Patent Publication Number: US-8528462-B2

Title: Coupling arrangement providing an axial space between a plunger and plunger adaptor of a high pressure fluid pump

Description:
FIELD OF INVENTION 
     The present invention relates to a high pressure fluid pump having a coupling arrangement providing a space between a plunger end and a plunger adaptor end of the pump. 
     BACKGROUND 
     U.S. Pat. No. 5,302,087 discloses a high pressure pump. The pump has a plunger or pump piston linearly movable within a pump chamber during stroking of the pump. A suitable coupling is depicted for interconnecting the pump piston and drive housing output rod. 
     U.S. Pat. No. 4,277,229 discloses a high pressure fluid delivery system. The high pressure fluid system has a plunger with a threaded end for connection to a driving source which reciprocates the plunger along the longitudinal axis thereof. 
     Prior art  FIG. 1  discloses a sectional view of a high pressure pump having an “L” or sectional design.  FIG. 1  generally illustrates the components which form the pump. The pump has a fluid end assembly  10 . The pump has a power end assembly  12 . A frame  14  connects the fluid end assembly  10  to the power end assembly  12 . The cross head  32  of the pump is positioned within the power end assembly in an orientation which would place the plunger  16  at the end of its suction stroke or beginning of its discharge stroke if the plunger  16  were assembled to the plunger adaptor  30 . 
       FIG. 1  shows the fluid end assembly  10  partially disassembled to illustrate how one typically removes plunger  16  from the high pressure pump. Removal of the plunger  16  requires disassembly of suction manifold  18  from fluid cylinder block  20 . Disassembly requires unscrewing bolts  22  to release suction manifold  18  from cylinder block  20 . Additionally, removal of the plunger requires removal of suction valve assembly  24  from valve seat support  26  of fluid cylinder block  20 . Once the suction manifold and valve assembly have been removed, one can remove plunger  16  by pulling plunger  16  axially away from the pump&#39;s power end  12   a  and fluid end  10   a , thereby uncoupling an end  17  of a plunger  16  from coupling  28  of pony rod or plunger adaptor  30 . The plunger is thus removed in the direction shown by arrow  31 . 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a prior art irregular sectional view of a high pressure pump partially disassembled; 
         FIG. 2  is an isometric view looking from a fluid end assembly towards a power end assembly of a high pressure pump which embodies the features of the present invention; 
         FIG. 3  is an isometric view looking from a power end assembly towards the fluid end assembly of the fluid pump shown in  FIG. 2 ; 
         FIG. 4  is an irregular sectional view taken along a longitudinal length of the pump extending from the power end assembly to the fluid end assembly; the pump is at the end of its discharge stroke; 
         FIG. 5  is the sectional view shown in  FIG. 4  except the pump is at the beginning of the discharge stroke and the coupling has been removed to allow for removal of the plunger from the well. 
         FIG. 6  is a close-up view of the plunger, plunger adaptor, and coupling shown in  FIG. 3  removed from the pump; the coupling has been partially sectioned; 
         FIG. 7   a  is a view of the assembly shown in  FIG. 6  without sectioning the coupling; 
         FIG. 7   b  is a perspective view of the assembly shown in  FIG. 6 ; 
         FIG. 7   c  is an exploded view of the assembly shown in  FIG. 6 ; 
         FIG. 8  is a blown-up view of detail A of  FIG. 6 ; 
         FIG. 9  is a blown-up view of detail B of  FIG. 6 . 
     
    
    
     SUMMARY 
     An example of a pump assembly embodying the present invention includes a pump frame. The frame defines a well. The well has an open end. A stuffing box is engaged with the frame. The stuffing box has an opening. A plunger having a first end with an end surface and a second end with an end surface is linearly movable in the well. The plunger is movable between a first position, wherein the plunger is at the beginning of a discharge stroke, and a second position, wherein the plunger is at an end of a discharge stroke. 
     The assembly further includes a plunger adaptor. The plunger adaptor has a first end with an end surface and a second end. The plunger adaptor is linearly movable in the well. The plunger adaptor is movable between a first position, wherein the plunger adaptor is at a beginning of said discharge stroke and a second position, wherein said plunger adaptor is at an end of said discharge stroke. 
     A space is between the plunger and the plunger adaptor. The space has a longitudinal length. The longitudinal length can be measured along a longitudinal axis of the plunger. 
     The assembly also includes an orientation selectable from a group of orientations. One selectable orientation is an assembled orientation wherein a coupling connects the plunger to the plunger adaptor, and the coupling spans the longitudinal length. Another orientation is a partially disassembled orientation wherein said plunger and plunger adaptor are not connected by the coupling, but in all other respects the assembly is the same. 
     The longitudinal length of the space is at least great enough to enable movement of the end surface of the second plunger end out of the stuffing box and into the well and out of the well open end, when the pump assembly is in the partially disassembled orientation, and when the plunger adaptor first end is in the well. 
