Abstract: The permanent magnet rotor is capable of making tolerance of attaching a magnet cover great, applying no stress to structural elements of the rotor, preventing the magnet cover from being damaged under an environment where thermal expansion and thermal contraction are repeated in response to temperature variation, and preventing scatter of magnets. The permanent magnet rotor of an inner rotor-type motor comprises: a rotor yoke; a plurality of permanent magnets being arranged on an outer circumferential face of the rotor yoke, the permanent magnets constituting a plurality of segments; and a ring-shaped magnet cover covering outer faces of the permanent magnets, the magnet cover being composed of a nonmagnetic material. An inner diameter of the magnet cover before covering the outer faces of the permanent magnets is smaller than an outer diameter of the circularly-arranged permanent magnets.

Abstract: A permanent magnet arrangement for an electrical machine comprises a support structure for carrying magnetic flux and a pole assembly fixed to the support structure. The pole assembly comprises a magnet pole comprising at least one piece of permanent magnet material, and a magnet carrier on which the magnet pole is mounted and which provides a magnetic flux path between the magnet pole and the support structure. The permanent magnet arrangement further comprises a sleeve containing the magnet pole and at least part of the magnet carrier. The magnet carrier is secured to the support structure to fix the pole assembly to the support structure and the sleeve is clamped to the support structure by the magnet carrier. A method for assembling the permanent magnet arrangement is also described.

Abstract: A mover assembly of a reciprocating motor includes: a mover body disposed at a gap between an inner stator and an outer stator; permanent magnets fixed at an outer circumferential surface of the mover body and reciprocally moved together with the mover body in a direction of an induction magnetic field between the inner stator and the outer stator; and a mixed member made of a fiber and a resin to cover and fix the permanent magnets. The permanent magnets are arranged at an outer circumferential face of the mover body, covered with the mixed member obtained by mixing a fiber and a resin, and hardened to be fixed. Therefore, the permanent magnets can be firmly and easily fixed at the mover body. In addition, by molding the mover body with a non-magnetic and non-conductive material, leakage of the magnetic force of the permanent magnets can be prevented.

Abstract: A motor rotor has a rotor yoke having a polygonal column structure, a plurality of magnet fixing sections formed on the lateral surface of the rotor yoke, segment magnets respectively fixed to the magnet fixing sections and extending in the axial direction of the rotor yoke, and projections provided on the rotor yoke and protruding outward from the rotor yoke, the projections being provided at each boundary section located between each of the adjacent magnet fixing sections and being provided in pairs in the axial direction of the rotor yoke.

Abstract: An electric machine system includes an electric machine and a companion device. The electric machine has a stationary member and a movable member that, by interaction of magnetic fields, at least one of moves relative to the stationary member or generates electricity when moved relative to the stationary member. One of the stationary member and the movable member includes a permanent magnet. The companion device is coupled to the electric machine to communicate mechanical movement with the movable member. In certain instances, the electric machine system has adaptations for operation of the electric machine system subsea and/or in a corrosive environment.

Abstract: A wedge for use in a generator rotor includes a wedge body having a generally triangular shape with flat surfaces, and such that when the wedge is placed in a generator rotor, the flat surfaces will define circumferential extents of the wedge body relative to a rotational axis of the rotor, and said flat surfaces extending to a radially outermost extent of the wedge body. A wedge and winding combination, a generator rotor, a generator and a method all using the wedges are disclosed and claimed.

Abstract: An assembly for mounting magnets on a steel sheet rotor pack, the assembly including a plurality of baseplates made of a magnetic material and fixed to the rotor pack, and a plurality of magnets being in turn fitted to each baseplate. In one embodiment, the baseplates are fixed to the rotor pack by means of inner locking bars housed in axial ducts provided inside said rotor pack. The baseplates are fitted to the inner locking bars by fixing means passing through longitudinal channels connecting the axial ducts and the outer surface of the rotor pack.

