Abstract:
A system for guiding movement of a chassis of a mining machine along a rack includes a shoe and a fluid line for receiving fluid from a fluid source. The shoe is configured to be coupled to the chassis and slidably engage the rack. The shoe is configured to extend at least partially around the rack. The shoe includes a first end, a second end, an inner surface, and an outer surface. At least a portion of the inner surface is configured to be positioned adjacent the rack. The fluid line includes an outlet positioned proximate the shoe for dispensing the fluid at an interface between the shoe and the rack.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority to co-pending, prior-filed U.S. Provisional Patent Application No. 62/217,169, filed Sep. 11, 2015, the entire contents of which are hereby incorporated by reference. 
     
    
     BACKGROUND 
       [0002]    The present disclosure relates to the field of mining machines, and particularly to a trapping shoe for a longwall shearer mining machine. 
         [0003]    Conventional longwall shearers include a frame and a pair of cutting assemblies mounted on each end of the frame. Each cutting assembly includes a cutting drum for engaging a mine wall. As the frame traverses a mine wall, the cutting drums cut material from the mine face. In some embodiments, the material is deposited on a conveyor and carried away from the mine face. The shearer includes a drive mechanism for moving the machine with respect to the mine wall. 
       SUMMARY 
       [0004]    In one aspect, a system for guiding movement of a chassis of a mining machine along a rack includes a shoe and a fluid line for receiving fluid from a fluid source. The shoe is configured to be coupled to the chassis and slidably engage the rack. The shoe is configured to extend at least partially around the rack. The shoe includes a first end, a second end, an inner surface, and an outer surface. At least a portion of the inner surface is configured to be positioned adjacent the rack. The fluid line includes an outlet positioned proximate the shoe for dispensing the fluid at an interface between the shoe and the rack. 
         [0005]    In another aspect, a drive system for driving a mining machine along a rack includes a drive mechanism configured to engage the rack to move the mining machine relative to the rack, a shoe positioned adjacent the drive mechanism, and a fluid system for conveying a lubricant. The shoe is configured to slidably engage the rack. The shoe aligns the drive mechanism relative to the rack. The shoe includes a first end and a second end. The fluid system including an outlet positioned adjacent at least one of the rack and the shoe. 
         [0006]    In yet another aspect, a mining machine is movable along a rack and includes a chassis, a cutter assembly, a shoe coupled to the chassis, and a fluid line for receiving a fluid from a fluid source. The cutter assembly includes an arm and a cutting drum. The arm includes a first end pivotably coupled to the chassis and a second end supporting the cutting drum for rotation relative to the arm. The shoe is configured to extend at least partially around the rack. The shoe includes a first surface and a second surface, and the first surface is configured to be positioned adjacent the rack. The fluid line includes an outlet positioned proximate the shoe for dispensing fluid to at least one of the rack and the shoe. 
         [0007]    Other aspects will become apparent by consideration of the detailed description and accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]      FIG. 1  is a perspective view of a mining machine. 
           [0009]      FIG. 2  is end view of the mining machine of  FIG. 1  engaging a mine wall. 
           [0010]      FIG. 3  is an enlarged perspective view of a portion of the mining machine of  FIG. 1 . 
           [0011]      FIG. 4  is a perspective view of a drive mechanism. 
           [0012]      FIG. 5  is an end view of a trapping shoe. 
           [0013]      FIG. 6  is a perspective view of a fluid reservoir. 
           [0014]      FIG. 7  is a perspective view of a drive mechanism and a lubrication system. 
           [0015]      FIG. 8  is a perspective view of a trapping shoe and a lubrication system according to another embodiment. 
           [0016]      FIG. 9  is an end view of the trapping shoe of  FIG. 5  engaged with a rack. 
       
    
    
     DETAILED DESCRIPTION 
       [0017]    Before any 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 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. 
