Patent Publication Number: US-2022235636-A1

Title: Rod rotator assembly for an artificial lift system

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority from and the benefit of U.S. Provisional Application Ser. No. 63/140,672, entitled “ROD ROTATOR ASSEMBLY FOR AN ARTIFICIAL LIFT SYSTEM”, filed Jan. 22, 2021, which is hereby incorporated by reference in its entirety. 
    
    
     BACKGROUND 
     The present disclosure relates generally to a rod rotator assembly for an artificial lift system. 
     Wells are drilled into reservoirs to discover and produce oil. The oil within the reservoirs may be under sufficient pressure to drive the oil through the well to the surface. However, over time, the natural pressure of the oil may decline, and an artificial lift system may be used to extract the oil from the reservoir. The artificial lift system may include a pump disposed within the reservoir and a wellhead at the surface. A tubing string may be supported by the wellhead and may extend to the reservoir, and the pump may drive the oil from the reservoir to the wellhead via the tubing string. 
     The pump is driven by a series of polish rods that extend through the tubing string to the pump. The polish rods are lifted and lowered by a pump jack, which supports the polish rods. The repeated lifting and lowering movement of the polish rods causes the polish rods to wear at the point(s) of contact with the tubing string. Accordingly, certain artificial lift systems include a rod rotator to drive the polish rods to rotate within the tubing string, thereby distributing the wear around the circumference of the polish rods. As a result, the longevity of the polish rods may be increased. 
     Certain artificial lift systems include a load cell configured to monitor the load on the polish rods. If the load on the polish rods is outside of a target range (e.g., above a maximum threshold load or below a minimum threshold load), an operator may adjust or terminate operation of the artificial lift system. In certain artificial lift systems, the load cell is disposed about a top polish rod and positioned between the rod rotator and a carrier, which is coupled to the pump jack by cables and supports the rod rotator. To substantially reduce the non-vertical load applied to the top polish rod due to misalignment of the rod rotator and the load cell, a first set of alignment plates may be disposed between the rod rotator and the load cell. In addition, to substantially reduce the non-vertical load applied to the top polish rod due to misalignment of the load cell and the carrier, a second set of alignment plates may be disposed between the load cell and the carrier. Unfortunately, the load cell and the two sets of alignment plates increases the height of the stack of equipment supported by the pump jack, which increases the stroke length of the pump jack. 
     BRIEF DESCRIPTION 
     In certain embodiments, a rod rotator assembly for an artificial lift system includes a housing configured to be supported by a carrier of the artificial lift system. The rod rotator assembly also includes a top cap configured to rotate relative to the housing, in which the top cap is configured to support a polish rod of the artificial lift system. In addition, the rod rotator assembly includes a load cell disposed within the housing. The load cell is configured to support the top cap, and the load cell is configured to output a sensor signal indicative of a load applied by the polish rod to the housing. 
    
    
     
       DRAWINGS 
       These and other features, aspects, and advantages of the present disclosure will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein: 
         FIG. 1  is a schematic side view of an embodiment of an artificial lift system having an embodiment of a rod rotator assembly; 
         FIG. 2  is a schematic side view of a portion of the artificial lift system of  FIG. 1 , including a wellhead and a polish rod connection assembly; 
         FIG. 3  is a schematic side view of the polish rod connection assembly of  FIG. 2 , in which the polish rod connection assembly includes the rod rotator assembly; 
         FIG. 4  is a schematic cross-sectional view of the rod rotator assembly of  FIG. 3 ; and 
         FIG. 5  is a cross-sectional perspective view of the rod rotator assembly of  FIG. 3 . 
     
    
    
     DETAILED DESCRIPTION 
     One or more specific embodiments of the present disclosure will be described below. In an effort to provide a concise description of these embodiments, all features of an actual implementation may not be described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers&#39; specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure. 
     When introducing elements of various embodiments of the present disclosure, the articles “a,” “an,” “the,” and “said” are intended to mean that there are one or more of the elements. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. Any examples of operating parameters and/or environmental conditions are not exclusive of other parameters/conditions of the disclosed embodiments. 
