Patent Description:
Covers may be used on fluid ends in the oil and gas industry, for example on fluid ends of frac pumps or mud pumps. Covers can back out of fluid ends, for example from high pressure operation of the fluid ends. Attempts to lock these covers carry extra parts, reduced efficiencies, increased operational times, complex design and operation, and increased costs. <CIT> discloses a locking assembly for a pump or fluid end. The described locking assembly is adapted to couple to a fluid end proximal to a valve cover opening, and includes an insert comprising a plurality of segments, and a cone adapted to be at least partially disposed within an opening in the insert.

Therefore, there is a need for a locking assembly that facilitates high operating pressure capabilities, sealing during operation, higher efficiencies, less parts, reduced operational times, less complex operation and design, and reduced costs.

Implementations of the present disclosure relate to a locking assembly apparatus for fluid ends, and associated components thereof.

In one implementation, a locking assembly for fluid ends includes a first actuator, the first actuator including one or more coupling surfaces. The locking assembly also includes a second actuator disposed at least partially below the first actuator. The second actuator includes a body, the body including one or more tapered interfacing surfaces. The second actuator also includes one or more coupling surfaces disposed in coupling engagement with the one or more coupling surfaces of the first actuator, and a center axis extending in a longitudinal direction through the body, where the one or more tapered interfacing surfaces taper inward at an angle relative to the center axis. The locking assembly also includes a plurality of wedges disposed about the second actuator and movable between an unlocked position and a locked position. Each wedge of the plurality of wedges includes a set of one or more external locking surfaces, and a set of one or more tapered interfacing surfaces, where the one or more tapered interfacing surfaces of each wedge is configured to engage with one of the one or more tapered interfacing surfaces of the second actuator. The locking assembly also includes a lock ring disposed about the plurality of wedges. The lock ring includes a set of one or more internal locking surfaces configured to engage with the external locking surfaces of each wedge of the plurality of wedges. The body of the second actuator comprises a plurality of guide blocks; and each wedge of the plurality of wedges comprises a guide slot formed in a respective tapered interfacing surface of the set of one or more tapered interfacing surfaces of the respective wedge, and each guide slot includes a guide block of the plurality of guide blocks disposed at least partially in the respective guide slot.

So that the manner in which the above-recited features of the disclosure can be understood in detail, a more particular description of the disclosure, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this disclosure and are therefore not to be considered as limiting the scope of the invention, which is solely defined by the appended claims.

It is contemplated that elements disclosed in one implementation may be beneficially utilized on other implementations without specific recitation.

Aspects of the disclosure relate to locking assembly apparatus and methods for fluid ends, and associated components thereof. In one aspect, the present disclosure relates to locking assembly apparatus and methods for a valve cover disposed in an opening of a fluid end.

<FIG> is a schematic isometric partial view of a fluid end <NUM> having a fluid end body <NUM> and a locking assembly <NUM> in a locked position, according to one implementation. The fluid end <NUM> includes a plurality of bores 110A-110D (bores 110A, bores 110B, and bores 110D are shown in <FIG>) formed in the side of the fluid end body <NUM>. The fluid end <NUM> illustrated includes a plurality of retainer nuts <NUM> disposed in each of the bores 110C. The fluid end <NUM> is adapted to couple to a power end <NUM> via a pony rod <NUM>. While only one pony rod <NUM> is shown, the power end <NUM> may have a pony rod that couples to each of the bores 110A (shown in <FIG>) of the fluid end <NUM>. A plunger clamp <NUM> or any other rod connector mechanism may be disposed between the fluid end <NUM> and the pony rod <NUM>. A discharge flange <NUM> may be coupled to opposing ends of the fluid end body <NUM> for connecting hoses with a discharge manifold. A locking assembly <NUM> is disposed above one of the valve covers <NUM>. The present disclosure contemplates that a locking assembly <NUM> may be disposed above each one of the valve covers <NUM> (five are illustrated). Although the locking assembly <NUM> is described herein as being used with a frac pump, the locking assembly <NUM> can be used with any other types of pumps, including but not limited to mud pumps, positive displacement pumps, etc..

The fluid end <NUM> includes a plurality of valve covers <NUM>. Each valve cover <NUM> is disposed at least partially in an opening <NUM> formed in the top of the fluid end body <NUM>. The openings <NUM> are at least part of the bores 110B. Four valve covers <NUM> are shown exposed along the top of the fluid end body <NUM>. The center valve cover <NUM> is secured to the fluid end body <NUM> by the locking assembly <NUM>. Although the locking assembly <NUM> is described herein as securing valve covers <NUM>, the locking assembly <NUM> may be used to secure a plug, a suction cover, a discharge cover, an access cover, a strainer cover, a retainer nut, and/or any other type of component (such as the cylindrical shaped valve cover <NUM> as shown in <FIG>) that needs to be secured to the fluid end body <NUM>. The fluid end <NUM> illustrated includes a retainer nut <NUM> disposed in each of the bores 110B and a valve cover <NUM> disposed in each opening <NUM>.

<FIG> is a schematic cross-sectional view of the fluid end <NUM> illustrated in <FIG> along lines 2A-2A, according to one implementation. Bores 110A, 110B, 110C, and 110D are shown <FIG>. A plunger <NUM> is shown disposed in the bore 110A, and a valve assembly <NUM> having a spring <NUM> is shown disposed in the bore 110B. A suction cover <NUM> is shown disposed in the bore 110C, and a suction valve assembly <NUM> is shown in the bore 110D. The suction cover <NUM> is disposed inwards of the retainer nut <NUM> relative to the fluid end body <NUM>. The valve cover <NUM> is a discharge cover. A valve body <NUM> as well as a valve seat <NUM> may also be disposed in the bores 110B and 110D. The fluid end body <NUM> may also include a discharge manifold <NUM> formed therein that is in selective communication with at least the bore 110B. The bores 110A-110D formed in the fluid end body <NUM> intersect within the fluid end body <NUM> at a junction <NUM>. The present disclosure contemplates that each of the suction covers <NUM> may be replaced with a cover similar to the valve covers <NUM>, and/or the retainer nuts <NUM> may be replaced with a locking assembly similar to the locking assembly <NUM>.

As shown in <FIG>, the locking assembly <NUM> is coupled to the fluid end body <NUM> by a plurality of bolts <NUM> that are disposed through a plurality of openings <NUM> formed in a lock ring <NUM> and threaded into the fluid end body <NUM>. A bolt <NUM> is disposed through each opening <NUM> to fasten the lock ring <NUM> to the fluid end body <NUM> and mount the lock ring <NUM> to an exterior surface <NUM> of the fluid end body <NUM>. The lock ring <NUM> is disposed about the plurality of wedges <NUM>. In one example, the lock ring <NUM> is a flange. The lock ring <NUM> includes an outer surface <NUM> and an inner surface <NUM>.

<FIG> is a schematic enlarged cross-sectional isometric view of the locking assembly <NUM> in a locked position, according to one implementation. <FIG> is a schematic enlarged cross-sectional side view of the locking assembly <NUM> in the locked position, according to one implementation. Referring to <FIG> and <FIG>, the locking assembly <NUM> includes a first actuator <NUM>, a second actuator <NUM> at least partially disposed within a central opening <NUM> of the first actuator <NUM>, and a plurality of wedges <NUM> that are each coupled to the first actuator <NUM>. The second actuator <NUM> is disposed at least partially below the first actuator <NUM> in the implementations shown in <FIG> and <FIG>. In one embodiment, which can be combined with other embodiments, the second actuator <NUM> is disposed at least partially above the first actuator <NUM>. In one embodiment, which can be combined with other embodiments, the second actuator <NUM> is not disposed above or below the first actuator <NUM> but is disposed about or within the first actuator <NUM>.

The lock ring <NUM> includes one or more internal locking surfaces <NUM>. In one embodiment, which can be combined with other embodiments, the locking surfaces <NUM> are part of one or more internal teeth <NUM> formed in the inner surface <NUM>. The internal locking surfaces <NUM> are angled. The internal teeth <NUM> are formed between a plurality of internal grooves <NUM> formed in the inner surface <NUM> of the lock ring <NUM>. The present disclosure contemplates that the lock ring <NUM> may be a separate component from the fluid end body <NUM>, or that the lock ring <NUM> may be integrally formed with the fluid end body <NUM> or any of the other fluid containing bodies. The present disclosure contemplates that the lock ring <NUM> may be disposed adjacent the opening <NUM> such that the sets of internal teeth <NUM> and the internal grooves <NUM> are disposed along the opening <NUM> of the fluid end body <NUM>.

The first actuator <NUM> is disposed at least partially above the second actuator <NUM>. In one example, the first actuator <NUM> is disposed at least partially about a shaft portion <NUM> of the second actuator <NUM>. The first actuator <NUM> includes the central opening <NUM> and one or more coupling surfaces <NUM>. The one or more coupling surfaces <NUM> includes a threaded inner surface. The second actuator <NUM> includes one or more coupling surfaces <NUM> interfacing with and disposed in coupling engagement with the one or more coupling surfaces <NUM> of the first actuator <NUM>. The one or more coupling surfaces <NUM> include a threaded outer surface. The one or more coupling surfaces <NUM> are formed on the shaft portion <NUM> of the second actuator <NUM>. The second actuator <NUM> includes a body portion <NUM>. In one example, the second actuator <NUM> includes and the shaft portion <NUM> that protrudes upwardly from the body portion <NUM> in a longitudinal direction D1, and the shaft portion <NUM> includes the one or more coupling surfaces <NUM>. The present disclosure contemplates that the longitudinal direction D1 may be disposed vertically, horizontally, perpendicularly, or at an oblique angle relative to gravitational forces, or in other orientations, all depending on the orientation of the fluid end body <NUM>. The longitudinal direction D1 extends upward and away from the fluid end body <NUM>, and away from the fluid end opening <NUM>.

The body portion <NUM> includes one or more tapered interfacing surfaces <NUM> and may include a recessed surface <NUM> formed in a lower surface <NUM> of the body portion <NUM>. The second actuator <NUM> also includes a center axis <NUM> extending through the body portion <NUM> and the shaft portion <NUM>. The center axis <NUM> extends through a center of the body portion <NUM> of the second actuator <NUM>. In one embodiment, which can be combined with other embodiments, the tapered interfacing surface <NUM> of the body portion <NUM> of the second actuator <NUM> tapers inward relative to the center axis <NUM> and upward in the longitudinal direction D1. The present disclosure contemplates that use of "longitudinal" or "longitudinally" herein may be parallel to gravitational forces, or, depending on orientations of the locking assemblies, may be disposed at an oblique angle relative to the gravitational forces or disposed perpendicularly to gravitational forces.

