Abstract: A method for obtaining, in a quick way, a strong, compact and waterproof permanent-magnet rotor (3), intended for a synchronous motor (1), particularly for pumps of washing machines for industrial and domestic use and the like, of the external stator (2) type, comprising a cylindrical hollow core (6) surrounded by a plurality of permanent magnets (10) comprising the steps of arranging a cup-like body (7) with a base end (8a), a free end (8b) and a side wall (9) exhibiting a plurality of passing longitudinal recesses (12) which define, between the same, a plurality of positioning seats (13) for the magnets (10), providing to insert the core (6) into the cup-like body (7) and arrange the magnets (10) in said seats (13) and injecting a plastic material with obtainment of a cage-like structure (50) having opposite bottoms (27, 28) abutting at the ends (8a, 8b) of the cup-like body (7) as well as columns (29) extended between the opposite bottoms (27, 28) housed in the recesses (12).

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: 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: An axial gap rotating electrical device includes a stator and a rotor. The stator has a stator core and a stator coil. The rotor is disposed in an axial direction with respect to the stator. The rotor includes a plurality of separate rotor components circumferentially arranged. Each of the rotor components includes a permanent magnet facing the stator core and a high-strength member enveloping an outer surface of the permanent magnet. The high-strength member is configured to prevent a centrifugal force on the permanent magnet from being transmitted between adjacent ones of the high-strength member during a rotation of the rotor.

Abstract: A motor rotor (22) of the invention is constituted by 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 uniformize 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 magnet encapsulated within a canister formed from two cans into a laminated structure particularly useful in plasma processing reactors. Each can includes an end wall and a cylindrical sidewall. One can additionally includes an annular lip that slidably fits outside the sidewall of the other can with a small gap therebetween. The magnet is inserted into the two cans together with a flowable and curable adhesive such as epoxy. The cans are slid together and compressed to cause the adhesive to flow between the magnet and the two cans and between the lip of one can and the sidewall of the other. The adhesive is cured to bond the magnet to the cans and to bond the cans together and to also hermetically seal the structure. The cans may be deep drawn from non-magnetic stainless steel with wall thicknesses of less than 0.064 mm.

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 rotor assembly includes several permanent magnets separated by spacers. The permanent magnets and the spacers are all fabricated from material having the same coefficient of thermal expansion. The spacers are in a non-magnetized state and provide support for a sleeve placed in a high interference fit with the permanent magnets. The sleeve is thereby fully supported about the inner circumference such that uneven bending stresses are significantly reduced to provide a desired operational life.

Abstract: The present invention relates to a rotor for an electric synchronous machine, which has at its outside at least one magnetic material area 10 surrounded by a wrapping 11, said magnetic material area 10 having an non-round outer contour.

Abstract: The invention is characterized in that in a motor rotor constituted by a motor shaft (30), a permanent magnet (31) surrounding the motor shaft (30) around an axis, a pair of end rings (32, 32) surrounding the motor shaft (30) around the axis and pinching the permanent magnet (31) from both sides in an axial direction, and a hollow cylindrical outer sleeve (33) surrounding the permanent magnet (31) and a pair of end rings (32, 32) in a fastening state around the axis, one end portion or both end portions of the outer sleeve (33) protrudes in the axial direction than an end surface of the end ring (32). A rotating balance correction is executed by pruning away a part of the protruding portion.

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: A permanent magnet rotor of a brushless direct current (BLDC) motor, in which cogging torque ripple and electromagnetic vibration noise transferred to the permanent magnet rotor can be blocked and a motor's power-to-weight ratio can be improved. A conventional BLDC motor has to use an electric steel sheet core so as to maintain the maximum magnetic flux density of the permanent magnet rotor and to minimize a rotating electric field loss. As a result, cogging torque vibration is unavoidably transferred to a load side through the motor rotary shaft. However, the rotor can enable stable driving of the BLDC motor by innovatively blocking the cogging torque vibration and the electromagnetic vibration noise and can greatly reduce the motor's weight by using a plastic or non-magnetic material instead of an electric steel sheet core.

Abstract: An electric motor for conveying media includes (a) a stator; (b) a rotor including a rotor magnet; and (c) a media throughput opening between the stator and the rotor. A smallest inner diameter of the stator is 1.5- to 8-times as large as a largest outer diameter of the rotor magnet.

