COUPLING ASSEMBLY FOR A POWER END AND A FLUID END OF A PUMP

A mounting assembly mounts a fluid end unit to a power end unit and includes first and second end members, and a coupling. A first end of the first end member is a threaded shaft configured to be received in a mounting aperture of a power end unit. A first end of the second end member is a threaded shaft configured to be received in a mounting aperture of a fluid end unit corresponding to the mounting aperture of the power end unit. The coupling couples and extends the first end member and the second end member and may be removed therefrom without changing a relative position of the second end member to the first end member.

TECHNICAL FIELD

The present disclosure relates to the field of oil and gas extraction and, in particular, pumps used for oil and gas extraction.

BACKGROUND

Pumps used in oil and gas extraction, such as with hydraulic fracturing, are high-powered pumps that typically include two primary mechanisms, a power end (e.g., power end unit) and a fluid end (e.g., a fluid end unit). The power end unit produces or otherwise outputs mechanical energy that operates the fluid end unit, which in turn pumps liquid at high pressures (e.g., up to approximately 15,000 psi or more) and/or flow rates (e.g., up to approximately 100 barrels per minute or more) depending on the application.

The fluid end unit is removably mounted to and supported by the power end unit. Structural components (e.g., stationary frames, plates, bases, or other members) of the power end unit and the fluid end unit are coupled to each other to prevent relative movement therebetween, while reciprocating components of the power end unit (e.g., one or more pistons or rods that move reciprocally relative to the structural components) are coupled to corresponding reciprocating components of the fluid end unit (e.g., one or more corresponding pistons, rods, or plungers) that are thereby moved in a reciprocating manner relative to the structural components to pump the liquid. For example, the power end unit includes one or more structural members positioned opposite and facing towards corresponding structural members of the fluid end unit, which are coupled to each other with solid rods (e.g., bolts). The fluid end unit may be coupled to and supported by multiple rods surrounding each set of reciprocating components (e.g., four or more rods surrounding each set of pistons/plungers, such as twelve rods for a triplex pump having three sets of pistons/plungers, or twenty rods for a quintuplex pump having five sets of pistons/plungers). Each of the rods has generally the same length extending generally horizontally or laterally between a first end coupled to the structural member of the power end unit and a second end coupled to the structural member of the fluid end unit. More specifically, the first end of each rod is threaded and received within a corresponding threaded aperture of the structural member of the power end unit. The second end is threaded and extends through a non-threaded aperture in the structural member of the fluid end unit with a nut being received on the threaded end to couple the rod to the fluid end unit.

SUMMARY

In use, the rods described above are subject to fatigue and may fail from push/pull loading caused by the reciprocating action of the pistons/plunger operating at high pressures, other vibrations associated with operation of the power end unit and/or the fluid end unit, and from supporting the fluid end unit (e.g., weighing up to approximately 5000 pounds or more) on the power end unit. Upon failure of a single rod, the rod must be removed and replaced, which requires removing the fluid end unit from the power end unit. This process requires independently supporting the fluid end unit and disconnecting each solid rod from the fluid end unit, which may require equipment not readily available in the field (e.g., a crane to support the fluid end unit) and significant labor (e.g., three people and several total man hours) and result in significant down time (e.g., while waiting for equipment and/or during the repair itself).

In contrast, the teachings herein describe a mounting system compatible with existing/conventional and/or new power end units and fluid end units whereby failure at a single attachment location may be corrected without entirely removing the fluid end unit and/or without disconnecting the fluid end unit at each of several attachment locations.