Abstract: A rotor having a substantially cylindrical configuration for use in a brushless direct current electric motor having a high torque to size ratio. The rotor has an outer peripheral surface. The rotor also has a central rotor shaft and a first and second retaining ends mounted on the central rotor shaft and spaced from one another. The rotor also has a plurality of magnets configured to provide a magnetic flux with a stator disposed around the central rotor shaft. The magnets are radially disposed on the shaft and the rotor also has a sheath. The sheath is crimped around the radially disposed permanent magnets, and holds the magnets around the shaft. The sheath is lightweight and minimizes a gap between the permanent magnets and the stator to provide for an electromagnetic flux between the magnets and the stator windings, and for rotation of the central rotor shaft.

Abstract: In a rotor structure of a permanent magnet type rotary machine comprising a cylindrical permanent magnet 3 fixed on an outer peripheral surface of a rotor shaft 2, wherein torque acting on the permanent magnet 3 is transmitted to the rotor shaft 2, the rotor structure further comprises two annular side plates 4 and a holding ring 5. Each side plate has an axial hole 4a into which the rotor shaft 2 is fitted so as to rotate with the side plates integrally and the side plates 4 are attached on the both end surface of the permanent magnet 3, respectively so as to confront with each other. A circular U-shaped groove 4c coaxially with the axial hole 4a is provided at a end surface 4b for facing with the permanent magnet 3 of each side plate 4. The holding ring 5 is formed cylindrically and covers circumferential sections of the permanent magnet 3 and the side plates 4 and fasten the permanent magnet 3 and the side plates 4 so as to move them integrally.

Abstract: A permanent magnet type rotating electric machine is comprised of a rotor and a stator opposed to each other keeping a predetermined clearance therebetween. The rotor having a rotor core formed by silicon steel plates being laminated in an axial direction of the rotor core, slots being formed near an outer periphery of the rotor core in the rotor core so as to be open at the outer periphery of the rotor core, permanent magnets being inserted into the slots respectively, and a non-magnetic sleeve covering the outer periphery of the rotor core. Each of the slots has inclined side faces outwardly broadening the slot in a radial direction of the rotor core. Each of the permanent magnets is fixed into the slot with a force applied from the sleeve so as to directing toward a center of the rotor core and an pressure applied from the inclined side faces of the slot.

Abstract: A motor rotor has a resin-impregnated thread layer formed by winding a thread of a reinforced fiber material around a permanent magnet layer with a gap between an outer peripheral surface of the thread layer and an inner peripheral surface of a cylindrical body, and impregnating the thread layer with a curable resin. A subsequent thread layer is formed by leading a continuous thread into an annular passage through thread passing recesses, winding the continuous thread around a bottom portion of the passage, and impregnating the subsequent thread layer with a curable resin. A curable resin is injected into the gap between the outer peripheral surfaces of the thread layer and the subsequent thread layer and the inner peripheral surface of the cylindrical body through resin injection passages and/or the thread passing recesses before heating and curing.

Abstract: Disclosed herein is a brushless motor that is simply constructed based on a vernier type motor to achieve high torque without the increase in size and complication thereof. The brushless motor includes a rotor having magnetized surfaces alternately magnetized as N and S poles and a stator having salient poles. The salient poles have tip end surfaces opposite to the magnetized surfaces in the radial direction. Grooves and protrusions are alternately formed at the tip end surfaces of the salient poles in the rotational direction. The grooves and the protrusions extend in the axial direction and have a width in the rotational direction approximately equal to that of the N pole or the S pole. Magnetic bodies are disposed in gaps defined between the grooves and the magnetized surfaces in a non-contact fashion. A magnetic connection member is spaced apart from the stator to interconnect the magnetic bodies.

Abstract: A brushless motor comprises a stator and a rotor rotatably mounted to the stator. The rotor comprises a shaft, a rotor core fixed onto the shaft and magnets fixed to the rotor core. Two covers are fitted to respective ends of the rotor core, with one of the covers covering one end of the rotor core and at least a part of the radially outer peripheral surface of the rotor core, while the other cover at least covering the other end of the rotor core. Preferably, the entire peripheral surface of the rotor core is substantially covered by the two covers and the gap between the two covers is sealed by adhesive.

