Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B53/00—Component parts, details or accessories not provided for in, or of interest apart from, groups F04B1/00 - F04B23/00 or F04B39/00 - F04B47/00
  • F04B53/007—Cylinder heads
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B19/00—Machines or pumps having pertinent characteristics not provided for in, or of interest apart from, groups F04B1/00 - F04B17/00
  • F04B19/20—Other positive-displacement pumps
  • F04B19/22—Other positive-displacement pumps of reciprocating-piston type
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B53/00—Component parts, details or accessories not provided for in, or of interest apart from, groups F04B1/00 - F04B23/00 or F04B39/00 - F04B47/00
  • F04B53/10—Valves; Arrangement of valves
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B53/00—Component parts, details or accessories not provided for in, or of interest apart from, groups F04B1/00 - F04B23/00 or F04B39/00 - F04B47/00
  • F04B53/10—Valves; Arrangement of valves
  • F04B53/102—Disc valves
  • F04B53/1022—Disc valves having means for guiding the closure member axially
  • F04B53/1025—Disc valves having means for guiding the closure member axially the guiding means being provided within the valve opening
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B53/00—Component parts, details or accessories not provided for in, or of interest apart from, groups F04B1/00 - F04B23/00 or F04B39/00 - F04B47/00
  • F04B53/10—Valves; Arrangement of valves
  • F04B53/102—Disc valves
  • F04B53/1032—Spring-actuated disc valves
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B53/00—Component parts, details or accessories not provided for in, or of interest apart from, groups F04B1/00 - F04B23/00 or F04B39/00 - F04B47/00
  • F04B53/14—Pistons, piston-rods or piston-rod connections
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B53/00—Component parts, details or accessories not provided for in, or of interest apart from, groups F04B1/00 - F04B23/00 or F04B39/00 - F04B47/00
  • F04B53/16—Casings; Cylinders; Cylinder liners or heads; Fluid connections
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B53/00—Component parts, details or accessories not provided for in, or of interest apart from, groups F04B1/00 - F04B23/00 or F04B39/00 - F04B47/00
  • F04B53/16—Casings; Cylinders; Cylinder liners or heads; Fluid connections
  • F04B53/162—Adaptations of cylinders
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B53/00—Component parts, details or accessories not provided for in, or of interest apart from, groups F04B1/00 - F04B23/00 or F04B39/00 - F04B47/00
  • F04B53/22—Arrangements for enabling ready assembly or disassembly

Definitions

• the present invention is related to reciprocating plunger and piston-type 5 pumps which are used, for example, in oil well service operations.
• the invention is related to an improved cross-bore geometry for the fluid end of such pumps.
• Plunger pumps for the oilfield industry typically include a power end and a fluid end.
• the fluid end generally includes a plunger which is positioned in a 10 plunger bore and is reciprocated by the power end, an access bore which is
• the plunger is reciprocated in the plunger bore to alternately draw fluid into the pump through the suction valve and then force the fluid out of the pump through 15 the discharge valve.
• the fluid end is subject to very high frequency and large magnitude pressure pulsations. These pressure pulsations generate large stress concentrations at the intersections of the bores. In cross- bore geometries in which the bore intersections form relatively sharp edges, 20 these stress concentrations may cause fatigue cracks to form in the fluid end proximate the intersections. In some prior art pumps, the intersecting edges of the bores are machined to have quasi radii and chamfered features in an attempt to smooth the bore intersections. Although smoothing the bore intersections in this manner may reduce the stress concentrations to a certain extent, the cross- 25 bore geometries of extreme service pumps remain susceptible to developing excessive stress concentrations due to the limitations imposed by the current configurations of the bore intersections.
• a reciprocating pump comprising a fluid end housing having a number of plunger sections, each plunger section including a plunger bore within which a plunger is slidably received, a suction bore within which a suction valve is positioned, a discharge bore within which a discharge valve is positioned, and a cross bore chamber which is located between said bores and is configured as a surface of revolution.
• Each of said bores intersects the cross-bore chamber to thereby define a respective cross curve which is spatially separated from each adjacent cross curve.
• the cross- bore chamber defines a single, contiguous surface which extends around and 5 between all of said cross curves.
• the cross-bore chamber is configured as an ellipsoid.
• the ellipsoid may comprise a first axis which is coaxial with a centerline of the plunger bore and a second axis which is coaxial with at least one of a centerline of the suction bore 10 and a centerline of the discharge bore.
