Threaded Connection with Secure Shoulder Ring for Electrical Submersible Pump

Abstract

An electrical submersible pump assembly has modules including a pump, a motor, and a seal section. A drive shaft assembly extends from the motor through each of the modules. A threaded connection between at least two of the modules includes a first adapter having external threads and a second adapter having a neck with an external load shoulder. A collar is rotatably carried and axially movable on the neck. The collar has internal threads and an internal load shoulder. A shoulder ring having two segments encircles the neck. The shoulder ring has a first surface in abutment with the external load shoulder and a second surface in abutment with the internal load shoulder. A resilient ring tits around an outer diameter of the shoulder ring for retaining the ring segments on the neck prior to the collar being in threaded engagement with the threads of the first adapter.

1 . An electrical submersible pump assembly, comprising:
 a plurality of modules including a pump and a motor;   a drive shaft assembly having an axis and extending from the motor through each of the modules;   a threaded connection between at least two of the modules, comprising:   a first adapter having threads;   a second adapter having a neck with an external load shoulder;   a collar rotatably carried and axially movable on the neck, the collar being in threaded engagement with the threads of the first adapter, the collar having an internal load shoulder axially spaced from and facing in a direction opposite to the external load shoulder;   a shoulder ring encircling the neck and comprising a plurality of separate ring segments, the shoulder ring having a first surface in abutment with the external load shoulder and a second surface in abutment with the internal load shoulder to transfer an axial load between the first and second adapters; and   retaining means for retaining the ring segments on the neck prior to the collar being in threaded engagement with the threads of the first adapter, the retaining means remaining a part of the assembly after the collar is secured to the first adapter.   
     
     
         2 . The assembly according to  claim 1 , wherein the retaining means comprises a resilient ring that fits around an outer diameter defined by the ring segments. 
     
     
         3 . The assembly according to  claim 1 , wherein the retaining means comprises:
 a circumferentially extending groove segment on an outer side of each of the ring segments, defining an annular retaining ring groove when the ring segments are installed around the neck; and   a resilient ring that locates in the retaining ring groove.   
     
     
         4 . The assembly according to  claim 1 , wherein the retaining means comprises:
 a circumferentially extending groove segment on an outer side of each of the ring segments, defining an annular retaining ring groove when the ring segments are installed around the neck; and   an elastomeric ring located in the retaining ring groove.   
     
     
         5 . The assembly according to  claim 1 , wherein the retaining means comprises:
 a circumferentially extending groove segment on an outer side of each of the ring segments, defining an annular retaining ring groove when the ring segments are installed around the neck;   a resilient ring having an inner diameter side in contact with the retaining ring groove; and   the resilient ring has an outer diameter side spaced radially inward from any portion of the collar.   
     
     
         6 . The assembly according to  claim 1 , wherein each of the ring segments has two ends, and the retaining means comprises:
 a roll pin protruding from at least one of the ends of one of the ring segments that is received within a hole in at least one of the ends of the other of the ring segments.   
     
     
         7 . The assembly according to  claim 1  wherein, each of the ring segments has first and second ends, and the retaining means comprises:
 a hinge connecting the first end of one of the ring segments to the first end of another of the ring segments; and 
 a roll pin protruding from one of the second ends that is received within a hole in the other of the second ends. 
 
     
     
         8 . The assembly according to  claim 1 , wherein each of the ring segments has two ends, and the retaining means comprises:
 a pawl protruding from at least one of ends of one of the ring segments into engagement with a lip on at least one of the ends of another of the ring segments.   
     
     
         9 . The assembly according to  claim 1 , wherein each of the ring segments has two ends, and wherein the retaining means comprises:
 a detent on an inner diameter portion of each of the ring segments adjacent one of the ends of the ring segments; and   a mating detent recess on the neck that receives the detents.   
     
     
         10 . The assembly according to  claim 1 , wherein each of the ring segments has two ends, and the ends of one of the ring segments are closely spaced to the ends of another of the ring segments when the ring segments are installed around the neck. 
     