One embodiment of a mounting assembly for mounting a fluid end unit of a pump to a power end unit of the pump described herein includes a first end member, a second end member, and a coupling. The first end member extends between a first end and a second end. The first end of the first end member is a threaded shaft configured to be received in a mounting aperture of a power end unit to couple the first end member thereto. The second end member extends between a first end and a second end. The first end of the second end member is a threaded shaft configured to be received in a mounting aperture of a fluid end unit corresponding to the mounting aperture of the power end unit. The coupling is configured to removably couple to and extend between the second end of the first end member and the second end of the second end member. The coupling may be configured to be coupled to the second end of the first end member and the second end of the second end member without changing a relative position of the second end member to the first end member. The second end of the first member and the first bore may be cooperatively threaded to couple first end member to the coupling, and the second end of the second end member and the second bore may also be cooperatively threaded to couple the second end member to the coupling. Alternatively, the second end of the first end member may include a first plurality of radial flanges and the first bore may further include a first plurality of corresponding radial recesses to receive the first plurality of radial flanges to couple the first end member to the coupling, while the second end of the second end member may also include a second plurality of radial flanges and the second bore further may include a second plurality of corresponding radial recesses to receive the second plurality of radial flanges to couple the second end member to the coupling.

One embodiment of a connector assembly for mounting a fluid end unit of a pump to a power end unit of the pump described herein comprises a first member, a second member, and a cylindrical connector. The first member includes a first threaded shaft and a second threaded shaft. The first threaded shaft is configured to couple to the power end unit, and the second threaded shaft is coaxial with and extends away from the first threaded shaft. The second member includes a first threaded shaft and a second threaded shaft. The first threaded shaft is configured to couple to the fluid end unit, and the second threaded shaft is coaxial with and extends away from the first threaded shaft. The cylindrical connector includes a first connector member and a second connector member that each form approximately one half of the cylindrical connector, and define a first threaded bore at a first axial end of the connector and a second threaded bore at a second axial end of the connector. The first threaded bore is for coupling to the second threaded shaft of the first member, and the second threaded bore is for coupling to the second threaded shaft of the second member. The connector assembly is configured to extend laterally from the power end unit to support the fluid end unit.

An embodiment of a pump described herein includes a power end unit, a fluid end unit, and a mounting system that mounts the fluid end unit to the power end unit. The power end unit includes a first structural member and a first reciprocating member, and is configured to output mechanical energy by reciprocally moving the first reciprocating member relative to the structural member. The structural member includes a plurality of first mounting locations. The fluid end unit comprises a second structural member and a second reciprocating member configured to be moved reciprocally relative to the second structural member by the first reciprocating member, and is configured to pump a liquid via the second reciprocating member. The second structural member includes a plurality of second mounting locations that are each aligned with an associated one of the first mounting locations. The mounting system that mounts the fluid end unit to the power end by coupling the first structural member to the second structural member. The mounting system includes a plurality of mounting assemblies that each comprise a first end member, a second end member, and a coupling. The first end member is removably coupled to the first structure at one of the first mounting locations. The second end member is removably coupled to the second structure at the second mounting location associated with the first mounting location. The coupling includes a first end and a second end. The first end is removably coupled to the first end member, which may be with a first threaded connection, and the second end is removably coupled to the second end member, which may be with a second threaded connection. Each mounting assembly may be removed from the pump without moving the fluid end unit relative to the power end unit.

DETAILED DESCRIPTION

As shown inFIG. 1, a pump1includes a power end unit10and a fluid end unit20mounted to the power end unit10with a mounting system100. The power end unit10is configured as described above and includes one or more structural members12(e.g., a mounting or stationary member, such as a plate or frame member), a plurality of reciprocating members14(e.g., pistons, rods, etc.) extending and reciprocating through or between the structural member12, and a plurality of mounting apertures (not shown) at mounting locations of the structural member12. The fluid end unit20is configured as described above and includes a structural member22(e.g., a mounting or stationary member, such as a plate or frame member), a plurality of reciprocating members24(e.g., pistons, plungers, rods, etc.) extending and reciprocating through and between the structural member22, and a plurality of mounting apertures (not shown) at mounting locations in the structural member22that are aligned with the mounting locations of the structural member12. The structural member12of the power end unit10is coupled to the structural member22of the fluid end unit20by the mounting system100to hold and support the fluid end unit20in a fixed relationship with the power end unit10, while each reciprocating member14of the power end unit10is coupled (directly or indirectly) to a corresponding one of the reciprocating members24of the fluid end unit20to reciprocate therewith.

