Patent Publication Number: US-2022219770-A1

Title: Guide rail for crawler track

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of co-pending U.S. Provisional Patent Application No. 63/137,059, filed Jan. 13, 2021, the entire content of which is incorporated herein by reference. 
    
    
     FIELD 
     The present disclosure relates to industrial machines and, more particularly, to a guide rail for a crawler of a mining machine. 
     Conventional earth-moving machines, such as mining shovels and excavators, include crawler mechanisms for moving the machine over the ground. The crawler mechanism includes an articulated track composed of multiple links or shoes coupled together to form a continuous loop. The shoes engage the ground and engage a row of rollers along a roller path as the track is driven. The weight of the machine and any loads supported by the machine are transmitted through the rollers to the shoes, thereby causing the shoes to wear down and/or deform over time. 
     SUMMARY 
     In one independent aspect, replaceable guide rail for a crawler including a frame and a track drivable around the frame includes a base elongated along a centerline, the base configured to be removably coupled to the frame; a wearable portion supported by the base and having an outer surface configured to be in contact with the track, the wearable portion having a first thickness at an initial stage of operation and a second thickness at a second stage of operation, the second thickness being less than the first thickness; and a wear indicator positioned in the wearable portion, the wear indicator being covered while the wearable portion has the first thickness, the wear indicator being exposed while the wearable portion has the second thickness. 
     In another independent aspect, a crawler assembly for an earthmoving machine includes a plurality of shoes coupled together to form a continuous track, the track being configured to be driven around a perimeter of a crawler frame; a replaceable guide rail configured to be removably coupled to the frame, the guide rail including a surface contacting the shoes as the track is driven around the perimeter of the frame, the surface including a material that wears away as the shoes contact the surface; and a wear indicator positioned on a portion of the guide rail, the wear indicator being exposed through the outer surface of the guide rail as the shoes contact the guide rail 
     In another independent aspect, a replaceable guide rail for a crawler of an earthmoving machine includes a base elongated along a centerline, the base including a flange; a hole extending laterally through the flange, the hole being configured to receive a fastener to secure a portion of the crawler to the flange; a guide member extending along the centerline and being configured to contact a track portion of the crawler and be worn down during movement of the track portion over the guide member, the guide member having a thickness that is reduced as the guide member is worn down; and a wear indicator positioned in the guide member configured to indicate whether the guide rail is in condition for replacement, the wear indicator being covered while the thickness is in a first range of thickness, and the wear indicator being exposed while the thickness is in a second range of thickness. 
     Other independent aspects will become apparent by consideration of the detailed description and accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a mining shovel. 
         FIG. 2  is a perspective view of a crawler. 
         FIG. 3  is a side view of a portion of the crawler of  FIG. 2 . 
         FIG. 4  is a perspective view of a shoe. 
         FIG. 5  is a perspective view of a portion of a track frame including a guide rail assembly. 
         FIG. 6  is a perspective view of a guide rail. 
         FIG. 7  is a section view of the guide rail of  FIG. 6  viewed along section  7 - 7 . 
         FIG. 8  is a section view of the guide rail of  FIG. 6  viewed along section  8 - 8 . 
         FIG. 9A  is another perspective view of the guide rail of  FIG. 6 , illustrating an initial condition of the guide rail with a plurality of openings not exposed. 
         FIG. 9B  is a section view of the guide rail of  FIG. 9B  viewed along section  9 B- 9 B. 
         FIG. 10A  is a perspective view of the guide rail of  FIG. 6 , illustrating a final condition of the guide rail with a plurality of openings exposed. 
         FIG. 10B  is a section view of the guide rail of  FIG. 10A  viewed along section  10 B  10 B. 
         FIG. 11  is a perspective view of a guide rail according to another embodiment. 
         FIG. 12  is a perspective view of a guide rail according to another embodiment. 
         FIG. 13  is a perspective view of a guide rail according to another embodiment. 
         FIG. 14  is a perspective view of a guide rail according to another embodiment. 
         FIG. 15  is a section view of a guide rail according to another embodiment. 
         FIG. 16  is a section view of a guide rail according to another embodiment. 
         FIG. 17  is a perspective view of a guide rail according to another embodiment. 
         FIG. 18  is a section view of the guide rail of  FIG. 17  viewed along section  18 - 18 . 
         FIG. 19  is a perspective view of a guide rail according to another embodiment. 