     
         11 . An electrical submersible pump assembly, comprising:
 a plurality of modules including a pump, a motor, and a seal section for reducing a pressure differential between lubricant in the motor and hydrostatic pressure of well fluid;   a drive shaft assembly having an axis and extending from the motor through each of the modules;   a threaded connection between at least two of the modules, comprising:   a first adapter having external threads;   a second adapter having a neck with an external load shoulder;   a collar rotatably carried and axially movable on the neck, the collar having internal threads that engage the external threads of the first adapter, the collar having an internal load shoulder axially spaced from and facing toward the external load shoulder;   a shoulder ring encircling the neck and comprising two separate ring segments, each of the ring segments having ends that are closely spaced to the ends of the other of the ring segments, the shoulder ring having a first surface in abutment with the external load shoulder and a second surface in abutment with the internal load shoulder to transfer an axial load between the first and second adapters; and   a resilient ring that fits around an outer diameter of the shoulder ring for retaining the ring segments on the neck prior to the collar being in threaded engagement with the threads of the first adapter.   
     
     
         12 . The assembly according to  claim 11 , further comprising:
 a circumferentially extending groove segment on an outer side and extending between the ends of each of the ring segments, defining an annular retaining ring groove when the ring segments are installed around the neck; and wherein   the resilient ring fits in the retaining ring groove.   
     
     
         13 . The assembly according to  claim 11 , further comprising:
 a circumferentially extending groove segment on an outer side of each of the ring segments, defining an annular retaining ring groove when the ring segments are installed around the neck; and wherein   the resilient ring is elastomeric and fits in the retaining ring groove.   
     
     
         14 . The assembly according to  claim 11 , further comprising:
 a circumferentially extending groove segment on an outer side and extending between the ends of each of the ring segments, defining an annular retaining ring groove when the ring segments are installed around the neck; wherein   the resilient ring has an inner diameter side in contact with the retaining ring groove; and   the resilient ring has an outer diameter side spaced radially inward from any portion of the collar.   
     
     
         15 . The assembly according to  claim 11 , further comprising:
 a circumferentially extending groove segment on an outer side and extending between the ends of each of the ring segments, defining an annular retaining ring groove when the ring segments are installed around the neck; wherein   the resilient ring is elastomeric and has an inner diameter side in contact with the retaining ring groove; and   the resilient ring has an outer diameter side that does not seal to any portion of the collar.   
     
     
         16 . A method for assembling an electrical submersible pump assembly having a plurality of modules including a pump, a motor, a drive shaft assembly having an axis and extending from the motor through each of the modules, a threaded connection between at least two of the modules, the threaded connection comprising a first adaptor having threads, a second adapter having a neck with an external load shoulder, and a collar rotatably carried and axially movable on the neck, the collar having an internal load shoulder axially spaced from and facing in a direction opposite to the external load shoulder, the method comprising:
 positioning a shoulder ring having two separate ring segments around the neck, and with a retainer, retaining the shoulder ring on the neck; then   moving the collar axially past the retainer and threadingly engaging the collar with the threads of the first adapter, placing a first surface of the shoulder ring in abutment with the external load shoulder and a second surface of the shoulder ring in abutment with the internal load shoulder and transferring an axial load between the first and second adapters.   
     
     
         17 . The method according to  claim 16 , wherein retaining the shoulder ring on the neck comprising installing a resilient ring around an outer diameter defined by the ring segments. 
     
     
         18 . The method according to  claim 16 , wherein:
 retaining the shoulder ring on the neck comprising providing an annular groove on an outer diameter defined by the ring segments; and   fitting a resilient ring in the annular groove.   
     
     
         19 . The method according to  claim 16 , wherein:
 retaining the shoulder ring on the neck comprising providing an annular groove in an outer diameter defined by the ring segments; and   fitting an elastomeric ring in the annular groove.   
     
     
         20 . The method according to  claim 16 , wherein:
 retaining the shoulder ring on the neck comprising providing an annular groove in an outer diameter defined by the ring segments;   fitting an elastomeric ring in the annular groove; and   positioning an outer diameter of the elastomeric ring radially inward from and out of contact with any portion of the collar.