Abstract: A rotor assembly for an electric motor includes a drive assembly, a cup that receives a portion of the drive assembly, and a magnet core assembly received between the drive assembly and the cup. The magnet core assembly is hermetically sealed between the drive assembly and the cup.

Abstract: A method is provided for encapsulating permanent magnets of a rotor of a generator. Magnets, which are shorter than a rotor yoke in an axial direction, are placed outside of the yoke leaving a short portion of the yoke free at both ends. Spacers of a non-magnetic material are placed between the magnets. End barriers are placed on the free portions of the yoke. A thin sheet of a non-magnetic material is folded around the magnets and the spacers, covering the entire length of the rotor, including the barriers. An air tight membrane is placed on the outside of the sheet and sealed to the ends of the yoke so that the membrane and the yoke together form an air tight enclosure. A vacuum is applied to the air tight enclosure between the membrane and the yoke. Resin is infused into the air tight enclosure and set.

Abstract: The invention relates to an electric drive having a stationary outer and inner stator and a rotor, a plurality of permanent magnet elements being disposed on the rotor for producing an excitation flux and at least one electrical field coil being provided. The rotor comprises at least one bell-shaped part having a cylindrical wall and a base wall. Said base wall is mounted perpendicularly and the cylindrical wall coaxially in relation to the axis of the rotor shaft. The base wall is connected to the rotor shaft for transmitting a force or a torque. The permanent magnet elements rest on one side on the cylindrical wall and are secured side by side to the rotor of the drive in the peripheral direction. The permanent magnets, interact with the outer and inner stator, to give magnetic circuits which completely extend through the cylindrical part of the rotor in the radial direction, the permanent magnet elements being arranged only on the exterior of the cylindrical wall.

Abstract: The present invention relates to an electrical machine including a rotor shaft, a hollow-cylindrical magnet element, a first covering disk, and a second covering disk, in which the first and second covering disks are secured to the rotor shaft, and the magnet element is secured on its first axial end to the first covering disk and on its second axial end to the second covering disk.

Abstract: A rotor structure of a permanent magnet electrical machine and a method for manufacture of the rotor structure. The rotor structure has a shaft. An outer surface of the shaft is provided with a permanent magnet. A support collar encircles the permanent magnet. A protective piece is located between the outer surface of the shaft and an inner surface of the support collar and is arranged as an axial mechanical extension for the permanent magnet. The protective piece reduces local maximum values of forces forming between the support collar and the permanent magnet during rotation of the rotor.

Abstract: A motor rotor is provided wherein a resin with which a thread layer is impregnated is preventing from being broken even if the motor rotor is rotated at a high speed. A thread layer 9 is formed by winding a thread of a reinforced fiber material around a permanent magnet layer 5 with a gap formed between an outer peripheral surface 9a of the thread layer 9 and an inner peripheral surface 53a of a cylindrical body 53. The thread layer 9 is impregnated with a curable resin. A subsequent thread layer 13 is formed by leading a continuous thread, which is continuous with the thread forming the thread layer 9, into an annular passage 35 through thread passing recesses 33a, and winding the continuous thread around a bottom portion of the passage 35. The subsequent thread layer 13 is impregnated with a curable resin. A cylindrical member 17 is fixed to first and second annular members 21, 7 by shrink fitting.

Abstract: A permanent-magnet generator rotor comprising a first rotor shaft end portion having in the axial center a hollow portion through which a bolt is passed; a second shaft end portion having in the axial center a hollow portion and a bearing portion through which the bolt is passed. A magnetic cylindrical body is sandwiched between the first and second shaft end portions. The permanent-magnet generator rotor includes the magnetic cylindrical body fixed between the first and second shaft ends, a permanent magnet held on the outer circumferential surface of the magnetic cylindrical body; a non-magnetic cylindrical body shrink-fit onto the outer circumferential surface of the permanent magnet; a stator disposed around the permanent magnet; and the bolt penetrating through the first and second shaft ends; the hollow portions in the generator, and the magnetic cylindrical body.

