Abstract: An electrical device and servo motor that includes a stator having a plurality of poles, wherein each pole includes a first surface and a second surface; the first surface and the second surface are spaced apart and have a pair of slots defined between the first surface and the second surface on respective sides of each pole. The pair of slots is configured to receive at least one winding, and each pole further includes a cooling tube coupled to the first surface, wherein the cooling tube is at least partially encompassed within the first surface.

Abstract: An electric machine can include a stator, a rotor frame and a pole arrangement with: plural segment pieces disposed circumferentially around, and fastened to, the rotor frame; permanent magnet pieces positioned on inclined side edges of each segment piece; and plural pole pieces disposed circumferentially around the rotor frame and disposed alternatingly with the segment pieces. The magnet pieces are pressed between inclined side edges of the pole pieces and the inclined side edges of the segment pieces. The segment pieces, the permanent magnet pieces and the pole pieces form a closed ring around the outer surface of the rotor frame, with plural such rings being arranged after each other in an axial direction. An axial air channel can pass through the rings, and at least one radial air duct (R1, R2) between the rings.

Abstract: A first cooling air passage is formed to let first cooling air generated by a cooling fan in from a radially outside of an inverter apparatus to cool a heat sink and out through exhaust holes provided on an outer peripheral side of a rear bracket by passing an inner periphery of the rear bracket. Also, a second cooling air passage is formed to let second cooling air generated by the cooling fan into a hollow portion of the inverter apparatus from an axially rear of a rotation shaft to cool a brush holder and a magnetic pole position detection sensor and out through the exhaust holes by passing the inner periphery of the rear bracket. Hence, cooling performance for the magnetic pole position detection sensor and the brush holder may be enhanced and an axial dimension may be reduced.

Abstract: A rear wheel driving apparatus (1) includes: a first right-left communication passage (FP) through which a left reservoir (RL) and a right reservoir (RR) are communicated with each other; and a second right-left communication passage (SP) which is provided in parallel with the first right-left communication passage (FP) and through which the left reservoir (RL) and the right reservoir (RR) are communicated with each other. Thus, flowability of a liquid fluid stored in a case (11) is enhanced, and smoothing of a fluid level is enabled.

Abstract: A system for cooling an electric motor, the electric motor including a stator disposed about a rotor, wherein cooling system includes a rotor assembly including a shaft with a shaft channel extending through the center of the shaft and radial channels extending radially from the shaft channel; a rotor with profiled rotor ends; and two guides, each coupled to a rotor end, that guides fluid from the shaft exterior to the rotor end. The system may additionally include interior channels that traverse through the rotor interior, wherein the interior channels fluidly couple the radial channels to a guide-rotor end pair. The system may also include stator cooling mechanisms, including cooling channels within the motor casing proximal to stator exterior surface and dispensing mechanisms that dispense working fluid to the stator coils.

Abstract: An inverter device is provided with a hollow portion in a center portion of a rotation shaft of a rotating electrical machine. The rotating electrical machine has a first cooling air passage for cooling air generated by a cooling fan to flow in from an outer side in a radial direction of the rotating electrical machine, then to cool a heat sink, and to be discharged through ventilation holes provided to a rear bracket on an outer peripheral side by passing an inner periphery of the rear bracket, and a second cooling air passage for cooling air to flow into the hollow portion from the rear in the axial direction, then to cool a brush holder and a magnetic pole position detection sensor, and to be discharged through the ventilation holes by passing the inner periphery of the rear bracket.

Abstract: A wind turbine rotary electric machine having a tubular body, in turn having a cylindrical wall; and a plurality of clips formed integrally with the cylindrical wall and configured so that each pair of facing clips defines a seat for housing an active sector.

Abstract: An electric machine including a rotor and a stator operably coupled with the rotor, electronic components, and a drive shaft disposed along a central axis of the machine. A bearing support supportively surrounds the drive shaft, and a frame end is connected to the stator and has a backface portion to which the electronic components are mounted. The backface portion defines a frame airflow space through which cooling air can flow. The backface portion is sloped relative to the central axis and defines a frame air inlet through which cooling air is received into the frame airflow space, and the frame air inlet is located between the bearing support and the backface portion.

Abstract: The invention relates to an air-cooled dynamoelectric machine (1), in particular for low voltage<1000 V, comprising a stator (2), grooves (10) extending axially and facing a stator bore (9), in which grooves a multi-phase winding system is arranged, which forms a winding head (7) at each end face of the stator (2), wherein a phase separator (8) is provided between the different phases of the winding system in the winding head (7), wherein the phase separator (8) comprises two layers, with spacing elements (11) lying therebetween.