     In the above example, when the pump assembly is in the assembled orientation, the coupling has a first section removably coupled to a second section. Also in this example the coupling has a first end with a recess, and the plunger first end is in the recess. The coupling has a second end with a recess, and the plunger adaptor first end is in the recess. Further a spacer is between the coupler first section and the coupler second section. The spacer prevents the first section from abutting up against the second section. There is a clearance between the surfaces defining the coupler recesses and the surfaces defining the plunger first end and plunger adaptor first end. The surfaces overlap. The coupling first end is clamped to the first plunger end. The coupling second end is clamped to the plunger adaptor first end. 
     An example of a coupling embodying the present invention is a coupling having a first end and a second end with a longitudinal length between the first end and the second end. The longitudinal length is at least a longitudinal length of a space between a plunger and plunger adaptor of a pump when said coupling connects the plunger to the adaptor. The longitudinal length is at least great enough to enable removal of an end surface of the plunger out of a stuffing box of the pump and into a well defined by the pump and out of the well through a well open end when the plunger and plunger adaptor are not coupled by the coupling and when the plunger adaptor has a first end within the well. 
     An example of a method for partially disassembling a pump embodying the present invention is a method which includes disconnecting a plunger from a plunger adaptor and sliding the plunger in a direction away from a fluid end of the pump and towards a power end of the pump and into a well defined by the pump. The plunger is next removed from an open end of the well without disconnecting a power end assembly from a frame of said pump. 
     DETAILED DESCRIPTION 
     The below discussion and attached drawings disclose examples of an embodiment encompassing the invention. Other embodiments of the invention are contemplated and the appended claims are intended to cover such other embodiments as are within the scope and spirit of the invention. 
       FIGS. 2-9  illustrate and describe a pump embodying the present invention. The pump has a coupling  100  which connects plunger adaptor  102  to plunger  104 . The coupling  100  provides, maintains, and allows for a space  106  between a first end  103  of plunger  104  and a first end  101  of plunger adaptor  102  during operation of the pump. 
     The space  106  facilitates disassembly of plunger  104  from the pump. The space allows for an operator or servicer or other person upon only disconnecting the coupling  100  from the plunger  104  and from the plunger adaptor  102  to remove, via the well  114 , the plunger  104  from the rest of the pump assembly. From the well, the operator slides the plunger  104  in a direction  108  away from fluid end assembly  110  towards power end assembly  112 . (See  FIG. 5 ) The plunger  104  is slid into well  114  defined by the pump frame  116  and removed from the well  114  through open end  118  of well  114 . The well  114  and well open end  118  are large enough for a servicer to directly access the coupling  100  with an average size adult hand. Opposite the open end  118  is a well floor  118   a . Thus, the plunger  104  can be removed from the rest of the pump with minimal disassembly and returned to the pump with minimal reassembly. The arrangement allows for replacement of the components in stuffing box  125 , plunger  104 , and plunger adaptor  102  with minimal effort. The components replaced within stuffing box  125  can include bushings  120 , spring  122  and packing  123 . 
     The plunger first end  103  forms a flange  103   a  of plunger  104 . The flange is circumferential and has a radius greater than the radius of a portion of the plunger immediately adjacent the flange  103   a . The portion with the smaller radius forms a radially inward surface  135   a  of a recess  135 . The recess  135  and flange  103   a  form a plunger first section. Adjacent the recess, opposite the flange, is a second plunger section  137  with a radius greater than the radius of the radially inward surface  135   a . Plunger second section has an end which has an end surface  139   a . The end surface forms a plunger second  139 . 
     The plunger adaptor first end  101  forms a flange  101   a  of plunger adaptor  102 . The flange is circumferential and has a radius greater than the radius of a portion of the plunger adaptor immediately adjacent plunger adaptor flange  101   a . The portion with the smaller radius forms a radially inward surface  141   a  of a recess  141 . The recess  141  and flange  101   a  form a plunger adapter first section. Adjacent the recess, opposite the flange, is second plunger adaptor section  143  with a radius greater than the radius of the radially inward surface  141   a . The plunger adaptor second section has an end which forms a plunger adaptor second end  145 . 
     The coupling has a first end  129  which has a first recess  129   a . The recess is circumferential. The coupling has a second end  131  which has a second recess  131   a . The recess is circumferential. 
     Coupling  100  when coupled to plunger  104  and plunger adaptor  102  has a particular arrangement. Coupling  100  spans at least the longitudinal length  107  of space  106 . The length  107  can be measured along longitudinal axis  127  of coupling  100 . Coupling  100 , at first end  129  is coupled to plunger first end  103 . Coupling  100  at second end  131  is coupled to plunger adaptor first end  101 . Plunger flange  103   a  is in coupler first recess  129   a  and clamped at coupling first end  129 . Plunger adaptor flange  101   a  is in coupler second recess  131   a  and clamped at coupling second end  131 . A portion  13  lb of coupling second end  131  is in plunger adaptor recess  141 . A portion  129   b  of coupling first end  129  is in plunger recess  135 . 