         [0018]      FIG. 1  illustrates a mining machine (e.g., a longwall shearer  10 ) including a chassis or frame  14  and a pair of cutting assemblies (i.e., a first cutting assembly  18   a  and a second cutting assembly  18   b ). Each cutting assembly  18  includes a ranging arm  22  and a cutting drum  26 . Each ranging arm  22  is pivotably coupled to the frame  14  and rotatably supports the associated cutting drum  26 . Each cutting drum  26  includes a generally cylindrical body. In some embodiments, each cutting drum  26  includes one or more helical vanes (not shown) and a plurality of cutting bits (not shown) positioned along the edges of each vane. For example, each cutting drum may be formed as shown in U.S. Publication No. 2014/0084666, filed Sep. 20, 2013, the entire contents of which are incorporated by reference herein. Each drum  26  is coupled to the respective ranging arm  22  and is rotatable about a respective drum axis. In the illustrated embodiment, each drum axis is generally perpendicular to the mining machine&#39;s directions of movement  38 ,  42 . 
         [0019]    As shown in  FIGS. 1 and 2 , the frame  14  is configured to tram or move along a mine face or wall  34  ( FIG. 2 ) of material to be mined. In the illustrated embodiment, the frame  14  moves in a first direction  38  ( FIG. 1 ) and a second direction  42  opposite the first direction  38 . The first direction  38  and the second direction  42  are generally parallel to the mine face ( FIG. 2 ). 
         [0020]    Referring now to  FIG. 2 , each drum  26  is configured to engage the mine wall  34  to cut material from the wall  34 . As each cutting drum  26  rotates about its axis, the vanes (not shown) carry the cut material from the wall  34  toward a rear end of each drum  26 , where the cut material is deposited onto a face conveyor  46 . As the frame  14  moves, for example, in the first direction  38 , the first cutting assembly  18   a  is in a first or leading position and the second cutting assembly  18   b  is in a second or trailing position. In the embodiment shown in  FIG. 1 , each cutting assembly  18   a,    18   b  is in an elevated position. However, in other embodiments, each cutting assembly  18   a,    18   b  may be positioned independently of the other (e.g., a leading cutting assembly may be positioned in an upper position and a trailing cutting assembly may be positioned in a lower position) to cut the material from the upper portion and a lower portion of the mine wall  34  in the same pass. In the illustrated embodiment, the mining machine  10  further includes a cable handler  114  to manage electrical, communication, and fluid conduits that are in communication with the machine  10 . 
         [0021]    With reference to  FIGS. 3-5 , the shearer frame  14  includes a downdrive or drive mechanism  50  configured to engage a rack  54  ( FIG. 3 ) and drive the frame  14 . More specifically, the drive mechanism  50  includes a sprocket  58  ( FIG. 5 ) rotationally coupled to a shaft (not shown) and driven by a motor (not shown) to engage the rack  54 . The sprocket  58  and rack  54  form a rack-and-pinion connection such that rotation of the sprocket  58  drives the frame  14  to move along the rack  54 . The trapping shoe  30  is pivotably coupled to the housing of the downdrive  50  (e.g., by a pin  62 ). The shoe  30  may also include a hook portion  64  extending around a portion of the rack  54  and engaging an underside or bottom surface of the rack  54  (see e.g.,  FIG. 9 ). The hook portion  64  maintains engagement between the shoe  30  and the rack  54  and guides the shoe  30  as it slides relative to the rack  54 . In one embodiment, an upper surface of the shoe  30  includes an opening and a portion of the sprocket  58  extends through the opening. The sprocket  58  includes teeth  66  extending around the perimeter of the sprocket  58 , which engage the rack  54  ( FIG. 3 ). The shoe  30  guides the movement of the frame  14  relative of the rack  54  and insures that the sprocket  58  remains aligned and engaged with the rack  54 . Although only one shoe  30  is shown in the illustrated embodiment, it is understood that one or more additional shoes  30  can be coupled to another portion of the frame  14 . 
         [0022]    Referring now to  FIGS. 6 and 7 , the mining machine  10  also includes a lubrication system to provide a lubricant directly to the rack  54 . In one embodiment, the lubrication system includes a hydraulic fluid reservoir  70  ( FIG. 6 ) at least one fluid line  74  in communication with the reservoir  70  via outlets  78   a - d,  and a hydraulic pump  82  for displacing fluid through the fluid line  74 . It is understood that there may be fewer or more outlets (e.g.,  78   e - j ) than shown in  FIG. 6 . In some embodiments, the lubricant source (i.e., the reservoir  70 ) is supported separate from the frame  14  and remotely pumps fluid to the mining machine  10  via the fluid line  74 . The fluid line  74  may be supported by the cable handler  114  ( FIG. 2 ) as the mining machine  10  moves along the mine wall. 