The mounting system100includes a plurality of mounting assemblies110(e.g., rod or bolt assembly, or connector). For example, four mounting assemblies110may be associated with and positioned around each pair of reciprocating members14,24. Each mounting assembly110is configured to be installed and/or removed from the pump1independent of each other mounting assembly110and without removing the fluid end unit20from the power end unit10. Stated differently, each mounting assembly110is configured to couple the power end unit10to the fluid end unit20in a manner that does not require changing a relative position of the power end unit10to the fluid end unit20as the mounting assembly110is installed or removed.

As shown inFIGS. 2A-2C, each mounting assembly110generally includes a first end member120configured to couple to the structural member12of the power end unit10, a second end member140configured to couple to the structural member22of the fluid end unit20, and a coupling160(e.g., a shaft, shank, or coupling subassembly) extending between and removably coupling the first end member120to the second end member140. With each mounting assembly110being configured as an assembly with multiple, smaller separable components, the mounting assembly110may be disassembled and removed from the pump1, as well as inserted and assembled in the pump1, independent of the other mounting assemblies110and without removal of the fluid end unit20from the power end unit10. Stated differently and as discussed in further detail below, the coupling160is configured to couple the first end member120to the second end member140in a manner that does not require changing a relative position of the first end member120the second end member140and, thereby, does not require changing a relative position of the power end unit10to the fluid end unit20.

As shown inFIGS. 3A-3C, the first end member120is a unitary member having a first end122(e.g., a first or power end portion, segment, or shaft), a second end124(e.g., a second or coupling end portion, segment, or shaft), and a body126(e.g., a central, intermediate, or body portion or segment) extending between the first end122and the second end124. The first end122is configured to removably couple to the structural member12of the power end unit10. The first end122forms a threaded shaft having a central axis, which is configured to be threaded into the threaded mounting aperture of the structural member12of the power end unit10(e.g., having a corresponding diameter, axial length, and thread pattern). The first end122is configured to provide a sufficiently strong connection to the structural member12of the power end unit10to support the fluid end unit20thereon, which may be provided, for example, with a sufficiently large axial length, sufficiently large diameter, and appropriate thread pattern depending on the particular power end unit10and fluid end unit20. In one example, the axial length is approximately 2 inches measured from the body126to be inserted into the mounting aperture, the diameter is between approximately one and 2.5 inches, such as approximately 2 inches, and the thread pattern is eight threads per inch. The first end122may be configured in other manners (e.g., different axial length, diameter, thread pattern, and connection to the structural member12, such as with a nut engaging an opposed surface of the structural member12), as may be appropriate for a given application (e.g., different power end unit10with different existing or designed mounting apertures, for example, being different in number and/or length, diameter, and thread pattern).

The second end124of the first end member120is configured to removably couple to the coupling160. The second end124forms a threaded shaft that is generally coaxial with the first end122. The second end124is configured to be received or positioned in a first bore166of a first end162of the coupling160(i.e., between two coupling members160a,160b) as discussed in further detail below. The second end124provides a sufficiently strong connection to the coupling160to support the fluid end unit20, which may be provided with a sufficiently large axial length, sufficiently large diameter, and appropriate thread pattern, or other configurations/dimensions as may be required for a particular application (e.g., particular power end unit10and fluid end unit20). In some embodiments, the second end124may have the same axial length, diameter, and thread pattern, or other configurations/dimensions, as the first end122.

