Patent Publication Number: US-2016236736-A1

Title: Link assembly for a machine

Description:
TECHNICAL FIELD 
     The present disclosure relates to a tracked undercarriage system for a machine, and more particularly relates to a link assembly of the tracked undercarriage system. 
     BACKGROUND 
     Machines, such as excavators may include a tracked undercarriage system for providing traction between ground surface and the machine. The undercarriage system includes a roller track frame having various guiding components to support a link assembly. The link assembly moves over the roller track frame relative to the guiding components to move the machine. The link assembly includes an endless track link assembly which slides over the roller track frame with the help of the guiding components. The track link assembly includes multiple pairs of track links. The link assembly further includes multiple track shoes corresponding to the multiple pairs of track links. The track shoes engage with the ground surface. Further, the track shoes are generally coupled to the pairs of track links via bolts and nuts. The bolts and nuts may loosen over a time, and hence the track shoe may be disconnected from the track link. Further, high tolerance requirements for bolted joints make design of the link assembly complex and cost intensive. Additionally, assembly of the track shoes with the pairs of track links may require increased time and effort. 
     US Patent Publication Number 2014/0001827 discloses an undercarriage assembly. The undercarriage assembly includes a link assembly having a plurality of laterally spaced pairs of track links pivotally connected to one another at pivot joints to form an endless chain. The undercarriage assembly may also include an idler. The idler includes a solid disk with substantially planar sides and an outer tread surface engaging an inner portion of the endless chain. 
     SUMMARY OF THE DISCLOSURE 
     In one aspect of the present disclosure, a link assembly for a track-type machine is provided. The link assembly includes a plurality of laterally spaced pairs of track links. Each track link of the pairs of track links includes an elongate body. The elongate body includes a first end and a second end distal to the first end. The elongate body further includes a shoe face extending between the first end and the second end. The elongate body further includes one or more protrusions extending from the shoe face. The link assembly further includes a plurality of track shoes configured to be engaged with the shoe face of the plurality of the pairs of track links. Each of the track shoes includes a base defining a top surface and a bottom surface distal to the top surface. The track shoe further includes one or more apertures extending between the top surface and the bottom surface configured to receive the one or more protrusions therethrough. The protrusions are configured to be deformed to fixedly engage the track shoe with the track link and further the bottom surface of the base abuts the shoe face of the track link. 
     In another aspect of the present disclosure, a link assembly for a track-type machine is provided. The link assembly includes a track shoe having a base. The base includes a top surface and a bottom surface distal to the top surface. The link assembly further includes a pair of track links laterally disposed with respect to each other. Each of the pair of track links includes a shoe face configured to abut the bottom surface of the track shoe. The link assembly further includes a retaining member disposed on the bottom surface of the track shoe and disposed between each track link of the pair of track links. The retaining member has a first end and a second end adjacent to a corresponding track link of the pair of track links. The first end and the second end of the retaining member are configured to be deformed to fixedly engage with the corresponding track link of the pair of track links. 
     In yet another aspect of the present disclosure, a link assembly for a track-type machine is provided. The link assembly includes a plurality of laterally spaced pairs of track links. Each track link of the pairs of track links includes an elongate body. The elongate body includes a first end and a second end distal to the first end. The elongate body further includes a shoe face extending between the first end and the second end. The elongate body further includes a protrusion extending from the shoe face. The protrusion includes a first leg member and a second leg member extending from the shoe face and defines a slot therebetween. The protrusion further includes a head member disposed adjacent to the first leg member and the second leg member. The head member has a diameter. The link assembly further includes a plurality of track shoes configured to be engaged with the shoe face of the plurality of the pairs of track links. Each of the track shoes includes a base defining a top surface and a bottom surface distal to the top surface. The track shoe further includes an aperture extending between the top surface and the bottom surface. The aperture is configured to receive the protrusion therethrough. The aperture defines a second diameter that is less than the first diameter of the head member. The first leg member and the second leg member are deflected to be received through the aperture. The head member of the first leg member and the second leg member is configured to engage the track shoe with the track link. 