         FIG. 20  is a section view of the guide rail of  FIG. 19  viewed along section  20 - 20 . 
     
    
    
     Before any independent embodiments are explained in detail, it is to be understood that the disclosure is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The disclosure is capable of other independent embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. Use of “including” and “comprising” and variations thereof as used herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Use of “consisting of” and variations thereof as used herein is meant to encompass only the items listed thereafter and equivalents thereof. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings. 
     DETAILED DESCRIPTION 
       FIG. 1  illustrates an earthmoving machine, such as a mining shovel  10 , including a frame  14  supporting a boom  26 , an elongated member or stick or handle  30 , and an attachment or dipper  34  coupled to the handle  30 . The frame  14  includes an upper portion  16  that is supported by an undercarriage  18  having crawlers  22 . The upper portion  16  supports a hoist drum (not shown) for reeling in and paying out a cable or hoist rope  42 . The boom  26  includes a first end  46  coupled to the upper portion  16  of the frame  14  and a second end  50  opposite the first end  46 , and a boom sheave  54  is coupled to the second end  50  of the boom  26  and guides the rope  42  over the second end  50 . In the illustrated embodiment, the shovel includes a saddle block  58  rotatably coupled to the boom  26  by a shipper shaft  62 , which is positioned between the first end  46  and the second end  50  of the boom  26 . The shipper shaft  62  extends through the boom  26  in a direction that is transverse to a longitudinal axis of the boom  26 . The hoist rope  42  is coupled to the dipper  34  by a bail  66 , and the dipper  34  is raised or lowered as the hoist rope  42  is reeled in or paid out, respectively, by the hoist drum. 
     The handle  30  includes a first end  82  and a second end  86 . In the illustrated embodiment, the second end  86  is movably received in the saddle block  58 , and the handle  30  passes through the saddle block  58  such that the handle  30  is capable of rotational and translational movement relative to the boom  26 . The saddle block  58  is rotatable relative to the boom  26  about the shipper shaft  62 , and the handle  30  rotates relative to the boom  26  while the handle  30  remains in the saddle block  58 . 
     As shown in  FIGS. 2 and 3 , each crawler  22  includes a track frame  90  and a track  92  including links or shoes  94  coupled together to form an articulated, continuous loop. The track frame  90  includes a first end  98 , a second end  102 , a first or lower portion  106 , and a second or upper portion  110 . In the illustrated embodiment, a driving member  114 , such as a first sprocket  114  ( FIG. 2 ), is supported for rotation at the first end  98 , and a second driving member  118  (e.g., second sprocket  118 ;  FIG. 3 ) is supported for rotation at the second end  102  of the frame  90 . At least one of the sprockets  114 ,  118  may be driven by a motor (not shown). The sprockets  114 ,  118  engage the crawler shoes  94  (e.g., by teeth extending into spaces between the shoes  94 ), thereby driving the shoes  94  around the perimeter of the track frame  90  in a continuous loop. The track  92  defines a first or lower run proximate the ground and a second or upper run extending along the upper portion  110  of the frame  90 . As the shoes  94  move along the lower run, the shoes  94  engage the ground to move the machine  10  with respect to the ground. 
     As shown in  FIG. 3 , rollers  126  are rotatably coupled to the lower side  106  of the frame  90 . In the illustrated embodiment, the rollers  126  are aligned with one another such that all of the rollers  126  rotate in a common plane. Stated another way, the rollers  126  are aligned along a direction of travel of the shoes  94 . As shown in  FIG. 4 , each shoe  94  includes a first end  130 , a second end  134 , and an intermediate portion  138  positioned between the first end  130  and the second end  134 . The shoes  94  are driven in a direction that is generally perpendicular to a line drawn between the first end  130  and the second end  134 . The intermediate portion  138  includes a wear surface or roller path area  142 . In the illustrated embodiment, the shoes  94  include sprocket engagement portions engaging the sprockets  114 ,  118 , which drive the shoes  94  around the frame  90 . 
       FIG. 5  illustrates a guide rail assembly  150  extending along an upper portion  110  of the track frame  90 . In the illustrated embodiment, the guide rail assembly  150  includes multiple rails  154  (e.g., four rails), each having an elongated shape and aligned parallel to the direction of travel of the shoes  94 . Stated another way, the rails  154  are aligned in an end-to-end configuration such that all of the rails  154  extend along a common plane. Each rail  154  is independently coupled to the upper portion  110  of the track frame  90  (e.g., by a bolted connection), and each rail  154  can be removed and replaced without requiring disassembly of any adjacent rails  154 . In other embodiments, the track frame  90  may include fewer or more rails, the rails may be oriented in a different manner, and/or the rails may be coupled to the track frame  90  in a different manner. 