• the ellipsoid may comprise a first axis which is coaxial with a centerline of the plunger bore and a second axis which is parallel to but offset from at least one of a centerline of the suction bore and a centerline of the discharge bore.
• the ellipsoid may comprise a first axis which is parallel to but offset from a centerline of the plunger 15 bore and a second axis which is coaxial with at least one of a centerline of the suction bore and a centerline of the discharge bore.
• the ellipsoid may comprise a first axis which is parallel to but offset from a centerline of the plunger bore and a second axis which is parallel to but offset from at least one of a centerline of the suction bore and a centerline of the discharge bore.
• each plunger section further comprises an access bore which intersects the cross-bore chamber to thereby define a corresponding cross curve that is spatially separated from each adjacent cross curve.
• the cross-bore chamber defines a single, contiguous surface which extends around and between all of said cross 25 curves.
• the cross-bore chamber may be configured as an ellipsoid.
• the access bore may be generally aligned with the plunger bore and the suction bore may be generally aligned with the discharge bore, and the access and plunger bores may be oriented at an angle of generally ninety degrees relative to the suction and discharge bores.
• the ellipsoid may 30 comprise a first axis which is coaxial with a centerline of the plunger bore and a second axis which is coaxial with at least one of a centerline of the suction bore and a centerline of the discharge bore.
• the ellipsoid may comprise a first axis which is coaxial with a centerline of the plunger bore and a second axis which is parallel to but offset from at least one of a centerline of the suction bore and a centerline of the discharge bore.
• the ellipsoid may comprise a first axis which is parallel to but offset from a centerline of the plunger bore and a second axis which is coaxial with at least one of a centerline of the suction bore and a centerline of the discharge bore.
• the ellipsoid 5 may comprise a first axis which is parallel to but offset from a centerline of the plunger bore and a second axis which is parallel to but offset from at least one of a centerline of the suction bore and a centerline of the discharge bore.
• the plunger bore, the suction bore and the discharge bore are oriented at an angle of
• the ellipsoid may comprise a first axis which is coaxial with a centerline of the plunger bore and a center point which is located at an intersection of the plunger bore, the suction bore and the discharge bore.
• the ellipsoid may comprise a first axis which is coaxial with a centerline of the plunger bore and a 15 center point which is offset from an intersection of the plunger bore, the suction bore and the discharge bore.
• the ellipsoid may comprise a first axis which is parallel to but offset from a centerline of the plunger bore and a center which is located at an intersection of the plunger bore, the suction bore and the discharge bore.
• the ellipsoid may comprise a first axis which is 20 parallel to but offset from a centerline of the plunger bore and a center which is offset from an intersection of the plunger bore, the suction bore and the discharge bore.
• the present invention is also directed to a method of reducing stress concentrations in a fluid end housing of a reciprocating pump, the fluid end 25 housing having a number of plunger sections, each plunger section including a plunger bore within which a plunger is slidably received, a suction bore within which a suction valve is positioned and a discharge bore within which a discharge valve is positioned.
• the method comprises forming a cross-bore chamber between said bores, said cross-bore chamber being configured as a surface of 30 revolution, wherein each of said bores intersects the cross-bore chamber to
• the cross-bore chamber defines a single, contiguous surface which extends around and between all of said cross curves.
• the cross-bore chamber may be configured as a spheroid.
• an improved cross-bore geometry is obtained by creating a cross-bore chamber at the intersection of the 5 plunger bore, the suction bore, the discharge bore and, if present, the access bore.
• the cross-bore chamber is configured as a surface of revolution which is created by rotating a two-dimensional curve around a reference axis.
• the cross-bore chamber may be configured as an ellipsoid, a particular case of which is a sphere.
• Figure 1 is a perspective, partial cut-away view of a prior art plunger pump 20 in which the cross-bore geometry of the present invention may be incorporated;
• Figure 2 is a cross sectional view of the fluid end of the plunger pump shown in Figure 1 ;
• Figure 3 is a cross sectional view similar to Figure 2 but with the internal components of the fluid end removed for clarity;
• Figure 4 is a schematic representation of the cross bore geometry in
• Figure 5 is a perspective, cut-away view of an embodiment of a fluid end of the present invention having an illustrative cross bore geometry
• Figure 6 is a cross sectional view of the fluid end shown in Figure 5;
• Figures 7-9 are cross sectional views of additional embodiments of fluid ends having differing illustrative cross-bore geometries.
