Abstract: An electrical submersible pump assembly has a seal section coupled to a motor that drives the pump. The seal section has first and second end members spaced axially apart from each other. An outer bellows has a fixed end mourned to the first end member and a floating end that moves axially relative to the fixed end. A rigid, tubular interconnect member has an inner end within the outer bellows and an cuter end fixed to the floating end of the outer bellows. An inner bellows has a floating end secured to the inner end of the interconnect member and a fixed end secured to the second end member. An interconnect evacuation passage extends axially through a side wall of the interconnect member. A first end member evacuation passage extends through the first end member and registers with the interconnect evacuation passage while the outer bellows is contracted.

Abstract: Propulsion unit (11) for propulsion and maneuvering of a maritime vessel, which includes a nozzle (12) exhibiting a curved following edge (12) at outlet of the nozzle (12), which results in that length of the nozzle (12) is longer in upper part of the nozzle (12) and shortest at the outermost points of a horizontal central axis through the nozzle (12), when the nozzle (12) is seen from behind.

Abstract: A well fluid submersible pump assembly includes a pump operatively coupled to a motor and a seal section located between the motor and the pump. The seal section has a single piece tubular housing with adapters secured to opposite ends of the housing. A shaft extends axially through the housing for driving the pump. An auxiliary seal carrier located in the housing has a central bore through which the shaft extends and has an outer diameter portion that seals to the bore of the housing. Opposed check valves in the seal carrier allow lubricant to flow from one side of the auxiliary carrier to an opposite side of the seal carrier in response to a selected pressure differential. A mechanical face seal mounts to the auxiliary seal carrier and seals around the shaft.

Abstract: A water pump has a pump section having radial impeller blades, a rotational shaft for rotating the radial impeller blades, and a motor section provided in the rear of the pump section and driving the rotational shaft. The motor section has a motor casing, a motor housed in the motor casing and rotating the rotational shaft, bearings provided on both sides of the motor interposed between them on the rotational shaft, interposed between an inner surface of the motor casing and the rotational shaft, and rotatably supporting the rotational shaft. In the motor casing, a vent hole for venting air between a motor space in which the motor is disposed in the motor casing and an outside of the motor casing is formed.

Abstract: Embodiments of the invention provide a variable frequency drive system and a method of controlling a pump driven by a motor with the pump in fluid communication with a fluid system. The drive system and method can provide one or more of the following: a sleep mode, pipe break detection, a line fill mode, an automatic start mode, dry run protection, an electromagnetic interference filter compatible with a ground fault circuit interrupter, two-wire and three-wire and three-phase motor compatibility, a simple start-up process, automatic password protection, a pump out mode, digital input/output terminals, and removable input and output power terminal blocks.

Abstract: A motor for a compressor, and a reciprocating compressor having the same, are provided. A winding coil may be formed by removing a bobbin from the winding coil, and then coating an insulating material on an outer circumferential surface of the winding coil, to allow heat and moisture generated by the winding coil to be emitted to outside and provide enhanced performance and reliability. As a bobbin is removed from the winding coil, a coil line may be wound on the removed portion of the bobbin to enhance an occupation ratio by the coil line on the same area, and thus enhance efficiency of the motor. An elastic member or an adhesive may be inserted or applied into a space between the winding coil and a coil insertion groove of an inner stator to minimize vibrations of a coil line. The insulating material, which is in the form of powder, may melt while the coil line is adhered as the self-bonding material melts, forming a coating layer.

Abstract: Primary and secondary pump assemblies are mounted to and supported by a supporting device in a well. The supporting device has a valve that has a first position allowing flow from the primary pump assembly while the secondary pump assembly is in a storage mode, and a second position allowing flow from the secondary pump assembly. A barrier in the intake of the secondary pump assembly blocks entry of well fluid into the secondary pump assembly while the valve is in the first position. The secondary pump is filled with a buffer fluid. A pressure compensator mounted to the secondary pump assembly has a movable element that moves in response to a difference between well fluid pressure on an exterior of the secondary pump assembly and the pressure of the buffer fluid contained in the secondary pump to reduce a pressure differential.