     Other features and aspects of this disclosure will be apparent from the following description and the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side view of a machine having an undercarriage system with a link assembly, according to an embodiment of the present disclosure; 
         FIG. 2  is a perspective view of a portion of the link assembly of  FIG. 1 , according to an embodiment of the present disclosure; 
         FIG. 3  is a perspective view of multiple pairs of track links of the link assembly, according to an embodiment of the present disclosure; 
         FIG. 4  is a perspective view of a track shoe of the link assembly, according to an embodiment of the present disclosure; 
         FIG. 5  is a sectional view taken along line X-X′ of  FIG. 2 , according to an embodiment of the present disclosure; 
         FIG. 6  is a sectional view taken along line Y-Y′ of  FIG. 2 , according to an embodiment of the present disclosure; 
         FIG. 7  is a perspective view of the track link, according to another embodiment of the present disclosure; and 
         FIG. 8  is a sectional view showing the track link and the track shoe, according to yet another embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Reference will now be made in detail to specific embodiments or features, examples of which are illustrated in the accompanying drawings. Wherever possible, corresponding or similar reference numbers will be used throughout the drawings to refer to the same or corresponding parts. 
       FIG. 1  shows a side view of a machine  100 . In the illustrated embodiment, the machine  100  is an excavator having a tracked undercarriage system. However, the machine  100  may be any other type of machine used in various industries, such as mining, construction, and the like, and having a tracked undercarriage system. The machine  100  includes a body  102  rotatably supported on a chassis  104 . An implement  106 , including a bucket  108 , is coupled to the body  102 . The bucket  108  may be used for performing various operations, such as excavation, dumping and loading. The machine  100  further includes an undercarriage system  110  coupled to the chassis  104 . The undercarriage system  110  may be used for supporting the body  102  and for moving the machine  100  along a ground surface. The undercarriage system  110  includes a track roller frame  112 . Further, one or more guiding components, such as the guiding component  114 , may be connected to the track roller frame  112 . The undercarriage system  110  further includes a link assembly  116  configured to be moved over the track roller frame  112  relative to the guiding components  114 . The undercarriage system  110  further includes a drive sprocket  118  to receive power from a power source, such as an engine (not shown), and to drive the link assembly  116  relative to an idler  120 . A plurality of rollers  122  and a plurality of guiding components  114  may be used for assisting movement of the link assembly  116  over the track roller frame  112 . 
       FIG. 2  shows a perspective view of a portion of the link assembly  116 . Referring to  FIGS. 1 and 2 , the link assembly  116  includes a plurality of laterally spaced pairs of track links  126  configured to be slidably engaged with the guiding components  114  of the track roller frame  112 . Each pair of track links  126  includes a first track link  128  and a second track link  130  disposed laterally to the first track link  128 . The first and the second track links  128 ,  130  are described in detail later with reference to  FIG. 3 . The link assembly  116  further includes a plurality of track shoes  132 . Each of the plurality of track shoes  132  is configured to be engaged with each pair of track links  126 . Further, the plurality of track shoes  132  may be configured to engage with the ground surface to provide traction between the machine  100  and the ground surface. Thus, the plurality of the pairs of track links  126  and the plurality of the track shoes  132  together may form endless link assembly  116  to slidably engage with the guiding components  114  of the track roller frame  112 . The plurality of track shoes  132  may move along with the plurality of the pairs of track links  126  to propel the machine  100  along the ground surface. 