• Figure 10 is a cross sectional view of another embodiment of a fluid end in which the cross-bore geometry of the present invention may be incorporated.
• DETAILED DESCRIPTION OF THE INVENTION An example of a prior art plunger pump in which the cross-bore geometry of the present invention may be incorporated is shown in Figure 1.
• the plunger pump 10 comprises a power end 12 and a fluid end 14. 5
• the power end 12 includes a gear reducer assembly 16 which is driven by a suitable motor (not shown).
• the gear reducer assembly 16 drives a crankshaft 18.
• the crankshaft 18 is rotatably connected to one end of a connecting rod 20, the opposite end of which is pivotally connected to a crosshead 22 that is supported for linear movement in a corresponding guide bore 24.
• the fluid end 10 14 includes a number of plungers 26 (only one of which is shown in Figure 1 ), each of which is slidably mounted in a respective plunger bore 28 and is connected to a respective crosshead 22 by a plunger rod 30.
• rotary motion of the crankshaft 18 is converted by the connecting rod 20 into linear reciprocating motion of the crosshead 22, which in turn reciprocates the plunger 15 26 in the plunger bore 28.
• the fluid end 14 comprises a laterally extending housing 32 having a number of plunger sections (in this case five) which are each aligned with a corresponding plunger 26.
• the middle plunger section is shown in greater detail in Figures 2 and 3. With the exception noted below, the middle plunger section is 20 similar to the remaining plunger sections.
• the middle plunger section includes a cross bore arrangement comprising the plunger bore 28, an access bore 34 which is generally aligned with the plunger bore, a suction bore 36 which is generally perpendicular to the plunger bore, and a discharge 25 bore 38 which is generally aligned with the suction bore.
• the plunger 26 is positioned in the plunger bore 28 and is sealed thereto by, e.g., an annular packing 40, which in the embodiment shown in Figure 2 is mounted in a stuffing box 42 that is secured to the housing 32 by a number of cap screws 44.
• the access bore 34 is sealed by a plug 46 which is secured to 30 the housing 32 by a first retainer nut 48.
• a suction valve 50 is positioned in the suction bore 36 between the plunger bore 28 and an inlet port 52.
• a discharge valve 54 is positioned in the discharge bore 38 between the plunger bore 28 and a pressure tap fitting 56 which is secured in the discharge bore by a second retainer nut 58.
• the discharge bores 38 of the remaining bore sets are sealed by plugs 60 (Fig.
• the inlet ports 52 of the several plunger sections are connected to an inlet manifold 64 having a pump inlet 66 which is connectable to, e.g., a source of well service fluid (not shown).
• a source of well service fluid not shown
• each plunger section is shown more clearly in Figure 3, which is similar to Figure 2 but with the internal components of the plunger section removed for clarity.
• the plunger bore 20 28 and the access bore 34 comprise respective centerlines C P and C A which are coaxial along an axis X
• the suction bore 36 and the discharge bore 38 comprise respective centerlines C S and C D which are coaxial along an axis Z that is perpendicular to the axis X.
• the suction bore 36 intersects the plunger bore 28 along a first curve 68
• the discharge 25 bore 38 intersects the plunger bore along a second curve 70.
• the curves 68, 70 define relatively sharp edges between the intersecting bores.
• an improved cross-bore geometry has been developed which greatly reduces the stress concentrations that can lead to fatigue cracks in the fluid end originating at and propagating from the bore 10 intersections.
• the improved cross-bore geometry is obtained by creating a
• the cross-bore chamber is configured as a surface of 15 revolution which is created by rotating a two-dimensional curve 74 around one of the X, Y or Z axes.
• the X, Y and Z axes are defined as the reference axes for the surface of revolution.
• the X axis may be coaxial with one or both of the plunger bore centerline C P and the access bore centerline C A and the Z axis may be coaxial 20 with one or both of the suction bore centerline C S and the discharge bore
• the two-dimensional curve 74 can have any practical configuration, provided that it comprises a diameter which is greater than the diameter of the 25 largest of the plunger bore 28, the access bore 34, the suction bore 36 and the discharge bore 38.
• the curve 74 is an ellipse which is centered at the origin O of the X, Y and Z axes.
• the surface of revolution defining the cross-bore chamber 72 has the general shape of an ellipsoid which is centered about the origin O and is 30 created by rotating the ellipse 74 about the X axis.