Abstract: A motor rotor (22) includes a motor shaft (30), a permanent magnet (319) surrounding the motor shaft (30) around an axis, a pair of end rings (32, 32) surrounding the motor shaft (30) around the axis and sandwiching the permanent magnet (32) from both sides in an axial direction, and a hollow cylindrical outer sleeve (33) fitted to the permanent magnet (31) and a pair of end rings (32) in accordance with a stationary fit. A longitudinal elastic modulus of the end ring (32) is larger than a longitudinal elastic modulus of the permanent magnet (32). A thickness of the outer sleeve (33) is different in correspondence to a position in the axial direction in such a manner as to make uniform a circumferential stress applied to the outer sleeve (33) fitted to the permanent magnet (32) and a pair of end rings (32) in the axial direction.

Abstract: A rotor assembly for an electromechanical machine includes a rotor core, an outer sleeve and an inner sleeve. The rotor core includes an outer diameter, and the outer sleeve is positioned about the outer diameter. The inner sleeve is positioned between the rotor core and the outer sleeve. One of the outer sleeve and the inner sleeve dampens electromagnetic flux generated by the rotor assembly.

Abstract: A surface magnet type motor having a magnet at a surface of a rotor includes an anti-scattering tube formed in a cylindrical configuration longer in length than the magnet of the rotor in the axial direction, having the magnet press-fitted inside to prevent scattering of the magnet. A stress alleviation portion is provided to alleviate stress generated at an end of the magnet press-fitted into the anti-scattering tube.

Abstract: An electric motor (100) for operating a shutter or solar protection element in a building, comprising at least two phases (10; 20, 30; 50, 60) and a magnetized rotor (16; 40; 70) common to both phases, each phase being relative to a rotor portion (41, 42; 71; 72) in the direction of the axis of the rotor and comprising two windings (14, 15), wherein each phase comprises an insulating yoke frame (13) on which the two windings are produced and which has a central portion (131) separating the windings, the central portion being provided with a first through-recess (134) able to surround a rotor portion passing through the phase.

Abstract: A permanent magnet rotor for an electric motor may include a rotor assembly that will hold the magnets in place. A pair of rings is added to the sleeve to tightly engage and press against the end plates and the magnets. This configuration provides additional securement against axial and radially shifting of the magnets.

Abstract: To improve resistance of a motor device against an organic solvent and to suppress degradation in performance of the motor device with time. In a motor device, an excitation magnet is formed using a hollow-cylinder shaped anisotropic bonded magnet 13. This bonded magnet 13 is press-fitted in a housing 12 and is held. The bonded magnet 13 is formed of a hollow-cylinder shaped anisotropic rare earth bonded magnet which is obtained by compounding an anisotropic rare earth magnet powder with a phenol-novolac type epoxy resin, followed by molding. The anisotropic rare earth bonded magnet 13 is press-fitted along an inner peripheral portion of the housing 12, and on an exposed surface layer of the anisotropic rare earth bonded magnet press-fitted in the housing, a coating layer is formed by an infiltration treatment using a polyamide-imide-based resin.

Abstract: A magnetic drive arrangement includes a multitude of permanent magnets (13) which are arranged along the periphery of a housing wall (15), wherein the magnets (13) are held with a non-positive fit by the housing wall (15) and bear on this. The manufacturing effort is simplified by way of the above-identified arrangement. One may advantageously apply parallelepiped magnets (13) as well.

Abstract: A fault tolerant synchronous permanent magnet machine is disclosed that reduces rotor losses by limiting eddy-current losses in the retaining sleeve. The machine limits eddy-current loss by any one or combination of axially segmenting the retaining sleeve, providing a highly electrically conductive non-magnetic shield to the retaining sleeve, and by configuring stator teeth width, stator teeth tip width, and slot distribution of the stator.

Abstract: The rotor for an electric motor used with a dental handpiece has a shaft with a rotational axis and a magnet arranged around the rotational axis. A centering element may be rigidly connected to the shaft or constructed as part of the shaft. The centering element presses on the magnet from the outside to center it in relation to the rotational axis of the shaft. The centering element may be pressed or shrunk on to two balancing rings. The balancing rings can be pressed or shrunk on the shaft. This allows precise centering of the magnet with respect to the rotational axis of the shaft to be achieved. The pressure exerted by the centering element on the magnet counteracts centrifugal forces during rotor rotation. Particularly high speeds may be achieved without the surface of the magnet exceeding a critical tensile stress.