Abstract: According to an embodiment, radially extending inner spacers are provided in a stator core at a distance from each other in the circumferential direction at intervals between a prescribed number of stacked magnetic steel plates, and ventilation ducts for cooling gas flow are formed in the radial direction. The perimeter of each ventilation duct is defined by the inner spacers and a magnetic steel plate separated by the inner spacers. The cooling gas, which flows in the rotation direction, is split laterally to both sides of a rotor coil and directed toward the outer circumference. Portions of the shoulder parts of a wedge are cut off such that the width of the shoulder parts of the wedge at positions corresponding to the ventilation ducts matches the slot width.

Abstract: In a rotor of a motor according to the present invention, a plurality of flow passages spaced apart from each other around an axis of rotation, each of which extends so as to be slanted relative to an axis of rotation and open to an exterior space of the rotor at both ends of the rotor. The flow passages are configured so that adjacent flow passages are slanted alternately in opposite directions and that a fluid for cooling the rotor circulates through the flow passages.

Abstract: A cooling system of a AC generator for vehicles has a stator with a stator winding, a rotor that is arranged in an inner circumferential side of the stator, a rectifier that converts an alternating current voltage generated in the stator winding into direct current, and a rear cover that covers the rectifier. The rear cover has an intake duct connecting portion that projects outside and an air intake duct is attached to a tip portion of the intake duct connecting portion. A dividing wall that divides an internal space of the rear cover into a plurality of spaces along a direction extending from the rectifier backwardly relative to the direction of rotation is disposed in the intake duct connecting portion.

Abstract: On an inner circumference side of a stator fixed in an inner housing, a rotor is arranged. The rotor rotates through a bearing with respect to a center shaft that is a stationary shaft fixed to outer housings. Oil introduced into a rotor oil inlet path in the center shaft flows through a communication path and a clearance on an outer circumference of the center shaft into an oil path in the rotor. The oil flowing through the oil path cools a permanent magnet, lubricates the bearing, and is discharged from a rotor oil discharge port to the outside of the inner housing. The oil in the clearance is sealed with a thread seal, i.e., an inner thread formed in an inner face of an end ring and is prevented from flowing toward the bearing.

Abstract: According to one embodiment, a motor for a vehicle includes a casing accommodating a rotor and a stator iron core inside thereof, and supporting each of both axial ends of the rotor shaft via a bearing, an air inlet port formed in a portion of the casing outside the bearing in the radial direction, and a fan provided between the rotor iron core and the bearing and rotating with the rotor shaft, wherein a portion of the casing positioned outside impellers of the fan in the axial direction forms a first housing and a second housing constituting a discharge channel, and the first housing includes a guide wall extending toward the outside in the radial direction, and the second housing includes a thinned wall portion located inside the guide wall in the axial direction to constitute the discharge channel between the thin wall portion and the guide wall.

Abstract: A motor generator for a vehicle includes a housing having a through hole along a central axis thereof, with a protrusion protruding outwards along a circumference of the through hole. A rotating shaft is disposed in the housing in such a way that a first end thereof is exposed outside through the through hole. A pulley is disposed outside the housing in such a way that the first end of the rotating shaft is inserted into and coupled to a central portion of the pulley. A rim of the pulley is surrounded by the protrusion and a central portion of the pulley passes through the through hole, so that a watertight flange having a larger diameter than the through hole is disposed in the housing.

Abstract: An electric motor assembly including a stator having a stator core and windings around the stator core is disclosed. The stator core has opposing ends and an outer surface extending between the opposing ends. The electric motor assembly also includes a housing having an inner surface enclosing at least a portion of the stator, and at least one fluid passage between the outer surface of the stator core and the inner surface of the housing. The fluid passage permits a coolant in the fluid passage to contact one or more portions of the outer surface of the stator core to remove heat from the stator core during operation of the electric motor assembly. Additional motor assemblies including stator and/or rotor cooling features are disclosed.

Abstract: A stator/rotor lamination sheet for a stator/rotor lamination of generators and electric motors has spacers, wherein the spacers are monolithic lamination sections that are bent out of a lamination sheet plane about a bending edge and create corresponding recesses in the lamination sheet, wherein the spacers transversely protrude from the lamination sheet plane. A method for manufacturing the stator/rotor lamination sheet provides that a stator/rotor lamination sheet is punched out of a metal sheet; lamination sections are partially punched out out of the metal sheet; and the partially punched-out lamination sections are bent out of a lamination sheet plane of the lamination sheet to form spacers of the lamination sheet.

