second lateral end, and a width from the front end to the rear end along the track chain traveling direction that is less than the lateral distance. A first link member may extend upwardly from the shoe member including a first lug member extending from the first link member in a first direction parallel to the track chain traveling direction, as well as a second lug member and a third lug member both extending from the first link member in a second direction opposite of the first direction, forming a first fork portion including a first lateral outside surface, a second lateral outside surface, a first lateral outside surface, a second lateral outside surface, a first lateral inside surface, and a second lateral inside surface. The second lug member defines a first aperture that extends laterally through the first lateral outside surface and the first lateral inside surface, forming a first intersection with the first lateral inside surface that includes a first blend extending from the first lateral inside surface to the first aperture.
A track pad according to another embodiment of the present disclosure may comprise a shoe member including a ground engaging surface, and defining a track chain traveling direction, a lateral direction perpendicular to the track chain traveling direction, and a vertical direction perpendicular to both the lateral direction, and the track chain traveling direction. The shoe member may further define a first lateral end, a second lateral end, a front end along the track chain traveling direction, and a rear end along the track chain traveling direction, a lateral distance from the first lateral end to the second lateral end, and a length from the front end to the rear end along the track chain traveling direction that is less than the lateral distance. A first link member may extend upwardly from the shoe member including a first top rail surface (e.g., may be planar), a first lug member extending from the first link member in a first direction parallel to the track chain traveling direction, and a second lug member and a third lug member both extending from the first link member in a second direction opposite of the first direction. The second and the third lug members may define a first pair of chamfered surfaces that are laterally opposite of each other and facing each other.
A track chain assembly according to an embodiment of the present disclosure may comprise a first track pad including a first pair of lugs defining a gap therebetween, and a second track pad including an intermediate lug disposed in the gap. The first pair of lugs and the intermediate lug each may define a concentric bore, defining an axis of rotation for a pinned joint of the track chain assembly, and the concentric bore of one of the first pair of lugs is in communication with the gap with a first blend disposed axially between the gap and the concentric bore of one of the first pair of lugs.
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.
Looking at
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 200, also referred to as track chain members. The track guiding rollers 124 guide the track pads 200 as the track chain assembly 126 is driven by the drive sprocket wheel 122.
The track chain assembly 126 according to an embodiment of the present disclosure may be further characterized as follows with reference to
As used herein, a “blend” means any transitional surface that connects two adjacent surfaces and may include an arcuate surface (e.g., a radius, an ellipse, a polynomial spline, etc.), or a chamfer (e.g., a conical face), etc.
Similarly, the concentric bore 206a of the other of the first pair of lugs may also be in communication with the gap 236 with a second blend 238a disposed axially between the gap 236, and the concentric bore 206a of the other of the first pair of lugs.
More specifically, the first blend 238 may take the form of a first interior chamfer 240 (so called since it faces laterally toward the gap 236), and the second blend 238a may take the form of a second interior chamfer 240a. This may not be the case for other embodiments of the present disclosure.
Each of the concentric bore 206, 206a, 206b may define the same diameter D206 (i.e., within 0.005 of an inch of each other), but not necessarily so. When true, and the track chain assembly 126 may further comprise a cartridge pin assembly 128 that is disposed in each concentric bore 206, 206a, 206b to help provide the pivoting function of the pinned joint 138.
To that end, the cartridge pin assembly 128 may include a bushing 140 defining a first bushing chamfer 142 at one of its lateral ends, and a second bushing chamfer 142a at the other of its lateral ends that are in communication with the gap 236. The first bushing chamfer 142 may be parallel to the first interior chamfer 240, and the second bushing chamfer 142a may be parallel to the second interior chamfer 240. In such a case, these chamfers by be symmetrical to each other about a midplane disposed laterally between them. This may not be the case for other embodiments of the present disclosure.