Abstract: A rotor includes a rotor core and disk-shaped end plates provided to sandwich the rotor core in the direction of a rotation shaft. The end plates are each formed to have one end face relatively closer to the rotor core and larger in outer diameter with the center at the rotation shaft than the other end face.

Abstract: The present invention provides a permanent magnet rotor arrangement that is particularly suitable for low-speed large-diameter electrical generators. The arrangement includes a rotor 2 having a radially outer rim 4. A circumferential array of magnet carriers 12 is affixed to the outer rim 4 of the rotor and have a radially outer surface. An inverted U-shaped pole piece retainer 18 made of non-magnetic material such as stainless steel is affixed to each magnet carrier 12 and is formed with an axially extending channel. At least one pole piece 16 made of a magnetic material such as steel is located adjacent to the radially outer surface of each magnet carrier 12 and in the channel formed in its associated pole piece retainer 18.

Abstract: A motor generally has a contradictory relation between decrease of cogging torque and increase of torque density. To overcome this problem, continuous direction control is provided for anisotropy with modification of magnetic poles so that the average absolute value of differences between M? and 90×sin [?{2?/(360/p)}] is set to be 3° or less, where M? is a direction of anisotropy with respect to a radial tangent line of a magnetic pole plane, ? is a mechanical angle, and p is the number of pole pairs.

Abstract: An electric machine system includes an electric machine and a companion device. The electric machine has a stationary member and a movable member that, by interaction of magnetic fields, at least one of moves relative to the stationary member or generates electricity when moved relative to the stationary member. One of the stationary member and the movable member includes a permanent magnet. The companion device is coupled to the electric machine to communicate mechanical movement with the movable member. In certain instances, the electric machine system has adaptations for operation of the electric machine system subsea and/or in a corrosive environment.

Abstract: A rotor of a rotating electrical machine is provided in which neither deterioration nor fluctuation in the cogging torque is caused and that causes neither physical enlargement nor cost increase. The rotor of a rotating electrical machine, provided with a plurality of magnetic poles 3 that are fixed on a rotor iron core 2 and arranged spaced apart from one another in the circumferential direction of the rotor iron core 2, is characterized by including a tube-shaped non-magnetic ring 4 mounted on the outer circumferential surfaces of the plurality of magnetic poles 3, and characterized in that the non-magnetic ring has a plurality of inner-diameter bulging portions 41 that abut on the corresponding outer circumferential surfaces of the plurality of magnetic poles.

Abstract: An electric motor cooling system is provided that includes a housing and first and second cooling sources that are different from one another respectively to provide first and second cooling flows. A stator is mounted in the housing and receives the first cooling flow. A rotor is rotatable relative to the stator and receives the second cooling flow. In the examples, the housing supports a journal bearing upon which the rotor is supported, and the second cooling flows through the journal bearing. The first cooling flow is provided by a low pressure source such as ram air, and the second cooling flow is provided by high pressure source such as bleed air, for example. A circumferential gap is provided between the rotor and stator. In one example, a seal is arranged between the housing and a stator for providing a cavity in fluid communication with the journal bearing and the gap. The cooling flow from the journal bearing passes through the cavity and into the gap for cooling the rotor.

Abstract: A permanent magnet unit is provided for an electrical machine. The electrical machine includes a stator and rotor. At least one permanent magnet is enclosed in a non-magnetic enclosure. The enclosure has means for connecting it to at least one other substantially similar enclosure containing a permanent magnet.

Abstract: A rotor assembly for an electric motor having at least one gas vent allowing for the release of gases from within an enclosed portion is provided. The rotor assembly comprises a rotor shaft with at least one magnet longitudinally extending a portion of an outer surface thereof in an axial direction and being retained therewith. A non-magnetic wedge spacer may be positioned between each of a plurality of magnets and a cylindrical sleeve may be positioned about the at least one magnet. An end cap or stub shaft is adhered or mechanically held to or within each end of the cylindrical sleeve adjacent the at least one magnet forming an enclosed portion of the rotor assembly. At least one vent hole, channel, or bevel provides a gas flow through passage in flow communication with the enclosed portion and an environment outside of the enclosed portion of the rotor assembly.