Abstract: A totally enclosed fan cooled (TEFC) induction motor or other type of induction motor auxiliary cooling system has a buffet thermal shroud that is oriented in opposed spaced relationship over existing motor housing cooling fins. An airflow channel is defined between the motor cooling fins and the shroud, for direction and passage of a cooling airflow. Tabs are oriented in the airflow channel between opposed cooling fins where they are in thermal and fluid communication with the cooling air flow. In some embodiments the tabs are shroud fingers that project inwardly from the shroud. The tabs or shroud fingers create turbulence in the cooling air flow that increases convective heat transfer efficiency and contact time between the cooling air and motor cooling fins. Tabs or shroud fingers also absorb heat from the cooling air flow. Shroud fingers also transfer that absorbed heat conductively to the shroud.

Abstract: An electric drive, particularly for vehicles, includes at least one first and at least one second electric machine. The electric machines are arranged relative to one another in a manner comparable to the cylinders of a conventional opposed-cylinder internal-combustion engine.

Abstract: An approach for cooling a stator core flange is provided. In one aspect, a pair of stator flanges each disposed at opposing ends of a stator core assembly maintains a compressive load on the stator core assembly. Heat transport tubes may be located about at least one of the stator flanges at an end of the stator core assembly to redistribute heat therefrom.

Abstract: A motorized drum having a drum shell with a motor therein, the motor having a stationary shaft, stator windings, and a stator support structure that is affixed to the stationary shaft. A rotor rotates coaxially around the stator, and a cycloidal reducer has an output that rotates at a reduced rate. The reducer output is rotationally fixed to, and is disposed within, the drum shell. An input gear of the reducer received a hollow eccentric input shaft, and is urged into eccentric motion as the input shaft rotates. The output gear urges the drum shell into rotation at same rate of rotation as the output gear. An harmonic drive speed reducer that has an input shaft provides rotatory motion to a wave generator that is disposed against a flexible splined member. The flexible splined member engages a rigid circular spline member at two radially opposed zones. Induction and permanent magnet forms of operation are used.

Abstract: An electric machine comprises an outer casing (2), a rotor and a stator (3) having at least one polar expansion (5) and at least one winding (8) having an annular shape and placed around the polar expansion (5). The casing (2) has a plurality of protrusions (13) each of which holds, by supporting, a corresponding portion (12) of a stator winding (8) to enable heat exchange between the winding (8) and the protrusion (13). Each portion (12) of the winding (8) is electrically insulated from the respective protrusion (13).

Abstract: An electric drive unit includes an electric motor, which has a stator and a rotor, a gearbox, an electric circuit and a housing. The housing forms a motor compartment in which the electric motor is arranged and a gearbox chamber in which at least a part of the gearbox is arranged. The electric drive unit also includes a lubricating circuit in which a lubricating fluid is conveyed in order to lubricate and cool the gearbox and the rotor of the electric motor, the lubricating fluid circulating between the motor compartment and the gearbox chamber. The drive unit further includes a cooling circuit in which a cooling fluid is conveyed in order to cool the electric circuit and also the stator of the electric motor. The cooling fluid of the cooling circuit is connected to the lubricating fluid of the lubricating circuit in such a manner as to be able to exchange heat.

Abstract: An electric motor includes a stator and a rotor. The rotor includes a motor shaft, at least one radial fan and at least one axial fan being non-rotatably situated on the motor shaft for motor cooling. The radial fan is situated in the area of one axial end of the motor shaft and the axial fan is situated in the area of a diametrically opposed axial end of the motor shaft.

Abstract: Ventilation apertures are respectively formed circumferentially so as to pass axially through an inner circumferential side of a rotor core, rotor grooves are respectively formed circumferentially on an outer circumferential surface of the rotor core so as to have groove directions in an axial direction, and a centrifugal fan is fixed to the shaft at an end of the rotor core near the front frame, and a cyclic path is formed in which, during operation of the centrifugal fan, cooling air flows into the ventilation apertures from near a rear frame, passes through the ventilation apertures and flows out near the front frame, flows radially outward near the front frame and flows into the rotor grooves, passes through the rotor grooves and flows out near the rear frame, and flows radially inward near the rear frame and flows into the ventilation apertures.

