Abstract: Provided are a rotor, a motor, and a wiper motor. An arc center of an outer circumferential surface of a rotor core and an arc center of an inner circumferential surface of a permanent magnet are off-centered radially outward from a rotational axis, with the circumferential center disposed on the radially outermost side. An angle formed by salient pole side surfaces facing each other of circumferentially adjacent two salient poles is equal to an angle formed by magnet side surfaces on both sides circumferentially of the permanent magnet. When the distance between the outer circumferential surface of the rotor core and the radially outermost end of the salient poles is Lt, and the distance between the inner circumferential surface of the permanent magnet and the radially outermost end of the magnet side surfaces is Lme, the distances Lt, Lme are set such that the relationship Lme<Lt is satisfied.

Abstract: A rotor includes a rotor core including laminated thin plate cores. A single thin plate core includes an inner plate portion defining a portion of an inner core portion and outer plate portions defining a portion of an outer core portion. At least some of the laminated thin plate cores include a connecting portion. A number of connecting portion is one or a plurality, and, when the number of connecting portions is a plurality, the connecting portions at positions other than both left and right sides of each other in a circumferential direction, and, in plan view, the thin plate core includes the connecting portion at a position different from that of a connecting portion in another thin plate core adjacent in an axial direction.

Abstract: Provided is a method for implementing skewing in a hybrid homopolar generator comprising. The method includes aligning inductor poles within an axial front segment of a rotor, with corresponding magnets within an axial back segment of the rotor. The method also includes moving, during assembly, the axial front segment and the axial back segment relative to each other such that inductor poles in the axial front segment and the axial back segment form a pattern.

Abstract: A rotor of a rotating electrical machine includes: a magnet; and a rotor yoke including at least a first core block and a second core block formed by stacking steel plates, each of the steel plates includes an opening portion serving as a coolant flow path, the opening portion positioned on an outermost diameter side includes an outer-diameter-side inner wall portion with a predetermined width in a circumferential direction and located on an imaginary circle centered on an axis of the rotor, the second core block is arranged adjacent to the first core block while the second core block is rotated by a predetermined angle with respect to the first core block, and the predetermined width is a length at which the outer-diameter-side inner wall portions of the opening portions of the first core block and the second core block overlap each other when seen from the axial direction.

Abstract: A rotating electric machine is equipped with a consequent-pole type rotor that includes a magnetic pole having a permanent magnet buried therein and a soft magnetic material pole that interposes two magnetic poles. The thickness of the permanent magnet and a circumferential width of the soft magnetic material pole have a relationship that prevents a spread of magnetic flux distribution in the circumferential direction within a gap between the soft magnetic material pole and a stator. As a result, a magnetic flux density difference in the circumferential direction is prevented, which enables a reduction of cogging torque based on an effective reduction of low-frequency space order components that originate from components other than a main component.

Abstract: A motor includes a stator, a rotor including an outer rotor core that includes a plurality of magnets arranged along a circumferential direction of the rotor, an inner rotor core that is located radially inward of the outer rotor core and that defines a shaft hole configured to receive a shaft, and an inner connecting portion that connects the outer rotor core to the inner rotor core and that is located at a central axis of a magnet from among the plurality of magnets. The inner connecting portion includes a radial rib that extends from the inner rotor core radially outward toward the outer rotor core, and an extension rib that extends from an outer end of the radial rib in the circumferential direction and that defines an angle with respect to the radial rib that is greater than or equal to 90 degrees.

Abstract: Advantageous machines, such as flux-switching machines (FSMs) are provided. An FSM can be yokeless and can have two rotors, which can be displaced from one another (e.g., by half a pole pitch). An FSM can be a flux-switching permanent magnet machine (FSPMM), and all magnets can be magnetized in the same circumferential direction. FSMs of the subject invention are cost-effective, have high torque density, and can operate well even under fault conditions.

Abstract: A single phase permanent magnet motor includes a stator core and a permanent magnet rotor rotatably disposed in the stator core. The stator core includes an end portion and a pole arm extending from the end portion. The pole arm includes two connecting arms connected to the end portion and two pole claws formed at distal ends of the connecting arms. The permanent magnet rotor is disposed between the two pole claws. The rotor comprises a rotor core and a plurality of permanent magnets embedded in the rotor core, and the rotor core is made of a magnetic material.

Abstract: Apparatus and methods of operating an electric motor are provided, comprising energizing a plurality of stator coils in sequence to rotate a rotor. Each said coil is energized with a repeating pulse sequence comprising at least a first portion and a second portion, the first and second portions repeating alternately to form the repeating pulse sequence. The first portion comprises a first pattern of pulses, each pulse in the first pattern having either a first polarity or second polarity, and at least two consecutive pulses in the first pattern having the same polarity. The second portion comprises a second pattern of pulses, the second pattern of pulses having the same pattern as said first pattern of pulses, but having inverted polarity with respect to said first pattern of pulses.

Abstract: A brushless motor includes a first rotor core, a second rotor core, and a field magnet member. The first rotor core includes primary projecting pieces arranged along a circumferential direction at equal intervals. The second rotor core has the same shape as the first rotor core, and includes secondary projecting pieces arranged along the circumferential direction at equal intervals. The secondary projecting pieces are positioned between the primary projecting pieces that are adjacent to one another in the circumferential direction. The field magnet member is arranged between the first rotor core and the second rotor core. The field magnet member is magnetized along an axial direction to generate primary magnetic poles in the primary projecting pieces, and generate secondary magnetic poles in the secondary projecting pieces. A rotor includes the first rotor core, the second rotor core, and the field magnet member.