The body126is generally coaxial with the first end122and the second end124. At all positions along its axial length, the body126has a larger cross-sectional diameter than the first end122and the second end124, and may include filleted transitions moving in an axial direction from the body126to the smaller diameters of the first end122and the second end124. The body126forms a first shoulder128and a second shoulder129(e.g., extending at approximately 90 degrees from the central axis). The first shoulder axially engages a surface of the structural member12(i.e., the surface facing the fluid end unit20), thereby allowing the first end member120to be tightened in the mounting aperture to be retained therein by pressing against the surface of the structural member12and causing teeth of the first end122to press against teeth in the mounting aperture of the structural member12. By engaging and bearing against the surface of the structural member12around the mounting aperture, the shoulder128may additionally prevent pivoting of the first end member120relative to the structural member12(e.g., from supporting the weight of the fluid end unit20positioned laterally thereto). In the mounting assembly110, the second shoulder129is positioned adjacent the coupling160and is spaced apart therefrom (e.g., ⅛ turn) or may directly engage the coupling160. The body126additionally includes hexagonal faceted surfaces130, which are flats or flat regions extending in a circumferential direction. The faceted surfaces130are configured to receive and be engaged by a conventional wrench or torque wrench for tightening the first end member120within the mounting aperture and to the structural member12of the power end unit10. The faceted surfaces130extend between the shoulders128,129the entire axial length of the body126. According to other embodiments, the faceted surfaces130may extend only a portion of the axial length of the body126. The body126may have a length of approximately 2.75 inches, a maximum diameter of approximately 3 inches, and spacing of the faceted surfaces130of approximately 2.75 inches, or other dimensions as may be suitable for a particular application (e.g., greater or lesser diameter, length, and/or facet spacing).

The first end member120may, for example, be made from a steel alloy, or other suitable material providing suitable characteristics to mount the fluid end unit20to the power end unit10(e.g., strength and fatigue characteristics, environmental tolerances, etc.). The end member120may, for example, be formed from a unitary piece of stock material, for example, cylindrical stock that is machined to include its various features such as ends122,124having particular diameters and thread patterns, faceted surfaces130(e.g., flats), etc. The first end member120may, for example, have an overall length of approximately 7 inches, or other length as may be appropriate for a given application.

As shown inFIG. 4A-4C, the second end member140is a unitary member having a first end142(e.g., a first or fluid end portion, segment, or shaft), a second end144(e.g., a second or coupling end portion, segment, or shaft), and a body146(e.g., a central, intermediate, or body portion or segment) extending between the first end142and the second end144. The first end142is configured to removably couple to the structural member22of the fluid end unit20. The first end142forms a shaft that is at least partially threaded, so as to receive a nut152thereon, and that is configured to be inserted through the structural member22of the fluid end unit20. An unthreaded portion of the first end142may be positioned axially inward of the threaded portion to be positioned against circumferential surfaces of the mounting aperture of the structural member22. The first end142is configured to provide a sufficiently strong connection to the structural member22of the fluid end unit20so as to support the fluid end unit20, for example, with a sufficiently large axial length, sufficiently large diameter, and appropriate thread pattern depending on the requirements and configurations of the power end unit10and the fluid end unit20. In one example, the axial length is approximately 4.5 inches of which approximately 2.5 inches form a threaded portion, and approximately 2 inches form an unthreaded portion adjacent the body146, the diameter is between approximately one and 2.5 inches, such as approximately 1.75 inches, and the thread pattern is eight threads per inch. The first end142may be configured in other manners (e.g., different axial length, diameter, thread pattern, and connection to the structural member22, such as being threaded into a threaded aperture), as may be appropriate for a given application (e.g., a different fluid end unit20with different existing or designed mounting apertures, for example, being different in number and/or length, diameter, and thread pattern). To facilitate manufacturing (e.g., locating during machining), a hole or recess (e.g., a live center) may be provided at one or more ends of the second end member140

The second end144of the second end member140is configured to removably couple to the coupling160. The second end144forms a threaded shaft that is generally coaxial with the first end142. The second end144is configured to be received or positioned in a second bore168of a second end164of the coupling160(i.e., between two coupling members160a,160b) discussed in further detail below. The second end144provides a sufficiently strong connection to the coupling160to support the fluid end unit20, which may be provided, for example, with a sufficiently large axial length, sufficiently large diameter, and appropriate thread pattern, or other configurations/dimensions as may be required for a given application (e.g., a particular power end unit10and fluid end unit20). In one example, the axial length is approximately 2 inches measured from the body146, the diameter is approximately 2 inches, and the thread pattern is eight threads per inch.