       FIG. 1  is a schematic side view of an embodiment of an artificial lift system  10  having an embodiment of a rod rotator assembly  12 . As illustrated, the artificial lift system  10  includes a pump  14  disposed within a reservoir  16 . The artificial lift system  10  also includes a wellhead  18  at the surface  20 . A tubing string  22 , which is supported by the wellhead  18 , extends from the surface  20  to the reservoir  16 . The pump  14  is configured to drive oil from the reservoir  16  to the surface  20  via the tubing string  22  and the wellhead  18 . 
     The pump  14  is driven by a series of polish rods that extend through the tubing string  22  to the pump  14 . As illustrated, a polish rod  24  at the end of the series of polish rods is coupled to a pump jack  26  of the artificial lift system  10 . The pump jack  26  is configured to lift and lower the polish rods, thereby driving the pump  14 . One or more polish rods may contact the tubing string  22  at one or more points along a circumference of the polish rod(s). Accordingly, as the polish rods are driven to move within the tubing string  22 , certain point(s) on the polish rod(s) may wear. The rod rotator assembly  12  is configured to drive the polish rods to rotate within the tubing string  22 , thereby distributing the wear around the circumference of the polish rod(s). As a result, the longevity of the polish rods may be increased. As discussed in detail below, the rod rotator assembly  12  is supported by a carrier (e.g., carrier bar) that is supported by the pump jack  26  via one or more cables. 
     In certain embodiments, the rod rotator assembly  12  includes a housing configured to be supported by the carrier of the artificial lift system  10 . In addition, the rod rotator assembly  12  includes a top cap configured to rotate relative to the housing, in which the top cap is configured to support the polish rod  24  (e.g., via a polish rod clamp). The rod rotator assembly  12  also includes a load cell disposed within the housing (e.g., between the top cap and a base of the housing). The load cell is configured to support the top cap, and the load cell is configured to output a sensor signal indicative of a load applied by the polish rod to the housing. Accordingly, load on the polish rods may be monitored (e.g., continuously, periodically, on demand, etc.) to facilitate operation of the artificial lift system  10 . For example, operation of the pump jack  26  may be adjusted or terminated (e.g., automatically or manually) in response to the load on the polish rods being outside of a target range (e.g., above a maximum threshold load or below a minimum threshold load). Because the load cell is disposed within the rod rotator assembly housing, the height of the stack supported by the carrier may be reduced (e.g., as compared to a configuration in which a load cell is positioned between the rod rotator and the carrier, a first set of alignment plates is positioned between the rod rotator and the load cell, and a second set of alignment plates is positioned between the load cell and the carrier), thereby reducing the stroke length of the pump jack. In addition, the number of component interfaces along the polish rod may be reduced (e.g., as compared to a configuration in which a load cell is positioned between the rod rotator and the carrier, a first set of alignment plates is positioned between the rod rotator and the load cell, and a second set of alignment plates is positioned between the load cell and the carrier), thereby reducing the possibility of misalignment of components at the interfaces. 
       FIG. 2  is a schematic side view of a portion of the artificial lift system  10  of  FIG. 1 , including the wellhead  18  and a polish rod connection assembly  28 . In the illustrated embodiment, the wellhead  18  includes a tubing spool  30  that supports the tubing string (e.g., via a tubing hanger coupled to an end of the tubing string and engaged with the tubing spool). The wellhead  18  also includes a pumping tee  32  coupled to the tubing spool  30  and to a flowline  34 . The pumping tee  32  is configured to receive oil from the tubing spool  30  and to control the flow of the oil through the flow line  34 . The flow line  34  may extend to a storage or processing facility. Furthermore, the wellhead  18  includes a stuffing box  36  coupled to the pumping tee  32 . The stuffing box is configured to establish a seal around the polish rod  24  that substantially blocks flow of oil through the polish rod/stuffing box interface while enabling the upward/downward movement of the polish rod. While the wellhead  18  includes the tubing spool  30 , the pumping tee  32 , and the stuffing box  36  in the illustrated embodiment, the wellhead may include other and/or additional components in other embodiments. 