Abstract: The segmented permanent-magnet rotor for high-speed synchronous machines reduces eddy-current losses by axially segmenting the containment sleeve and the permanent magnets. The axial segmentation of the containment sleeve includes forming grooves circumferentially around the outer surface of the containment sleeve. The circumferential grooves disrupt the generation of eddy currents on the outer surface of the containment sleeve and therefore reduce eddy-current losses in the containment sleeve. Axial segmentation of the permanent magnets also disrupts eddy current formation, thereby reducing eddy current losses in the permanent magnets. In addition, the presence of an electrically insulating layer between the containment sleeve and the permanent magnets reduces eddy current migration from the containment sleeve to the permanent magnets, and therefore provides additional reduction of eddy-current losses.

Abstract: Manufacturing costs of releasable permanent magnet rotors or asynchronous squirrel cages should be reduced. Accordingly, a rotor is proposed which includes at least one ring-shaped fastening device (23) secured in fixed rotative engagement to one of the end faces of a magnet device (21, 22) and for form-fitting or force-locking connection to a shaft (25). This makes it possible to eliminate the need for a special bearing sleeve, and the laminated armature core (21) can be provided with a larger axial hole diameter. As a result, the minimum joint pressure can be reduced so that deformations of the spindle and complicated refinishing processes can be avoided. In addition, less stringent manufacturing tolerances of the spindle (25) can be selected.

Abstract: A magneto generator can provide a flywheel with a high circularity while reducing man hours in processing the flywheel. A bowl-shaped flywheel has a cylindrical portion and a bottom. A plurality of permanent magnets are arranged on an inner peripheral wall surface of the cylindrical portion. A magnet cover is arranged along inner surfaces of the magnets, bent into a cylindrical shape, and has its opposite ends bonded to each other by a diametrally extending joint portion. A resin material is arranged on an inner side of the flywheel to integrate the magnets and the magnet cover with the flywheel. The flywheel is formed, at the bottom side of the cylindrical portion, with a pair of concave and convex portions arranged in opposition to each other. The joint portion is sandwiched between the concave and convex portions whereby the circumferential positioning of the magnets with respect to the flywheel is performed.

Abstract: The present invention provides a permanent-magnet-synchronous-motor having a stator with concentrated windings with the following structure so that permanent magnet (6) is hard to subjected to demagnetization magnetic field: 0.3 Lg<La?2.0 Lg, where La is a clearance between teeth of stator (1), and Lg is an air-gap between stator (1) and rotor (2). Outer walls of both ends of the permanent magnet (6) disposed within rotor (2) in a rim direction may be tapered toward inside from a rotor rim in a radial direction and to form a recessed section on the outer walls of the magnets. As a result, withstanding force against demagnetization is expected to increase.

Abstract: The object of the invention is a rotor for a permanent-magnet synchronous machine in which a pole structure is fitted onto the surface of the rotor body structure facing the air gap. Each of the rotor's pole structures comprises at least one permanent magnet and a shell structure fitted on top of it. According to the invention, an intermediate layer made of magnetic composite is fitted between the permanent magnet and the shell structure.

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: A rotor is disclosed for a galvanometer system. A rotor includes a permanent magnet core, a sleeve and at least one shaft unit. The sleeve encloses and attaches to at least a portion of the permanent magnet core. The sleeve is formed of a material having a density of less than about 0.283 lb/in3. The shaft unit is attached to both the permanent magnet core and to the sleeve. An output device may be coupled to the shaft unit, and the shaft unit is formed of a material having a dynamic stiffness of at least about 1.00×109 lb in7/slug.

Abstract: A rotor structure for an electric motor includes a cylindrical rotor core assembly and a plurality of permanent magnets disposed on an outer circumference of the rotor core assembly. Wrapped around the rotor core assembly is a bandage to secure the permanent magnets in place, wherein the bandage has a bandage edge arranged in proximity of an end surface of the rotor core assembly. In order to securely fix the bandage edge in place, a securing ring is disposed radially over the bandage edge of the bandage to hold the bandage against the rotor core assembly.

Abstract: A magneto generator can provide a flywheel with a high circularity while reducing man hours in processing the flywheel. A bowl-shaped flywheel has a cylindrical portion and a bottom. A plurality of permanent magnets are arranged on an inner peripheral wall surface of the cylindrical portion. A magnet cover is arranged along inner surfaces of the magnets, bent into a cylindrical shape, and has its opposite ends bonded to each other by a diametrally extending joint portion. A resin material is arranged on an inner side of the flywheel to integrate the magnets and the magnet cover with the flywheel. The flywheel is formed, at the bottom side of the cylindrical portion, with a pair of concave and convex portions arranged in opposition to each other. The joint portion is sandwiched between the concave and convex portions whereby the circumferential positioning of the magnets with respect to the flywheel is performed.