The body146is generally coaxial with the first end142and the second end144. At all positions along its axial length, the body146has a larger cross-sectional diameter than the first end142and the second end144, and may include filleted transitions to the smaller diameters of the first end142and the second end144. The body146forms a first shoulder148and a second shoulder149(e.g., extending at approximately 90 degrees from the central axis). The first shoulder148axially engages a surface of the structural member22(i.e., the surface facing the power end unit10), thereby allowing structural member22of the fluid end unit20to be tightened (i.e., compressed) between the nut152and the shoulder148. By engaging and bearing against the surface of the structural member22around the mounting aperture, the shoulder148may additionally prevent pivoting of the second end member140relative to the structural member22(e.g., from supporting the weight of the fluid end unit20positioned laterally thereto). In the mounting assembly110, the second shoulder149is positioned adjacent the coupling160and is spaced apart therefrom (e.g., ⅛ turn) or may directly engage the coupling160. The body146additionally includes hexagonal faceted surfaces150(e.g., positioned adjacent the shoulder148), which are configured to receive and be engaged by a conventional wrench to hold the second end member140in a rotational position, while the nut152is tightened to the first end142thereof. The faceted surfaces150extend between the shoulders148,149the entire axial length of the body146. According to other embodiments, the faceted surfaces150may extend only a portion of the axial length of the body146. The body146may have a length of approximately 1.5 inches, a maximum diameter of approximately 3 inches, and spacing of the faceted surfaces150of approximately 2.75 inches, or other dimensions as may be suitable for a particular application (e.g., greater or lesser diameter, length, and/or facet spacing).

The second end member140may be made from similar materials (e.g., steel alloy) and similar methods (e.g., machining from cylindrical stock) as the first end member120described above. The second end member140may have an overall length of approximately 8 inches, for example, or other length as may be appropriate for a given application.

As shown inFIGS. 5A-5D, the coupling160is a multicomponent subassembly that forms an intermediate or central shaft or shank that extends between and couples the first end member120to the second end member140to form a rigid mounting assembly110. The coupling160includes first and second coupling members160a,160bthat individually form approximate circumferential halves of the coupling160, which are positioned around the second ends124,144of the first and second end members120,140. The first and second coupling members160a,160bmay be approximate mirror images of each other. The first and second coupling members160a,160bextend circumferentially approximately 180 degrees (or less) between circumferential ends170a,170b,respectively, thereof (i.e., facing a tangential direction relative to the central axis), and extend axially between first axial ends162a,162band second axial ends164a,164b,thereof. With the circumferential ends170a,170bpositioned adjacent and/or engaging each other, the first and second coupling members160a,160bcooperatively form the coupling160as a generally cylindrical, rigid subassembly extending axially between the first end162and the second end164. When the coupling160is assembled, the coupling members160a,160bcompress therebetween the second ends124,144of the first and second end members120,140, which prevents rotation of the coupling160relative to the first and second end members120,140.

The first end162and the second end164of the coupling160each include a threaded bore (i.e., a first bore166and a second bore168, respectively) configured to receive and couple to the second end124of the first end member120and the second end144of the second end member140, respectively. The first bore166is cooperatively formed or defined by a first inner circumferential surface166aof the first coupling member160aand a first inner circumferential surface166bof the second coupling member160b,which face radially inward toward the central axis. The first bore166has a complementary diameter and thread pattern to the second end124of the first end member120, so as to engage and couple to the threaded portion of the second end124of the first end member120, the threads being formed on the first inner circumferential surfaces166a,166bof the first and second coupling members160a,160b,respectively. The threaded connection between the second end124and the bore166may provide for relative axial positioning therebetween. This relative axial positioning allows for adjustments to the axial length of the mounting assembly110, for example, to account for variations in relative positioning and/or other inconsistencies of the structural member12of the power end unit10and the structural member22of the fluid end unit20. The first bore166may additionally include an unthreaded region positioned axially inward of the threaded portion, which has a sufficient diameter to receive the threaded second end124, so as to allow further relative axial movement between the coupling160the first end member120. The second bore168is configured and formed similar to the first bore166with respect to the second end144of the second end member140(e.g., being defined by second inner circumferential surfaces168a,166bof the first and second coupling members160a,160bto have threaded and unthreaded regions complementary to the second end of the second end member140).