In the implementation shown in <FIG>, the first actuator <NUM> is a single integral body. The first actuator <NUM> may be formed of a plurality of bodies. In one example, the first actuator <NUM> is formed of a first body <NUM> (e.g., a nut body) and a second body <NUM> (e.g., a retainer body) coupled to the first body <NUM>. In one example, the first body <NUM> and the second body <NUM> interface along a ledge interface profile <NUM>. The second body <NUM> may include a weather shield. In one example, the second body <NUM> is coupled to the first actuator <NUM> using one or more fasteners.

An upper portion <NUM> of the first actuator <NUM> is hexagonal in shape (as shown in <FIG>) but can be any other shape configured to be gripped and rotated by a tool, such as a wrench. The upper ends of the plurality of wedges <NUM> have a shoulder portion <NUM> that is inserted in an internal groove <NUM> formed in a base portion <NUM> of the first actuator <NUM> such that the first actuator <NUM> is rotatable relative to the plurality of wedges <NUM>, and such that the wedges <NUM> can move laterally relative to the first actuator <NUM>. The internal groove <NUM> is formed in the single integral body, in an embodiment where the first actuator <NUM> is a single integral body. The internal groove <NUM> is formed in the second body <NUM> in an embodiment where the first actuator <NUM> includes the second body <NUM>. The shoulder portion <NUM> of each wedge <NUM> includes an outer surface <NUM>. The first actuator <NUM> includes the upper portion <NUM> and the base portion <NUM> disposed below the upper portion <NUM>. The base portion <NUM> is wider than the upper portion <NUM>. The base portion <NUM> of the first actuator <NUM> includes an upper surface <NUM>, a lower surface <NUM>, an upper inner surface <NUM>, a lower inner surface <NUM>, and a recessed inner surface <NUM> formed at least partially by the internal groove <NUM>.

The locking assembly also includes a flexible seal <NUM> coupled between the first actuator <NUM> and the lock ring <NUM>. In an embodiment where the first actuator <NUM> includes the second body <NUM>, the flexible seal <NUM> is coupled between the second body <NUM> and the lock ring <NUM>. The flexible seal <NUM> facilitates protecting components of the locking assembly <NUM> from environmental conditions, such as fluid and/or debris.

The plurality of wedges <NUM> are coupled to the second actuator <NUM> by a plurality of guide blocks <NUM>. Each guide block <NUM> may be formed of a single body, or a plurality of bodies coupled together. The second actuator <NUM> has one or more tapered interfacing surfaces <NUM> that interface with and engage a set of one or more tapered interfacing surfaces <NUM> of each of the wedges <NUM> such that the one or more tapered interfacing surfaces <NUM> slide upward and downward along the one or more tapered interfacing surfaces <NUM> of the wedges <NUM>. In one embodiment, which can be combined with other embodiments, the one or more tapered interfacing surfaces <NUM> of each wedge <NUM> taper inward relative to the center axis <NUM> and upward in the longitudinal direction D1. In one embodiment, which can be combined with other embodiments, the one or more tapered interfacing surfaces <NUM> include one or more tapered outer surfaces and the one or more tapered interfacing surfaces <NUM> include one or more tapered inner surfaces.

The guide blocks <NUM> are coupled to the second actuator <NUM> (as shown in <FIG>) by a plurality of fasteners <NUM>, such as screws. In one embodiment, which can be combined with other embodiments, the guide blocks <NUM> may be integrally formed with the second actuator <NUM>. In one example, the guide blocks <NUM> are integrally formed with the second actuator <NUM> such that each guide block <NUM> is a protrusion that protrudes from the tapered interfacing surface <NUM>. Each wedge <NUM> includes an upper surface <NUM>, a lower surface <NUM>, and a guide slot <NUM> formed in the tapered interfacing surface <NUM> of the respective wedge <NUM>. The tapered interfacing surface <NUM> of each wedge <NUM> extends from the lower surface <NUM> each respective wedge <NUM> to the upper surface <NUM>.

The guide blocks <NUM> are located within the guide slots <NUM> formed within each wedge <NUM> (as shown in <FIG> and <FIG>) to rotationally couple the second actuator <NUM> to the plurality of wedges <NUM> but allow axial relative movement between the second actuator <NUM> and the plurality of wedges <NUM>. The guide blocks <NUM> and the guide slots <NUM> form a guide mechanism configured to keep the wedges <NUM> coupled to the second actuator <NUM>. The guide mechanism can be a dovetail, circular, or other shaped interface. In one embodiment, which can be combined with other embodiments, the guide mechanism can be reversed such that the guide slots <NUM> are formed on the second actuator <NUM> and the guide blocks <NUM> are coupled to or integrally formed with the wedges <NUM>.

The plurality of wedges <NUM> have a set of one or more external locking surfaces <NUM> that engage with the one or more internal locking surfaces <NUM> of the lock ring <NUM> and the plurality of internal grooves <NUM> formed on the inner surface <NUM> of the lock ring <NUM>. In one embodiment, which can be combined with other embodiments, the locking surfaces <NUM> are part of one or more external teeth <NUM> formed on the wedges <NUM>. The locking surfaces <NUM> are angled. The plurality of wedges <NUM> are positioned on top of an upper surface <NUM> of a load ring <NUM>, which is positioned on top of the valve cover <NUM>. In one embodiment, which be combined with other embodiments, the load ring <NUM> may be integrally formed with the valve cover <NUM> (or integrally formed with any other component, such as a plug, that is secured within the fluid end body <NUM>). The load ring <NUM> includes an inner surface <NUM> and an upper shoulder <NUM> formed above the inner surface <NUM>.

<FIG> illustrates the valve cover <NUM> disposed in the opening <NUM>. The valve cover <NUM> includes a shoulder <NUM> that engages an inner shoulder <NUM> of the fluid end body <NUM>. The valve cover <NUM> includes an upper surface <NUM> and a lower surface <NUM>. The valve cover <NUM> includes a recessed surface <NUM> formed in the upper surface <NUM>. The recessed surface <NUM> interfaces with a lower surface <NUM> of the load ring <NUM>. The valve cover <NUM> includes a recessed surface <NUM> formed in the lower surface <NUM>. The recessed surface <NUM> engages the spring <NUM> (illustrated in <FIG>).

<FIG> and <FIG> illustrate the locking assembly <NUM> in the locked position, which secures the valve cover <NUM> within the fluid end body <NUM> during operation. <FIG> and <FIG> illustrate the locking assembly <NUM> in an unlocked position when first attaching the locking assembly <NUM> to the fluid end body <NUM> or when wanting to remove and repair/replace the valve cover <NUM> or otherwise requiring access to the internal components of the fluid end <NUM>.

When the locking assembly <NUM> is in the unlocked position, the second actuator <NUM> is in a lower position and the plurality of wedges <NUM> are in an unlocked position. In the unlocked position, the external locking surfaces <NUM> are disengaged from and disposed at a gap from the internal locking surfaces <NUM> of adjacent internal grooves <NUM> formed in the lock ring <NUM>. When the locking assembly <NUM> is in the unlocked position and the wedges <NUM> are in the unlocked position, the first actuator <NUM>, the second actuator <NUM>, and the wedges <NUM> may be inserted into the lock ring <NUM> or removed from the lock ring <NUM> as an assembly.

The operation of attaching the locking assembly <NUM> to the fluid end <NUM> and actuating the locking assembly <NUM> from the unlocked position to the locked position will now be described. The locking assembly <NUM> is attached to the fluid end body <NUM> by bolting the lock ring <NUM> to the fluid end body <NUM> such that the load ring <NUM> is positioned on top of the valve cover <NUM>. As stated above, the lock ring <NUM> may be integrally formed with the fluid end body <NUM> such that no bolting is required. The locking assembly <NUM> is in the unlocked position as shown in <FIG> and <FIG>.

The first actuator <NUM> is then rotated (such as by a wrench used to grip and rotate an upper portion <NUM> of the first actuator <NUM>) in a first rotational direction RD1 about the center axis <NUM> and relative to the second actuator <NUM> and the plurality of wedges <NUM> such that the second actuator <NUM> is driven upward in the longitudinal direction D1 and away from the valve cover <NUM> via a threaded interface <NUM> formed between the upper portion <NUM> of the first actuator <NUM> and an upper portion <NUM> of the second actuator <NUM>. The upper portion <NUM> of the second actuator <NUM> may be a threaded shaft including the one or more coupling surfaces <NUM> that engage the one or more coupling surfaces <NUM> of the first actuator <NUM>. The threaded outer surface of the second actuator <NUM> engages the threaded inner surface of the first actuator <NUM> to form the threaded interface <NUM> that moves the second actuator <NUM> upward or downward depending on the direction of rotation of the first actuator <NUM>.

As the upper inner surface <NUM> of the first actuator <NUM> is engaged with the shoulder portions <NUM> of the wedges <NUM>, turning the first actuator <NUM> to rotate the first actuator <NUM> moves (such as by threading) the one or more coupling surfaces <NUM> of the second actuator <NUM> upward and into the one or more coupling surfaces <NUM> of the first actuator <NUM>. The threading of the second actuator <NUM> into the first actuator <NUM> moves the second actuator <NUM> upward in the longitudinal direction D1 from the lower position to an upper position (illustrated in <FIG>). The second actuator <NUM> moves upward in the longitudinal direction D1 relative to the valve cover <NUM>, the fluid end body <NUM>, the lock ring <NUM>, the load ring <NUM>, the wedges <NUM>, and the first actuator <NUM>.

As the second actuator <NUM> is pulled upward in the longitudinal direction D1 by the first actuator <NUM>, the tapered interfacing surface <NUM> of the second actuator <NUM> engages the tapered interfacing surfaces <NUM> of the wedges <NUM> and forces the wedges <NUM> radially outward in the direction D2 and into engagement with the lock ring <NUM>. As the second actuator <NUM> moves upward in the longitudinal direction D1, the tapered interfacing surface <NUM> slides upward along the tapered interfacing surfaces <NUM> of the wedges <NUM> and applies outward forces to the wedges <NUM> to push the wedges <NUM> outward. The guide slots <NUM> and the guide blocks <NUM> are substantially parallel with the tapered surfaces <NUM>, <NUM> of the second actuator <NUM> and the wedges <NUM>.

As the second actuator <NUM> moves upward from the lower position to the upper position, the wedges <NUM> move outward in directions D2 from the unlocked position to a locked position (illustrated in <FIG>). The wedges <NUM> move outward from the second actuator <NUM> to the lock ring <NUM>. As the wedges <NUM> move outward, the lower surface <NUM> of each wedge <NUM> slides along the upper surface <NUM> of the load ring <NUM> and outward. As the wedges <NUM> move outward, each set of external locking surfaces <NUM> moves toward one of the internal grooves <NUM>.

