Permanent magnet submersible motor with a one-piece rotor/yoke configuration and resin embedded magnets
AssigneeFlowserve Management Company
InventorMichael Klahn
Life of this patent
Estimating the term…
Abstract
A permanent magnet submersible motor for electric submersible pump systems and a method of making the rotor of such a motor. The unitary construction of the rotor shaft and the yoke provides improved protection of the damage-prone magnets, while the larger effective shaft diameter also improves shaft bending resistance. Shaped form closures on the yoke promote secure magnet retention, even under highly centrifugal loads, while an exterior cladding tube and a cast resin filler material are used to further secure the magnets around the yoke periphery while also providing hermetic sealing against a working fluid.
Claims19
A rotor for use in an electric submersible pump, the rotor comprising:
- a shaft in rigid communication with and configured to rotate one or more pump impellers, said shaft comprising a concentric yoke integrally-formed therewith, the yoke comprising a fore end and an aft end;
- one or more permanent magnets disposed about the circumference of the yoke, the one or more permanent magnets positioned to axially coincide with the yoke and form an interface with the yoke to comprise an outer dimension form closure on the circumference of the yoke such that form closed torque transmission is present between the one or more permanent magnets and the yoke;
- a cladding tube disposed around the circumference of the permanent magnets to secure the one or more permanent magnets to the shaft through the yoke;
- and
- a stepped collar located on each of the fore end and the aft end of the yoke, wherein the one or more permanent magnets are sealed between the yoke and the cladding tube by the stepped collar.
A method of constructing a rotor for an electric submersible pump, the method comprising the assembly of a yoke, a stepped collar, and a cladding tube to define a magnet channel sized to accept one or more permanent magnets, the method further comprising:
- placing a shaft in rigid communication with and configuring to rotate one or more pump impellers, said shaft comprising a concentric yoke integrally-formed therewith, the yoke comprising a fore end and an aft end;
- disposing the one or more permanent magnets about the circumference of the yoke to form an interface with the yoke that comprises an outer dimension form closure on the circumference of the yoke in order to enhance torque transmission between the one or more permanent magnets and the yoke;
- further positioning the one or more permanent magnets to axially coincide with the yoke;
- positioning a stepped collar on each of the fore end and the aft end of the yoke;
- and
- disposing a cladding tube around the circumference of the one or more permanent magnets, the cladding tube securing the one or more permanent magnets to the shaft through the yoke.
An electric submersible pump comprising a motor section, a pump section, a fluid inlet section disposed axially between the motor section and the pump section, and a fluid outlet section disposed at the top of the pump section;
- wherein
- the motor section comprises a synchronous motor, an outer casing enclosing the motor assembly, and a thermal transfer solution maintained within the outer casing and in fluidic contact with the synchronous motor, wherein the synchronous motor further comprises a rotor and a stator, the rotor comprising:
- a shaft which extends over the length of the motor section in rigid communication with and configured to rotate one or more pump impellers, said shaft comprising a concentric yoke integrally-formed with the shaft, the yoke comprising a fore end and an aft end;
- one or more permanent magnets disposed about the circumference of the yoke to form an interface with the yoke to comprise an outer dimension form closure on the circumference of the yoke such that form closed torque transmission is present between the one or more permanent magnets and the yoke, the one or more permanent magnets positioned to axially coincide with the yoke;
- a cladding tube disposed around the circumference of the permanent magnets, the cladding tube secures the one or more permanent magnets to the shaft through the yoke;
- and
- a stepped collar located on each of the fore end and the aft end of the yoke, wherein the one or more permanent magnets are sealed between the yoke and the cladding tube by the stepped collar;
- and
- the pump section disposed above the motor section comprises one or more pump bowls, the pump bowls comprising centrifugal impellers, wherein the centrifugal impellers are rotated by the turning of the shaft, the centrifugal impellers receive an extracted fluid through the fluid inlet and expel the extracted fluid through the fluid outlet.
Dependencies are inferred from the claim text.