Abstract: A magneto rotor which has a cup-like rotor yoke, a plurality of magnets secured on an inner periphery of a peripheral wall portion of the rotor yoke, and a magnet protecting cover having a cylindrical portion that covers inner peripheries of the magnets, and an outer flange being integrated with one axial end of the cylindrical portion and covering end surfaces of the magnets, wherein an annular protrusion protruding toward the opening of the rotor yoke is formed on an area closer to an inner periphery of the outer flange of the magnet protecting cover, an annular adhesive storage portion is formed between the peripheral wall portion closer to the open end of the rotor yoke and the annular protrusion, a groove opening into the adhesive storage portion and continuing circumferentially of the rotor yoke is also formed in the peripheral wall portion closer to the open end of the rotor yoke, and the adhesive storage portion and the groove are filled with an adhesive to seal a boundary between the outer flange of

Abstract: A drive system for a compressor of a chiller system includes a variable speed drive. The variable speed drive receives an input AC power at a fixed input AC voltage and a fixed input frequency, and provides an output AC power at a variable voltage and variable frequency. The variable speed drive includes a converter connected to an AC power source. The converter is arranged to convert the input AC voltage to a DC voltage. A DC link is connected to the converter and configured to filter and store the DC voltage from the converter. An inverter is connected to the DC link. A motor is connectable to the compressor for powering the compressor. A controller is arranged to control switching in the converter and the inverter. The controller is arranged to apply randomized pulse width modulation to vary the switching frequency of transistors in the converter and the inverter at each switching cycle. The motor may be a permanent magnet synchronous motor.

Abstract: A hybrid motor for powering a compressor of a chiller system includes a first rotor portion and a first stator portion configured as a permanent magnet motor and a second rotor portion and a second stator portion configured as a reluctance motor. The second rotor portion includes a reluctance-type rotor, and the second stator portion includes electromagnetic windings capable of inducing a rotary magnetic field. The first rotor portion and the second rotor portion are attached to a common drive shaft. The reluctance motor is arranged to generate start-up torque and initiate rotation of the drive shaft until the drive shaft achieves a predetermined rotational speed. The permanent magnet motor is arranged to power the drive shaft between the predetermined rotational speed and a maximum rotational speed.

Abstract: A rotor having a substantially cylindrical configuration for use in a brushless direct current electric motor having a high torque to size ratio. The rotor has an outer peripheral surface. The rotor also has a central rotor shaft and a first and second retaining ends mounted on the central rotor shaft and spaced from one another. The rotor also has a plurality of magnets configured to provide a magnetic flux with a stator disposed around the central rotor shaft. The magnets are radially disposed on the shaft and the rotor also has a sheath. The sheath is crimped around the radially disposed permanent magnets, and holds the magnets around the shaft. The sheath is lightweight and minimizes a gap between the permanent magnets and the stator to provide for an electromagnetic flux between the magnets and the stator windings, and for rotation of the central rotor shaft.

Abstract: A drive system for a compressor of a chiller system includes a variable speed drive. The variable speed drive is arranged to receive an input AC voltage at a fixed AC input voltage and provide an output AC power at a variable voltage and variable frequency. The variable speed drive includes a converter connected to an AC power source providing the input AC voltage. The converter is arranged to convert the input AC voltage to a DC voltage. A DC link is connected to the converter. The DC link filters and stores the DC voltage from the converter. An inverter is connected to the DC link. A motor connectable to the compressor for powering the compressor. An active filter connected in parallel with the motor. The active filter is arranged to generate high frequency currents having a magnitude and opposite polarity, with respect to the output AC power of the variable speed drive. The high frequency currents generated by active filter substantially cancel out high frequency currents flowing into the motor.

