Patent ID: 8109746

Claim:
A progressing cavity pump/motor for positioning along a tubular string in a well to pump fluids to the surface through the tubular string or to create downhole mechanical energy from fluid transmitted downhole to the pump/motor, comprising: an upper stator tube having an upper contoured interior surface along an axial length thereof; a lower stator tube structurally separate from the upper stator tube and having a lower contoured interior surface along an axial length thereof; a rotor extending axially between the upper stator tube and the lower stator tube, the rotor having a contoured exterior surface creating progressing cavities between the upper contoured interior surface and the contoured exterior surface and between the lower contoured interior surface and the contoured exterior surface when the rotor rotates with respect to both the upper stator tube and the lower stator tube; and a coupling assembly for interconnecting the upper stator tube and the lower stator tube while maintaining the tubes in circumferential alignment for cooperation with the rotor, the coupling assembly comprising (a) an outer sleeve supported at one of a lower end of the upper stator tube and an upper end of the lower stator tube, the outer sleeve having a first stop surface thereon and an external thread thereon, (b) an inner sleeve supported on the other of the upper stator tube and the lower stator tube, the inner sleeve extending between the upper stator tube and the lower stator tube and circumferentially aligned with each of the upper stator tube and the lower stator tube, the inner sleeve having a second stop surface for engagement with the first stop surface when the coupling assembly is assembled, and (c) a nut having internal threads for threaded engagement with the external threads on the outer sleeve and engaging the inner sleeve to move axially and bring the second stop surface into engagement with the first stop surface.