Abstract: Provided is a compressor motor that can achieve reduction in length of a motor lead wire, compactification of a motor housing, and reduction in size and weight of an electric compressor, and also provided is an electric compressor including the compressor motor. A cluster block (39) that is connected to a stator coil end of a motor (10) via a motor lead wire is placed in an outer circumferential region of a stator coil end cover (38) or a bobbin (37A) of the motor (10) such that a terminal connection port of the cluster block (39) faces an outer circumferential side. An opening (34) and a placement bearing surface (35) for inserting and placing a hermetic terminal (8) are provided in an outer circumferential region of a motor housing (4), the outer circumferential region facing the cluster block (39) provided on the motor (10) side.

Abstract: A method for mounting a bush round a part (2) of a shaft with a force fit, which method comprises the following steps: providing a guide element (7, 23) with an outer surface (8) which is at least partly conical; providing the guide element (7, 23) in the extension of the aforesaid part (2) of the shaft (1); pushing the bush (5) over the guide element (7, 23) on the part (2) of the shaft (1).

Abstract: A motor that is operable in response to an external power supply includes a stator core that is electrically connected to the external power supply and a rotor core positioned adjacent the stator core and rotatable about an axis in response to power being delivered to the stator core by the external power supply. A first encasement member is formed around the stator core to define a cavity and a second encasement member is formed around the rotor core and is sized such that at least a portion of the second encasement member and rotor core is disposed within the cavity. A quantity of coolant is disposed within the cavity.

Abstract: Systems and methods for improved generators are described. One embodiment includes an assembly for an axial flux generator, the assembly comprising an arc-shaped rotor section that includes a rotor support configured to rotate around an axis of a generator, and an at least one rotor element for power generation that is connected to the rotor support; an arc-shaped stator section comprising a stator support and an at least one stator element for power generation connected to the stator support; wherein the rotor section and the stator section are configured to provide an axial air gap between the at least one rotor element and the at least one stator element, and wherein the at least one rotor element and the at least one stator element are positioned to be at substantially the same radial distance from the axis of the generator.

Abstract: An electrical submersible pump motor has motor oil flowing through external circulation tubes for cooling the motor. A substantial portion of the exterior of each tube is submerged in and exposed to wellbore fluid. Heat is transferred from the motor to the motor oil, and then circulated through the external circulation tubes to conduct heat to the wellbore fluid. Internal or external motor oil pumps may be used to propel the motor oil through the circulation tubes. Guards or baffles may be used to protect the circulation tubes and to influence the flow of production fluid over the circulation tubes.

Abstract: Systems and methods for configuring stators for downhole electric motors, where a single master stator can be configured to function as multiple different types of stators. In one embodiment, a configurable stator has a plurality of magnet windings disposed within its body, wherein the windings are connected to a plurality of electrical terminals that are accessible from the exterior of the body of the stator. Each of the terminals is configured to enable any one of a plurality of different types of lead wires to be attached to it, thereby enabling the stator to be configured in various different ways. In one embodiment, the master stator can be configured as a single stator, an upper tandem stator, a middle tandem stator, or a lower tandem stator.

Abstract: An electrical submersible pumping (ESP) system for use in a wellbore that can be assembled in the wellbore. Upper and lower pump tandems are fitted with connectors that align the tandems when coupled in the wellbore. The connectors on the lower tandems have bores with enlarged openings on upward facing surfaces. Downward pointing pins are on lower facing surfaces of the connectors on the upper tandems. The cross sectional area of each bore decreases with distance away from the openings, so that as the pins insert into the bores the pins move along a helical path that in turn rotates the upper tandem into a designated azimuth and into alignment with the lower tandem. Properly aligning the upper and lower tandems couples respective drive and driven shafts in the tandems as the upper tandem lands on the lower tandem.

Abstract: A permanent magnet machine, a rotor assembly for the machine, and a pump assembly. The permanent magnet machine includes a stator assembly including a stator core configured to generate a magnetic field and extending along a longitudinal axis with an inner surface defining a cavity and a rotor assembly including a rotor core and a rotor shaft. The rotor core is disposed inside the cavity and configured to rotate about the longitudinal axis. The rotor assembly further including a plurality of permanent magnets for generating a magnetic field which interacts with the stator magnetic field to produce torque. The permanent magnets configured as one of internal or surface mounted. The rotor assembly also including a plurality of retaining clips configured to retain the plurality of permanent magnets relative to the rotor core. The pump assembly including an electric submersible pump and a permanent magnet motor for driving the pump.