Abstract: An oil cooled generator may have stator windings with first portions in contact with a stator core and second non-contact portions. One or more nozzles may be configured to provide a spray pattern of oil which impinges on the non-contact portions even though the nozzles may have orifices oriented so that the lines projected in alignment with longitudinal axes of the orifices do not intersect the non-contact portions of the stator windings.

Abstract: A rotor and a dynamoelectric machine including a rotor are disclosed. In an embodiment, the rotor includes a rotor body having a plurality of axially extending slots disposed radially about the rotor body, and at least one coil having at least one turn positioned within each of the plurality of axially extending slots. The rotor further includes a plurality of subslots disposed in the rotor body such that each subslot extends axially through the rotor body parallel to an axis of rotation of the rotor body, and is in fluid communication with a radially inner end of a slot; a passageway extending substantially radially outwardly along each axially extending slot for cooling the at least one turn disposed in the slot; and a retaining member in each of the slots for retaining the at least one turn within the slot. Various embodiments provide ventilation via the passageway for cooling the rotor coils.

Abstract: In an arrangement for cooling an electrical machine, the electrical machine includes a rotor and a stator located at the end of an air gap from the rotor. The rotor includes at least one axial cooling channel originating from the first end of the rotor that is connected to at least two axially successive cooling channels that are substantially radial within the rotor. The stator is made of sheets using axially successive core modules. The stator includes a radial cooling channel between two core modules. Gaseous cooling agent is led to the cooling channels of the rotor and stator from the end of the rotor. The outer surface of the stator core module includes a cooling jacket by the length (L) of the stator core module at maximum, and liquid cooling agent is led to the cooling jacket.

Abstract: Systems and methods are provided for cooling and lubrication of high power density electric machines with an enhanced fluid injection system. Multiple fluid flow passages are within the electric machine, which include a bearing fluid flow pathway and a rotor fluid flow pathway. The bearing fluid flow pathway comprises a passage which directs fluid to contact a bearing for lubrication and cooling. The rotor fluid flow pathway comprises a passage which directs fluid along the rotatable shaft toward the rotor and stator for cooling. A fluid flow passage may lead to a junction, and may split between the bearing fluid flow pathway and the rotor fluid flow pathway. Additionally, a fluid flow metering device at the junction between the bearing fluid flow pathway and the rotor fluid flow pathway, may determine the relative amount of fluid that flows to the bearing and that flows toward the rotor and stator.

Abstract: The electric machine includes a stator. The stator includes stacked lamination plates. The lamination plates form at least two lamination packages. The electric machine includes a first cooling circulation with a first cooling fluid. The stator of the electric machine includes a second cooling circulation with a second cooling fluid. A heat exchanger is part of the second cooling circulation and is arranged to connect the first cooling circulation and the second cooling circulation. Thus heat is transferred from the first cooling fluid to the second cooling fluid. A spacer element is arranged between the two lamination packages. The spacer element is prepared to set a predetermined distance between the lamination packages, thus the first cooling fluid is allowed to flow between the lamination packages. The heat exchanger arrangement is an integral or at least partly integrated part of the spacer elements.

Abstract: A first inverter ventilation aperture is disposed so as to pass through a portion of a fin base that faces a bearing, a first rotor ventilation aperture is disposed so as to pass through a portion of a bottom surface portion that faces the bearing, and a first cooling airflow ventilation channel is formed in which a cooling airflow flows radially inward through radiating fins, then flows toward a first surface side of a mount portion through the first inverter ventilation aperture, flows axially through an interior portion of a stator core, and then flows out between the bottom surface portion and a base portion through the first rotor ventilation aperture, and subsequently flows radially outward between the bottom surface portion and the base portion due to rotational driving of a centrifugal fan.

Abstract: The arrangement of an electric machine, a connecting system and a converter, includes the connecting system connected between the electric machine and the converter. The connecting system has an enclosure that houses non-shielded conductors each non-shielded conductor is connected between a phase of the electric machine and the inner side of the converter. The non-shielded conductors of the connecting system that are connected to an operating phase of the electric machine are adjacent to conductors of the connecting system that are not connected to operating phases of the electric machine.

Abstract: A rotating electric machine (1) having a stator (4) in a housing (2) and a rotor (10) supported by a shaft (6). The housing (2) circumferential wall (12) and first and second axially opposing end walls (14, 16) support bearing flanges with bearings (18) for the shaft (6). Two cooling fan impellers (20, 22) are connected to the shaft (6). An inner cooling fan impeller (20) positioned inside the housing (2) generates an inner cooling air circuit (A) inside the housing (2). An outer cooling fan impeller (22) provided outside the housing (2), generates an outer cooling air flow (B). The first end wall (14) is formed with a thermal conductivity of at least a specified value and has an outer cooling rib geometry (28) on its outer side facing the outer cooling fan impeller (22), and an inner cooling rib geometry (30) on its opposing inner side.