Abstract: Holder anchoring grooves are arranged on the outer periphery of a rotor core so as to extend axially. A holder arm having a substantially T-shaped cross section is fitted to each of the holder anchoring grooves. The holder arm has a main body section, an engaging projection and magnet holding pieces. The engaging projection is engaged with the corresponding one of the holder anchoring grooves. Each of the magnet holding pieces includes a first contact section, a second contact section and a non-contact area. A magnet containing section is defined by the magnet holding pieces that are located vis-à-vis relative to each other of any two adjacently located holder arms and the outer peripheral surface of the rotor core. In the magnet containing sections, a rotor magnet is press fitted and anchored from the shaft direction. Thus, there is provided a magnet fixing structure that can accurately anchor magnets to a rotor core or the like at low cost.

Abstract: An electric machine system includes an electric machine and a companion device. The electric machine has a stationary member and a movable member that, by interaction of magnetic fields, at least one of moves relative to the stationary member or generates electricity when moved relative to the stationary member. One of the stationary member and the movable member includes a permanent magnet. The companion device is coupled to the electric machine to communicate mechanical movement with the movable member. In certain instances, the electric machine system has adaptations for operation of the electric machine system subsea and/or in a corrosive environment.

Abstract: A sleeve about an electric machine rotor core and the plurality of permanent magnets has a fiber-reinforced composite layer about the rotor core and the plurality of permanent magnets. At least a portion of the sleeve about the rotor core and the permanent magnets has a coefficient of thermal expansion that is substantially equal to the aggregate coefficient of thermal expansion of the rotor core and the plurality of permanent magnets.

Abstract: A rotor for an electrical machine includes an elongate rotor core assembly comprising a rotor core and a plurality of permanent magnets arranged in a plurality of rings around the rotor core. A composite sleeve resides around the rotor core assembly. The sleeve includes a primarily axially-oriented outer layer and an intermediate layer beneath the outer layer. The intermediate layer includes a circumferential band of composite material positioned orthogonal to a longitudinal axis of the rotor core assembly.

Abstract: A rotor for an electric machine may include a rotor hub, a plurality of permanent magnets disposed about the rotor hub, a first sleeve circumjacent the plurality of permanent magnets, and a second sleeve. The second sleeve may be formed from a metal tape wrapped over the first sleeve. The second sleeve may be bonded to first and second end rings disposed at adjacent ends of the rotor hub. The metal tape may be applied in tension and may wrapped to form butt laps over the first sleeve. The metal tape may be corrosion resistant. Further, the second sleeve formed from the metal tape may protect the rotor from erosion and abrasion from fluid passing over the rotor.

Abstract: A cup-shaped sleeve is made mainly of a resin and has an end where a plurality of pieces of a permanent magnet are insert-molded. An auxiliary ring made mainly of a resin is provided along an inner peripheral surface of the cup-shaped sleeve other than an inner peripheral surface thereof where the permanent magnet is provided. The auxiliary ring has its inner peripheral surface identical to the inner peripheral surface of the permanent magnet or located outside relative to the inner peripheral surface of the permanent magnet. When the cup-shaped sleeve is resin-molded, the resin which is a component of the cup-shaped sleeve is prevented from shrinking inward. Therefore, contact between the resin supporting the permanent magnet and the cylinder is prevented. Accordingly, a linear drive device is obtained in which the reciprocation of the piston is prevented from being hindered.

Abstract: A rotor for a brushless permanent magnet generator/motor comprises a retention slot extending into a rotor flange for receiving a root of a permanent magnet. The retention slot comprises a base extending axially into the rotor flange, a pair of side walls extending radially from the base, and a pair of lugs projecting from the side wall to engage the root to provide radial and tangential retention of the permanent magnet. In other embodiments, the permanent magnet is further restrained in the axial direction by a spring pre-loaded axial retention ring.

Abstract: A permanent magnet type generator includes a rotor having 4n (n is a positive integer) permanent magnet poles disposed in a circumferential direction of the rotor to have circumferential gap between adjoining poles and a stator that has 3n teeth and coils wound around the teeth. The stator core includes a pair of core end plates and a laminate core disposed between the core end plates. Each core end plate has a circumferential width that relates to the gap distance at portions opposite the permanent magnet poles.