Patent EA-000478-B1 (EA)
Title: Progressive cavity pumps using composite materials
Inventor: WOOD STEVEN
IPC: E21B43/12
Filed: 1997-04-24
Abstract: 1. A progressive cavity pump comprising a stator, said stator formed of a unitary support section having an outer cylindrical surface and a bonded internal helical surface section, said support section comprised of a composite non-resilient material formed of filament, selected from the group comprising carbon fibers, boron fibers, ceramic fibers, glass fibers, thermoplastic fibers, natural fibers, metallic fibers, and synthetic fibers, all of which are typically impregnated with thermal setting resins; said helical surface section comprised of a bonded resilient elastomer; a helical rotor operational within said stator; and means to rotate said rotor. 2. The progressive cavity pump of Claim 1 wherein said rotor is a rigid composite material. 3. The progressive cavity pump of Claim 1 wherein said means to rotate said rotor includes a composite material flex shaft, wherein said flex shaft comprises a body formed of spaced metal end fittings for connection to said means to rotate and to said rotor, a flexible and axial mandrel connected to each said fitting, and composite filament and resin windings around said mandrel to create said body. 4. The pump of Claim 3 wherein said filament windings and resin are wound at alternate angles of +45 degree  and -45 degree  to the axis of said mandrel. 5. The pump of Claim 3 wherein a flex section is created in said flex shaft. 6. The pump of Claim 5 wherein said portions of said filament windings and resin are wound at angles of 45 degree  to said axis while another portion is wound at -< 45 degree  to create said flex section. 7. The pump of Claim 3 wherein said flex section is formed of an inward indentation. 8. The pump of Claim 7 wherein said indentation is curved. 9. The pump of Claim 8 wherein said curve is concave in axial cross-section. 10. The pump of Claim 1 wherein said flex shaft comprises a body formed of spaced composite end fittings for connection to said means to rotate and to said rotor, a flexible and axial mandrel connected to each said fitting, and composite filament and resin windings around said mandrel to create said body. 11. The pump of Claim 10 wherein said filament windings and resin are wound at alternate angles of +45 degree  and -45 degree  to the axis of said mandrel. 12. The pump of Claim 10 wherein a flex section is created in said flex shaft. 13. The pump of Claim 12wherein said portions of said filament windings and resin are wound at angles of 45 degree  to said axis while another portion is wound at -< 45 degree  to create said flex section. 14. The pump of Claim 12 wherein said flex section is formed of an inward indentation. 15. The pump of Claim 14 wherein said indentation is curved. 16. The pump of Claim 15 wherein said curve is concave in axial cross-section. 17. The progressive cavity pump comprising a stator, said stator formed of a unitary support section having an outer cylindrical surface and a bonded internal helical surface section, said support section comprises a body formed substantially from a composite non-resilient material comprised of filament typically impregnated with thermal resin and said helical surface section comprised of a bonded resilient elastomer.