Abstract: A rotating machine including a stator iron core having a plurality of slots installed in the direction of a rotary shaft, a plurality of armature windings alternately inserted and wound round an outer layer of one of the slots and an inner layer of another slot, and a rotor having a plurality of magnetic poles for rotating inside the stator iron core and each of the armature windings is composed of a single covered conductor wound and has a leading line on the one-end side of the stator iron core.

Abstract: Provided is a high speed electric motor including a stator installed at an inner circumferential surface of a motor housing; and a rotor installed inside the rotor to form a rotational magnetic field by application of a current to the stator, and having a cooling passage through which fluid flows and a magnet installed at one side of the cooling passage.

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.

Abstract: A rotor for a permanent magnet motor of an outer rotor type having a plurality of permanent magnets and disposed around a stator includes a frame, an annular iron core combined integrally with the frame, and a plurality of insertion holes formed in the core so that the permanent magnets are inserted in the insertion holes respectively. The frame, the core and the permanent magnets are combined integrally with one another by a synthetic resin. Each insertion hole includes a magnet disposing portion in which the permanent magnet is disposed, a space portion located in at least one of circumferential both ends of each permanent magnet disposed in the magnet disposing portion, and a positioning portion positioning each permanent magnet in the magnet disposing portion, and the molten synthetic resin is poured into the space portion.

Abstract: The present invention provides a permanent-magnet-synchronous-motor having a stator with concentrated windings with the following structure so that permanent magnet (6) is hard to subjected to demagnetization magnetic field: 0.3 Lg<La?2.0 Lg, where La is a clearance between teeth of stator (1), and Lg is an air-gap between stator (1) and rotor (2). Outer walls of both ends of the permanent magnet (6) disposed within rotor (2) in a rim direction may be tapered toward inside from a rotor rim in a radial direction and to form a recessed section on the outer walls of the magnets. As a result, withstanding force against demagnetization is expected to increase.

Abstract: The invention relates to a method for manufacturing a permanent-magnet excited rotor for a high speed electric motor, according to which method a support sleeve (1) is mounted with a pre-tension around the rotor body (2), characterised in that the sleeve is expanded by a liquid that solidifies and is solid at the working temperatures of the rotor, said liquid is injected under pressure between the sleeve and the rotor body and held under pressure during solidification.

Abstract: An inner magnet assembly for a rotary magnetic coupling, the inner magnet assembly having an inner ring body with magnet guides, magnets and an overlying sleeve.

Abstract: A motor rotor. The motor rotor adapted to be used in a fan includes a hub, a metal plate and a magnet. The metal plate has a first end and a second end. The metal plate is disposed in the hub. The magnet is disposed in the metal plate. A method for manufacturing a motor rotor mentioned includes providing a metal plate having a first end and a second end; connecting the first and second ends to shape the metal plate as a ring; placing the metal plate in a hub; and placing a magnet in the metal plate.

Abstract: A rotor for an electrical machine includes a rotor carrier of metallic material with a back wall extending radially to the axis of rotation of the electrical machine and a tubular section extending in the axial direction, in which a laminated core is installed. The rotor carrier is designed as a single, flow-formed part with axially extending ribs which engage in grooves on the laminated core.

Abstract: An inner sleeve, having threads on each end, is formed on a motor or generator rotor. A pair of stub shafts are threadably attached to the inner sleeve at each end and a magnet is placed in between. The stub shafts are turned on the inner sleeve to bring them together, thereby creating an axial compressive force on the magnet. By keeping the magnet in a compressive state at all times, cracking of the magnet is prevented, thus keeping the rotor stable during use of the motor or generator. An outer sleeve is shrunk-fit around the magnet and stub shafts to provide a further radial force on the rotor. The magnet assembly of the present invention also enlarges the required radial shrink-fit tolerance of the outer sleeve on the magnet, thereby reducing costs conventionally required to match the outer sleeve to the magnet within close tolerances.

