Patent attributes
A coupling assembly is disclosed for connecting and centralizing a first threaded-end member and a second threaded-end member, the coupling assembly comprising: a mandrel having a rotor receiving surface bounded by a first stop and a second stop, the mandrel having a first threaded pin at a first end for connection to a first threaded box coupling for the first threaded-end member, and a second threaded pin at a second end for connection to a second threaded box coupling for the second threaded-end member; each of the first stop and the second stop having respective outer diameters and the respective outer diameters being less than or equal to the respective outer diameters of the first threaded box coupling and the second respective box coupling; and a rotor with raised fins mounted on the rotor receiving surface between the first stop and the second stop.