Abstract: The present invention proposes a generator for arrangement on a shaft of an accessory gearbox of an engine with a stator and with a rotor which can be coupled to a shaft of the accessory gearbox of the engine and which is rotatably mounted relative to the stator, where a stator area receiving the stator can be separated from a rotor area receiving the rotor. The rotor can be supplied with cooling medium in the rotor area. It furthermore proposes an accessory gearbox of an engine with a drive shaft operatively connectable to a main shaft of the engine and with at least one generator arranged on a shaft of the accessory gearbox.

Abstract: Systems and methods for rotor bearings that enable improved oil circulation, wherein axial grooves are formed in the outer periphery of each bearing to form channels that allow axial flow of oil through the channels. Each bearing includes a collar, a sleeve and an interference ring. The collar has a bore through its center in which a rotatable sleeve is positioned. The outer periphery of the collar has a circumferential groove and at least one axial groove that extends from one face of the collar to the other. An axially permeable interference ring positioned within the circumferential groove extends radially outward from the groove beyond the outer periphery of the collar. The interference ring (e.g., a looped coil spring) allows fluid in the axial groove to flow through the interference ring. The axial groove may have a different depth than the circumferential groove.

Abstract: A can of a drive motor is provided for a pump assembly, wherein the can (22) is manufactured at least partly of plastic (52). At least in a part of the can (22) the plastic (52) is reinforced by individual fibers (32) distributed in the plastic (52). The fibers (32) in at least one layer (35) of the can (32) are aligned in a defined manner in the peripheral direction with respect to the longitudinal axis (Z) of the can (22). A method for manufacturing such a can is also provided.

Abstract: 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.

Abstract: A motor includes a cover made of a resin material. The cover includes a first annular portion arranged to extend in an annular shape above coils, a side wall portion arranged to extend downward from an outer circumferential portion of the first annular portion, and a second annular portion arranged to extend radially outward or radially inward from a lower end portion of the side wall portion along an upper surface of a circuit board. The side wall portion is arranged to extend in an axial direction while filling in gaps between teeth on a radially inner side of radially outer end surfaces of the teeth. The coils are covered by the cover to be protected from dust, water droplets, etc. The radially outer end surfaces of the teeth are exposed from the cover, and are thus arranged to be in radial proximity to a rotor magnet.

Abstract: The present disclosure relates to a ship's propulsion unit such as a ship's azimuthing propulsion unit. The propulsion unit can include at least one supporting metal sheet arranged between an support section of a shell structure of the propulsion unit and an cylindrical outer surface of a cylindrical section of a motor housing section of the shell structure for providing additional support for the motor housing section of the shell structure at the shell structure of the support section.

Abstract: A sealing liner for use in a pump motor incorporates a radially enlarged portion at one end, and a radially smaller portion extending from the one end to an opposed end. A length of the overall sealing liner including the radially smaller portion and the radially enlarged portion is defined as a first length. A length of said radially enlarged portion is defined as a second length. A ratio of the first length to the second length is between about 6.5 and about 8.5. A stator assembly, a pump and a method are also disclosed.

Abstract: A system and method is provided for producing a hydrocarbon fluid from a subterranean environment. The system and method utilize an electric submersible pumping system having a motive unit comprising a combined submersible motor section and protector section.

Abstract: The present invention relates to a watertight apparatus for an underwater motor, comprising a double oil jacket for preventing high-pressure water from entering the underwater motor along a rotary shaft of the underwater motor. According to the present invention, high-pressure water is prevented from entering the underwater motor along the rotary shaft of the underwater motor even in the case of mechanical devices which operate in deep water, thereby preventing failure in the operation of or damage to mechanical devices caused by the ingress of water. In addition, the oil jacket can be easily replaced, thereby enabling the effective performance of maintenance and repair of mechanical devices.

Abstract: A replaceable motor module for a groundwater sampling device including an inner housing defined by a cylindrical shape and having a first alignment pin. A DC-operated electric motor is positionable within the inner housing, and includes a first set of electrical input terminals, an output shaft capable of downwardly extending through a sealed hole in the inner housing, and a first alignment groove for mating with the first alignment pin of the inner housing. An inner housing cap includes a second set of electrical input terminals and electrical output terminals, and is pressingly engageable with the inner housing.