Abstract: A mechanical drive system operating by magnetic force, to be fitted on a pump, comprises a basic structure on which a drive shaft, which extends along a longitudinal axis, is supported rotatably. A driving element operatively connected to the drive shaft is provided with driving magnets arranged in a ring. A driven element provided with driven magnets arranged in a ring is also mounted on the basic structure. A bell is inserted between the driving element and the driven element and isolates the environment containing the driven element. The driving element and the driven element comprise respective cages each having seats for housing the respective driving magnets or driven magnets.

Abstract: A rotor body assembly includes a rotor and a containment shell surrounding the rotor, the containment shell having an external peripheral surface provided with a plurality of surface deformations.

Abstract: In a rotor for a rotary electric machine, a predetermined number of main pole magnets and a predetermined number of yoke magnets are fixed in contact with a hub. Each main pole magnet is magnetized so that its radial inside portion and its radial outside portion have the opposite polarity from each other, of north pole and south pole. Also, each main pole magnet has its radial inside and radial outside polarities reversed from its closest main pole magnets. The yoke magnets are disposed to allow magnetic flux to flow through circumferential surfaces of the main pole magnets. The hub is provided as a heat radiating member and made of metal having high heat conductivity. The hub includes an inner cylindrical portion and an outer cylindrical portion, and forms an air passage spaces.

Abstract: A rotary electric machine is disclosed having stator windings and a rotor incorporating permanent magnets distributed about the axis of the rotor to create a magnetic field having circumferentially alternating north and south poles. In the invention, the principal structural member is an external sleeve, this providing resistance to bending and to centrifugally induced stresses due to rotation. The direction of polarization of the permanent magnets 214 is such that the parts of the magnetic circuits that lie within the outer circumference of the rotor pass predominantly through the bodies of the permanent magnets 214, thereby avoiding the need for a central ferromagnetic core to complete the magnetic circuit of the magnets.

Abstract: A permanent magnet element intended especially for electrotechnical devices and an electric machine, the element (1) comprising at least one permanent magnet piece (10). The permanent magnet element (1) also comprises a protective cover (11) that is arranged to partly surround the permanent magnet pieces (10) arranged in the element, and the permanent magnet element (1) also comprises one or more fastening elements (13; 21).

Abstract: An electric machine (2) comprising a rotor (4) and a stator (6) arranged coaxially therewith, at least one of said rotor (4) and stator (6) being formed of a plurality of parts and there being provided a bandage (16) holding together the plurality of parts of said rotor and/or stator (6), wherein the bandage (16) is formed of an electrically non-conducting fiber material having a coefficient of thermal expansion similar to the coefficient of thermal expansion of the parts of said rotor (4) and/or stator (6).

Abstract: An electric motor is provided with rotor and stator. The stator includes stator poles radially facing the rotor and surrounded by stator windings. An insulating sleeve is positioned between the rotor and stator. The sleeve includes projections arranged radially with respect to the rotor. The projections project in a direction away from the sleeve and rotor and towards the stator. The projections project between adjacent stator poles and may further serve to anchor the poles. The projections may have a T or elongated T shape. The projections and sleeve are rigid and either or both may be made of plastic. The sleeve provides a moisture or liquid tight insulation for the stator so that the motor can be used in moist or liquid environments.

Abstract: A high-speed rotor, in particular a permanent-magnet rotor (1) for dynamoelectric machines of high power density, and also its production are proposed. The permanent-magnet rotor (1) comprises a spindle (2) and armouring (4) coaxial with the spindle (2), a number of ceramic permanent magnets (3a-3d) that are distributed between the spindle (2) and the cylindrical sheath (4), and also a gap-filling filling compound. Said filling compound made of filled polymers seals the gaps in the permanent-magnet rotor (1) by injection moulding. Due to the remanent pretension, the permanent magnets (3a-3d) remain permanently rigidly joined even against high centrifugal forces.

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 method is disclosed for fitting a rotor enclosure over at least one assembly of field windings mounted on a rotor core, said method comprising the steps: applying a force to elastically reduce a circumference of the at least one assembly of field windings mounted on the rotor core, where the reduction in circumference is greater than a circumference reduction due to just eliminating clearances between adjacent end-turns of windings; generating a clearance between the field windings and the rotor enclosure due to the application of the force; axially sliding the rotor enclosure over the at least one assembly of field windings while the circumference is reduced, and releasing the force to allow the circumference of the at least one assembly of field windings to expand and cause the enclosure to tightly fit on the at least one assembly of field windings.