In the locked position, the external locking surfaces <NUM> of the wedges <NUM> are engaged with and received in the internal grooves <NUM> formed on the inner surface <NUM> of the lock ring <NUM> to help secure the load ring <NUM> and the valve cover <NUM> within the fluid end body <NUM>. In one embodiment, which can be combined with other embodiments, the load ring <NUM> and the valve cover <NUM> form an integral component. The external locking surfaces <NUM> and the internal locking surfaces <NUM> may be tapered surfaces that engage with each other as the wedges <NUM> moved from the unlocked position to the locked position. When the wedges <NUM> are moved radially outward into contact with the lock ring <NUM>, the wedges <NUM> move slightly downward toward the fluid end body <NUM> to apply a force to the load ring <NUM> and the valve cover <NUM> due to the tapered external locking surfaces <NUM> engaging and moving along the tapered internal locking surfaces <NUM> of the internal grooves <NUM>. The wedges <NUM> may move slightly downward relative to the lock ring <NUM> since the lock ring <NUM> is bolted to (or integrally formed with) the fluid end body <NUM>. Also, the shoulder portion <NUM> of each wedge <NUM> has enough space to move laterally (radially outward in the direction D2) within the internal groove <NUM> formed in the base portion <NUM> of the first actuator <NUM>.

In the locked position, the internal teeth <NUM> of the lock ring <NUM> are engaged with and at least partially between the external teeth <NUM> of the wedges <NUM>. In the locked position, the internal teeth <NUM> are interleaved between the external teeth <NUM> of the wedges <NUM>. In the locked position, the outer surface <NUM> of the shoulder portion <NUM> of each wedge <NUM> is disposed at a first gap (shown in <FIG>) from the recessed inner surface <NUM>. In the locked position, external locking surfaces of the external locking surfaces <NUM> of the wedges <NUM> are engaged with internal locking surfaces of the internal locking surfaces <NUM> of the lock ring <NUM>.

In the locked position, the external locking surfaces <NUM> engaged with the internal locking surfaces <NUM>, the wedges <NUM> engaged with the load ring <NUM>, and the load ring <NUM> engaged with the valve cover <NUM> facilitate retaining the valve cover <NUM> in the opening <NUM> and into sealing engagement with the fluid end body <NUM> during operation of the fluid end <NUM>. For example, the external locking surfaces <NUM> engaged against the internal locking surfaces <NUM> facilitates retaining the wedges <NUM> in a substantially fixed position relative to the fluid end body <NUM>, and the engagements between the wedges <NUM>, the load ring <NUM>, and the valve cover <NUM> facilitate retaining the valve cover <NUM> in a substantially fixed position relative to the fluid end body <NUM>. The wedges <NUM> may apply retaining surfaces directly or indirectly to the valve cover <NUM>. The aspects also facilitate preventing the valve cover <NUM> from backing out of the opening <NUM> during high pressure operations of the fluid end <NUM>. In the locked position, the wedges <NUM> and the second actuator <NUM> are retained within the lock ring <NUM>. The locking assembly <NUM> including the wedges <NUM> is mounted to the fluid end body <NUM> in the locked position using at least the lock ring <NUM> mounted to the fluid end body <NUM>. The aspects of the locking assembly <NUM> facilitate preventing backing out of the valve covers <NUM> and maintaining sealed connections of the fluid end <NUM> during high pressure operations of the fluid end <NUM>.

<FIG> is a schematic cross-sectional view of the locking assembly <NUM> illustrated in <FIG> along lines 2D - 2D, with the locking assembly <NUM> in the locked position, according to one implementation. The lock ring <NUM> includes ten openings <NUM> disposed circumferentially about the lock ring <NUM>, and ten bolts <NUM> disposed in the openings <NUM>. The lock ring <NUM> may also include an opening that is used with a handle, such as a T-shaped handle, to lift, lower, and move the locking assembly <NUM>. The lock ring <NUM> may omit the openings <NUM>, such as in an embodiment where the lock ring <NUM> is welded to the fluid end body <NUM> or an embodiment where the lock ring <NUM> is integrally formed with the fluid end body <NUM>. The locking assembly <NUM> includes five wedges <NUM> disposed circumferentially about the second actuator <NUM>. The body portion <NUM> includes one tapered interfacing surface <NUM>. The guide blocks <NUM> (five are shown) are coupled to the body portion <NUM> of the second actuator <NUM> circumferentially about the body portion <NUM>. Each wedge <NUM> includes a guide slot <NUM> (five are shown) formed in the tapered interfacing surface <NUM> of the respective wedge <NUM>. Each guide block <NUM> is disposed within a respective guide slot <NUM>.

Each guide block <NUM> and each guide slot <NUM> includes a circular portion (as illustrated in <FIG>) and a rectangular portion (as illustrated in <FIG>) disposed inward of the circular portion and toward the center axis <NUM>. The circular portion of each guide block <NUM> and circular portion of each guide slot <NUM> includes a first width. The rectangular portion of each guide block <NUM> and the rectangular portion of each guide slot <NUM> includes a second width that is less than the first width. The second width being less than the first width facilitates the guide blocks <NUM> pulling inward on the wedges <NUM> as the second actuator <NUM> moves from the upper position to the lower position. The fasteners <NUM> are disposed through the body portion <NUM> and at least partially through a respective one of the guide blocks <NUM> to couple the guide blocks <NUM> to the second actuator <NUM>. The fasteners <NUM> may be disposed such that head portions of the fasteners <NUM> are disposed within the second actuator <NUM> (as shown in <FIG> and <FIG>). The fasteners <NUM> may be disposed such that head portions of the fasteners <NUM> are disposed outside of the second actuator <NUM> and within or outside of the guide blocks <NUM>. The fasteners <NUM> may be disposed completely through the body portion <NUM> (as shown in <FIG>) or partially through the body portion <NUM> in openings that extend partially through the body portion <NUM>.

As the second actuator <NUM> moves upward from the lower position to the upper position and the tapered interfacing surface <NUM> slides upward along the tapered interfacing surfaces <NUM>, the tapered interfacing surface <NUM> applies outward forces to each tapered interfacing surface <NUM> to push each wedge <NUM> outward to the locked position. Additionally, each guide block <NUM> of the second actuator <NUM> applies an outward force to each wedge <NUM> to push the wedge <NUM> outward to the locked position. Each guide block <NUM> moves upward in the respective guide slot <NUM> as the second actuator <NUM> moves upward from the lower position to the upper position. As the second actuator <NUM> moves downward from the upper position to the lower position and the tapered interfacing surface <NUM> slides downward along the tapered interfacing surfaces <NUM>, the guide blocks <NUM> apply an inward force to each wedge <NUM> to pull each wedge <NUM> inward to the unlocked position. Each guide block <NUM> moves downward in the respective guide slot <NUM> as the second actuator <NUM> moves downward from the upper position to the lower position.

The guide blocks <NUM> and the guide slots <NUM> are shown as circular in shape. The present disclosure contemplates that dovetail shapes, or any other shapes, may be used. In one embodiment, which can be combined with other embodiments, the guide blocks <NUM> and the guide slots <NUM> includes dovetail shapes such that the guide blocks <NUM> includes dovetail tails and the guide slots <NUM> include dovetail pins to form dovetail joints. In one embodiment, which can be combined with other embodiments, the guide blocks <NUM> and the guide slots <NUM> include dovetail shapes such that the guide blocks <NUM> includes dovetail pins and the guide slots <NUM> include dovetail tails to form dovetail joints.

In one embodiment, which can be combined with other embodiments, the guide blocks <NUM> are tee-shaped and the guide slots <NUM> are tee-shaped to form tee-shaped joints.

The joints formed by the guide blocks <NUM> of the second actuator <NUM> and the guide slots <NUM> of the wedges <NUM> facilitate the movement of the wedges <NUM> between the unlocked position and the locked position closely following the movement of the second actuator <NUM> between the upper position and the lower position as the first actuator <NUM> is turned. The close following facilitates reliable unlocking and locking of the locking assembly <NUM> to maintain the valve cover <NUM> in sealing engagement with the fluid end body <NUM> during high pressure operations. The joints also facilitate pulling the wedges <NUM> inward from the locked position to the unlocked position as the first actuator <NUM> is turned without using springs or other biasing elements to bias the wedges <NUM> inward. Reducing the need for biasing elements to bias the wedges <NUM> inward reduces cost, increases efficiencies, simplifies the design of the locking assembly, and facilitates easier manual operation of the locking assembly <NUM> and reduced operations times. The present disclosure, however, contemplates that springs or other biasing elements may be used in conjunction with the locking assembly <NUM> to facilitate operations of the locking assembly <NUM>.

Additionally, the tapering inward and upward in the longitudinal direction D1 of the one or more tapered interfacing surfaces <NUM> and the tapered interfacing surfaces <NUM> facilitates design simplicity and locking simplicity, effective and stable locking and unlocking of the locking assembly <NUM>, weight savings, quick and easy installation and removal of the locking assembly <NUM>, smaller overall size of the locking assembly <NUM>, cost savings, and enhanced operational lifespans for the locking assembly <NUM>. Moreover, the movement of the second actuator <NUM> upward to the upper position to push the wedges <NUM> outward to the locked position also facilitates design simplicity and locking simplicity, effective and stable locking and unlocking of the locking assembly <NUM>, weight savings, quick and easy installation and removal of the locking assembly <NUM>, smaller overall size of the locking assembly <NUM>, cost savings, and enhanced operational lifespans for the locking assembly <NUM>. As an example, such aspects facilitate design simplicity and compactness as the second actuator <NUM> may be used without a hole that extends completely from a top end to a bottom end of the second actuator <NUM>. As another example, the tapering inward and upward of tapered surfaces <NUM>, <NUM>, and the upward movement of the second actuator <NUM>, also facilitate a simple load path between the first actuator <NUM> and the second actuator <NUM> during operation, thereby facilitating relatively low stresses and increased operational lifespans for the locking assembly <NUM>.

Additionally, the upper surfaces <NUM> of the wedges <NUM> are planar and horizontal surfaces. The upper inner surface <NUM> of the first actuator <NUM> interfacing with upper surfaces <NUM> of the wedges <NUM> that are planar facilitates effective and stable actuation using the first actuator <NUM> that effectively and stably extends and retracts the wedges <NUM>. The operation of actuating the locking assembly <NUM> from the locked position to the unlocked position and removing the locking assembly <NUM> from the fluid end <NUM> will now be described.