• the ellipsoid may have any configuration which is defined by the following standard equation:
• cross-bore chamber 72 defines a respective cross curve 28a, 34a, 36a and 38a.
• the particular shape of each cross curve will of course depend on the shape of the surface of revolution which defines the cross-bore chamber 72.
• the cross-bore chamber 72 provides a single, smooth contiguous connecting surface between each of the cross curves.
• This single, smooth contiguous connecting surface is created by virtue of the fact that, rather than intersecting each other, the plunger bore 28, the access bore 34, the suction bore 36 and the discharge bore 38 intersect the cross-bore chamber 72.
• the smooth contiguous connecting surface formed by the cross-bore chamber 72 extends around and between the cross curves 28a, 34a, 36a and 38a.
• the stress concentrations in the cross-bore geometry are significantly reduced, and 20 the fluid end is therefore less susceptible to fatigue crack formation.
• the cross-bore chamber 72 comprises a spherical configuration.
• the plunger bore centerline C P and the access bore centerline C A are coaxial with the X axis and the suction bore centerline C S and the discharge 25 bore centerline C D are coaxial with the Z axis.
• the spherical configuration of the cross-bore chamber 72 forms a single, smooth contiguous connecting surface 76 between and around the cross curves 28a, 34a, 36a and 38a.
• the bore with the largest diameter is the suction bore 36, and the sphere defining the cross-bore chamber 72
• the cross-bore chamber 72 comprises a diameter which is larger than the diameter of the suction bore.
• the shape and size of the surface of revolution which is used to form the cross-bore chamber 72 may be
• cross bore geometry of the present invention is determined empirically for a particular cross-bore geometry in order to provide desired stress and flow characteristics for the fluid end. Further illustrative and non-limiting embodiments of the cross bore geometry of the present invention are shown in Figures 7-9.
• the cross bore geometry shown in Figure 7 is similar to that shown in Figure 6. In the
• the X axis is offset from the plunger 5 bore centerline C P and the access bore centerline C A , which in this case are
• the X axis is offset in the Z direction 0.50" from the plunger bore centerline C P toward the suction bore 36.
• the X 10 axis is coaxial with the plunger bore centerline C P and the access bore centerline C A , but the Z axis is offset from the suction bore centerline C S and the discharge bore centerline C D , which in this instance are coaxial.
• the Z axis is offset in the X direction 0.20" from the discharge bore centerline C D toward 15 the access bore 34.
• the X axis is offset from the plunger bore centerline C P and the access bore centerline C A , which in this instance are coaxial, and the Z axis is offset from the suction bore centerline C S and the discharge bore centerline C D , which in this case are 20 also coaxial.
• the cross-bore chamber 72 is defined by a sphere having a diameter of 8.50
• the X axis is offset in the Z direction 0.50" from the plunger bore centerline C P toward the suction bore 36
• the Z axis is offset in the X direction 0.20" from the discharge bore centerline C D toward the access bore 34.
• FIG. 25 Another example of a fluid end in which the cross-bore geometry of the present invention may be incorporated is shown in Figure 10.
• the fluid end of this embodiment, generally 14', is described more fully in U.S. Patent No.
• the fluid end 14' comprises a Y-shaped cross bore arrangement in which the 30 access bore is omitted and the plunger bore 26, the suction bore 36 and the
• discharge bore 38 are oriented approximately 120° from each other.
• a cross-bore chamber (not shown) may be machined into the fluid end to provide the advantages described above.
• the cross-bore chamber may comprise a surface of revolution, such as an ellipsoid, which is centered at the origin O of the X, Y and Z reference axes.
• the X axis may be either aligned with or offset from the plunger bore centerline C P , and the origin O of the reference axes may be located at or offset from the intersection of the plunger bore

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• 2015
  • 2015-05-22 MX MX2016015372A patent/MX2016015372A/es unknown
  • 2015-05-22 CA CA2949708A patent/CA2949708C/en active Active
  • 2015-05-22 US US15/311,504 patent/US20170082103A1/en not_active Abandoned
  • 2015-05-22 EP EP15796267.1A patent/EP3146210B1/en active Active
  • 2015-05-22 CN CN201580034503.3A patent/CN106460820B/zh active Active
  • 2015-05-22 WO PCT/US2015/032300 patent/WO2015179839A1/en active Application Filing

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