Abstract: Systems and methods for rotor bearings that enable improved oil circulation, wherein axial grooves are formed in the outer periphery of each bearing to form channels that allow axial flow of oil through the channels. Each bearing includes a collar, a sleeve and an interference ring. The collar has a bore through its center in which a rotatable sleeve is positioned. The outer periphery of the collar has a circumferential groove and at least one axial groove that extends from one face of the collar to the other. An axially permeable interference ring positioned within the circumferential groove extends radially outward from the groove beyond the outer periphery of the collar. The interference ring (e.g., a looped coil spring) allows fluid in the axial groove to flow through the interference ring. The axial groove may have a different depth than the circumferential groove.

Abstract: Electric motor systems and methods may provide highly efficient operation. The electric motor systems and methods discussed herein provide an oil filled motor that is low speed and utilizes permanent magnets. The electric motor may utilize a large number of poles and fractional slot design. Further, in some embodiments, the electric motor systems and methods may be suitable for use downhole.

Abstract: A heat exchanger to serve ESP equipment installed on the seabed located in either a caisson or skid. A hot oil line connects the base of the ESP motor with the externally located heat exchanger, allowing hot motor oil to be circulated through coils externally exposed to seawater. The heat from the oil is rejected to the seawater and the cooled oil is reintroduced to the motor via a cold oil line that communicates with the seal section. The heat exchanger arrangement reduces the temperature of an ESP motor, thus allowing the motor to operate longer and more reliably.

Abstract: An electric motor assembly configured for use in a downhole pumping system includes a plurality of stator coils. Each of the plurality of stator coils includes magnet wire that has an insulator surrounding a conductor. In preferred embodiments, the insulator is manufactured from a material selected from the group consisting of polyether ketone and polyether ketone ether ketone ketone.

Abstract: A canned motor pump, wherein a motor stator is housed in a stator chamber that is a space between a tubular stator can for housing a motor rotor and a tubular stator band disposed coaxially with the stator can. The stator chamber is closed by annular end plates at the cylindrical ends between the stator can and the stator band. The stator chamber is filled with a filler. The filler is produced from spherical inorganic material particles filled into the stator chamber and resin for causing the particles to stick to each other. Consequently, the heat release performance of the stator of the canned motor pump is improved.

Abstract: A vibration monitoring system for an electrical submersible pump (ESP) that includes a fiber optic cable coupled with the ESP and an optical sensor coupled with the fiber optic cable. The optical sensor emits electromagnetic radiation into the fiber optic cable, some of which reflects back from optical discontinuities provided in the fiber optic cable. By receiving the reflected electromagnetic radiation, the optical sensor estimates the location of the optical discontinuities. Displacement and rate of displacement of the optical discontinuities can be estimated when the reflections are received over a period of time. Because the fiber optic cable, and the optical discontinuities, move with the ESP, displacement measurements of the optical discontinuities correlate to ESP movement, including ESP vibration.

Abstract: Electric submersible well pumping systems operable in well temperatures of above about 180° C. (356° F.) utilize high temperature electrical insulation. The electrical insulation includes E-base polyimide films or perfluoropolymer TE films on various components. The insulation films are employed around magnet wires that are threaded through slots in the stator. Slot insulation of E-base polyimide or perfluoropolymer TE surrounds the magnet wires in the stator slots. Sheets of E-base polyimide or perfluoropolymer TE film extend around and between phase loops of the magnet wire at the lower end of the stator. The magnet wires in the stator have lead portions that extend The motor contains a PAO oil having additives to dissipate acid generated by epoxy used in the motor.

Abstract: A pump unit includes a motor, a pump, a shaft spanning the motor and the pump, and at least a first magnetic bearing supporting the shaft. A hydrocarbon production system includes an underwater well and a pump unit exposed to an underwater environment. The pump unit is operable to pump a production fluid from the well and includes a motor, a pump, a shaft spanning the motor and the pump, and at least a first magnetic bearing supporting the shaft.

Abstract: An electric pump which includes a rotor rotationally supported by a housing at a rotation shaft, a stator positioned at an outer side in radial direction of the rotor and fixed to the housing, a pump portion for taking in and discharging fluid in response to a rotation of the rotor, and a can positioned in between the rotor and the stator for preventing the fluid in the pump portion from flowing into the stator. The can possesses conductivity. The stator is grounded via the can.