Abstract: A three-phase rotary electrical machine including a stator including a stator core including split cores, a rotor, a bobbin attached to each of the split cores, a winding being wound around each split core to which the bobbin is attached, and a bobbin unit including three of the bobbins which are arranged in a circumferential direction of a rotation axis as one unit, wherein the bobbin positioned at a center of the bobbin unit are formed in a bendable manner integrally with the bobbins positioned adjoining to the bobbin positioned at the center, the bobbin unit is sealed with the bobbin unit positioned adjoining thereto, and a cooling passage extending in the axial direction is provided at each clearance between the windings for three phases.

Abstract: A method of inserting a continuous conductor having a rectangular cross-section into slot segments formed in a stator core includes forming a core member having a plurality of slot segments each having an opening and inserting a stator winding having a plurality of phases into select ones of the slot segments. Each of the plurality of phases has at least one conductor including a plurality of substantially straight segments alternately connected by a plurality of end loop segments. A section of the at least one conductor includes three consecutive end loop segments and three consecutive straight segments formed from a single continuous conductor. The method further includes narrowing the opening of each of the plurality of slot segments by forming an annular stator core having a central axis. The three consecutive straight segments are substantially similarly radially spaced from the central axis.

Abstract: A driver system, cooling apparatus for a driver system, and method are provided. The driver system includes a driver, a device configured to move a cooling fluid, and a shroud disposed at least partially over the driver. The shroud includes a plurality of inlet orifices and a plurality of outlet orifices in fluid communication with the device, and a plurality of fins extending at least partially between the shroud and the driver, at least partially in the driver, or both, the plurality of fins being spaced apart and defining flowpaths therebetween, wherein the flowpaths communicate with the inlet orifices and the outlet orifices.

Abstract: A rotor for a turbo generator is provided. The rotor includes a cylindrical rotor shaft that expands in the center to form a rotor body, grooves introduced into the cylindrical surface of the rotor body, an excitation winding accommodated in the grooves, a feeding duct through which a cooling gas flows, and cooling ducts which penetrate the excitation winding substantially in the radial direction and connect the feeding duct to respective outlets in the cylindrical surface of the rotor body A distribution duct extending in the longitudinal direction of the shaft is arranged in the area of the central longitudinal axis. The feeding ducts are connected to the distribution duct via junction ducts. An admission duct for feeding the cooling gas is provided for each distribution duct.

Abstract: A heat-dissipation structure for a motor including a motor shell, a control box, and a coupling shell. One end of the coupling shell is connected to the bottom of the motor shell and the other end thereof is connected to the top of the control box and a plurality of air vents are arranged on a side wall of the coupling shell. The introduction of the coupling shell enlarges the inner space of the control box and achieves rapid heat dissipation and a better heat dissipation effect. The heat-dissipation structure features rapid heat dissipation, excellent heat dissipation effect, a simple structure, an attractive shape, and great universality.

Abstract: An electrical machine has passages in the rotor. The passages have an inlet port and an exit port disposed at different locations. The passages remove heat from the electrical machine during operation. Another embodiment is an electrical machine rotor. The rotor has passages that remove heat from an electrical machine during operation. Other embodiments include apparatuses, systems, devices, hardware, methods, and combinations for electrical machines and the cooling of electrical machine rotors and/or stators.

Abstract: The present invention relates to a rotor for a rotary electric machine, extending along a longitudinal axis, including: projecting poles having pole shoes, and at least one internal cooling channel extending axially along at least one pole shoe.

Abstract: An electric machine includes a housing having inner and outer sheet metal members attached to one another to form a coolant channel therebetween, a plurality of power electronic components mounted to an axial end of the electric machine adjacent the coolant channel, and a cover secured to the axial end for enclosing the electronic components. A method of cooling an electric machine includes forming a coolant channel at an axial end of the machine, between inner and outer sheet metal members, attaching a power electronics component to the outer sheet metal member proximate the coolant channel, thereby cooling the electronics component by conduction with the coolant channel, and securing a cover to the axial end for enclosing the power electronics component.

Abstract: In one aspect, an electric machine is provided. The electric machine includes a housing including at least one air intake, an air outlet, and an air passage extending between the at least one air intake and the air outlet. The electric machine also includes a first heat sink positioned at least partially within the air passage, and a second heat sink positioned at least partially within the air passage downstream of the first heat sink.