     In more detail the coupling has a first section  150  removably coupled to a second section  152 . The sections are coupled by hex-head screws  154 . A pin or spacer  156 , between the first  150  and second  152  sections, separates the sections&#39; along their longitudinal lengths. The screws extend through aperatures of the first coupling section, through the pin separating the first and second sections and into the second coupling section. Each coupling section forms a half of coupling  100 . Each half has an arcuate surface  158   a ,  158   b  and an opposite flat surface  160   a ,  160   b . Pin or spacer has a diameter sufficient to prevent the flat surfaces  160   a ,  160   b  along their longitudinal lengths from abutting each other. Thus the sections  150 ,  152  do not abut each other. 
     The clearance  300  between the sections  150 ,  152  and in particular flat surfaces  160   a ,  160   b  provides a clearance  162  between a surface  129   á  defining coupling first recess  129   a  and a surface  103   á  defining plunger flange  103   a . The clearance between flat surfaces  160   a ,  160   b  also provides a clearance  164  between a surface  131   á  defining coupling second recess  131   a  and a surface  101   á  defining adaptor flange  101   a . Each of the recess defining surfaces  129   á ,  131   á  form a radially recessed surface which is circumferential. Each of the flange defining surfaces  101   á ,  103   á  form a radial surface which is circumferential. The clearances  162 ,  164  between the flange surfaces  101   á ,  103   á  and coupling recess defining surfaces of  129   á ,  131   á  are radial clearances. The clearances extend in the radial direction and span the entire overlap between surfaces  101   á ,  103   á  and surfaces  129   á ,  131   á.    
     Clearance  162  is also provided between portion  129   b  of coupling first end  129  and surface  1135   a  of recess  135 . The clearance is also radial and spans the entire overlap of surfaces. Clearance  164  is also provided between portion  131   b  of coupling second end  131  and surface  141   a  of recess  141 . The clearance is also radial and spans the entire overlap of surfaces. 
     The clearances allow for plunger first end  103 , adaptor first end  101 , and coupler  100  to shift relative to each other to help accommodate any misalignment between plunger  104 , plunger adaptor  102 , and coupler  100  along their axis. 
     As can be seen, the longitudinal length  107  extends a distance, herein referred to as “X”, between an end surface  166  at plunger first end  103  and an end surface  168  of plunger adaptor first end  101  when coupler  100  connects plunger  104  to plunger adaptor  102 . The distance X is about the axial distance between an end wall  170  at first coupler end  129  and an end wall  172  at second coupler end  131 . The distance “X” is equal to or greater than the length of plunger  104  measured along the plunger&#39;s longitudinal axis, less the stroke length  171  of the pump. The distance “X” should be at least a length, measured in the axial and longitudinal direction  140 , sufficient to enable a servicer, from the well, to move end surface  139   a  of plunger second end  139  in the axial direction  140  out of stuffing box  125 , and through and out of pump frame opening  174  and into well  114 , when the plunger is at the beginning of its discharge stroke, and the coupling is removed from the plunger  104  and adaptor  102 . 
     To remove the plunger, a servicer would adjust the pump so that the plunger is at the beginning of its discharge stroke. (See  FIG. 5 ) The servicer would remove coupling  106  and gland nut  176  from stuffing box  125 . The plunger  104  would then be pulled out from well  114  without disassembling the suction manifold  178 , discharge manifold  180 , fluid cylinder block  182 , suction valve assembly  184 , discharge valve assembly  186 , or bolts  188  from the rest of the pump. Also the servicer does not have to remove plunger adaptor  102  from cross head  190 . The power end assembly  112  can remain coupled to the frame  116 . The plunger adaptor first end  101  may remain in the well. The power end assembly includes connecting rod  194  and crank shaft  196 , and cross head  190 . 
     When coupling  100  is connected to plunger  104  and plunger adaptor  102  and in well  114 , the pump assembly is in an orientation which can be considered an assembled orientation. When coupling  100  is not connected to plunger  104  and plunger adaptor  102  but plunger adaptor first end and plunger first end are still in well  114 , the pump assembly is in an orientation which can be considered a partially disassembled orientation. In the partially disassembled orientation the plunger and plunger adaptor are not connected. In all other respects the assembly is the same. The servicer may select the orientation. 
     The fluid end assembly  110  includes suction manifold  178 , discharge manifold  180 , fluid cylinder block  182 , suction valve assembly  184 , and discharge valve assembly  186 . Notably removal of plunger  104  does not require disassembly of the fluid end assembly or uncoupling the fluid end assembly from frame  116 .