Patent ID: 8444901

Claim:
A method of fabricating a progressive cavity motor stator comprising: centralizing a helical mandrel having an outer surface smaller in diameter than the inner surface of a longitudinal bore of a stator body leaving a space between said inner surface of the stator body; filling said space between the outer surface of said helical mandrel and the inner surface of the longitudinal bore of the stator body with a polymer having a glass transition temperature of between 50° C. and 180° C.; affixing the polymer to the inner surface of the longitudinal bore of the stator body; removing the mandrel from the stator body; providing a second layer with a glass transition temperature different than that of the affixed polymer and substantially covering the internal surface of the affixed polymer with the second layer; and sizing the affixed polymer and the second layer to create an internal profile for receiving a rotor with a loose fit at ambient temperatures such that the internal profile and the rotor do not operationally engage until the temperature is sufficiently raised to create an interference between the internal profile and the rotor.