The locking assembly <NUM> may be moved from the locked position (illustrated in <FIG>) back to the unlocked position (illustrated in <FIG>), for example, to remove the valve cover <NUM> from the fluid end body <NUM> and/or to perform maintenance on the fluid end <NUM>. The locking assembly <NUM> may be moved back to the unlocked position such that the first actuator <NUM>, the second actuator <NUM>, and the wedges <NUM> may be removed as an assembly from a central opening <NUM> (illustrated in <FIG>) of the lock ring <NUM>. The locking assembly <NUM> is moved back to the unlocked position by turning the first actuator <NUM> in a second rotational direction RD2 that is opposite of the first rotational direction RD1 to drive the second actuator <NUM> downward in a longitudinal direction D3 toward the valve cover <NUM> using the threaded interface <NUM>.

Turning the first actuator <NUM> in the second rotational direction RD2 moves (such as by threading) the one or more coupling surfaces <NUM> of the second actuator <NUM> out of the one or more coupling surfaces <NUM> of the first actuator <NUM>. Threading the second actuator <NUM> out of the first actuator <NUM> moves the second actuator <NUM> downward in the longitudinal direction D3 that is opposite of the upward longitudinal direction D1. The second actuator <NUM> moves downward from the upper position back to the lower position. As the second actuator <NUM> moves downward, the tapered interfacing surface <NUM> slides downward along the tapered interfacing surfaces <NUM> of the wedges <NUM>. As the second actuator <NUM> moves downward, the guide blocks <NUM> coupled to the body portion <NUM> of the second actuator <NUM> apply an inward force to each wedge <NUM> to pull the wedges <NUM> inward in inward directions D4 toward the center axis <NUM> and from the lock ring <NUM>. The guide blocks <NUM> pull on the wedges <NUM> using the engagement between the guide blocks <NUM> and the guide slots <NUM> of the wedges <NUM>. As the wedges <NUM> move inward, the lower surfaces <NUM> slide inward in the inward directions D4 toward the center axis <NUM>. The wedges <NUM> are retracted and moved radially inward in the inward directions D4 and out of engagement from the lock ring <NUM>. The entire locking assembly <NUM> can then be removed to provide access to the valve cover <NUM> and/or internal components of the fluid end <NUM>.

The ability of the second actuator <NUM> to move in the longitudinal direction D1 and the opposite longitudinal direction D3, and the ability of the first actuator <NUM> to move in opposite first and second rotational directions RD1 and RD2, facilitate moving the locking assembly <NUM> to the unlocked position using the assistance of the guide blocks and the guide slots, if the locking assembly <NUM> becomes locked up and stuck in the locked position due to frictional forces, which may have been affected by exposure to external debris, surface corrosion buildup, or other factors detrimental to moving between the locked and unlocked positions.

Aspects of the first actuator <NUM> and the wedges <NUM>, such as one or more of the internal groove <NUM> and/or the shoulder portions <NUM> of the wedges <NUM>, facilitate guiding the wedges <NUM> horizontally as the wedges <NUM> move between the locked position and the unlocked position. The first actuator <NUM> may include additional guide members, such as protrusions or additional grooves that interface with protrusions or grooves of the wedges <NUM>, to horizontally guide the wedges <NUM>.

In the unlocked position (illustrated in <FIG>), the outer surface <NUM> of the shoulder portion <NUM> of each wedge <NUM> is disposed at a second gap from the recessed inner surface <NUM>. The second gap is larger than the first gap (illustrated in <FIG>).

<FIG> is a schematic isometric partial view of the first actuator <NUM> of the locking assembly <NUM>, according to one implementation. The first actuator <NUM> includes a center axis extending through a center of the first actuator <NUM> and through the central opening <NUM>. The center axis is longitudinally aligned with the center axis <NUM> of the second actuator <NUM> in the locking assembly <NUM>, as illustrated in <FIG> and <FIG>. The upper surface <NUM> and the lower surface <NUM> of the first actuator <NUM> extend perpendicularly to the center axis of the first actuator <NUM>.

<FIG> is a schematic isometric partial view of the second actuator <NUM> of the locking assembly <NUM>, according to one implementation. Each guide block <NUM> coupled to the body portion <NUM> of the second actuator <NUM> may be partially disposed in or on a plurality of guide block mounting surfaces <NUM> formed in the one or more tapered interfacing surface <NUM>. In one example, the guide block mounting surfaces <NUM> are recessed, flat, or another shape. In one example, the body portion <NUM> is a base portion of the second actuator <NUM>. In one example, at least a portion of the rectangular portion of each guide block <NUM> is at least partially disposed in or on one of the guide block mounting surfaces <NUM>. The one or more tapered interfacing surfaces <NUM> taper inward and upward toward the center axis <NUM> in the longitudinal direction D1. The one or more tapered interfacing surfaces <NUM> are neither parallel nor perpendicular to the center axis <NUM>.

<FIG> is a schematic isometric partial view of the wedges <NUM> of the locking assembly <NUM>, according to one implementation. The wedges <NUM> are disposed circumferentially about a longitudinal axis <NUM>. The longitudinal axis <NUM> is longitudinally aligned with the center axis <NUM> of the second actuator <NUM> in the locking assembly <NUM>, as illustrated in <FIG> and <FIG>.

<FIG> is a schematic isometric partial view of one of the wedges <NUM> of the locking assembly <NUM>, according to one implementation.

<FIG> is a schematic isometric view of the load ring <NUM> of the locking assembly <NUM>, according to one implementation. The load ring <NUM> includes a cylindrical shaped member <NUM> having a central opening <NUM>. The load ring <NUM> may also include lifting provisions <NUM> which are shown as two openings formed on a top surface of the load ring <NUM>. Other types of lifting provisions may be used to install and remove the load ring <NUM>.

<FIG> is a schematic isometric partial view of the lock ring <NUM> of the locking assembly <NUM>, according to one implementation. The lock ring <NUM> includes a cylindrical member and a central opening <NUM> that extends from an upper surface to a lower surface of the cylindrical member. The lock ring <NUM> includes a center axis extending through the central opening <NUM> and through a center of the cylindrical member. The center axis of the lock ring <NUM> is longitudinally aligned with the center axis <NUM> of the second actuator <NUM> in the locking assembly <NUM>, as illustrated in <FIG> and <FIG>.

<FIG> is a schematic isometric partial view of the valve cover <NUM> of the fluid end <NUM>, according to one implementation. The valve cover <NUM> includes a center axis extending through a center of the valve cover <NUM>. The center axis of the valve cover <NUM> is longitudinally aligned with the center axis <NUM> of the second actuator <NUM> of the locking assembly <NUM>, as illustrated in <FIG> and <FIG>.

The present disclosure contemplates that the surfaces and slots described herein, such as the one or more tapered interfacing surfaces <NUM> and the tapered interfacing surfaces <NUM>, may be planar in profile or arcuate in profile.

<FIG> is a schematic isometric partial view of a fluid end <NUM> having a fluid end body <NUM> and a locking assembly <NUM> in an unlocked position, according to one implementation. <FIG> is a schematic cross-sectional view of the fluid end <NUM> illustrated in <FIG> along lines 4A - 4A, according to one implementation. The fluid end <NUM> includes a plurality of bores 110A-110D (110A and 110D are shown <FIG>) formed in the fluid end body <NUM>. The fluid end <NUM> is adapted to couple to a power end <NUM> via a pony rod <NUM>. While only one pony rod <NUM> is shown, the power end <NUM> may have a pony rod that couples to each of the bores 110A of the fluid end <NUM>.

The fluid end <NUM> includes valve covers <NUM>. Each valve cover <NUM> is disposed at least partially in an opening <NUM> formed in the fluid end body <NUM>. The valve covers <NUM> may be an opening plug, a suction cover, a discharge cover, an access cover, and/or a retainer nut. The fluid end <NUM> illustrated includes a retainer nut <NUM> disposed in each of the bores 110B and a valve cover <NUM> disposed in each opening <NUM>. A locking assembly <NUM> is disposed above one of the valve covers <NUM>. The present disclosure contemplates that a locking assembly <NUM> may be disposed above each one of the valve covers <NUM> (five are illustrated). A discharge flange <NUM> may be coupled to opposing ends of the fluid end body <NUM> for connecting hoses with a discharge manifold. A plunger clamp <NUM> may be disposed between the fluid end <NUM> and the pony rod <NUM>.

Referring to <FIG>, the internal components of the fluid end <NUM> will be described. A plunger <NUM> is shown disposed in the bore 110A, and a valve assembly <NUM> having a spring <NUM> is shown disposed in the bore 110B. A suction cover <NUM> is shown disposed in the bore 110C, and a suction valve assembly <NUM> is shown in the bore 110D. The suction cover <NUM> is disposed inwards of the retainer nut <NUM> relative to the fluid end body <NUM>. The valve cover <NUM> is a discharge cover. A valve body <NUM> as well as a valve seat <NUM> may also be disposed in the bores 110B and 110D. The fluid end body <NUM> may also include a discharge manifold <NUM> formed therein that is in selective communication with at least the bore 110B. The bores 110A-110D formed in the fluid end body <NUM> intersect within the fluid end body <NUM> at a junction <NUM>. The present disclosure contemplates that each of the suction covers <NUM> may be replaced with a cover similar to the valve covers <NUM>, and/or the retainer nuts <NUM> may be replaced with a locking assembly similar to the locking assembly <NUM>.

<FIG> is a schematic enlarged cross-sectional partial view of the fluid end <NUM> and the locking assembly <NUM> illustrated in <FIG>, according to one implementation. The locking assembly <NUM> is illustrated in the unlocked position in <FIG>. The locking assembly <NUM> includes a second actuator <NUM>. The second actuator <NUM> includes a body <NUM> and a shaft <NUM> that protrudes upwardly from the body <NUM> in a longitudinal direction D1. In one example, the body <NUM> is a base of the second actuator <NUM>. The body <NUM> includes one or more tapered interfacing surfaces <NUM> and a recessed surface <NUM> formed in a lower surface <NUM> of the body <NUM>. The second actuator <NUM> also includes a center axis <NUM> extending through the body <NUM> and the shaft <NUM>. The center axis <NUM> extends through a center of the second actuator <NUM>. The tapered interfacing surfaces <NUM> of the body <NUM> of the second actuator <NUM> taper inward relative to the center axis <NUM> and upward in the longitudinal direction D1. The second actuator <NUM> includes one or more coupling surfaces <NUM>. In one example, the one or more coupling surfaces <NUM> include a threaded outer surface of the shaft <NUM>. The second actuator <NUM> also includes a plurality of guide blocks <NUM> (shown in ghost in <FIG>). In the implementation shown, the guide blocks <NUM> are protrusions that are integrally formed with the second actuator <NUM> and protruding from the tapered interfacing surfaces <NUM>. The present disclosure contemplates that the guide blocks <NUM> may be components separate from the second actuator <NUM> that are coupled, such as by using fasteners, to the second actuator <NUM>.