Abstract: Electric submersible well pumping systems operable in well temperatures of above about 180° C. (356° F.) utilize high temperature electrical insulation. The electrical insulation includes E-base polyimide films or perfluoropolymer TE films on various components. The insulation films are employed around magnet wires that are threaded through slots in the stator. Slot insulation of E-base polyimide or perfluoropolymer TE film surrounds the magnet wires in the stator slots. Sheets of E-base polyimide or perfluoropolymer TE film extend around and between phase loops of the magnet wire at the lower end of the stator. The motor contains a PAO oil having additives to dissipate acid generated by epoxy used in the motor.

Abstract: A motor drive, particularly for submersed electric pumps, has a jacket closed hermetically by a bottom and a head in order to form a first hermetic chamber, which contains an electric motor that is immersed in a bath of dielectric cooling liquid; the jacket is associated with an enclosure in order to form a second hermetic chamber, which contains a power supply and control unit connected to the electric motor. The motor drive includes a compensation means that balances the variations in volume of the dielectric cooling liquid and generates an overpressure within the first hermetic chamber, the first hermetic chamber is substantially independent of the second hermetic chamber.

Abstract: The submerged motor comprises an external case (2) having a tubular shape inside which is coaxially inserted an electric motor unit (3). Closure means (10, 20) are suitable to isolate a room for housing the motor unit (3) inside said case (2) from the fluid present outside the same case (2). Said closure means (10, 20) comprise an upper occlusion member (20) suitable to peripherally engage the internal surface of said case (2) and axially provided with a tubular body (21) carrying, in its internal side, a thrust bearing rolling means (22) suitable to be blocked on an upper portion of said motor shaft (4) to absorb the axial thrusts on the same motor shaft (4).

Abstract: The present invention provides an underwater electric rotating device and an underwater generator using the same. The device includes a rotating shaft, at least a portion of which is rotated in an underwater environment; a rotor which is rotated along with the rotating shaft; a stator which is provided around the rotor and rotates the rotor using electric energy or generates electric energy using rotation of the rotor; and a housing which has at least two waterproof spaces therein which are separated from each other by a partition wall formed perpendicular to the rotating shaft. In the at least two waterproof spaces, a waterproof space that is disposed at the outermost position based on a waterproof space having the rotor and the stator therein is filled with a material that is higher in specific gravity or viscosity than water at room temperature under atmospheric pressure.

Abstract: Electric submersible well pumping systems operable in well temperatures of above about 180° C. (356° F.) utilize high temperature electrical insulation. The electrical insulation includes E-base polyimide films or perfluoropolymer TE films on various components. The insulation films are employed around magnet wires that are threaded through slots in the stator. Slot insulation of E-base polyimide or perfluoropolymer TE film surrounds the magnet wires in the stator slots. Sheets of E-base polyimide or perfluoropolymer TE film extend around and between phase loops of the magnet wire at the lower end of the stator. The motor contains a PAO oil having additives to dissipate acid generated by epoxy used in the motor.

Abstract: A module for a rotor of an electric machine, said rotor being excited by means of permanent magnets and rotating in a liquid medium, wherein the module contains a cylindrical, active part having a plurality of circular, magnetically soft laminations which form a laminated stack and have a central opening for receiving a rotor shaft; wherein at least two permanent magnets protected against the liquid medium are arranged in at least two corresponding cutouts in the laminated stack, the cutouts being formed under a cylindrical circumferential surface of the laminated stack.

Abstract: The present invention relates to a downhole electrical motor elongated in a longitudinal direction, comprising a housing, a stator comprised inside the housing, a rotor comprised inside the stator rotatably connected to the stator, wherein the rotor has a locked end and a non-locked end and is locked in the locked end to avoid movement of the rotor in the longitudinal direction, and the rotor is able to move along the longitudinal direction in the non-locked end of the rotor to avoid thrust loads on the rotor due to thermal expansion of the rotor during rotor heating when the electrical motor is in operation and further comprising a locked bearing connected to the stator for supporting the rotor in the locked end and a non-locked bearing connected to the stator for supporting the rotor in the non-locked end, wherein the bearings are at least partially made from a ceramic material.