Abstract: A permanent magnet motor has rotor structure that includes magnetically permeable backing material attached to magnets for enhancing flux density distribution. A plurality of permanent magnets are circumferentially distributed about an axis of rotation, adjacent magnets successively alternating in magnetic polarity. The magnetically permeable material is configured with apertures therethrough at areas of low flux density, such as at central portions of the magnets, while in contact with perimeter areas of the magnets. Additional apertures in the material may be located at spaced intersections at which no significant flux density exists. The apertures may be replaced with backing material portions of reduced radial thickness.

Abstract: In a permanent magnet rotor, a power transmitting shaft is connected to an axial end of a solid cylindrical permanent magnet, and a reinforcement sleeve is fitted on the outer circumferential surface of the permanent magnet. Thus, the shaft is not required to be passed through the permanent magnet as was the case with the conventional permanent magnet rotor for the purpose of transmitting the rotational torque and increasing the overall rigidity, and the increase in the axial dimension of the rotor due to the reduction in the cross sectional area of the permanent magnet can be avoided. Also, because the sleeve surrounds the permanent magnet, the resistance to centrifugal stress resulting from a high speed rotation and repeated bending stress owing to vibrations can be improved.

Abstract: A magnetic coupling having two opposed annular arrays of angularly spaced permanent magnets magnetized to create magnetic north poles and magnetic south poles alternately spaced about each array. The north-pole and south-pole magnets of each array are tapered in cross-section from their surfaces at the gap to an annular surface of the array spaced from the gap, and permanent magnet spacer magnets completely fill in the space between the north-pole and south-pole magnets from the annular surface of the array at the gap to the spaced annular surface with the spacer magnets being magnetized generally transversely to the direction of magnetization of the adjacent north-pole, south-pole magnets so that the magnetic field created by the permanent magnets extends across the gap and annularly through each array to cause one of the arrays to rotate in synchronism with the other array.

Abstract: A rotor body assembly includes a rotor and a containment shell surrounding the rotor, the containment shell having an external peripheral surface provided with a plurality of surface deformations.

Abstract: The rotor has a core with an internal space. Permanent magnets are arranged on the core. These permanent magnets are surrounded by an outer cylinder, which is connected flush to closure disks which bear stub shafts. Channels run out from the internal space in the radial direction to the region of the permanent magnets. A resin mass is first introduced in the internal space. The rotor is thereafter heated and run up to centrifuging rotational speed. As a result, the molten resin mass flows through the channels to the region of the permanent magnets and fills up all the cavities present there and also cracks which form in the brittle permanent magnets on running up to speed. The resin mass hardens while the rotor is kept at centrifuging rotational speed. Each surface region of the permanent magnets is thus reliably protected against corrosion.

Abstract: A rotary electric machine is disclosed having stator windings and a rotor incorporating permanent magnets distributed about the axis of the rotor to create a magnetic field having circumferentially alternating north and south poles. In the invention, the principal structural member is an external sleeve, this providing resistance to bending and to centrifugally induced stresses due to rotation. The direction of polarization of the permanent magnets 214 is such that the parts of the magnetic circuits that lie within the outer circumference of the rotor pass predominantly through the bodies of the permanent magnets 214, thereby avoiding the need for a central ferromagnetic core to complete the magnetic circuit of the magnets.

Abstract: A hybrid synchronous machine includes a cylindrical element having slots; excitation windings situated in at least some of the slots; and permanent magnets situated in at least some of the slots. For a hybrid salient pole machine 16 a cylindrical element has salient poles with excitation windings situated around the salient poles and permanent magnets supported by the salient poles.

Abstract: A rotary electrical machine (1) has at least one stator (23). The stator is provided with at least one radial channel (107) for ducting cooling air. The channel (107) extends between a first position (113) at or substantially near the rim (109) of a winding region of the stator (23) and a second position (119) at or substantially near the center (51) of the winding region. The machine (1) has cooling means (91-97) for causing cooling air to enter the radial channel (107) via the second position (119) and exit via the first position (113). The stator may have electrical windings arranged as coil sectors (183-197) disposed substantially equi-angularly in a generally circular pattern. At least some of the coil sectors are wound in a generally spiral fashion when viewed axially. A rotor (13), for the machine may have a plurality of equi-angularly spaced magnets (127), which are generally circular but with a cut-away portion, when viewed axially.