     As discussed in detail below, the polish rod connection assembly  28  includes the rod rotator assembly  12 , which is configured to drive the polish rod  24  to rotate relative to the wellhead  18  and the tubing string. The polish rod connection assembly  28  also includes a carrier  38  (e.g., carrier bar) configured to support the rod rotator assembly  12 . The carrier  38  may be coupled to the pump jack by one or more cables. In addition, the polish rod connection assembly  28  includes one or more polish rod clamps  40  configured to non-movably couple to the polish rod  24 . The polish rod clamps  40  transfer the load (e.g., substantially vertical load) of the polish rods to the rod rotator assembly  12 , the load flows through the rod rotator assembly  12  to the carrier  38 , and the load applied to the carrier is transferred to the pump jack via the cable(s). Accordingly, during an upward movement of the pump jack, the pump jack lifts the carrier  38  via the cable(s), the carrier  38  drives the rod rotator assembly  12  to move upwardly, and the rod rotator assembly  12  drives the polish rods to move upwardly via engagement of the rod rotator assembly  12  with the polish rod clamp(s). During a downward movement of the pump jack, the pump jack drives the polish rod  24  downwardly. Because the polish rod clamp(s)  40  are non-movably coupled to the polish rod  24 , the polish rod clamp(s)  40  drive the rod rotator assembly  12  to move downwardly, thereby driving the carrier  38  to move downwardly. 
       FIG. 3  is a schematic side view of the polish rod connection assembly  28  of  FIG. 2 . As previously discussed, the polish rod connection assembly  28  includes the rod rotator assembly  12 , the carrier  38 , and the polish rod clamps  40 . In the illustrated embodiment, the rod rotator assembly  12  includes a housing  42 , which is supported by the carrier  38 . The rod rotator assembly  12  also includes a top cap  44  configured to rotate relative to the housing  42 . As illustrated, the top cap  44  is engaged with the polish rod clamp(s)  40 , thereby supporting the polish rods. In addition, due to the engagement of the top cap  44  with the polish rod clamp(s)  40 , rotation of the top cap  44  relative to the housing  42  drives the polish rods to rotate, thereby increasing the longevity of the polish rods. While the polish rod connection assembly  28  includes two polish rod clamps  40  in the illustrated embodiment, in other embodiments, the polish rod connection assembly may include more or fewer polish rod clamps (e.g., 1, 3, 4, or more). 
     In the illustrated embodiment, the rod rotator assembly  12  includes a lever  46  configured to drive the top cap to rotate. In certain embodiments, the lever  46  is coupled to a worm gear of the rod rotator assembly  12 , and movement of the lever drives the worm gear to rotate. As discussed in detail below, the worm gear is engaged with a main gear of the rod rotator assembly  12  and configured to drive the main gear to rotate. The main gear, in turn, is non-rotatably coupled to the top cap  44 . Accordingly, movement of the lever  46  drives the top cap  44  to rotate, thereby driving the polish rods to rotate via contact between the top cap  44  and the polish rod clamps  40 . The lever  46  may be driven to move via a cable extending between the lever  46  and a base of the pump jack. As the rod rotator assembly  12  moves upwardly and downwardly with the polish rod during operation of the pump jack, the cable may cyclically drive the lever  46  to move in response to the rod rotator assembly  12  moving to a distance away from the pump jack cable anchor point that is greater than the length of the cable. While the top plate  44  is driven to rotate by the lever  46 , the worm gear, and the main gear in the embodiment disclosed herein, the top plate may be driven to rotate relative to the rod rotator assembly housing via any other suitable device/assembly (e.g., electric motor, pneumatic actuator, another suitable mechanical drive assembly, etc.). 