       FIG. 3  shows a perspective view of multiple pairs of track links  126 , according to an embodiment of the present disclosure. In  FIG. 3 , two pairs of track links  126  of a plate type offset track link assembly are shown for illustration purpose of the present disclosure. Further, the first track link  128  is illustrated in detail below. The first track link  128  includes an elongate body  134 . The elongate body  134  includes a first end  134 A and a second end  134 B distal to the first end  134 A. The elongate body  134  further includes a shoe face  134 C extending between the first and the second ends  134 A,  134 B. The shoe face  134 C is configured to engage with the track shoe  132 . Further, the elongate body  134  includes a roller face  134 D distal to the shoe face  134 C and extending between the first and the second ends  134 A,  134 B. As shown in  FIG. 1 , the roller face  134 D may be configured to slidably engage with the guiding components  114  of the track roller frame  112 . The elongate body  134  further includes a first side surface  134 E and a second side surface  134 F distal to the first side surface  134 E. The first track link  128  further defines a first opening  128 A and a second opening  128 B extending between the first and the second side surfaces  134 E,  134 F and adjacent to the first and the second ends  134 A,  134 B, respectively. 
     The elongate body  134  further includes one or more protrusions  136  extending from the shoe face  134 C. The protrusions  136  are configured to engage the track shoe  132  with the track link  126 . In the illustrated embodiment, the elongate body  134  includes a first protrusion  136 A extending from the shoe face  134 C adjacent to the first end  134 A. The elongate body  134  further includes a second protrusion  136 B extending from the shoe face  134 C adjacent to the second end  134 B. However, it may be contemplated that the elongate body  134  may include any number of protrusions  136  to engage the track shoe  132  with the track link  126 . In an embodiment, the first protrusion  136 A and the second protrusion  136 B are integrally formed with the elongate body  134  of the first track link  128 . In an alternative embodiment, the first and the second protrusions  136 A,  136 B may be a separate part. In such a case, the first track link  128  may include a pair of holes defined on the shoe face  134 C to engage with the first and the second protrusions  136 A,  136 B. Further, the first protrusion  136 A and the second protrusion  136 B extend vertically from the shoe face  134 C. 
     Similar to the first track link  128 , the second track link  130  includes an elongate body  138  having a first end  138 A, a second end  138 B, a shoe face  138 C, a roller face  138 D, a first side surface  138 E and a second side surface  138 F. Further, the second track link  130  includes a first opening  130 A and a second opening  130 B. The elongate body  138  also includes protrusions  140 , such as a first protrusion  140 A and a second protrusion  140 B. The above described construction of the first and second track links  128 ,  130  is exemplary. 
     In various examples, the link assembly  116  may include a forged offset track link assembly, a forged inline track link assembly and a plate type inline track link assembly. In the forged offset and inline track link assemblies, the first and second protrusions  136 A,  136 B,  140 A,  140 B may be integrally forged with the elongate bodies  134 ,  138  of each of the track links  128 ,  130 , respectively, of the pair of track links  126 . 
     In the illustrated embodiment, each of the protrusions  136 ,  140  may have a circular cross section defining a diameter. In various embodiments, the cross section of the protrusions  136 ,  140  may be a square, a rectangular, an elliptical or a polygonal shape. 
     In an exemplary embodiment, a method of assembling the plate type offset track link assembly is described in detail for illustration purpose of the present disclosure. Each pair of track links  126  includes a pin member  142  having a first end  144  and a second end  146  distal to the first end  144 . Each of the first end  144  and the second end  146  includes a first diameter portion (not shown) and a second diameter portion (not shown) adjacent to the first diameter portion. The first diameter portions at the first and the second ends  144 ,  146  of the pin member  142  may be configured to engage with the second openings  128 B,  130 B of the first and the second track links  128 ,  130 , respectively. 
     During assembly of the pair of track links  126 , the first track link  128  and the second track link  130  may be laterally spaced adjacent to the first and second ends  144 ,  146 , respectively, of the pin member  142 . Further, the pin member  142  may be co-axially aligned with the second openings  128 B,  130 B. The first track link  128  and the second track link  130  may be moved towards each other to engage with the first diameter portions of the first and the second ends  144 ,  146 , respectively, of the pin member  142 . The first openings  128 A,  130 A of the first and the second track links  128 ,  130  of another pair of track links  126  may be pivotally engaged with the second diameter portions at the first and second ends  144 ,  146 , respectively, of the pin member  142 . Thus, the pair of track links  126  may pivotally move relative to the adjacent pair of track links  126  about the pin member  142 . Thus, each of the pair of track links  126  of the link assembly  116  pivotally move relative to the adjacent pair of track links  126  about the corresponding pin member  142 . 