     As the shoes  94  are driven around the track frame  90 , the wear surface  142  of the shoe  94  moves along the guide rail  154  while in a vicinity of the upper portion  110  of the track frame  90  and contacts the rollers  126  in a vicinity of the lower side  106 . Each time the wear surface  142  of the shoe  94  contacts the guide rail  154 , a portion of the guide rail  154  wears at least slightly. 
     Referring now to  FIGS. 6-10B , each guide rail  154  includes a base  162  for coupling to the frame  90  ( FIG. 4 ), and a guide member  164 . The guide member  164  includes an outer surface  166  for engaging the shoes  94  as they move around the frame  90 , and the guide member  164  extends along a centerline  170  ( FIGS. 9A-10B ). In the illustrated embodiment, the base  162  includes a pair of flanges  174  oriented parallel to one another and parallel to the centerline  170 , and a central portion or web  178  extends between the flanges  174 . Openings or holes  182  extend laterally through the flanges  174 , and are configured to receive a fastener (e.g., a bolt) to secure a portion of the track frame  90  between the flanges  174 . In other embodiments, the base may be constructed in a different manner. 
     The guide member  164  includes a first end  186  and a second end  190  opposite the first end  186 , and the centerline  170  extends between the first end  186  and the second end  190 . Side portions or wings  194  extend between the first end  186  and the second end  190  and are positioned laterally outward from the centerline  170 . In the illustrated embodiment, the ends  186 ,  190  of the guide member  164  are angled toward the frame  90 . 
     The guide member  164  also includes a wear indicator portion  198 . As best shown in  FIG. 9B , the wear indicator portion  198  may include a portion having a thickness that is less than a thickness of the adjacent portion of the guide member  164 . In the illustrated embodiment, the wear indicator portion  198  includes a recess formed on a lower surface of the guide member  164 , opposite the outer surface  166 . The wear indicator portion  198  is positioned on the wing  194 , between a lateral edge of the guide member  164  and the associated flange  174 , and between the ends  186 ,  190  and the central portion of the base  162 . 
     As shown in  FIGS. 9A and 9B , the guide member  164  has an initial wearable thickness T. In the illustrated embodiment, the outer surface  166  has an initial condition in which the outer surface  166  has an initial radius of curvature R 1  with and initial arclength. In the illustrated embodiment, the initial arclength can be defined by an amount of material that forms the outer surface  166 . As the guide member  164  wears, the thickness is reduced from the initial thickness T, and the outer surface  166  approaches a final condition in which the outer surface  166  has a radius that is different from the initial radius R 1 . Once the thickness of the guide member  164  wears to a predetermined level, as defined below, the outer surface  166  has a final arclength and a final radius of curvature R 2 . In the illustrated embodiment, the final arclength is less than the initial arclength or substantially similar to the initial arclength. The initial radius R 1  and the final radius R 2  may be substantially similar when measured from offset center points (e.g., offset by an amount the thickness T wears). In the illustrated embodiment, outer surface  166  has an arched profile at an initial stage, and has a flatter (e.g., less arched) profile at a later stage as the thickness T is reduced. 
     For example, as the shoes  94  are driven around the track frame  90  against the outer surface  166  of the guide member  164 , the material thickness is reduced from the initial thickness T and the radius is increased from the initial radius R 1  (e.g., due to a curved overall cross-section of the guide member  164 ). In some embodiments, the outer surface  166  may have little to no curvature such that the initial arclength and final arclength remain substantially similar as the initial thickness T is decreased; in other embodiments, the final arclength may be less than the initial arclength. 
     When the outer surface  166  has worn to a predetermined level, such as an end-of-life or alert level, one or more of the wear indicator portions  198  will create a visible opening or window  196  ( FIGS. 10A and 10B ) extending through the guide member  164 . In the illustrated embodiment, the window  196  is elongated. A lip  195  may be formed on the guide member  164  and positioned between the wear indicator portion  198  and an outer surface of the wing  194 . In some instances along the centerline  170 , the lip  195  may be situated between a portion of the window  196  and the outer surface of the wing  194 . 