     In the illustrated embodiment, a set of alignment plates  48  is positioned between the housing  42  of the rod rotator assembly  12  and the carrier  38  (e.g., carrier bar). The set of alignment plates  48  may include a first alignment plate having a hemispherical recess and a second alignment plate having a hemispherical protrusion. The hemispherical protrusion of the second alignment plate is engaged with the hemispherical recess of the first alignment plate, thereby enabling the alignment plates to slide relative to one another. One alignment plate of the set may be engaged with the rod rotator assembly housing  42 , and the other alignment plate of the set may be engaged with the carrier  38 . The set of alignment plates  48  facilitates a transfer of load (e.g., substantially vertical load) from the rod rotator assembly housing  42  to the carrier  38  even while the housing  42  and the carrier  38  are not aligned with one another (e.g., the bottom surface of the housing  42  is not parallel to the top surface of the carrier  38 ). Accordingly, the non-vertical load (e.g., load that is not along the direction of extension/movement of the polish rod  24 ) applied to the polish rod  24  at the interface between the housing  42  and the carrier  38  may be substantially reduced, thereby increasing the longevity of the polish rod  24 . While a set of alignment plates having a hemispherical protrusion/hemispherical recess is disclosed above, the set of alignment plates may have another suitable arrangement that facilitates transfer of load (e.g., substantially vertical load) from the rod rotator housing to the carrier while substantially reducing the non-vertical load applied to the polish rod due to misalignment of the housing/carrier. Furthermore, in certain embodiments, the set of alignment plates may be omitted. 
       FIG. 4  is a schematic cross-sectional view of the rod rotator assembly  12  of  FIG. 3 . As previously discussed, the rod rotator assembly  12  includes the housing  42  and the top cap  44 . The housing  42  is configured to be supported by the carrier, and the top cap  44  is configured to rotate relative to the housing  42 . The top cap  44  is also configured to support the polish rod via the polish rod clamp(s). In the illustrated embodiment, the rod rotator assembly  12  also includes a load cell  50 , a bearing  52 , and the main gear  54  disposed within the housing  42 . The main gear  54  is non-rotatably coupled to the top cap  44  and configured to be driven to rotate by a worm gear or an electrical rotary motor. In addition, the load cell  50  is disposed within the housing  42  (e.g., between the top cap  44  and a base  56  of the housing  42 ). The load cell  50  is configured to support the top cap  44 , and the load cell  50  is configured to output a sensor signal indicative of a load applied by the polish rod to the housing  42 . As illustrated, the bearing  52  is disposed between the load cell  50  and the main gear  54 , thereby enabling the main gear  54  to rotate relative to the load cell  50 , which may be non-rotatably coupled to the housing  42 . However, in other embodiments, the load cell may be non-rotatably coupled to the main gear. In such embodiments, the bearing may be disposed between the load cell and the base of the housing. As used herein, “disposed between” refers to an arrangement in which one component is positioned between at least a portion of another component and at least a portion of a further component. 
     While the rod rotator assembly  12  includes a single bearing  52  in the illustrated embodiment, in other embodiments, the rod rotator assembly may include more or fewer bearings (e.g., 0, 2, 3, or more). In addition, in certain embodiments, one or more bushings may be disposed between components within the rod rotator assembly housing (e.g., alone or in combination with the bearing(s)). For example, the bearing may be omitted, and a bushing may be disposed between the main gear and the load cell. Furthermore, while the top cap  44  is driven to rotate by the main gear  54  in the illustrated embodiment, in other embodiments, the top cap may be driven to rotate by any other suitable device/assembly (e.g., in which at least a portion of the device/assembly is disposed within the housing between the top cap and the load cell). For example, in certain embodiments, an electrical rotary motor (e.g., gimbaled or non-gimbaled) may be disposed between the load cell and the top cap. In such embodiments, a first portion (e.g., body) of the motor may be non-rotatably and translatably coupled to the housing, and a second portion (e.g., rotary shaft) may be non-rotatably coupled to the top cap to drive the top cap to rotate. Furthermore, in such embodiments, the main gear, the worm gear, the lever, and the bearing may be omitted. 