       FIG. 4  shows a perspective view of exemplary track shoe  132 . The track shoe  132  is an elongate body extending between a first end  148  and a second end  149 . The track shoe  132  includes a base  150  having a top surface  152  extending between the first and the second ends  148 ,  149 . The top surface  152  includes a plurality of leg members  154  extending between the first and the second ends  148 ,  149  configured to engage with the ground surface. Further, the track shoe  132  includes a bottom surface  156  distal to the top surface  152 . The bottom surface  156  is configured to abut the shoe faces  134 C,  138 C of the first and the second track links  128 ,  130 , respectively. The track shoe  132  further includes one or more apertures  158  extending between the top and the bottom surfaces  152 ,  156 . In the illustrated embodiment, the track shoe  132  includes a first set of apertures  158 A and a second set of apertures  158 B. The first and second set of apertures  158 A,  158 B may be laterally spaced with respect to each other. Each of the apertures  158  may have a diameter greater than the diameter of each of the protrusions  136 ,  140  to receive corresponding protrusion of the set of protrusions  136 ,  140 . In an example, the first set of apertures  158 A may be configured to receive the first and the second protrusions  136 A,  136 B of the first track link  128 . Similarly, the second set of apertures  158 B may be configured to receive the first and the second protrusions  140 A,  140 B of the second track link  130 . The above described construction of the track shoe  132  is exemplary, and it may be contemplated that any known type of track shoes may be provided with the first and second set of apertures  158 A,  158 B to receive the protrusions  136 ,  140 , respectively. 
       FIG. 5  shows a sectional view taken along line X-X′ of  FIG. 2 , according to an embodiment of the present disclosure. Referring to  FIG. 2 , the first protrusions  136 B,  140 B of one of the pairs of track links  126  are shown in a deformed condition for illustration purpose of the present disclosure. During an assembly of the track shoe  132  with the pair of track links  126 , the first and the second set of apertures  158 A,  158 B may be aligned with the set of protrusions  136 ,  140 , respectively. Further, the track shoe  132  may be disposed on the pair of track links  126  such that the bottom surface  156  of the base  150  abut the shoe faces  134 C,  138 C of the first and the second track links  128 ,  130 , respectively. Referring to  FIGS. 2 and 5 , each of the set of protrusions  136 ,  140 , has a thickness ‘T 1 ’ greater than a thickness ‘T 2 ’ defined between the top and the bottom surfaces  152 ,  156  of the base  150  of the track shoe  132 . Further, a portion  160  of each of the set of protrusions  136 ,  140  projects above the top surface  152  of the base  150 . In  FIG. 5 , only the portions  160  of the first protrusions  136 B,  140 B are shown for illustrative purposes. 
       FIG. 6  shows a sectional view taken along line Y-Y′ of  FIG. 2 , according to an embodiment of the present disclosure. The portion  160  of each of the set of protrusions  136 ,  140  is deformed to define a deformed portion  162  having a diameter greater than the diameter of the apertures  158 . In  FIG. 6 , only the deformed portions  162  of first protrusions  136 B,  140 B are shown. The deformed portion  162  of each of the set of protrusions  136 ,  140  may be configured to fixedly engage the track shoe  132  with the track link  126 . In a deformed condition of the set of protrusions  136 ,  140 , the bottom surface  156  of the base  150  abuts the shoe faces  134 C,  138 C of the first and the second track links  128 ,  130 , respectively. Similarly, the set of protrusions  136 ,  140  of each pair of the plurality of pairs of track links  126  may be deformed to fixedly engage with the corresponding track shoe  132 . 