The locking assembly <NUM> includes a plurality of wedges <NUM> disposed about the second actuator <NUM>. Each wedge <NUM> includes a tapered interfacing surface <NUM>, an outer surface <NUM>, and a set of one or more external locking surfaces <NUM> formed in the outer surface <NUM>. The external locking surfaces <NUM> are angled. In one embodiment, which can be combined with other embodiments, each set of one or more external locking surfaces <NUM> is part of a set of external teeth <NUM>. The tapered interfacing surface <NUM> of each wedge <NUM> is engaged with one of the tapered interfacing surfaces <NUM> of the second actuator <NUM> such that the tapered interfacing surfaces <NUM> slide upward and downward along the tapered interfacing surfaces <NUM> of the wedges <NUM>.

In one embodiment, which can be combined with other embodiments, the one or more tapered interfacing surfaces <NUM> include one or more tapered outer surfaces and the one or more tapered interfacing surfaces <NUM> include one or more tapered inner surfaces.

The tapered interfacing surface <NUM> of each wedge <NUM> tapers inward relative to the center axis <NUM> and upward in the longitudinal direction D1. The longitudinal direction D1 extends upward and away from the fluid end body <NUM>. Each wedge <NUM> includes an upper surface <NUM>, a lower surface <NUM>, a first guide slot <NUM> (illustrated in <FIG>), and a second guide slot <NUM> (shown in ghost in <FIG>). Each wedge <NUM> includes a first shoulder <NUM>, a second shoulder <NUM> disposed above the first shoulder <NUM>, and a recessed surface <NUM> formed by a recess in an inner surface <NUM> of the respective wedge <NUM>. The tapered interfacing surface <NUM> of each wedge <NUM> extends from the first shoulder <NUM> of the respective wedge <NUM> to the lower surface <NUM>. The first guide slot <NUM> and the second guide slot <NUM> of each wedge <NUM> extend from the first shoulder <NUM> and end short of the lower surface <NUM> to form a third shoulder <NUM> (shown in <FIG>) and a fourth shoulder <NUM> (shown in ghost in <FIG>), respectively. The present disclosure contemplates that the formation of the guide blocks <NUM> and the first and second guide slots <NUM>, <NUM> may be reversed such that the guide blocks <NUM> are disposed on the wedges <NUM> and the first and second guide slots <NUM>, <NUM> are formed on the second actuator <NUM>. The guide blocks <NUM> of the implementation shown hereafter will be referred to as "the protrusions <NUM>.

The locking assembly <NUM> includes a first actuator <NUM> disposed at least partially above the second actuator <NUM> and at least partially about the shaft <NUM> of the second actuator <NUM>. The first actuator <NUM> includes a central opening <NUM> and one or more coupling surfaces <NUM>. In one example, the one or more coupling surfaces <NUM> include a threaded inner surface interface with and thread with the threaded outer surface of the shaft <NUM> of the second actuator <NUM>. The one or more coupling surfaces <NUM> interface with and are disposed in coupling engagement with the one or more coupling surfaces <NUM> of the second actuator <NUM>. The first actuator <NUM> includes an upper surface <NUM> and a lower surface <NUM>. The central opening <NUM> extends between the upper surface <NUM> and the lower surface <NUM>. The first actuator <NUM> includes a tool interface <NUM>, such as a hex tool interface, for turning the first actuator <NUM>. The lower surface <NUM> of the first actuator <NUM> is engaged with the first shoulder <NUM> of each wedge <NUM> of the plurality of wedges <NUM>. In one example, the first actuator <NUM> includes a first portion <NUM> and a second portion <NUM> disposed below the first portion <NUM>. The second portion <NUM> is wider than the first portion <NUM>. The second portion <NUM> includes an outer surface <NUM> and an upper surface <NUM> between the lower surface <NUM> and the upper surface <NUM> of the first portion <NUM>. The outer surface <NUM> of the second portion <NUM> may be engaged with the recessed surface <NUM> of each wedge <NUM> and the upper surface <NUM> of the second portion <NUM> may be engaged with the second shoulder <NUM> of each wedge <NUM>. In one example, the first actuator <NUM> is a nut and the second shoulder <NUM> of each wedge <NUM> is omitted.

The second actuator <NUM> is disposed at least partially below the first actuator <NUM> in the implementations shown in <FIG> and <FIG>. In one embodiment, which can be combined with other embodiments, the second actuator <NUM> is disposed at least partially above the first actuator <NUM>. In one embodiment, which can be combined with other embodiments, the second actuator <NUM> is not disposed above or below the first actuator <NUM> but is disposed about or within the first actuator <NUM>.

The locking assembly <NUM> includes a lock ring <NUM> disposed about the plurality of wedges <NUM>. In one example, the lock ring <NUM> is a flange. The lock ring <NUM> includes an outer surface <NUM> and a plurality of inner surfaces <NUM>, an upper surface <NUM>, and a lower surface <NUM>. The lock ring <NUM> includes a plurality of fastener openings <NUM> extending from the upper surface <NUM> to the lower surface <NUM> of the lock ring <NUM>. A bolt <NUM> of a plurality of bolts <NUM> is disposed through each fastener opening <NUM> to fasten the lock ring <NUM> to the fluid end body <NUM> and mount the lock ring <NUM> to an exterior surface <NUM> of the fluid end body <NUM>. The lock ring <NUM> includes a set of one or more internal locking surfaces <NUM> formed in each inner surface <NUM>. The internal locking surfaces <NUM> are angled. In one embodiment, which can be combined with other embodiments, each set of one or more internal locking surfaces <NUM> is a part of a set of internal teeth <NUM>. Each set of internal teeth <NUM> is formed between a set of internal grooves <NUM> formed in the inner surface <NUM>. The present disclosure contemplates that the lock ring <NUM> may be a separate component from the fluid end body <NUM>, or that the lock ring <NUM> may be integrally formed with the fluid end body <NUM>. The present disclosure contemplates that the lock ring <NUM> may be disposed adjacent the opening <NUM> such that the sets of internal locking surfaces <NUM> and the sets of internal grooves <NUM> are disposed along the opening <NUM> of the fluid end body <NUM>. The lock ring <NUM> may also include an opening that is used with a handle, such as a T-shaped handle, to lift, lower, and move the locking assembly <NUM>. The lock ring <NUM> may omit the fastener openings <NUM>, such as in an embodiment where the lock ring <NUM> is welded to the fluid end body <NUM> or an embodiment where the lock ring <NUM> is integrally formed with the fluid end body <NUM>.

<FIG> illustrates the valve cover <NUM> disposed in the opening <NUM>. The valve cover <NUM> includes a shoulder <NUM> that engages an inner shoulder <NUM> of the fluid end body <NUM>. The valve cover <NUM> includes an upper surface <NUM> and a lower surface <NUM>. The valve cover <NUM> includes a channel <NUM> formed in the upper surface <NUM>. The channel <NUM> receives a portion <NUM> of the body <NUM> of the second actuator <NUM> when the locking assembly <NUM> is in the unlocked position. The valve cover <NUM> includes a recessed surface <NUM> formed in the lower surface <NUM>. The recessed surface <NUM> engages the spring <NUM> (illustrated in <FIG>).

<FIG> illustrates the locking assembly <NUM> in the unlocked position. When the locking assembly <NUM> is in the unlocked position, the second actuator <NUM> is in a lower position and the wedges <NUM> are in an unlocked position. In the unlocked position, the external locking surfaces <NUM> of the wedges <NUM> are disengaged from and disposed at a gap from the internal locking surfaces <NUM> of adjacent sets of internal grooves <NUM> formed in the lock ring <NUM>. The lock ring <NUM> is mounted to the fluid end body <NUM> using the bolts <NUM> that mount the lock ring <NUM> to the exterior surface <NUM>. The lower surface <NUM> of each wedge <NUM> is disposed in engagement with the upper surface <NUM> of the valve cover <NUM>. When the locking assembly <NUM> is in the unlocked position and the wedges <NUM> are in the unlocked position, the second actuator <NUM>, the first actuator <NUM>, and the wedges <NUM> may be inserted into the lock ring <NUM> or removed from the lock ring <NUM> as an assembly.

The first actuator <NUM> is turned in a first rotational direction RD1 about the center axis <NUM>. The first actuator <NUM> is turned using for example the tool interface <NUM>. As the lower surface <NUM> of the first actuator <NUM> is engaged with the first shoulders <NUM> of the wedges <NUM>, turning the first actuator <NUM> to rotate the first actuator <NUM> moves (such as by threading) the one or more coupling surfaces <NUM> of the second actuator <NUM> upward and into the one or more coupling surfaces <NUM> of the first actuator <NUM>. The threading of the second actuator <NUM> into the first actuator <NUM> moves the second actuator <NUM> upward in the longitudinal direction D1 from the lower position to an upper position (illustrated in <FIG>). The second actuator <NUM> moves upward in the longitudinal direction D1 relative to the valve cover <NUM>, the fluid end body <NUM>, the lock ring <NUM>, the wedges <NUM>, and the first actuator <NUM>. As the second actuator <NUM> moves upward in the longitudinal direction D1, the tapered interfacing surfaces <NUM> slide upward along the tapered interfacing surfaces <NUM> of the wedges <NUM> and apply outward forces to the wedges <NUM> to push the wedges <NUM> outward.

As the second actuator <NUM> moves upward from the lower position to the upper position, the wedges <NUM> move outward in outward directions OD1 from the unlocked position to a locked position (illustrated in <FIG>). The wedges <NUM> move outward in outward directions OD1 from the second actuator <NUM> to the lock ring <NUM>. As the wedges <NUM> move outward, the lower surface <NUM> of each wedge <NUM> slides along the upper surface <NUM> of the valve cover <NUM> and outward in one of the outward directions OD1. As the wedges <NUM> move outward, each set of external locking surfaces <NUM> moves toward one of the sets of internal locking surfaces <NUM> and one of the sets of internal grooves <NUM>.