     Because the load cell  50  is positioned between the top cap  44  and a portion (e.g., base  56 ) of the housing  42 , the load applied by the polish rods to the top cap  44  is transferred through the load cell  50  to the housing  42 , which is supported by the carrier. Accordingly, the load on the polish rods may be monitored by the load cell (e.g., continuously, periodically, on demand, etc.) to facilitate operation of the artificial lift system  10 . For example, operation of the pump jack may be adjusted or terminated (e.g., automatically or manually) in response to the load on the polish rods being outside of a target range (e.g., above a maximum threshold load or below a minimum threshold load). The load cell may output the sensor signal indicative of the load applied by the polish rods to the housing  42  via a wired or wireless connection. In the illustrated embodiment, a load cell cable  58  extends between the load cell and a monitoring/control system, and the sensor signal may be output via the load cell cable  58 . However, in other embodiments, the load cell may be communicatively coupled to the monitoring/control system via a wireless connection. The wireless connection may utilize any suitable wireless communication protocol, such as Bluetooth, WiFi, radio frequency identification (RFID), a proprietary protocol, or a combination thereof. Furthermore, the load cell  50  may include any suitable sensor(s) configured to monitor the load on the polish rods, such as piezoelectric sensor(s), strain gauge(s), other suitable type(s) of sensor(s), or a combination thereof. 
     Because the load cell is disposed within the rod rotator assembly housing, the height of the stack supported by the carrier may be reduced (e.g., as compared to a configuration in which a load cell is positioned between the rod rotator and the carrier, a first set of alignment plates is positioned between the rod rotator and the load cell, and a second set of alignment plates is positioned between the load cell and the carrier). Accordingly, the stroke length of the pump jack may be reduced. In addition, the number of component interfaces along the polish rod may be reduced (e.g., as compared to a configuration in which a load cell is positioned between the rod rotator and the carrier, a first set of alignment plates is positioned between the rod rotator and the load cell, and a second set of alignment plates is positioned between the load cell and the carrier). As a result, the possibility of misalignment of components at the interfaces may be reduced. While a set of alignment plates is not disposed within the housing in the illustrated embodiment, in other embodiments, at least one set of alignment plates may be disposed within the housing (e.g., between the main gear and the load cell). 
       FIG. 5  is a cross-sectional perspective view of the rod rotator assembly  12  of  FIG. 3 . As previously discussed, the rod rotator assembly  12  includes a housing  42 , which is supported by the carrier. In the illustrated embodiment, the housing  42  includes the base  56  and a body  60  extending upwardly from the base  56  along a longitudinal axis  62  of the rod rotator assembly  12 . The body  60  forms a first opening  64  on an opposite longitudinal side of the housing  42  from the base  56 , and the first opening  64  provides access to an interior  66  of the housing  42 . Furthermore, in the illustrated embodiment, the base  56  of the housing  42  forms a second opening  68 . The openings in the housing  42  facilitate passage of the polish rod through the housing  42 . In the illustrated embodiment, an annular bushing  70  is disposed within the second opening  68 . The annular bushing  70  is configured to contact the polish rod, thereby substantially blocking dirt and/or debris from entering the housing interior  66  via the second opening  68 . While the housing  42  includes the annular bushing  70  in the illustrated embodiment, in other embodiments, the annular bushing may be omitted. Furthermore, while the housing  42  has an annular shape in the illustrated embodiment, in other embodiments, the housing may have any other suitable shape (e.g., polygonal, elliptical, irregular, etc.). 
