PROGRESSIVE CAVITY PUMP/MOTOR STATOR, AND APPARATUS AND METHOD TO MANUFACTURE SAME BY ELECTROCHEMICAL MACHINING

摘要

Electrochemical machining is used to generate the helical lobe profiles of the stator of a progressive cavity pump or motor. A thin, elastomeric liner, of uniform thickness is bonded either to the interior of the stator, or to the exterior of the rotor. Where the elastomeric liner is to be bonded to the interior or the stator, bonding is improved by electrically etching the interior of the stator during the electrochemical machining process to produce a roughened surface.