Abstract: An electric machine has a stator that comprises a plurality of laminations with teeth and cooling apertures about a central opening. When the laminations are stacked to form the stator core, the teeth of adjacent laminations cooperate to form slots disposed circumferentially about the central opening that are configured to receive a plurality of stator windings, and the cooling apertures angularly spaced about the central opening cooperate to form cooling manifolds that extend along a length of the stator core. A portion of the laminations has their cooling apertures offset from other laminations in the stack in a manner to create a plurality of flow paths transverse to the manifolds. The transverse flow paths extend angularly between laminations and adjacent manifolds. A header assembly directs flow into and out of the stator core.

Abstract: An electric machine has a stator that comprises a plurality of laminations with an outer periphery, and each of the laminations has teeth about a central opening such that when the laminations are stacked side-by side to form the stator core, the plurality of teeth of adjacent laminations cooperate to form slots disposed circumferentially about the central opening that are configured to receive a plurality of stator windings. Each of the laminations has a plurality of cooling apertures angularly spaced about the central opening. The cooling apertures of adjacent laminations cooperate to form cooling manifolds that extend along a length of the stator core. A portion of the laminations has their cooling apertures offset from other laminations in the stack in a manner to create a plurality of flow path transverse to the manifolds and angularly between laminations and adjacent manifolds.

Abstract: An electric motor includes a stator operable to produce a magnetic field and defining an opening, and a rotor at least partially disposed within the opening. The rotor includes a shaft extending along a rotational axis, a first rotor magnetic core portion including a plurality of laminations stacked contiguously on the shaft, and a second rotor magnetic core portion coupled to the plurality of laminations. The first rotor magnetic core portion and the second rotor magnetic core portion cooperate to define the rotor magnetic core. A plurality of windings is coupled to the rotor magnetic core and an air flow path is formed as part of the second rotor magnetic core portion. The air flow path includes an axial portion that passes through the shaft axially along the rotational axis and a radial portion that extends radially outward through the second rotor magnetic core portion.

Abstract: A generator motor cooling structure for cooling a generator motor, which includes a housing storing an input/output shaft to which a rotor is attached and a stator disposed at an outer periphery portion of the rotor, by a cooling medium, includes: a protrusion portion that protrudes toward the rotor from a surface at a side of the housing of an end side member disposed at one end portion of the housing in a direction of a central rotation axis of the input/output shaft, wherein the protrusion portion is provided on an inner side of a coil of the stator in a radial direction, on an outer side of a bearing attached to the input/output shaft in the radial direction, in at least a partial region on a periphery of the central rotation axis.

Abstract: The invention relates to a rotor for a rotary electric machine, extending along a longitudinal axis and including: an assembly of electrical sheets forming projecting poles, two projecting poles defining an interpolar region therebetween; and at least two internal cooling channels formed in the assembly of electrical sheets in at least one interpolar region.

Abstract: An electric machine includes a stator having an outer circumference. Spaced apart first walls are arranged about the outer circumference and provide generally parallel first channels. A second wall adjoins the first wall and is arranged about the outer circumference providing a second channel in fluid communication with the first channels, thus, providing a tortuous fluid flow path about the circumference. The first and second channels have an inner surface. A structure is provided within at least one of the first and second channels. The structure has an outer surface spaced radially outward from the inner surface and at least partially defines the tortuous flow path between the outer and inner surfaces. The stator includes an end turn. An end cap extends axially and radially outward from the stator and provides an enclosure about the end turn in fluid communication with the exit associated with the flow path.

Abstract: A rotor of an electric machine including a rotor body, axial slots in the rotor body, a plurality of tubular conductive bars in each axial slot, and apertures in at least some of the tubular conductive bars. The apertures are provided on walls of tubular conductive bars that intersect a radial axis of the rotor body. The rotor includes tubular elements that are housed in at least some of the holes and pass through at least one tubular conductive bar.

Abstract: A multistage electric motor includes a plurality of motor stages connected in series, each motor stage comprising a stator, and a rotor; a plurality of cooling fluid paths, each cooling fluid path forming a recirculating loop independent of the other cooling fluid paths, each cooling fluid path in communication with the stator of one of motor stages; and a cooling fluid flowing through each cooling fluid path, the cooling fluid removing heat from the stator of each motor stage. A submersible pump including the multistage electric motor, and a method of cooling the multistage electric motor are also described.