     Furthermore, as previously discussed, the rod rotator assembly  12  includes a top cap  44  configured to rotate relative to the housing  42 . The top cap  44  is configured to rotate along a circumferential axis  72  of the rod rotator assembly  12 . Furthermore, as previously discussed, the top cap  44  is configured to support the polish rods via the polish rod clamp(s). In the illustrated embodiment, the top cap  44  includes a body  74  and a platform  76 . The body  74  extends through the first opening  64  in the housing  42  into the interior  66  of the housing  42 , and the platform  76  has an engagement surface  78  configured to engage the polish rod clamp(s), thereby supporting the polish rods. In the illustrated embodiment, the platform  76  of the top cap  44  has an opening  80  configured to facilitate passage of the polish rod (e.g., top polish rod) through the platform  76 . In addition, the body  74  of the top cap  44  is configured to be disposed outwardly from the polish rod along a radial axis  82  of the rod rotator assembly  12 , thereby facilitating passage of the polish rod through the body  74 . While the body  74  of the top cap  44  extends through the first opening  64  of the housing  42  into the interior  66  of the housing  42  in the illustrated embodiment, in other embodiments, the body may not extend into the housing interior (e.g., the body may be non-rotatably coupled to a component of the rod rotator assembly positioned at least partially outside of the housing, such as the main gear). Furthermore, in certain embodiments, the body of the top cap may be omitted (e.g., the platform of the top cap may be non-rotatably coupled to a component of the rod rotator assembly, such as the main gear). 
     In the illustrated embodiment, the rod rotator assembly  12  includes a main gear  54  non-rotatably coupled to the body  74  of the top cap  44 . The main gear  54  may be non-rotatably coupled to the body  74  of the top cap  44  via any suitable type(s) of connection(s), such as welded connection(s), a press-fit connection, fastener connection(s), adhesive connection(s), other suitable type(s) of connection(s), or a combination thereof. As previously discussed, the main gear  54  is configured to be driven to rotate by a worm gear. In the illustrated embodiment, movement of the lever  46  drives the worm gear to rotate, thereby driving the main gear  54  to rotate. Due to the non-rotatable coupling between the main gear  54  and the body  74  of the top cap  44 , rotation of the main gear  54  drives the top cap  44  to rotate, thereby driving the polish rods to rotate via the contact between the engagement surface  78  of the top cap  44  and the polish rod clamp(s). While the main gear  54  is driven to rotate by a worm gear coupled to the lever  46  in the illustrated embodiment, in other embodiments, the main gear may be driven to rotate by a motor (e.g., electric motor, hydraulic motor, pneumatic motor, etc.). Furthermore, in certain embodiments, the main gear may be omitted, and a motor (e.g., electric motor, hydraulic motor, pneumatic motor, etc.) may drive the top cap to rotate, as discussed above with reference to  FIG. 4 . 
     In addition, as previously discussed, the rod rotator assembly  12  includes a load cell  50 , which is disposed within the interior  66  of the housing  42 . The load cell  50  is configured to support the top cap  44 , and the load cell  50  is configured to output a sensor signal indicative of a load applied by the polish rods to the housing  42 . Because the load cell  50  is positioned between the top cap  44  and a portion (e.g., base  56 ) of the housing  42 , the load applied by the polish rods to the top cap  44  is transferred through the load cell  50  to the housing  42 , which is supported by the carrier. Accordingly, the load on the polish rods may be monitored by the load cell (e.g., continuously, periodically, on demand, etc.) to facilitate operation of the artificial lift system  10 . Furthermore, as previously discussed, the load cell  50  may include any suitable sensor(s) configured to monitor the load on the polish rod, such as piezoelectric sensor(s), strain gauge(s), other suitable type(s) of sensor(s), or a combination thereof. 
     In the illustrated embodiment, the rod rotator assembly  12  includes a bearing  52  disposed between the load cell  50  and the main gear  54  along the longitudinal axis  62  of the rod rotator assembly  12 . The bearing  52  enables the main gear  54  to rotate relative to the load cell  50 , which may be non-rotatably coupled to the housing  42 . In the illustrated embodiment, the bearing  52  includes a ball bearing (e.g., including multiple bearing balls between two races). However, in other embodiments, the bearing may include other suitable type(s) of bearing(s) (e.g., alone or in combination with one or more ball bearings), such as roller bearing(s), fluid bearing(s), other suitable type(s) of bearing(s), or a combination thereof. Furthermore, while the rod rotator assembly  12  includes a single bearing  52  in the illustrated embodiment, in other embodiments, the rod rotator assembly may include more or fewer bearings (e.g., 0, 2, 3, 4, or more). 