The first and second bores166,168may be in communication with each other via a third bore169having a smaller diameter than both the first and second bores166,168. The third bore169is defined or formed by third inner circumferential surfaces169a,169bof the first and second coupling members160a,160b,respectively (i.e., which face radially inward toward the central axis).

The first coupling member160aand the second coupling member160bare configured to be received around or removed from opposing sides of the second ends124,144of the first and second end members120,140, respectively, in a radial direction. This receipt and removal in a radial direction provides for installing and removing the mounting assembly110from the pump1without moving the first end member120to the second end member140and, thereby, without moving the fluid end unit20relative to the power end unit10.

The first and second coupling members160a,160bare configured to be coupled to each other with fasteners161received in corresponding apertures176a,176b,respectively, thereof. The threaded fasteners161(e.g., socket head capscrews) pull the first and second coupling members160a,160buntil the circumferential ends170a,170btightly engage each other, the inner circumferential surfaces166a,166btightly engage the second end124of the first end member120, and/or the inner circumferential surfaces168a,168btightly engage the second end144of the second end member140. The apertures176a,176band, thereby the fasteners161, are positioned radially outward of the first and second bores166,168and extend in a tangential direction relative to the central axis (e.g., generally perpendicular to the circumferential ends170a,170b). Each aperture176aof the first coupling member160amay be threaded or unthreaded and include a flange surrounding the aperture to receive a head of the fastener161thereagainst, while the apertures176bof the second coupling member160bmay be threaded to receive and engage threads of the fastener161. For example, the first coupling member160amay include eight total unthreaded apertures176a,two apertures176abeing spaced along each of two sides of each of the first and second inner circumferential surfaces166a,168a,while the second coupling member160bincludes eight corresponding threaded apertures176bsimilarly positioned along sides of the first and second inner circumferential surfaces166b,168b.The apertures176a,176bmay, for example, being configured to receive bolts having a nominal diameter of ⅜ inch with 24 threads per inch, or other suitable fasteners.

Each of the coupling members160a,160bmay, for example, be made from a steel alloy, or other suitable material providing suitable characteristics to mount the fluid end unit20to the power end unit10(e.g., strength and fatigue characteristics, environmental tolerances, etc.). The coupling members160a,160bmay, for example, be formed from a unitary piece of cylindrical stock that is machined and split to form the two coupling members160a,160b,or from separate pieces of material that are formed into the coupling members160a,160b(e.g., cast or stock material that is machined).

The coupling160may, for example, have an overall length of approximately 8.5 inches and an outer diameter of approximately 3.625 inches. The first and second bores166,168may, for example, have an overall length of approximately 2.5 inches of which the threaded portion has an axial length of approximately 2 inches and the unthreaded portion has an axial length of approximately ½ inch. The first and second bores166,168may additionally have a nominal diameter (e.g., approximately 2 inches) and thread pattern (e.g., eight threads per inch) that correspond to those of the second ends124,144of the first and second end members120,140. The third bore169may, for example, have a nominal diameter of approximately 1.5 inches. The outer diameter and bore diameters result in wall thickness of the first and second coupling members160a,160bof approximately ¾ inch at the first and second bores166,168and of approximately one inch at the third bore169. According to other exemplary embodiments, the diameters, lengths, thread pattern, and wall thicknesses may be altered to depending on the particular application.

Based on the dimensions of the first end member120, second end member140, and the coupling160, the mounting assembly110may have nominal, but adjustable, overall length of approximately 19 inches and a nominal, but adjustable, shoulder-to-shoulder axial length (i.e., between the shoulders128,148) of approximately 13 inches, or other lengths as may be required for a particular application (e.g., particular power end unit10, fluid end unit20, and required spacing therebetween).

In order to mount the fluid end unit20to the power end unit10with the mounting system100, the power end unit10is moved to a desired position (e.g., a use position), and the fluid end unit20is temporarily supported (e.g., with a crane, removable frame, etc.) in a position relative to the power end unit10with the support members12,22and corresponding mounting apertures in alignment.