<FIG> is a schematic enlarged cross-sectional partial view of the fluid end <NUM> and the locking assembly <NUM> illustrated in <FIG>, with the locking assembly <NUM> in a locked position, according to one implementation. When the locking assembly <NUM> is in the locked position, the second actuator <NUM> is in the upper position and the wedges <NUM> are in the locked position, as illustrated in <FIG>. In the locked position, the outer surface <NUM> of the first actuator <NUM> is disposed at a gap from the recessed surface <NUM> of each wedge <NUM>. In the locked position, the teeth of the sets of external teeth <NUM> of the wedges <NUM> are engaged with and received in the recesses of the sets of internal grooves <NUM>. In the locked position, the external locking surfaces <NUM> of the wedges <NUM> are engaged with the internal locking surfaces <NUM> of the recesses of the sets of internal grooves <NUM>. In the locked position, the teeth of the sets of external teeth <NUM> of the wedges <NUM> are at least partially between the teeth of the sets of internal teeth <NUM> of the lock ring <NUM>. In the locked position, the teeth of the sets of internal teeth <NUM> of the lock ring <NUM> are interleaved between the teeth of the sets of external teeth <NUM> of the wedges <NUM>. As the wedges <NUM> move outward from the unlocked position to the locked position, the external locking surfaces <NUM> of the wedges <NUM> moved outward and downward along the internal locking surfaces <NUM> to align the teeth of the sets of external teeth <NUM> in the internal grooves <NUM> of the lock ring <NUM>.

In the locked position, the external locking surfaces <NUM> engaged with the internal locking surfaces <NUM> and the lower surfaces <NUM> of the wedges <NUM> engaged with the upper surface <NUM> of the valve cover <NUM> facilitate retaining the valve cover <NUM> in the opening <NUM> and into sealing engagement with the fluid end body <NUM>. For example, the external locking surface <NUM> engaged against the internal locking surfaces <NUM> of the lock ring <NUM> facilitates retaining the wedges <NUM> in a substantially fixed position relative to the fluid end body <NUM>, and the engagement between the lower surfaces <NUM> and the upper surface <NUM> facilitates retaining the valve cover <NUM> in a substantially fixed position relative to the fluid end body <NUM>. The wedges <NUM> may apply retaining surfaces directly (such as through the lower surfaces <NUM> and the upper surface <NUM>) or indirectly to the valve cover <NUM>. The aspects also facilitate preventing the valve cover <NUM> from backing out of the opening <NUM> during high pressure operations of the fluid end <NUM>. In the locked position, the second actuator <NUM>, the first actuator <NUM>, and the wedges <NUM> are retained within the lock ring <NUM>. The locking assembly <NUM> including the wedges <NUM> are mounted to the fluid end body <NUM> in the locked position using at least the lock ring <NUM> mounted to the fluid end body <NUM>. The aspects of the locking assembly <NUM> facilitate preventing backing out of the valve covers <NUM> and maintaining sealed connections of the fluid end <NUM> during high pressure operations of the fluid end <NUM>.

The locking assembly <NUM> may be moved from the locked position (illustrated in <FIG>) back to the unlocked position (illustrated in <FIG>), for example, to remove the valve cover <NUM> from the fluid end body <NUM> and/or to perform maintenance on the fluid end <NUM>. The locking assembly <NUM> may be moved back to the unlocked position such that the second actuator <NUM>, the first actuator <NUM>, and the wedges <NUM> may be removed as an assembly from the central opening <NUM> (illustrated in <FIG>) of the lock ring <NUM>. The locking assembly <NUM> is moved back to the unlocked position by turning the first actuator <NUM> in a second rotational direction RD2 that is opposite of the first rotational direction RD1. Turning the first actuator <NUM> in the second rotational direction RD2 moves (such as by threading) the one or more coupling surfaces <NUM> of the second actuator <NUM> out of the one or more coupling surfaces <NUM> of the first actuator <NUM>. Threading the second actuator <NUM> out of the first actuator <NUM> moves the second actuator <NUM> downward in a downward longitudinal direction D2 that is opposite of the longitudinal direction D1. The second actuator <NUM> moves downward from the upper position back to the lower position. As the second actuator <NUM> moves downward, the tapered interfacing surfaces <NUM> slide downward along the tapered interfacing surfaces <NUM> of the wedges <NUM>. As the second actuator <NUM> moves downward, the protrusions <NUM> that protrude from the second actuator <NUM> apply an inward force to each wedge <NUM> to pull the wedges inward in inward directions ID1 toward the center axis <NUM> and from the lock ring <NUM>. As the wedges <NUM> move inward, the lower surfaces <NUM> slide inward in the inward directions ID1 toward the center axis <NUM>.

The ability of the second actuator <NUM> to move in the longitudinal direction D1 and the opposite second longitudinal direction D2, and the ability of the first actuator <NUM> to move in opposite first and second rotational directions RD1 and RD2, facilitate moving the locking assembly <NUM> to the unlocked position if the locking assembly <NUM> becomes locked up and stuck in the locked position due to frictional forces.

Aspects of the first actuator <NUM>, such as one or more of the lower surface <NUM>, the upper surface <NUM>, and/or the outer surface <NUM>, facilitate guiding the wedges <NUM> horizontally as the wedges <NUM> move between the locked position and the unlocked position. The first actuator <NUM> may include guide members, such as protrusions or grooves that interface with protrusions or grooves of the wedges <NUM>, to horizontally guide the wedges <NUM>.

<FIG> is a schematic cross-sectional view of the locking assembly <NUM> illustrated in <FIG> along lines 4D - 4D, with the locking assembly <NUM> in the unlocked position, according to one implementation. The lock ring <NUM> includes ten fastener openings <NUM> disposed circumferentially about the lock ring <NUM>, and ten bolts <NUM> disposed in the fastener openings <NUM>. The lock ring <NUM> includes six inner surfaces <NUM>, six sets of one or more internal locking surfaces <NUM>, and six sets of internal teeth <NUM> disposed hexagonally about the wedges <NUM> and the second actuator <NUM>. The locking assembly <NUM> includes six wedges <NUM> disposed hexagonally about the second actuator <NUM>. The body <NUM> of the second actuator <NUM> includes the plurality of protrusions <NUM> (six are shown) disposed hexagonally about the body <NUM>. The body <NUM> includes six tapered interfacing surfaces <NUM>. The body <NUM> also includes a plurality of slots <NUM> (six are shown) between the protrusions <NUM>. Each protrusion <NUM> is disposed at least partially between two adjacent wedges <NUM> of the plurality of wedges <NUM>. Each protrusion <NUM> includes a first edge <NUM> that protrudes at least partially into the first guide slot <NUM> of a first wedge 448A of the plurality of wedges and a second edge <NUM> that protrudes at least partially into the second guide slot <NUM> of a second wedge 448B that is adjacent the first wedge 448A. Each protrusion <NUM> includes a third edge <NUM> disposed outward of the first edge <NUM> and the second edge <NUM>. The third edge <NUM> interfaces with a wedge interface where the respective first wedge 448A interfaces with the second wedge 448B when the wedges <NUM> are in the unlocked position.

Each wedge <NUM> includes the first guide slot <NUM> and the second guide slot <NUM> formed in the tapered interfacing surface <NUM> of the respective wedge <NUM>. The first guide slot <NUM> and the second guide slot <NUM> are formed into the tapered interfacing surface <NUM> of each wedge <NUM> to form a protrusion <NUM> (six are shown) of each wedge that includes the tapered interfacing surface <NUM>. The protrusion <NUM> of each wedge <NUM> protrudes at least partially into and is disposed in a slot <NUM> of the plurality of slots <NUM> of the second actuator <NUM>. Each protrusion <NUM> of each wedge <NUM> includes a first edge <NUM> and a second edge <NUM>.

As the second actuator <NUM> moves upward from the lower position to the upper position and the tapered interfacing surfaces <NUM> slide upward along the tapered interfacing surfaces <NUM>, the tapered interfacing surfaces <NUM> apply outward forces to each tapered interfacing surface <NUM> to push each wedge <NUM> outward to the locked position. Additionally, each protrusion <NUM> of the second actuator <NUM> applies an outward force to the first guide slot <NUM> and the second guide slot <NUM> of each wedge <NUM> to push the wedge <NUM> outward to the locked position. Each protrusion <NUM> moves upward in the respective first guide slot <NUM> and second guide slot <NUM> as the second actuator <NUM> moves upward from the lower position to the upper position. As the second actuator <NUM> moves downward from the upper position to the lower position and the tapered interfacing surfaces <NUM> slide downward along the tapered interfacing surfaces <NUM>, the protrusions <NUM> apply an inward force to each protrusion <NUM> of each wedge <NUM> to pull each wedge <NUM> inward to the unlocked position. Each protrusion <NUM> moves downward in the respective first guide slot <NUM> and second guide slot <NUM> as the second actuator <NUM> moves downward from the upper position to the lower position.

In one embodiment, which can be combined with other embodiments, the protrusions <NUM> that protrude from the tapered interfacing surfaces <NUM> are dovetail pins of the second actuator <NUM> and the slots <NUM> are dovetail tails of the second actuator <NUM> that are disposed between the dovetail pins. In one embodiment, which can be combined with other embodiments, the protrusion <NUM> of each wedge <NUM> is a dovetail pin of the respective wedge <NUM>. In such embodiments, the first guide slot <NUM> of a first wedge 448A and the second guide slot <NUM> of an adjacent second wedge 448B form a dovetail tail between the dovetail pins of the wedges <NUM>. The dovetail pins of the second actuator <NUM> are disposed in the dovetail tails of the wedges <NUM>, and the dovetail pins of the wedges <NUM> are disposed in the dovetail tails of the second actuator <NUM> to form a plurality of dovetail joints.

In one embodiment, which can be combined with other embodiments, the protrusions <NUM> that protrude from the tapered interfacing surfaces <NUM> are tee-shaped protrusions of the second actuator <NUM> and the slots <NUM> are tee-shaped slots of the second actuator <NUM> that are disposed between the tee-shaped protrusions. In one embodiment, which can be combined with other embodiments, the protrusion <NUM> of each wedge <NUM> is a tee-shaped protrusion of the respective wedge <NUM>. In such embodiments, the first guide slot <NUM> of a first wedge 448A and the second guide slot <NUM> of an adjacent second wedge 448B form a tee-shaped guide slot between the dovetail pins of the wedges <NUM>. The tee-shaped protrusions of the second actuator <NUM> are disposed in the tee-shaped guide slots of the wedges <NUM>, and the tee-shaped protrusions of the wedges <NUM> are disposed in the tee-shaped slots of the second actuator <NUM> to form a plurality of tee-shaped joints.

