Systems and methods for producing fluids from a subterranean well include an electrical submersible pump assembly with a motor-pump unit. The motor-pump unit has a motor housing and a stator is located within the motor housing. The stator has a stator body with an interior cavity. A rotor assembly is located within the interior cavity of the stator. The rotor assembly includes a rotor shaft extending along the central axis of the stator, a rotor member, and an intermediate rotor bearing assembly. The rotor member and the intermediate rotor bearing assembly circumscribe the rotor shaft. An impeller is mounted on the rotor shaft and located within the interior cavity of the stator. A liner with a polygonal cross section is located along an interior surface of the interior cavity. The liner is secured to the motor housing and seals the stator body from a wellbore fluid.

An electric motor comprising a stator having a stator cavity with an axis extending in a longitudinal direction, said stator cavity having a stator inlet for receiving a fluid and a stator outlet for discharging said fluid, a rotor arranged inside the stator cavity and rotatable around said axis, a tubular sleeve, arranged between the stator and the rotor, coaxial with said axis, and attached to the stator through attachment members. The tubular sleeve is spaced from the stator by a first tubular gap, and from the rotor by a second tubular gap, the first tubular gap extends along the longitudinal direction between a first gap inlet and a first gap outlet, the second tubular gap extends along the longitudinal direction between a second gap inlet and a second gap outlet, the first and second gap inlets are in direct fluid communication with the stator inlet, and the first and second gap outlets are in direct fluid communication with the stator outlet, such that the fluid entering the stator cavity at said stator inlet divides into a first fluid flow and a second fluid flow respectively flowing through the first tubular gap and the second tubular gap and exiting the stator cavity at said stator outlet, the tubular sleeve is made of a thermal insulating material, thereby thermally insulating the first tubular gap from the second tubular gap.

Systems and methods for electric motor, where the stator core has one or more stator core sections, each of which is a single-piece unit formed of soft magnetic composite (SMC) material, and where the stator core sections are positioned end-to-end with seals at each end to form a plurality of stator slots, where each of the stator slots extends through each of the stator core sections and is in fluid communication with the others to form a sealed stator chamber. The sealed stator chamber may have an expansion chamber to allow expansion and contraction of dielectric fluid in the stator chamber while maintaining separation of the dielectric oil from lubricating oil which is within the motor but external to the stator chamber. The sealed stator chamber can prevent well fluids that leak into the motor from reaching the stator windings and degrading their insulation.

An electric submersible pump (ESP) assembly. The ESP assembly comprises an electric motor, a centrifugal pump, and a hybrid magnetic radial bearing, wherein the hybrid magnetic radial bearing is disposed inside the electric motor or disposed inside the centrifugal pump.

A stator for a downhole-type motor includes a housing. The housing includes a sleeve. The sleeve includes a first layer, a second layer, and a third layer. The first layer is erosion-resistant. The second layer is corrosion-resistant. The third layer can provide structural support. The stator includes a motor stack. The stator can be used to drive a rotor disposed within an inner bore of the housing.

The present inventions include a rotating electromagnetic machine such as a motor or generator wherein changes of flux direction adjacent the air gap are avoided. The disclosed improvements apply to permanent magnet alternators, induction motors and generators, doubly fed induction generators, and the like. Adaptation of coils to and fixation within the required slot geometries are disclosed. Excitation systems co-located within the primary rotor core and primary stator core are also disclosed. The use of rubber vulcanized to the rotor in conjunction with a stainless steel rotor sleeve is also disclosed.

An electric submersible pump (ESP) assembly. The ESP assembly comprises an electric motor, a centrifugal pump, and a hybrid magnetic radial bearing, wherein the hybrid magnetic radial bearing is disposed inside the electric motor or disposed inside the centrifugal pump.

Systems and methods for producing fluids from a subterranean well include an electrical submersible pump assembly with a motor-pump unit. The motor-pump unit has a motor housing and a stator is located within the motor housing. The stator has a stator body with an interior cavity. A rotor assembly is located within the interior cavity of the stator. The rotor assembly includes a rotor shaft extending along the central axis of the stator, a rotor member, and an intermediate rotor bearing assembly. The rotor member and the intermediate rotor bearing assembly circumscribe the rotor shaft. An impeller is mounted on the rotor shaft and located within the interior cavity of the stator. A liner with a polygonal cross section is located along an interior surface of the interior cavity. The liner is secured to the motor housing and seals the stator body from a wellbore fluid.

Systems and methods for electric motor, where the stator core has one or more stator core sections, each of which is a single-piece unit formed of soft magnetic composite (SMC) material, and where the stator core sections are positioned end-to-end with seals at each end to form a plurality of stator slots, where each of the stator slots extends through each of the stator core sections and is in fluid communication with the others to form a sealed stator chamber. The sealed stator chamber may have an expansion chamber to allow expansion and contraction of dielectric fluid in the stator chamber while maintaining separation of the dielectric oil from lubricating oil which is within the motor but external to the stator chamber. The sealed stator chamber can prevent well fluids that leak into the motor from reaching the stator windings and degrading their insulation.

Systems and methods for electric motor, where the stator core has one or more stator core sections, each of which is a single-piece unit formed of soft magnetic composite (SMC) material, and where the stator core sections are positioned end-to-end with seals at each end to form a plurality of stator slots, where each of the stator slots extends through each of the stator core sections and is in fluid communication with the others to form a sealed stator chamber. The sealed stator chamber may have an expansion chamber to allow expansion and contraction of dielectric fluid in the stator chamber while maintaining separation of the dielectric oil from lubricating oil which is within the motor but external to the stator chamber. The sealed stator chamber can prevent well fluids that leak into the motor from reaching the stator windings and degrading their insulation.