     In an embodiment, the portion  160  of the each of the set of protrusions  136 ,  140  is deformed to the deformed portion  162  by a hot upset forming process. In an example, the hot forming process may use heat and pressure to engage the track shoe  132  with the pair of track links  126 . Machine used for the hot upset forming process may heat the portion  160  of each of the set of protrusions  136 ,  140  to make the portions  160  malleable. Further, a pressure may be applied on the heated portion to form the deformed portion  162 , thereby engaging the track shoe  132  with the pair of track links  126 . In another embodiment, the portions  160  may be deformed by press forming using a pressing machine, such as a hydraulic press. 
       FIG. 7  shows a perspective view of a track link  202 , according to another embodiment of the present disclosure. Similar to the first track link  128 , the track link  202  includes an elongate body  204  having a first end  204 A, a second end  204 B, a shoe face  204 C, a roller face  204 D, a first side surface  204 E and a second side surface  204 F. Further, the track link  202  includes a first opening  202 A and a second opening  202 B. 
     The elongate body  204  further includes one or more protrusions  206  extending from the shoe face  204 C. The protrusions  206  are configured to engage the track shoe  132  with the track link  202 . In the illustrated embodiment, the elongate body  204  includes a first protrusion  206 A extending from the shoe face  204 C adjacent to the first end  204 A of the elongate body  204 . The elongate body  204  also includes a second protrusion  206 B extending from the shoe face  204 C adjacent to the second end  204 B of the elongate body  204 . However, it may be contemplated that the elongate body  204  may include any number of protrusions  206  to engage the track shoe  132  with the track link  202 . The first protrusion  206 A and the second protrusion  206 B are integrally formed with the elongate body  204  of the track link  202 . Further, the first protrusion  206 A and the second protrusion  206 B extend vertically from the shoe face  204 C. In various embodiments, the first and second protrusions  206 A,  206 B may be integrally formed with a track link associated with the forged offset and inline track link assemblies and the plate type inline track link assembly. 
     Referring to  FIG. 7 , the first protrusion  206 A is described in detail for illustration purpose of the present disclosure. The first protrusion  206 A includes a first leg member  208  and a second leg member  210 . The first and the second leg members  208 ,  210  define a slot  212  therebetween. The slot  212  may allow the first and the second leg members  208 ,  210  to deflect towards each other. A head member  214  is disposed adjacent to each of the first and the second leg members  208 ,  210 . The head member  214  may have a diameter greater than the diameter of the apertures  158 . Further, the first protrusion  206 A may have a circular cross section between the shoe face  204 C and an inner face  214 A of the head member  214 . The first protrusion  206 A further defining a diameter less than the diameter of the apertures  158 . The head member  214  may further include a tapered portion  218  defined at a periphery adjacent to a top face opposite to the inner face  214 A. Each of the first and the second protrusions  206 A,  206 B define a thickness ‘T 3 ’ between the shoe face  204 C and the inner face  214 A of the head member  214 . The thickness ‘T 3 ’ is equal to or greater than the thickness ‘T 2 ’ of the base  150  of the track shoe  132 . 
     During assembly of the track shoe  132  with each of the pair of track links  202 , the set of apertures  158 A,  158 B of the track shoes  132  may be aligned with the set of protrusions  206  of each track link  202 . The tapered portion  218  may facilitate the track shoe  132  to move towards the shoe face  204 C of the track link  202 . Further, the first and the second leg members  208 ,  210  may deflect towards each other to pass through each of the corresponding apertures  158 . The bottom surface  156  of the track shoe  132  further abuts the shoe face  204 C of the track link  202  and the inner face  214 A of the head member  214  abuts the top surface  152  of the track shoe  132 . Thus, the head members  214  of the first and the second leg members  208 ,  210  are configured to engage the track shoe  132  with the track link  202 . 