         [0023]    In the embodiment as illustrated in  FIG. 7 , a distal end  86  of the fluid line  74  terminates at the downdrive  50 , and is spaced apart from the trapping shoe  30 . A passage  90  in communication with the fluid line  74  may be positioned on an exterior surface of the downdrive  50 . Fluid from the passage  90  may be sprayed or dripped onto the rack  54 . In one embodiment, the fluid flows onto the rack  54  in direction  94 . In this particular embodiment, the fluid is pumped from one of the outlets  78   a - j,  through the fluid line  74  and the passage  90 , and expelled out of a port  98  at the distal end  86 . Although the passage  90  is illustrated in  FIG. 7  on the exterior of the downdrive  50 , it is understood that the passage  90  could also be disposed on the interior of the downdrive  50 . 
         [0024]      FIG. 8  illustrates another embodiment in which the fluid line  74  extends through an internal passage  290  formed in the body of the shoe  30 . In one embodiment, the fluid line  74  is coupled to a first elbow fitting  102  coupled to the downdrive  50 , and a second fluid line  274  is in fluid communication with a second elbow fitting  104  coupled to the trapping shoe  30 . An internal passage  290  extends through the body of the shoe  30  between an outer surface  106  and an inner surface  110  of the shoe  30 . A distal end  286  of the internal passage  290  terminates at the inner surface  110 , forming an opening or port  298 . Thus, fluid is conveyed through each fluid line  74 ,  274 , the respective elbow fittings  102 ,  104 , the passage  290 , and is expelled at a port  298  positioned on the inner surface  110  of the shoe  30 . As such, the fluid is applied directly to the rack  54 . 
         [0025]    In the illustrated embodiment, the port  298  is located on a vertical wall of the inner surface  110 , between an upper portion and the hook portion  64 . In other embodiments, the fluid lines and passages may be formed in a different manner. Although only one fluid line  274  is shown, more than one fluid line  274  may be provided in the trapping shoe  30 , and multiple fluid lines may convey fluid to multiple ports positioned at various locations on the inner surface  110  of the shoe  30 . In some embodiments, each fluid line  274  may be in fluid communication with each outlet  78   a - d ( e - j ). Also, in the illustrated embodiment, the fluid line  274  is provided with sufficient length to permit movement of the trapping shoe  30  relative to the downdrive  50  while minimizing stress on the fluid lines  74 ,  274  and the fittings  102 ,  104 . 
         [0026]    For each of the previously described embodiments, the reservoir  70  can either be positioned on-board or off-board the frame  14 . In the case where the reservoir  70  is separate from the machine (i.e., off-board), the fluid line  74 ,  274  may be supported by the cable handler  114  ( FIG. 2 ) of the frame  14 , such that the fluid line  74 ,  274  is able to extend from at least one of the outlets  78   a - d ( e - j ) to the downdrive  50  and/or the trapping shoe  30  without becoming entangled with the shearer  10 . Positioning the reservoir  70  away from the machine  10  may be advantageous for maintaining a low profile of the machine  10 , especially for low mine seam applications. 
         [0027]    With reference to  FIG. 9 , during operation the shoe  30  is exposed to large loads (e.g., due to the weight of the shearer  10 ). The large loads increase friction between the shoe  30  and the rack  54 . As a result, the shoe  30  may experience wear in multiple zones (e.g., zones A, B, C, D, and E). Furthermore, debris (e.g., lumps of rock or the like) cut from the mine wall  34  clogs the space between the shoe  30  and the rack  54 , which compounds the amount of wear on the shoe  30 . Wear on the shoe  30  may result in poor engagement between the sprocket  58  and the rack  54 . By supplying lubricant via the lubrication system, friction is decreased between the rack  54  and the shoe  30 , thereby decreasing wear and prolonging the working life of the rack  54  and the shoe  30 . As a result, the rack  54  and sprocket  58  may maintain sufficient engagement for a longer period of time. In some embodiments, the lubrication system may provide lubricant directly to each one of zones A, B, C, D, and E, or some subset thereof. 
         [0028]    Although some aspects have been described in detail with reference to certain preferred embodiments, variations and modifications exist within the scope and spirit of one or more independent aspects as described.