Shaft locking couplings for submersible pump assemblies

#1. Field of the Invention

#The invention relates to devices and techniques for coupling shafts and other portions of submersible pump assemblies and like components.

#2. Description of the Related Art

#FIG. 1 is a side cross-sectional view of an exemplary electrical submersible pump assembly disposed within a well bore on production tubing.

#FIG. 2 is a partially exploded, side cross-sectional view of a first exemplary connection assembly used for interconnecting the two pumps in the pump assembly depicted in FIG. 1.

#FIG. 3 is a side cross-sectional view of the components depicted in FIG. 2 with the adjacent shaft sections being moved toward interconnection with one another.

#FIG. 1 represents an exemplary well bore 10 that has been drilled through earth 12 into a formation (not shown). The well bore 10 is a producing well and contains a string of production tubing, the lower end of which is shown at 14. The production tubing has incorporated therein an electric submersible pump assembly, generally shown at 16. The pump assembly 16 is made up of a series of interconnected modular sections. In this case, there are a motor section 18, a seal section 20 and two pump sections 22, 24. The ESP assembly 16 is a reverse, or bottom intake pump assembly since the pump sections 22, 24 are located downhole from the motor and seal sections 18, 20. A fluid intake manifold 26 is interconnected to the lower pump section 24. The motor section 18 has a power cable 30 which extends from the motor section 18 to the surface (not shown) of the well 10.

#FIG. 2 is representative of an exemplary connection assembly 40 used to form the interconnection between the two pump sections 22, 24. It should be understood, however, that the interconnection shown could also be that between the seal section 20 and the upper pump section 22 or the motor section 18 and the seal section 20, as the same principles of interconnection would apply since each of the devices listed includes a radially outer housing or body and a rotatable shaft member contained radially there within. The upper pump section 22 and the lower pump section 24 have the same construction. As can be seen in FIG. 2, each pump section 22, 24 includes a radially outer housing body 42, 44 that defines a longitudinal central chamber 46, 48 therein. A shaft member 50, 52 is secured by rotatable bearing 54, 56 within the central chamber 46 or 48 of each pump section 22, 24. Fluid flow paths 58, 60 permit fluid to flow through each bearing 54, 56. In each pump section 22, 24, a pair of fluid ports is disposed through the housing body. Fluid ports 62 are shown in the housing body 44 of the lower pump 24. These ports 62 are normally closed by caps 64.

#The upper end of the housing body for each pump section 22, 24 defines an annular landing shoulder 66, one of which is shown on the lower pump section 24. The lower end of each housing body 42, 44 includes a reduced diameter portion 68, one of which is shown at the lower end of the upper pump section 22. Radially enlarged annular flange 70 is located immediately below the reduced diameter portion 68, while a reduced diameter seating portion 72 is located just beneath the flange 70. Annular elastomeric seals 74 are disposed upon the seating portion 72.