       FIGS. 10A and 10B  illustrate a guide member  164  that has worn beyond the predetermined level (e.g., to an end-of-life level) to expose the elongated window  196  in each of the wear indicator portions  198 . In the illustrated embodiment of  FIGS. 10A and 10B , the guide member includes four discrete windows  196  generally positioned in four corners of the guide member  164  and/or in four separated regions, such as four indicator portions  198 . As illustrated in  FIG. 9B , the initial thickness T is defined from the outer surface  166  to the window  196 . Thus, the window  196  may have a material thickness of zero such that the window  196  can be an opening, void, and/or the like. However, to maintain some strength in the guide member  164 , the lip  195  may be present, and the lip  195  may have thickness. 
     In practice, less than all of the windows  196  may become exposed at one time. While  FIGS. 10A and 10B  illustrate a guide member  164  that has worn evenly (e.g., uniformly, with equal amounts of reduction in thickness or arclength, etc.) to expose each window  196  by a similar amount, the guide member  164  could experience wear in different regions and by different amounts such that non-uniform wear occurs. For example, the guide member  164  could wear by a greater amount at the first end  186  than at the second end  190 , thereby exposing the window or windows  196  adjacent the first end  186  before exposing the window or windows  196  adjacent the second end  190 . The presence of one or more windows  196  provides a clear and effective visual indicator that a guide rail  154  (or at least a guide member  164 ) needs replacement. The wear indicators  198  may also permit inspection of the guide member  164  while the crawler is assembled to the machine (i.e., without requiring significant disassembly). 
     As stated above, the guide members  164  wear over time as the shoes  94  ( FIG. 4 ) contact the outer surface  166 . A user may inspect the track  92  ( FIG. 2 ) for the presence of windows  196  visible beneath the shoes  94 . In one instance, a user could shine a light on the track  92  from above or below the shoes  94 . If light can be seen by the user, for example, shining through a window  196  in one of the guide members  164  or on an opposing side or edge of the shoe  94 , then the presence of such light can indicate to the user that at least one of the guide member  164  and the shoe  94  needs replacing and/or maintenance. In one specific example, a user standing next to the crawler below the guide member  164  could look upwardly toward the bottom of the guide rail  154 . If light (e.g., daylight) is visible through the guide rail  154  as the shoves  94  pass over the guide rail  154 , the guide rail  154  may require replacement. 
     In other embodiments ( FIGS. 11-20 ), the wear indicator portions  198  can be formed in a different manner. The guide members  164  and features thereof described in  FIGS. 11-20  are identified with like reference numbers. The wear indicator portions or “wear indicators” are identified with similar reference numbers as wear indicator portions  198  of  FIGS. 1-10 , plus  100 . It should be stated that, while each embodiment of a guide member  164  discussed herein is illustrated as including one embodiment of the wear indicator portion(s)  198 , each guide member  164  could include more than one type of wear indicator portion  198  described herein. The guide member  164  is not limited to including only a single type of wear indicator portion, nor are the wear indicator portions limited in discrete parts of the guide member  164 , such that different wear indicator portion could be provided in a common part or region of a single guide member  164 . Further, it should be understood that multiple guide rails  154  with guide members  164  can be coupled to the track frame  90  in a series or row. Adjacent guide rails  154  can include different wear indicator portions  198 . Adjacent guide rails  154  on the track could also include no wear indicator portion  198  such that only a single guide rail  154  in a series includes wear indicators  198 . In other words, different embodiments of wear indicator portion  198  may be incorporated in various combinations throughout the series of guide rails  154  on the track frame  90 . 
     As illustrated in  FIGS. 11 and 12 , each wear indicator  298 ,  398  may include small recesses and may be positioned along lateral portions of the lower surface of the guide member  164  ( FIGS. 11 and 12 ). As further illustrated in  FIGS. 11 and 12 , the guide member  164  could include multiple wear indicators  298 ,  398  in different regions of the guide member  164 . 
     In the embodiment illustrated in  FIG. 11 , the guide member  164  includes more than two wear indicators  298 , such as six generally circular wear indicators  298 , on each side of the guide member  164 . The wear indicators  298  have a circular shape or cross-section. The wear indicators  298  could also be dome shaped and have a base extending from the bottom surface of the guide member  164 . 
     As illustrated in  FIG. 12 , some embodiments of the guide member  164  include four elliptical or slightly oblong wear indicators  398  on each side of the guide member  164 . The wear indicators  398  could also be slotted. 