Abstract: An electrical submersible pumping (ESP) system for use in a wellbore having a pressure equalization system that employs modules with a bellows. The bellows axially expands and contracts in response to pressure fluctuations encountered in the wellbore. The modules are attachable in series on a lower end of a motor of the ESP to form the string, where the string can range from a single module to a multiplicity of modules, depending on the application. The bellows has a conduit axially inserted through the bellows that includes an umbilical and has an end in pressure communication with the motor.

Abstract: Apparatus is provided for use in a submersible pump, comprising; a stator having electrical windings and configured with a cavity to receive a rotor of a motor and to provide an electromotive force to drive the rotor arranged inside the cavity; a switch having circuitry configured to response to a level of fluid and control the operation of the stator; and electrical leads and connections configured to electrically couple the stator and the switch, and to provide power to operate the stator and the switch to drive the stator and to turn the electromotive force on and off to control the pumping of the fluid by submersible pump; the stator, the switch and electrical leads and connections being at least partly encapsulated in a material so as to form an encapsulated stator assembly with a watertight seal to prevent fluid from contacting the electrical windings, the circuitry of the switch and the electrical leads and connections.

Abstract: An electric submersible pump (ESP) motor includes a polymer or ceramic component made by curing a thermosetting polymer in situ in the ESP motor, wherein the thermosetting polymer is selected from the group consisting of cyanate ester, bismaleimide, polyimide, benzoxazine, a preceramic polymer, and a mixture thereof, or the thermosetting polymer is a hybrid polymer having less than 50% by weight of an epoxy component and a second component selected from the group consisting of cyanate ester, bismaleimide, polyimide, benzoxazine, a preceramic polymer, and a mixture thereof.

Abstract: An electric device includes: a circuit board arranged in cooling medium in a housing and having an electric element and an external coupling electrode, wherein the electric element is sealed in and mounted in a substrate, and the electric element is electrically coupled with the external coupling electrode; an external coupling terminal electrically coupled with the external coupling electrode; and a separation member for separating the external coupling terminal and a connection portion between the external coupling electrode and the external coupling terminal away from the cooling medium.

Abstract: A pressure-resistant explosion-proof connector that allows even a different type of sensor to be mounted via a common connector, and thereby eliminates the need for replacement of each sensor is provided. A canned motor pump includes a centrifugal pump, a stand that supports a body, a motor, a bearing holder of the motor, a terminal flange mounted to an outer cylinder of the motor, a terminal box mounted onto the terminal flange, a motor monitoring unit mounted onto the terminal box, and a pressure-resistant explosion-proof connector mounted to the terminal flange. Also, the pressure-resistant explosion-proof connector includes a base joint mounted to the terminal flange, and a connection cylinder connected to the base joint, and a pressure sensor is connected to the distal end of the connection cylinder.

Abstract: A submersible motor pump includes a water jacket having a circulation passage of a coolant, a centrifugal impeller for circulating the coolant, a suction passage configured to provide fluid communication between the circulation passage and a fluid inlet of the centrifugal impeller, and a discharge passage configured to provide fluid communication between a fluid outlet of the centrifugal impeller and the circulation passage. The discharge passage includes a heat-exchange passage formed by two wall surfaces, one of which is constituted by a member which contacts a liquid conveyed by a main impeller. The heat-exchange passage has a circular shape extending radially outwardly from the fluid outlet of the centrifugal impeller. The heat-exchange passage includes at least one axial passage section having a length component in an axial direction of the rotational shaft.

Abstract: An expansion chamber to serve ESP equipment installed on the seabed located in either a caisson or a conduit on a skid. The expansion chamber provides an external reservoir for expansion and contraction of motor oil in the ESP equipment. During operation of an ESP, the heat generated in the motor raises the temperature of the motor oil, causing it to expand. The expansion chamber is connected to the ESP equipment via oil lines that allow oil to expand into the expansion chamber when the temperature of the motor oil increases. The expansion chamber has a movable barrier therein that defines primary and secondary chamber. Oil communicates with the primary chamber. Formation fluid within the conduit surrounding the motor communicates with the secondary chamber.

Abstract: A dynamo-electric machine, for example a marine propulsion unit, includes a stator and a rotor in the form of an impeller. The impeller is rim-driven and includes an annular core of ferromagnetic material, on which are provided layers in the form of an environmental enclosure and electrically conductive sleeves. Appropriate selection of the materials and thicknesses of the layers enables the starting and normal running performance of the machine to be optimised.

Abstract: 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.