The mounting assemblies110are then each coupled to the power end unit10and the fluid end unit20. The first end member120is coupled to the structural member12of the power end unit10by inserting (i.e., threading) its first end122in one of the mounting apertures in the structural member12and tightening the first end member120therein to a final torque level (e.g., 2450 ft-lbs).

The second end member140is coupled to the structural member22of the fluid end unit20by inserting its first end142through one of the mounting apertures in the structural member22and tightening the nut152on the first end142to an initial or loose torque level, which allows for subsequent adjustment. After adjustments of the second end member140relative to the coupling160or the end unit20(as discussed below), the nut152is tightened to a final torque value (e.g., 2450 ft-lbs). This coupling of the second end member140may compress the structural member22between the nut152and the shoulder148of the second end member140. The first end member120may be coupled to the power end unit10and/or the second end member140may be coupled to the fluid end unit20before or after the power end unit10and/or the fluid end unit20are moved into position, which may provide clearer access to the mounting apertures for coupling thereto.

After the first end member120is coupled to the power end unit10and the second end member140is coupled to the fluid end unit20, and after the power end unit10and the fluid end unit20are moved into their final positions relative to each other, the coupling160is coupled to the first and second end members120,140. The first and second coupling members160a,160bare positioned around the second ends124,144of the first and second end members120,140in a radial direction (i.e., being moved generally perpendicular to the central axis passing through the first end member120and the second end member140). More particularly, the inner circumferential surfaces166a,166b(forming the first bore166) of the first and second coupling members160a,160b,respectively, are moved toward each other and toward the second end124of the first end member120, such that the threads of the inner circumferential surfaces166a,166bengage and receive the threads of the second end124of the first end member120. Additionally, the inner circumferential surfaces168a,168b(forming the second bore168) of the first and second coupling members160a,160b,respectively, are moved toward each other and toward the second end144of the second end member140, such that the threads of the circumferential surfaces168a,168bengage and receive the threads of the second end144of the second end member140. Subsequently, the fasteners161are inserted in each of the apertures176a,176band are tightened, so as to draw the first and second coupling members160a,160btoward each other. The fasteners161may be tightened in a single stage to a final torque level, or in multiple stages, such as initially to a preliminary or loose torque level and subsequently to a final torque level. The fasteners161bring the first and second coupling members160a,160binto tight engagement with each other and/or to compress the second ends124,144of the first and second end members120,140, respectively.

As may be needed after the coupling160is coupled to the first end member120and the second end member140, the second end member140may be adjusted and/or further tightened. For example, the second end member140may be adjusted by rotating the second end member140relative to the coupling160resulting in axial displacement relative to the coupling160(i.e., via the threaded connection in the bore168), so as to engage a surface of the structural member22. The nut152is then further tightened to its final torque level on the first end142of the second end member140. In some installation methods, the second end member140may still be adjusted after the fasteners161are tightened to a final torque level (e.g., whether in one or multiple stages).

After each mounting assembly110of the mounting system100is installed according to the process described above, the temporary support is removed from the fluid end unit20.

Individual mounting assemblies110may also be removed and/or replaced, for example, upon failure of one of the mounting assemblies110or component thereof. Removal and replacement of one of the mounting assemblies110can be performed independent of other mounting assemblies110and without entirely removing the fluid end unit20from the power end unit10, or otherwise moving the fluid end unit20relative to the power end unit10. To remove the mounting assembly110, the coupling160is removed from the first and second end members120,140by removing the fasteners161and moving the coupling members160a,160bout of engagement with the second ends124,144of the first and second end members120,140. The first end member120may then be removed or decoupled (i.e., by unthreading) from the power end unit10, and the second end member140may then be removed or decoupled by removing the nut152, and extracting the first end142from the mounting aperture from the fluid end unit20. If it is determined that the first end member120and/or the second end member140do not require replacement (e.g., because a failure occurred with another component of the mounting assembly110), the first end member120and/or the second end member140may optionally not be removed.