       FIG. 8  shows a sectional view illustrating a pair of track links  302  and a track shoe  304 , according to yet another embodiment of the present disclosure. The pair of track links  302  associated with the plate type offset track link assembly is illustrated in detail for illustration purpose. The track shoe  304  includes a base  305  having a top surface  306  and a bottom surface  308 . The pair of track links  302  includes a first track link  302 A and a second track link  302 B. The first and the second track links  302 A,  302 B are laterally disposed with respect to each other. Further, each of the first and the second track links  302 A,  302 B includes a shoe face  316 . The shoe faces  316  are configured to abut the bottom surface  308  of the track shoe  304 . As shown in  FIG. 8 , the track shoe  304  includes a retaining member  318  disposed on the bottom surface  308  thereof. In an embodiment, the retaining member  318  is integrally formed with the base  305  of the track shoe  304 . In an alternative embodiment, the retaining member  318  may be a separate component coupled to the bottom surface  308  of the base  305 . The retaining member  318  is further configured to be disposed between the first and the second track links  302 A,  302 B. 
     The retaining member  318  further includes a first end  320  and a second end  322 . As shown in  FIG. 1 , the first and the second ends  320 ,  322  are configured to engage with the first and the second track links  302 A,  302 B, respectively. Further, each of the first and the second ends  320 ,  322  of the retaining member  318  is configured to form a curvilinear shape to engage with the corresponding first and the second track links  302 A,  302 B of each pair of the plurality of pairs of track links  302 . 
     In an embodiment, the first track link  302  includes a side surface  312  and the second track link  302 B includes a side surface  314  facing the side surface  312  of the first track link  302 A. The side surfaces  312 ,  314  of the first and the second track links  302 A,  302 B are configured to engage with the first and the second ends  320 ,  322 , respectively, of the retaining member  318 . 
     During assembly of the pair of track links  302  with the track shoe  304 , the first and the second track links  302 A,  302 B may be disposed on the bottom surface  308  of the base  305  adjacent to the first and the second ends  320 ,  322 , respectively, of the retaining member  318 . Further, the side surfaces  312 ,  314  of the first and the second track links  302 A,  302 B may face each other. The first and the second track links  302 A,  302 B may be moved towards the first and the second ends  320 ,  322  of the retaining member  318  relative to the bottom surface  308  of the base  305 . The first and the second ends  320 ,  322  of the retaining member  318  deform to fixedly engage with the corresponding first and the second track links  302 A,  302 B. Thus, each pairs of the plurality of track links  302  may be engaged with the retaining member  318  disposed on the corresponding track shoe  304 . In various embodiments, the pair of track links  302  may be associated with the forged offset and inline track link assemblies and the plate type inline track link assembly. 
     INDUSTRIAL APPLICABILITY 
     The present disclosure relates to the link assembly  116  in which each pair of the multiple pairs of track links may be engaged with the corresponding multiple track shoe via integral members. In an embodiment, the integral member includes the set of protrusions  136 ,  140  of the first and the second track links  128 ,  130  of the pair of track links  126 . In another embodiment, the integral member includes the set of protrusions  206  of the track link  202 . In yet another embodiment, the integral member includes the retaining member  318  of the track shoe  304 . 
     As the track links  126 ,  202 ,  302  and the track shoes  132 ,  304 , are engaged with each other via the corresponding integral members formed with either the track link or the track shoe, the coupling between the track shoe and the track link may become robust and reliable. Time and effort required for assembling the track links and the track shoe may be reduced compared to the existing assemblies with bolts and nuts. Complexity in design and manufacture of the track links and the track shoe may also be reduced. 
     While aspects of the present disclosure have been particularly shown and described with reference to the embodiments above, it will be understood by those skilled in the art that various additional embodiments may be contemplated by the modification of the disclosed machines, systems and methods without departing from the spirit and scope of what is disclosed. Such embodiments should be understood to fall within the scope of the present disclosure as determined based upon the claims and any equivalents thereof.