     In the embodiment illustrated in  FIG. 13 , each wear indicator portion  498  may include elongated recesses that are integrated with the vertical surface of the flanges  174  ( FIG. 13 ). Such embodiments may include more than one wear indicator portion  498  on each side of the guide member  164 . As further illustrated in  FIG. 13 , each of the wear indicators  498  is sloped or chamfered with a surface of the flanges  174 . In the illustrated embodiment, the wear indicator  498  is positioned adjacent the holes  182  extending laterally through the flanges  174 . The sloped parts of the wear indicators  498  may provide additional space for the fastener (e.g., bolt) received in the holes  182  for securing the guide rail  154  to a portion of the track frame  90  ( FIG. 5 ). 
     In other embodiments, such as in the embodiment illustrated in  FIG. 14 , each wear indicator portion  598  may include an elongated pocket having multiple raised sections ( FIG. 14 ), although a pocket having a single raised section ( FIG. 6 ) may avoid restricting directional solidification during manufacture. In addition, the wear indicator portions  598  permit an operator to inspect the guide member  164  while the crawler is assembled on the machine. The wear indicator  598  allows for viewing of the wear indicator  598  from a side of the guide member  164  even when the wear indicator  598  is not viewable from above the guide member  164 . 
     As shown in  FIG. 15 , in other embodiments, the wear indicator portion  698  may include and/or be formed as a runner or groove  202  positioned on a lateral edge of each wing  194  and extending between the first end  186  and the second end  190  ( FIG. 14 ). The groove  202  may permit an operator to easily inspect the guide member  164  from the side while the crawler is assembled on the machine, and to gauge the remaining working life of the guide member  164  (i.e., by evaluating the distance between the outer surface  166  and the groove  202 ). For example, if the operator views the wear indicator  698  and sees that half of the groove  202  is visible/remains, then the operator can assume that at least a portion of the guide member  164  has begun to wear. 
     As shown in  FIG. 16 , in some embodiments, the wear indicator portion  798  may be formed as an angled recess in the lower surface of the guide member  164 . The recess has a root  206  positioned closest to the outer surface  166 . As the guide member  164  wears, a narrowest portion of the recess will become exposed initially as a narrow window. The window will gradually become larger as the guide member  164  wears further (e.g., as the thickness of the outer surface  166  wears). The window may be designed to become visible at an early stage (e.g., adjacent the root  206 ) to allow an operator to plan for replacement. For example, a large amount of visible wear indicator  798  widow may indicate that the guide rail  154  should be replaced. 
       FIGS. 17 and 18  illustrate a guide member  164  in which the wear indicator  898  is formed as a plurality of through-holes extending through the guide member  164  from the outer surface  166  to a lower surface. The through-holes permit an operator to accurately and consistently measure thickness at any time and plan for replacements without requiring the track to be removed from the rail. As shown best in  FIG. 18 , a depth of the wear indicator  898  becomes more shallow as the thickness of the guide member  164  is reduced. 
       FIGS. 19 and 20  illustrate a guide member  164  in which the wear indicator portions  998  include recesses formed on a lower surface of the guide member  164  between flanges  174 , and aligned along a centerline  170  of the guide member  164 . As the guide member  164  wears, openings or windows of the wear indicator  998  will appear along the centerline  170  of the guide rail. The wear indicator  998  further includes a root portion  210 . The root portion  210  is generally curved or domed. The wear indicator  998  begins to show once the root portion  210  becomes visible from above the guide member  164 . As best illustrated in  FIG. 20 , the root portion  210  will begin to be visible as a dot, small circle, and/or the like, and gradually increase in diameter as more of the wear indicator  998  becomes visible. Once the root portion  210  is no longer visible/depleted, an opening (e.g., void, recess, etc.) diameter/cross-section of the wear indicator  998  will begin to increase more rapidly. In other words, on opening present in the root portion  210  increases more gradually and indicates that the guide member  164  has begun to wear. In some embodiments, the more rapid increase corresponds to a warning zone for the operator to know that the guide member  164  has begun wearing in a critical zone. The gradual increase may alert the operator that the guide rail  154  will need to be replaced soon. 
     The embodiment(s) described above and illustrated in the figures are presented by way of example only and are not intended as a limitation upon the concepts and principles of the present disclosure. As such, it will be appreciated that variations and modifications to the elements and their configuration and/or arrangement exist within the spirit and scope of one or more independent aspects as described.