Flexible coupling for progressive cavity downhole drilling motor
AssigneeBaker Hughes Incorporated
InventorsHerb Beimgraben, Benny Melton, Jay Eppink, Paul Reinhardt
Life of this patent
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Abstract
A composite flexible torsion bar coupling is used to connect the orbiting rotor of a Moineau-type motor to the concentrically rotating output drive shaft. The two-piece torsion bar coupling is hollow, to allow fluid passage through the rotor. This permits large quantities of fluid flow through the bit without passing all the fluid through the motor. The torsion bar is connected to the rotor at an inside surface adjacent to a power-producing surface of the rotor. This configuration provides the shortest possible coupling distance, thereby considerably reducing the overall length of the motor without decreasing its power output.
Claims20
In combination with a downhole drilling motor having a progressive cavity stator and a rotor rotating and gyrating within the stator in response to fluid flow through the stator wherein a housing connected to the stator contains a shaft mounted within the housing for rotation about the longitudinal axis of the shaft, the improvement therein comprising:
- a flexible rod having an upper end and a lower end, said rod being connected to said rotor at its upper end, and connected to said shaft at its lower end for translating the rotation and gyration of said rotor to the axial or true rotation of said shaft,
- said rod comprising a composite assembly of an upper section and a lower section, said upper section having external threads along a predetermined distance of its length, said rotor being hollow with internal threads, fitting over said upper section and threadably engaging the external threads of said upper section, said lower section including a threaded connection means at the lower end of said lower section for connecting said flexible rod to said shaft, said upper section being made of steel and said lower section being made of titanium.
In combination with a downhole drilling motor having a progressive cavity stator and a rotor rotating and gyrating within the stator in response to fluid flow through the stator wherein a housing connected to the stator contains a shaft mounted within the housing for rotation about the longitudinal axis of the shaft, the improvement therein comprising:
- a flexible rod having an upper end a lower end, said rod being connected to said rotor at its upper end, and connected to said shaft at its lower end for translating the rotation and gyration of said rotor to the true rotation of said shaft, said rod having an internal bore along its entire length from upper end to lower end, said bore mating with an internal bore in said rotor at its upper end and with an internal bore in said shaft at its lower end,
- said flexible rod comprising a composite assembly of an upper section and a lower section, said upper section being made of steel and said lower section being made of titanium.
In combination with a downhole drilling motor having a progressive cavity stator and a rotor rotation and gyrating with the stator in response to fluid flow through the stator wherein a housing connected to the stator contains a shaft mounted within the housing for rotation about the longitudinal axis of the shaft, the improvement therein comprising:
- a flexible rod having an upper end and a lower end, said rod being connected to said rotor at its upper end, and connected to said shaft at its lower end for translating the rotation and gyration of said rotor to the axial or true rotation of said shaft, said rod being a composite assembly of an upper section and a lower section, wherein said upper section is made of steel and said lower section is made of titanium.
In combination with a downhole drilling motor having a progressive cavity stator and a rotor rotating and gyrating within the stator in response to fluid flow through the stator wherein a housing connected to the stator contains a shaft mounted within the housing for rotation about the longitudinal axis of the shaft, the improvement therein comprising:
- a flexible rod having an upper end and a lower end, said rod being a composite assembly of an upper section and a lower section, said lower section being attached to said upper section inside said rotor adjacent to a power-producing surface of said rotor, said rod being connected to said rotor at its upper end, and connected to said shaft at its lower end for translating the rotation and gyration of said rotor to the axial or true rotation of said shaft.
In combination with a downhole drilling motor having a progressive cavity stator and a rotor rotating and gyrating within the stator in response to fluid flow through the stator wherein a housing connected to the stator contains a shaft mounted within the housing for rotation about the longitudinal axis of the shaft, the improvement therein comprising:
- a flexible rod having an upper end and a lower end, said rod being connected to said rotor at its upper end, and connected to said shaft at its lower end for translating the rotation and gyration of said rotor to the true rotation of said shaft, said rod having an internal bore along its entire length from upper end to lower end, said bore mating with an internal bore in said rotor at its upper end and with an internal bore in said shaft at its lower end, said flexible rod comprising a composite assembly of an upper section and a lower section;
- said lower section being attached to said upper section inside said rotor adjacent to a power-producing surface of said rotor.
Dependencies are inferred from the claim text.