     In the illustrated embodiment, the body  74  of the top cap  44  overlaps the main gear  54 , the bearing  52 , and a portion of the load cell  50  along the longitudinal axis  62 . In addition, the body  74  of the top cap  44  includes a ledge  84  (e.g., annular ledge) engaged with the main gear  54 . As illustrated, the main gear  54  is disposed between the ledge  84  of the body  74  of the top cap  44  and the bearing  52  along the longitudinal axis  62  of the rod rotator assembly  12 . Accordingly, the load applied by the polish rods to the top cap  44  is transferred to the main gear  54  via the ledge  84 , to the bearing  52  via the main gear  54 , to the load cell  50  via the bearing  52 , and to the housing  42  via the load cell  50 . Accordingly, the load applied by the polish rods is transferred through the load cell  50 , thereby enabling the load cell to monitor the load applied by the polish rods to the housing  42 . In embodiments in which the main gear and/or the bearing is omitted, the load may be transferred from the ledge to the load cell via another suitable path (e.g., through the main gear alone, through a bushing, through a motor, etc.). Furthermore, while the body of the top cap engages a corresponding component of the rod rotator assembly (e.g., the main gear, a motor, etc.) via the ledge in the embodiments disclosed above, in certain embodiments, the body of the top cap may engage the corresponding component via another suitable surface of the body (e.g., a bottom surface of the body, etc.). In such embodiments, the ledge may be omitted. In addition, in certain embodiments, the body of the top cap may be omitted, and the platform of the top cap may engage the corresponding component of the rod rotator assembly. 
     In the illustrated embodiment, the load cell  50  is disposed between the body  74  of the top cap  44  (e.g., the ledge  84  of the body  74  of the top cap  44 ) and the base  56  of the housing  42 . Accordingly, the load applied by the polish rods to the top cap  44  is transferred through the load cell  50  to the base  56  of the housing  42 . While the load cell  50  is supported by the base  56  of the housing  42  in the illustrated embodiment, in other embodiments, the load cell may be supported by another suitable portion of the housing. For example, in certain embodiments, the body of the housing may include a ledge, and the load cell may be supported by the ledge. In such embodiments, the load applied by the polish rods to the top cap may be transferred through the load cell to the housing via the ledge. Furthermore, in certain embodiments, the load cell may be coupled to the body of the housing by any suitable type(s) of connection(s), such as fastener connection(s), adhesive connection(s), a press fit connection, other suitable type(s) of connection(s), or a combination thereof. Additionally or alternatively, the load cell may be coupled to the body of the housing via one or more protrusion/recess interfaces. In embodiments in which the load cell is coupled to the body of the housing, the body supports the load cell, and the load applied by the polish rods to the top cap may be transferred through the load cell to the body of the housing. 
     In the illustrated embodiment, the rod rotator assembly  12  includes an adapter ring  86  disposed between the body  74  of the top cap  44  and the load cell  50  along the radial axis  82  of the rod rotator assembly  12 . The adapter ring  86  is configured to substantially block radial movement of the top cap body  74  relative to the load cell  50  and to facilitate establishment of a seal between the top cap body  74  and the load cell  50  (e.g., to substantially block dirt and/or debris from entering a cavity between the top cap body and the housing body). In the illustrated embodiment, a first seal  88  (e.g., o-ring, etc.) is disposed between the adapter ring  86  and the top cap body  74 , and a second seal  90  (e.g., o-ring, etc.) is disposed between the adapter ring  86  and the load cell  50 , thereby establishing the seal between the top cap body  74  and the load cell  50 . While the rod rotator assembly includes two seals at the adapter ring in the illustrated embodiment, in other embodiments, the rod rotator assembly may include more or fewer seals at the adapter ring (e.g., 0, 1, 3, 4, or more). For example, in certain embodiments, at least one of the first and second seals may be omitted. Furthermore, in the illustrated embodiment, the rod rotator assembly  12  includes a third seal  92  (e.g., o-ring, etc.) disposed between the platform  76  of the top cap  44  and the body  60  of the housing  42  along the radial axis  82 . The third seal  92  is configured to substantially block dirt and/or debris from entering the cavity between the top cap body and the housing body. While a single seal is disposed between the platform and the housing body along the radial axis in the illustrated embodiment, in other embodiments, more or fewer seals (e.g., 0, 2, 3, 4, or more) may be disposed between the platform and the housing body along the radial axis. 
