A submersible electric thruster operable to propel underwater vehicles, surface vehicles, amphibious vehicles, etc. The submersible electric thruster includes a stator assembly having a base, stator, windings, and bearings and an external rotor assembly having a cylindrical arrangement of permanent magnets with a hub that is secured to a shaft. The stator forms the center of the motor and the permanent magnets spin around the stator. A propeller hub is integrally connected to the rotor assembly with angularly spaced propeller blades extending radially from the propeller hub. An annular nozzle surrounds the propeller and motor, forming an inlet and outlet for water flow. A nose cone is connected to the stator assembly and a tail cone is integrally connected to the nozzle assembly. Supporting arms may extend from the stator assembly to support the nozzle and/or supporting arms may extend from the nozzle to the support the tail cone.

A motor includes a housing, a back cover, a brush card, a brush, and a connector member. The back cover includes a first rear wall portion and a first peripheral wall portion. The first peripheral wall portion includes a through-hole and a cut-out. The through-hole vertically penetrates through the first peripheral wall portion at or near a lower end portion of the first peripheral wall portion. The cut-out is disposed farther on an upper side than the through-hole. The connector member is fitted into the cut-out. An outer surface of the connector member is provided with a flow path groove that extends in both peripheral and axial directions. The motor includes a flow path surface on an inner surface of the back cover. The flow path surface continues from a portion that opposes the flow path groove on a lower side of the flow path groove to the through-hole.

The invention provides an encapsulated magnetically geared brushless electric marine propulsion system with the principle components arranged axially around the central shaft. The marine propulsion system includes: the brushless DC motor, comprised of the stator fixed to the central shaft and motor magnets fixed within the motor rotor coupled to the central shaft using precision ball bearings; the high-speed magnetic gear rotor coupled to the motor rotor comprising an alternating array of magnets fixed to a ferromagnetic backing; the environmental barrier which protects the motor and additionally houses pole pieces to modulate magnetic flux; the low-speed magnetic gear rotor coupled to the central shaft and comprised of an alternating array of magnets fixed to a ferromagnetic backing; the propeller coupled to the low-speed magnetic gear rotor; and the shroud coupled to the struts of the motor mounting system.

A submersible electrical machine includes a first magnetic package spaced axially from a second magnetic package, a first stator displaced axially from the first magnetic package by a first air gap, a second stator displaced axially from the second magnetic package by a second air gap. The electrical machine can be operated as a generator or as a motor. When operating as a generator, a turbine can rotate the magnetic packages relative to the stators in response to fluid flowing axially across the electrical machine.

A subsea pump assembly includes a tubular conduit that has an upstream end plate and an inlet for flowing well fluid into an interior of the conduit. A power cable opening extends through the upstream end plate. An electrical submersible pump and motor are in the interior of the conduit. The motor has a motor assembly housing with an upstream end having an electrical insulator opening. An end connection secures the upstream end to an interior side of the upstream end plate with the insulator opening registering with the power cable opening. An insulated electrical connector is mounted in the insulator opening. A motor wire in the motor assembly housing joins to an inner end of the electrical connector. A power conductor extends from exterior of the conduit through the power cable opening and joins to an outer end of the electrical connector.

The invention provides an encapsulated magnetically geared brushless electric marine propulsion system with the principle components arranged axially around the central shaft. The marine propulsion system includes: the brushless DC motor, comprised of the stator fixed to the central shaft and motor magnets fixed within the motor rotor coupled to the central shaft using precision ball bearings; the high-speed magnetic gear rotor coupled to the motor rotor comprising an alternating array of magnets fixed to a ferromagnetic backing; the environmental barrier which protects the motor and additionally houses pole pieces to modulate magnetic flux; the low-speed magnetic gear rotor coupled to the central shaft and comprised of an alternating array of magnets fixed to a ferromagnetic backing; the propeller coupled to the low-speed magnetic gear rotor; and the shroud coupled to the struts of the motor mounting system.

A downhole system for use in a wellbore in a subterranean formation includes an electromechanical motor or generator. The electromechanical motor or generator may, respectively, be configured convert electricity to mechanical energy or convert mechanical energy in the form of fluid flow for use in one or more downhole tools. The electromechanical motor or generator includes one of a rotor and a stator disposed concentrically around and operatively coupled to the other of the rotor and the stator. A sleeve is disposed concentrically between the rotor and the stator. The sleeve contacts a body to enclose and hermetically seal one of the rotor and the stator therein. The sleeve comprises at least one metal portion and at least one non-magnetic and non-conductive portion. Related methods involve the formation of such a motor or generator.

Systems and methods for preventing electrical arcing in motors by placing an electrically conductive roller assembly between the stator and rotor of the motor. A rotor is mounted on a shaft, and this assembly is positioned within the bore of a stator. The roller assembly has a stationary portion that is secured to the stator. The roller assembly also has a movable portion on which a roller is mounted. The movable portion of the roller assembly is spring-loaded to urge the roller toward the shaft and thereby maintain contact between the roller and the shaft. When the shaft rotates within the bore, the roller rotates and rolls on the surface of the shaft, maintaining contact without rubbing against the shaft. An electrically conductive pathway is formed from the stator, through the roller assembly to the shaft and rotor thereby preventing an electrical potential from developing between the rotor and stator.

A flow-conditioning system includes a pump, process tubing coupling the pump to a source of multiple component process fluid, and an in-line flow-mixing device positioned in the process tubing upstream of the pump. A system includes a well disposed below a body of water and providing a source of multiple component fluid, a pump disposed in and exposed to the water, process tubing coupling the pump to the well, and an in-line flow-mixing device positioned in the process tubing upstream of the pump.

The invention relates to an electrical machine for submerged applications and an energy conversion system for conversion of mechanical energy of unidirectional or reciprocating linear or rotational motion into electric energy and vice versa. The electric energy may be in the form of DC or AC current and voltage. The system is totally submerged in pure or salt water. The enabling element of the invention is multi-pole permanent magnet synchronous machine with separately encapsulated stator and rotor, integrated with mechanical system and power electronics.