The joints formed by the protrusions <NUM> and the slots <NUM> of the second actuator <NUM>, and the protrusions <NUM> and the first and second guide slots <NUM>, <NUM> of the wedges <NUM>, facilitate the movement of the wedges <NUM> between the unlocked position and the locked position closely following the movement of the second actuator <NUM> between the upper position and the lower position as the first actuator <NUM> is turned. The close following facilitates reliable unlocking and locking of the locking assembly <NUM> to maintain the valve cover <NUM> in sealing engagement with the fluid end body <NUM> during high pressure operations. The joints also facilitate pulling the wedges <NUM> inward from the locked position to the unlocked position as the first actuator <NUM> is turned without using springs or other biasing elements to bias the wedges <NUM> inward. Reducing the need for biasing elements to bias the wedges <NUM> inward reduces cost, increases efficiencies, simplifies the design of the locking assembly, and facilitates easier manual operation of the locking assembly <NUM> and reduced operations times. The present disclosure, however, contemplates that springs or other biasing elements may be used in conjunction with the locking assembly <NUM> to facilitate operations of the locking assembly <NUM>.

<FIG> is a schematic isometric partial view of the locking assembly <NUM> and the valve cover <NUM> illustrated in <FIG> and <FIG>, with the locking assembly <NUM> in the unlocked position, according to one implementation.

<FIG> is a schematic isometric partial view of the second actuator <NUM> of the locking assembly <NUM>, according to one implementation. Each protrusion <NUM> protruding from the body <NUM> of the second actuator <NUM> is disposed at an intersection of two of the tapered interfacing surfaces <NUM>. In one embodiment, which can be combined with other embodiments, the one or more tapered interfacing surfaces <NUM> taper inward and upward toward the center axis <NUM> in the longitudinal direction D1. In one example, the one or more tapered interfacing surfaces <NUM> are neither parallel nor perpendicular to the center axis <NUM>.

<FIG> is a schematic isometric partial view of the lock ring <NUM> of the locking assembly <NUM>, according to one implementation. The lock ring <NUM> includes a central opening <NUM> that extends from the upper surface <NUM> to the lower surface <NUM>. The central opening <NUM> is hexagonal in shape. The lock ring <NUM> includes six inner surfaces <NUM> formed hexagonally about the central opening <NUM>. The lock ring <NUM> includes rounded surfaces <NUM> formed between the inner surfaces <NUM>. Each rounded surface <NUM> is formed between two adjacent inner surfaces <NUM>. Each set of internal grooves <NUM> (six are included in the lock ring <NUM>) is formed in one of the inner surfaces <NUM>. Each set of internal teeth <NUM> (six are included in the lock ring <NUM>) is formed in one of the inner surfaces <NUM> between the internal grooves of a set of internal grooves <NUM>. Each set of internal locking surfaces <NUM> (six are included in the locking ring <NUM>) formed in one of the inner surfaces <NUM>. The lock ring <NUM> includes a center axis <NUM> extending through the central opening <NUM> and through a center of the ring. The center axis <NUM> of the lock ring <NUM> is longitudinally aligned with the center axis <NUM> of the second actuator <NUM> in the locking assembly <NUM>, as illustrated in <FIG> and <FIG>.

<FIG> is a schematic isometric partial view of two of the wedges <NUM> of the locking assembly <NUM>, according to one implementation. The wedges <NUM> are disposed circumferentially about a longitudinal axis <NUM>. The longitudinal axis <NUM> is longitudinally aligned with the center axis <NUM> of the second actuator <NUM> in the locking assembly <NUM>, as illustrated in <FIG> and <FIG>.

<FIG> is a schematic isometric partial view of the first actuator <NUM> of the locking assembly <NUM>, according to one implementation. The first actuator <NUM> includes a center axis <NUM> extending through a center of the first actuator <NUM> and through the central opening <NUM>. The center axis <NUM> is longitudinally aligned with the center axis <NUM> of the second actuator <NUM> in the locking assembly <NUM>, as illustrated in <FIG> and <FIG>. The upper surface <NUM> and the lower surface <NUM> of the second portion <NUM> extend perpendicularly to the center axis <NUM>.

<FIG> is a schematic isometric partial view of the valve cover <NUM> of the fluid end <NUM>, according to one implementation. The valve cover <NUM> includes a center axis <NUM> extending through a center of the valve cover <NUM>. The center axis <NUM> is longitudinally aligned with the center axis <NUM> of the second actuator <NUM> of the locking assembly <NUM>, as illustrated in <FIG> and <FIG>.

<FIG> is a schematic enlarged cross-sectional isometric view of a locking assembly <NUM> in a locked position, according to one implementation. <FIG> is a schematic enlarged cross-sectional side view of the locking assembly <NUM> in the locked position, according to one implementation. The locking assembly <NUM> may be used in place of the locking assembly <NUM> and/or the locking assembly <NUM> described above. Referring to <FIG> and <FIG>, the locking assembly <NUM> includes a first actuator <NUM>, a second actuator <NUM> disposed about the first actuator <NUM>, and a plurality of wedges <NUM> that are each coupled to the second actuator <NUM>. The first actuator <NUM> is received in a central opening of the second actuator <NUM>. One or more coupling surfaces (such as a threaded outer surface) of the first actuator <NUM> are disposed in coupling engagement with one or more coupling surfaces (such as a threaded inner surface) of the second actuator <NUM>. The second actuator <NUM> includes a body <NUM> that is pentagonal in shape, including rounded or chamfered edges between the five sides of the pentagonal shape. The first actuator <NUM> includes a stud <NUM> that is rotatable. The stud <NUM> includes a hex portion <NUM> for interfacing with a tool, such as a wrench, and a threaded portion <NUM>.

The body <NUM> includes one or more tapered interfacing surfaces <NUM>. In one embodiment, which can be combined with other embodiments, the tapered interfacing surfaces <NUM> taper inwardly toward a center axis of the body <NUM> and downward in the longitudinal direction D3 that points toward the fluid end body <NUM>. The present disclosure contemplates that use of "downward" or "downwardly" herein may be parallel to gravitational forces, or, depending on orientations of the locking assemblies, may be disposed at an oblique angle relative to the gravitational forces or disposed perpendicularly to gravitational forces.

The plurality of wedges <NUM> are coupled to the second actuator <NUM> by a plurality of guide blocks <NUM>. Each guide block <NUM> may be formed of a single body, or a plurality of bodies coupled together. In the implementation shown in <FIG>, each guide block <NUM> includes a rectangular body <NUM> coupled to a second body <NUM> that includes one or more arcuate sides (such as two arcuate sides), such as one or more semi-circular sides. The one or more tapered interfacing surfaces <NUM> (five are included as part of the pentagonal shape) interface with and engage a set of one or more tapered interfacing surfaces <NUM> of each of the wedges <NUM> (five wedges <NUM> are included) such that the one or more tapered interfacing surfaces <NUM> slide upward and downward along the one or more tapered interfacing surfaces <NUM> of the wedges <NUM>. In one embodiment, which can be combined with other embodiments, the one or more tapered interfacing surfaces <NUM> of each wedge <NUM> taper inward relative to the center axis of the body <NUM> and downward in the longitudinal direction D3. In one embodiment, which can be combined with other embodiments, the one or more tapered interfacing surfaces <NUM> include one or more tapered outer surfaces and the one or more tapered interfacing surfaces <NUM> include one or more tapered inner surfaces.

The guide blocks <NUM> (five guide blocks <NUM> are included) are coupled to the second actuator <NUM> (as shown in <FIG>) by a plurality of fasteners <NUM>, such as screws. The fasteners <NUM> extend through the respective guide block <NUM> and partially through the body <NUM> of the second actuator <NUM>. In one embodiment, which can be combined with other embodiments, the guide blocks <NUM> may be integrally formed with the second actuator <NUM>. In one example, the guide blocks <NUM> are integrally formed with the second actuator <NUM> such that each guide block <NUM> is a protrusion that protrudes from the tapered interfacing surface <NUM>. Each wedge <NUM> includes an upper surface <NUM>, a lower surface <NUM>, and a guide slot <NUM> formed in the tapered interfacing surface <NUM> of the respective wedge <NUM>. The tapered interfacing surface <NUM> of each wedge <NUM> extends from the lower surface <NUM> each respective wedge <NUM> to the upper surface <NUM>.

The guide blocks <NUM> are located at least partially within the guide slots <NUM> formed within each wedge <NUM> to rotationally couple the second actuator <NUM> to the plurality of wedges <NUM> but allow axial relative movement between the second actuator <NUM> and the plurality of wedges <NUM>. The guide blocks <NUM> and the guide slots <NUM> form a guide mechanism configured to keep the wedges <NUM> coupled to the second actuator <NUM>. The guide mechanism can be a dovetail, circular, or other shaped interface. In one embodiment, which can be combined with other embodiments, the guide mechanism can be reversed such that the guide slots <NUM> are formed on the second actuator <NUM> and the guide blocks <NUM> are coupled to or integrally formed with the wedges <NUM>.

The plurality of wedges <NUM> have a set of one or more external locking surfaces <NUM> that engage with one or more internal locking surfaces <NUM> of a lock ring <NUM> and one or more internal grooves <NUM> (two are shown) formed on an inner surface <NUM> of the lock ring <NUM>. In one embodiment, which can be combined with other embodiments, the locking surfaces <NUM> are part of one or more external teeth formed on the wedges <NUM>. The locking surfaces <NUM> are angled. The plurality of wedges <NUM> are positioned on top of an upper surface <NUM> of a plate <NUM>, which is positioned on top of a valve cover <NUM>. In one example, the plate <NUM> is a ring, such as a load ring. In one embodiment, which can be combined with other embodiments, the plate <NUM> may be integrally formed with the valve cover <NUM> (or integrally formed with any other component, such as a plug, that is secured within the fluid end body <NUM>).

When the locking assembly <NUM> is in the unlocked position, the second actuator <NUM> is in an upper position, the first actuator <NUM> is in an upper positions, and the plurality of wedges <NUM> are in an unlocked position. In the unlocked position, the external locking surfaces <NUM> are disengaged from and disposed at a gap from the internal locking surfaces <NUM> of adjacent internal grooves <NUM> formed in the lock ring <NUM>. When the locking assembly <NUM> is in the unlocked position and the wedges <NUM> are in the unlocked position, the first actuator <NUM>, the second actuator <NUM>, and the wedges <NUM> may be inserted into the lock ring <NUM> or removed from the lock ring <NUM> as an assembly.

The operation of attaching the locking assembly <NUM> to the fluid end <NUM> and actuating the locking assembly <NUM> from the unlocked position to the locked position will now be described. The locking assembly <NUM> is attached to the fluid end body <NUM> by bolting the lock ring <NUM> to the fluid end body <NUM> such that the plate <NUM> is positioned on top of the valve cover <NUM>. As stated above, the lock ring <NUM> may be integrally formed with the fluid end body <NUM> such that no bolting is required. The locking assembly <NUM> is in the unlocked position as shown in <FIG> and <FIG>.