     As previously discussed, the load cell  50  may output a sensor signal indicative of the load applied by the polish rods to the housing  42  via a wired or wireless connection. In the illustrated embodiment, the load cell  50  is configured to output the sensor signal via a wired connection, and the wired connection includes a load cell cable  58 , which may extend between the load cell  50  and a monitoring/control system. Furthermore, in the illustrated embodiment, the rod rotator assembly  12  includes a connector  94  coupled to the body  60  of the housing  42 . The connector  94  is configured to establish a wired connection to the load cell  50 . For example, the connector may include one or more conductors electrically coupled to the load cell, and the connector may be configured to selectively establish an electrical connection between the conductor(s) and the load cell cable  58 . In the illustrated embodiment, the connector  94  is coupled to the body  60  of the housing  42  via a threaded connection. However, in other embodiments, the connector may be coupled to the housing body via other suitable type(s) of connection(s) (e.g., alone or in combination with the threaded connection), such as adhesive connection(s), fastener connection(s), other suitable type(s) of connection(s), or a combination thereof. Furthermore, while the connector is coupled to the body of the housing in the illustrated embodiment, in other embodiments, the connector may be coupled to another suitable portion of the housing, such as the base. In addition, while electrical connections are disclosed above, in certain embodiments, the load cell cable may be configured to establish an optical connection between the load cell and the monitoring/control system. In such embodiments, the connector may be configured to establish an optical connection between the load cell and the load cell cable. Furthermore, in certain embodiments, the connector may be omitted. In such embodiments, the load cell cable may extend through an opening in the housing to the load cell. In addition, as previously discussed, the load cell may be communicatively coupled to the monitoring/control system via a wireless connection. 
     Because the load cell is disposed within the interior of the rod rotator assembly housing, the height of the stack supported by the carrier may be reduced (e.g., as compared to a configuration in which a load cell is positioned between the rod rotator and the carrier, a first set of alignment plates is positioned between the rod rotator and the load cell, and a second set of alignment plates is positioned between the load cell and the carrier). Accordingly, the stroke length of the pump jack may be reduced. In addition, the number of component interfaces along the polish rod may be reduced (e.g., as compared to a configuration in which a load cell is positioned between the rod rotator and the carrier, a first set of alignment plates is positioned between the rod rotator and the load cell, and a second set of alignment plates is positioned between the load cell and the carrier). As a result, the possibility of misalignment of components at the interfaces may be reduced. While a set of alignment plates is not disposed within the interior of the housing in the illustrated embodiment, in other embodiments, at least one set of alignment plates may be disposed within the interior of the housing (e.g., between the main gear and the load cell). 
     While only certain features have been illustrated and described herein, many modifications and changes will occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the disclosure. 
     The techniques presented and claimed herein are referenced and applied to material objects and concrete examples of a practical nature that demonstrably improve the present technical field and, as such, are not abstract, intangible or purely theoretical. Further, if any claims appended to the end of this specification contain one or more elements designated as “means for [perform]ing [a function] . . . ” or “step for [perform]ing [a function] . . . ”, it is intended that such elements are to be interpreted under 35 U.S.C. 112(f). However, for any claims containing elements designated in any other manner, it is intended that such elements are not to be interpreted under 35 U.S.C. 112(f).