To install an individual or replacement mounting assembly110(e.g., in place of a failed mounting assembly) or components thereof, the installation process described above is performed by coupling the first end member120to the power end unit10as may be required; coupling the second end member140to the fluid end unit20as may be required; coupling the coupling160to the first and second end members120,140; and as needed, adjusting and/or tightening the first and second end members120,140.

As shown inFIGS. 6A-6D, another exemplary embodiment of a mounting assembly210includes a first end member220, a second end member240, and a coupling260. As compared to the mounting assembly110, second ends224and244of the first and second end members220,240, respectively, and the coupling260include corresponding retention features that are non-threaded. The first end member220includes a first end222and a body224that are configured as described above for the first end member120. The second end member240similarly includes a first end242and a body246that are configured as described above for the second end member240. Instead, the second end224of the first end member220and/or the second end244of the second end member260include a series of radially extending flanges230,250(e.g., barbs) that are received in a series of corresponding recesses of the coupling260.

The second end224of the first end member220includes a plurality of radially-extending flanges230having circular peripheries. The radial flanges230are spaced apart along an axis of the first member220(e.g., are coaxial). The radial flanges230may have different radii from each other, for example, reducing in radius the further the radial flange230is spaced apart from the body246. Each individual radial flange230may, itself, however, have a constant radius. The radial flanges230are spaced apart by intermediate shafts232, which may include a tapered portion232a(i.e., having a reducing radius) and/or a non-tapered portion232b(i.e., having a constant radius). The tapered portion may engage a corresponding tapered portion of the coupling260, which is then compressed between one of the radial flanges230and the tapered portion232aof the shaft232in an axial direction. The second end244of the second end member240similarly includes radially extending flanges250and intermediate shafts252with tapered and non-tapered portions252a,252b,or may include other retention features (e.g., threads). According to other exemplary embodiments, the radial flanges230,250may have non-circular peripheries (e.g., ovular, square or rectangular, interrupted with separate flange or barb elements, etc.).

The coupling260is configured substantially similar to the coupling160, and includes two circumferential members260a,260b,but is adapted for receipt and retention of the second ends224,244of the first and second end members220,240. In particular, the first bore266and the second bore268include radial recesses266a,268athat are shaped to receive and tightly fit (e.g., compress) the radial flanges230,250of the first and second end members220,240in a radial direction, while also engaging axial facing surfaces of the radial flanges230,250to prevent relative axial movement therebetween. For example, the radial recesses266a,268ahave radii that are approximately equal to or slightly smaller than the constant radii of each radial flange230,250, and widths that are approximately equal to or slightly larger than the widths of the radial flanges230,250.

As shown inFIGS. 7A-7D, another exemplary embodiment of a mounting assembly310includes a first end member320, a second end member340, and a coupling360. As compared to the mounting assembly210, second ends324and344of the first and second end members320,340, respectively, differ in their configuration of circumferential flanges330,350and intermediate shafts332,352therebetween. In particular, each circumferential flange330,350has a frustoconical outer periphery that reduces in radius moving away from the body326,346. Each successive circumferential flange330,350reduces in radius moving away from the body326,346as compared to the previous circumferential flange330,350, such that the outer peripheries of the flanges330,350cooperatively form a frustoconical shape. Intermediate shaft portions332,352between the radial flanges330,350may each have a constant radius, while each successive intermediate shaft portion332,352reduces in radius from the previous intermediate shaft portion332,352. According to other embodiments, the second ends224,244of the first and second end members220,240may have differently configured retention features from each other (e.g., threads, differently shaped radial flanges, etc.).

The coupling360is configured substantially similar to the coupling260, and includes two circumferential members360a,360b,but is adapted for receipt and retention of the second ends324,344of the first and second end members320,340. In particular, the first bore366and the second bore368include radial recesses366a,368athat are shaped to receive and tightly fit (e.g., compress) the radial flanges330,350of the first and second end members320,340. For example, the radial recesses366a,368ahave radii that are approximately equal to or slightly smaller than the reducing radii (i.e., forming a frustoconical shape) of each radial flange330,350.