In other embodiments as shown in
More particularly, the first bushing chamfer 142 may be spaced away from the first interior chamfer 140 a minimum distance 144 (see
Focusing on
Looking at
As best seen in
Other components of the cartridge pin assembly 128 include a pin 152 or shaft, a first end collar 154 attached to the pin, a second end collar 156 attached to the pin, a first bearing 158 disposed radially and axially between the bushing 140, the pin 152 and the first end collar 154, and a second bearing 158a disposed radially and axially between the bushing 140, the pin 152, and the second end collar 156.
The bearings may help prevent the seal assembly 150 from being crushed by axial loads (so they may also be referred to as thrust bearings) while the bushing provides lubrication voids 160 to ease the rotation of the bushing, and therefore one track pad 200 relative to the pin and the end collars, and the other track pad 200a.
Details of various embodiments of the track pad that may be used to construct and/or repair, etc. the track chain assembly will now be discussed in detail with reference to
Such a track pad 200 may comprise a shoe member 208 including a ground engaging surface 204, and defining a track chain traveling direction 210, a lateral direction 212 that is perpendicular to the track chain traveling direction 210, and a vertical direction 214 that is perpendicular to both the lateral direction 212, and the track chain traveling direction 210. The shoe member 208 further defines a first lateral end 216, a second lateral end 218, a front end 220 along the track chain traveling direction 210, and a rear end 222 along the track chain traveling direction 210. A lateral distance 224 may be measured from the first lateral end 216 to the second lateral end 218 (see
Looking at
Referring now to
The third lug member 234 may define a third aperture (e.g., see 206b) that extends from the second lateral inside surface 252 toward the second lateral outside surface 248, forming a second intersection with the second lateral inside surface 252 including a second blend (e.g., see 238a) extending from the second lateral inside surface 252 to the third aperture.
As alluded to earlier herein, the first blend, and the second blend may take the form of a plurality of chamfers (e.g., see 240, 240a). At least one of the plurality of chamfers may define an acute angle 256 with the lateral direction 212 that ranges from 30.0 degrees to 60.0 degrees (e.g., may be 45.0 degrees, see
Also, the first aperture defines a first diameter (e.g., see D206 in
Looking at
A track pad 200 according to another embodiment of the present disclosure may also be described as follows looking at
The second and the third lug members 232, 234 may define a first pair of chamfered surfaces (e.g., see 240, 240a) that are laterally opposite of each other and facing each other.
In addition, each of the first pair and the second pair of chamfered surfaces may form an acute angle 256 with the lateral direction 212 as mentioned earlier herein that ranges from 30.0 degrees to 60.0 degrees.
In such a case, at least one of the plurality of bores defines a first diameter (e.g., D206), and at least one of the first pair of chamfered surfaces defines a first radial chamfer distance 264. A ratio of the first diameter to the first radial chamfer distance may range from 15.0 to 30.0 (e.g., 18.0 to 22.0) in some embodiments of the present disclosure. When present, the first radial chamfer distance 264 may range from 3.0 mm to 7.0 mm (e.g., 5.0 mm).
The track pad may be a unitary body as shown or be an assembly of different parts. Often, the shoe member and the first rail member, and the second rail member consist essentially of metallic material such as cast iron, steel, grey cast iron, etc.
Any of the aforementioned features and their associated dimensions and/or ratios may be altered to be different than what has been shown or mentioned herein in other embodiments of the present disclosure.
In practice, a track chain assembly, a track pad 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 track chain assembly, track pad 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 track pads, may be used from any suitable material such as cast iron, grey cast iron, steel, etc.
As can be seen, various embodiments of the track pad disclosed herein may provide reduce the likelihood of fouling of a seal assembly and/or a cartridge pin assembly by contaminants by providing a debris path for the egress of such contaminants away from the seal assembly. This may prolong the useful life of a track chain assembly using such track pads before maintenance is necessary, increasing the profit of an economic endeavor using the track pad(s).
As used herein, the articles “a” and “an” are intended to include one or more items, and may be used interchangeably with “one or more.” Where only one item is intended, the term “one” or similar language is used. Also, as used herein, the terms “has”, “have”, “having”, “with” or the like are intended to be open-ended terms. Further, the phrase “based on” is intended to mean “based, at least in part, on” unless explicitly stated otherwise.
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.