The first actuator <NUM> is then rotated (such as by a wrench used to grip and rotate the hex portion <NUM> of the first actuator <NUM>) in a first rotational direction RD3 and relative to the second actuator <NUM> and the plurality of wedges <NUM> such that the second actuator <NUM> and the first actuator <NUM> is driven downward in the longitudinal direction D3 and toward the valve cover <NUM> via a threaded interface formed between the first actuator <NUM> and the second actuator <NUM>. The threaded inner surface of the first actuator <NUM> engages the threaded outer surface of the second actuator <NUM> to form the threaded interface that moves the second actuator <NUM> upward or downward depending on the direction of rotation of the first actuator <NUM>. The first actuator <NUM> may include a second threaded portion <NUM> that interfaces with a threaded inner surface of the plate <NUM>. The second threaded portion <NUM> and the threaded portion <NUM> may be threaded in opposite directions such that both the first actuator <NUM> and the second actuator <NUM>.

As the guide blocks <NUM> of the of the second actuator <NUM> are engaged with the wedges <NUM> using the guide slots <NUM>, turning the first actuator <NUM> to rotate the first actuator <NUM> moves (such as by threading) the one or more coupling surfaces of the first actuator <NUM> (such as the threaded portion <NUM>) upward and out of the one or more coupling surfaces (such as a threaded inner surface) of the second actuator <NUM>. The threading of the first actuator <NUM> out of the second actuator <NUM> moves the second actuator <NUM> downward in the longitudinal direction D3 from the upper (shown in <FIG> and <FIG>) position to the lower position. The second actuator <NUM> moves downward in the longitudinal direction D3 relative to the valve cover <NUM>, the fluid end body <NUM>, the lock ring <NUM>, the plate <NUM>, the wedges <NUM>, and the first actuator <NUM>. The rotation of the first actuator <NUM> also moves (such as by threading) the second threaded portion <NUM> downward and into the threaded inner surface of the plate <NUM>.

In one embodiment, which can be combined with other embodiments, the first actuator <NUM> functions as a turnbuckle. In one example, threaded portion <NUM> includes a left-hand thread and the second threaded portion <NUM> includes a righthand thread.

As the second actuator <NUM> is pushed downward in the longitudinal direction D3 by the first actuator <NUM>, the tapered interfacing surfaces <NUM> of the second actuator <NUM> engage the tapered interfacing surfaces <NUM> of the wedges <NUM> and force the wedges <NUM> radially outward and into engagement with the lock ring <NUM>. As the second actuator <NUM> moves downward in the longitudinal direction D3, the tapered interfacing surfaces <NUM> slide downward along the tapered interfacing surfaces <NUM> of the wedges <NUM> and apply outward forces to the wedges <NUM> to push the wedges <NUM> outward. The guide slots <NUM> and the guide blocks <NUM> are substantially parallel with the tapered surfaces <NUM>, <NUM> of the second actuator <NUM> and the wedges <NUM>.

As the second actuator <NUM> moves downward from the upper position to the lower position, the wedges <NUM> move outward from the unlocked position to the locked position. As the wedges <NUM> move outward, a lower surface <NUM> of each wedge <NUM> slides along the upper surface <NUM> of the plate <NUM> and outward. As the wedges <NUM> move outward, each set of external locking surfaces <NUM> moves toward one of the internal grooves <NUM>.

In the locked position, the external locking surfaces <NUM> of the wedges <NUM> are engaged with and received in the internal grooves <NUM> formed on the inner surface <NUM> of the lock ring <NUM> to help secure the plate <NUM> and the valve cover <NUM> within the fluid end body <NUM>. In one embodiment, which can be combined with other embodiments, the plate <NUM> and the valve cover <NUM> form an integral component. The external locking surfaces <NUM> and the internal locking surfaces <NUM> may be tapered surfaces that engage with each other as the wedges <NUM> moved from the unlocked position to the locked position. When the wedges <NUM> are moved radially outward into contact with the lock ring <NUM>, the wedges <NUM> move slightly downward toward the fluid end body <NUM> to apply a force to the plate <NUM> and the valve cover <NUM> due to the tapered external locking surfaces <NUM> engaging and moving along the tapered internal locking surfaces <NUM> of the internal grooves <NUM>. The wedges <NUM> may move slightly downward relative to the lock ring <NUM> since the lock ring <NUM> is bolted to (or integrally formed with) the fluid end body <NUM>.

In the locked position, the internal teeth of the lock ring <NUM> are engaged with and at least partially between the external teeth of the wedges <NUM>. In the locked position, the internal teeth of the lock ring <NUM> are interleaved between the external teeth of the wedges <NUM>. In the locked position, external locking surfaces of the external locking surfaces <NUM> of the wedges <NUM> are engaged with internal locking surfaces of the internal locking surfaces <NUM> of the lock ring <NUM>.

In the locked position, the external locking surfaces <NUM> engaged with the internal locking surfaces <NUM>, the wedges <NUM> engaged with the plate <NUM>, and the plate <NUM> engaged with the valve cover <NUM> facilitate retaining the valve cover <NUM> in the opening <NUM> and into sealing engagement with the fluid end body <NUM> during operation of the fluid end <NUM>. For example, the external locking surfaces <NUM> engaged against the internal locking surfaces <NUM> facilitates retaining the wedges <NUM> in a substantially fixed position relative to the fluid end body <NUM>, and the engagements between the wedges <NUM>, the plate <NUM>, and the valve cover <NUM> facilitate retaining the valve cover <NUM> in a substantially fixed position relative to the fluid end body <NUM>. The wedges <NUM> may apply retaining surfaces directly or indirectly to the valve cover <NUM>. The aspects also facilitate preventing the valve cover <NUM> from backing out of the opening <NUM> during high pressure operations of the fluid end <NUM>. In the locked position, the wedges <NUM> and the second actuator <NUM> are retained within the lock ring <NUM>. The locking assembly <NUM> including the wedges <NUM> is mounted to the fluid end body <NUM> in the locked position using at least the lock ring <NUM> mounted to the fluid end body <NUM>. The aspects of the locking assembly <NUM> facilitate preventing backing out of the valve covers <NUM> and maintaining sealed connections of the fluid end <NUM> during high pressure operations of the fluid end <NUM>.

<FIG> is a schematic enlarged cross-sectional isometric view of the locking assembly <NUM> in the unlocked position, according to one implementation.

<FIG> is a schematic enlarged cross-sectional side view of the locking assembly <NUM> in the unlocked position, according to one implementation.

Benefits of the present disclosure include at least unlocking the locking assembly <NUM> if the locking assembly <NUM> is locked up due to frictional forces; close following of the wedges <NUM> with the second actuator <NUM>; quick operational times for the locking assembly <NUM>; quick access to inside the fluid end body <NUM> for maintenance, replacement, and/or repair; reduced need of springs or other biasing elements; reduced costs; increased efficiencies; reduced operational and maintenance times for fluid ends; light weight for the locking assembly <NUM>; ease of manual operation; long operational lifespans for the locking assembly <NUM>; and maintained seal engagements at high operating pressures for fluid ends.

Aspects of the present disclosure include at least upward movement of the second actuator <NUM> to push the wedges <NUM> outward to the locked position; the guide blocks <NUM>, guide slots <NUM>, protrusions <NUM>, first guide slots <NUM>, and second guide slots <NUM> forming joints; the one or more tapered interfacing surfaces <NUM>, <NUM> and the tapered interfacing surfaces <NUM>, <NUM> tapering inward and upward in the longitudinal direction D1; the guide blocks <NUM> of the second actuator <NUM> pulling the wedges <NUM> inward; the engagement of the shoulder portions <NUM> with the internal groove <NUM> to horizontally guide the wedges <NUM>; and applying downward retaining forces to the valve cover <NUM> using the wedges <NUM>. It is contemplated that one or more of these aspects disclosed herein may be combined. Moreover, it is contemplated that one or more of these aspects may include some or all of the aforementioned benefits.

As an example, the present disclosure contemplates that one or more of the aspects, features, components, and/or properties of the locking assembly <NUM> may be combined with one or more of the aspects, features, components, and/or properties of the locking assembly <NUM> and/or the locking assembly <NUM>.

Claim 1:
A locking assembly (<NUM>, <NUM>, <NUM>) for fluid ends (<NUM>), comprising:
a first actuator (<NUM>, <NUM>, <NUM>), the first actuator comprising one or more coupling surfaces (<NUM>, <NUM>);
a second actuator (<NUM>, <NUM>, <NUM>) disposed at least partially below the first actuator, the second actuator comprising:
a body (<NUM>, <NUM>, <NUM>), the body comprising one or more tapered interfacing surfaces (<NUM>, <NUM>, <NUM>);
one or more coupling surfaces (<NUM>, <NUM>) disposed in coupling engagement with the one or more coupling surfaces (<NUM>, <NUM>) of the first actuator; and
a center axis (<NUM>, <NUM>) extending in a longitudinal direction through the body (<NUM>, <NUM>, <NUM>), wherein the one or more tapered interfacing surfaces (<NUM>, <NUM>, <NUM>) taper inward at an angle relative to the center axis;
a plurality of wedges (<NUM>, <NUM>, <NUM>) disposed about the second actuator (<NUM>, <NUM>, <NUM>) and movable between an unlocked position and a locked position, each wedge of the plurality of wedges comprising:
a set of one or more external locking surfaces (<NUM>, <NUM>, <NUM>);
a set of one or more tapered interfacing surfaces (<NUM>, <NUM>, <NUM>), wherein the one or more tapered interfacing surfaces of each wedge is configured to engage with one of the one or more tapered interfacing surfaces (<NUM>, <NUM>, <NUM>) of the second actuator; and
a lock ring (<NUM>, <NUM>, <NUM>) disposed about the plurality of wedges (<NUM>, <NUM>, <NUM>), the lock ring comprising a set of one or more internal locking surfaces (<NUM>, <NUM>, <NUM>) configured to engage with the external locking surfaces (<NUM>, <NUM>, <NUM>) of each wedge of the plurality of wedges; and
wherein the body (<NUM>, <NUM>, <NUM>) of the second actuator (<NUM>, <NUM>, <NUM>) comprises a plurality of guide blocks (<NUM>, <NUM>, <NUM>); and each wedge of the plurality of wedges (<NUM>, <NUM>, <NUM>) comprises a guide slot (<NUM>, <NUM>, <NUM>, <NUM>) formed in a respective tapered interfacing surface of the set of one or more tapered interfacing surfaces of the respective wedge, and each guide slot includes a guide block of the plurality of guide blocks disposed at least partially in the respective guide slot.