Abstract: A variable magnetic flux-type rotary electric machine includes a stator and a rotor. The stator includes a stator coil wound on teeth. The rotor defines an air gap between the rotor and the stator. The rotor has at least one permanent magnet arranged in the d-axis magnetic path. The stator and the rotor are arranged relative to the permanent magnet to set a characteristic of d(Kt(I))/dI?0 in a range of at or below magnetic saturation of a core material of at least one of the stator and the rotor, where KT represents a torque constant, and I represents an applied current, and a function of KT with respect to I is represented by KT=Kt(I) for a torque Tr acting on the rotor that is represented by Tr=KT×I.

Abstract: A motor includes a rotor and a stator. The rotor includes a plurality of magnets, which function as first magnetic poles, and salient poles, which function as second magnetic poles. A ratio X1:X2 of a quantity X1 of magnetic pole portions of the rotor, which is the sum of the quantity of the magnets and the quantity of the salient poles, and the quantity X2 of slots is 2n:3n (n being a natural number). The sum of a magnetic pole occupying angle ?1 of the magnet and a magnetic pole occupying angle ?2 of the salient pole is 360°. The magnetic pole occupying angle ?1 is set in a range of 180°<?1?230°.

Abstract: A motor driving apparatus for a washing machine, in which a motor is a washing machine motor with a double stator and a double rotor respectively having first and second U-phase, V-phase, and W-phase stator coils, includes: a motor controller for generating a drive signal in accordance with a washing mode, a rinsing mode and a dewatering mode; an inverter for generating a three-phase alternating-current (AC) power, in which any one-phase AC power of the three-phase AC power is applied in common to any one-phase stator coil of the first and second U-phase, V-phase, and W-phase stator coils for the washing machine motor; and a switching unit for switching to apply the remaining two-phase AC power of the three-phase AC power to any two-phase stator coils of the remaining two-phase stator coils of the first and second U-phase, V-phase, and W-phase stator coils for the washing machine motor.

Abstract: A rotating electric machine includes a rotor including: a rotor core divided into blocks in an axial direction, the blocks being arranged to have a phase angle therebetween in a circumferential direction, the rotor core having magnet through holes arrayed in the circumferential direction and formed in an outer circumferential region; and permanent magnets inserted into the magnet through holes. The magnet through hole includes: a magnet insertion portion into which the permanent magnet is inserted; and a non-magnetic portion provided on an outer side of the magnet insertion portion in the circumferential direction. A bridge portion is formed between the outer circumferential surface and an outer circumferential inner wall of the non-magnetic portion. A bridge angle, which is an angle between both circumferential ends of the bridge portion with a rotation center of the rotor core set as a vertex, is larger than a skew angle.

Abstract: A rotating electrical machine includes a stator core, a rotor core, and permanent magnets. The stator core includes a yoke and tooth portions projecting from the yoke in a radial inward direction. Each tooth portion has a base joined to the yoke and an end opposite to the base. The rotor core includes a boss portion and projections. The projections project from the boss portion in a radial outward direction and spaced in a circumferential direction. Each permanent magnet is located between and spaced from adjacent projections to forma gap in the circumferential direction. A width of the gap is not greater than a width of the end of the tooth portion in the circumferential direction.

Abstract: A rotor for an electric machine includes a base body and a plurality of support bodies that are fixed on the base body and support permanent magnets. The rotor is characterized in that two first support bodies that are located at a distance from one another form a receiving region for a second support body, allowing the first support body to be positively connected to the second support body.

Abstract: In an arrangement in accordance with the invention for attaching a permanent magnet to an electrical machine's rotor, the rotor comprises at least two magnetic poles, and there is a pole gap between two magnetic poles. Permanent magnets are installable on the surface of the magnetic core. A pole piece is installable on the permanent magnet side facing the air gap. There is fixing means on the sides of the pole piece facing the pole gap for attaching the pole piece to the rotor using the locking parts, and the fixing means are connected to the pole piece through an articulated joint.

Abstract: In one embodiment, a permanent magnet rotor is provided. The rotor includes at least one permanent magnet and a substantially cylindrical rotor core including a plurality of stacked laminations, a hub having an inner edge defining a central opening, and a shaft inserted through the central opening, the shaft magnetically isolated from the hub. The rotor includes at least one connected pole piece coupled to the hub and at least one independent pole piece separated from the hub. The at least one permanent magnet is disposed between the at least one connected pole piece and the at least one independent pole piece.

Abstract: In one embodiment, a permanent magnet rotor is provided. The permanent magnet rotor includes a substantially cylindrical rotor core including an outer edge, an inner edge, and opposed first and second ends. The rotor further includes a first wall and a second wall defining at least one radial aperture extending radially through the rotor core. The rotor further includes at least one permanent magnet positioned within the at least one radial aperture. A first indentation is formed in one of the at least one permanent magnet and the first wall, the first indentation defining a first space between the at least one permanent magnet and the radial aperture first wall. The rotor further includes a first material positioned within the first space, the material configured to substantially prevent movement of the permanent magnet relative to the at least one radial aperture.

Abstract: In one embodiment, an electric machine is provided. The electric machine includes a machine housing and a stator disposed at least partially within the housing, the stator comprising a plurality of teeth and an aluminum winding wound around at least one tooth of the plurality of teeth. The electric machine further includes a radially embedded permanent magnet rotor disposed at least partially within the housing, the rotor comprising at least one radially embedded permanent magnet and configured to provide increased flux to reduce motor efficiency loss compared to a copper winding.

Abstract: A stator and a rotor are oppositely arranged having a gap between the stator and the rotor in a direction parallel to a rotary shaft. The rotor has permanent magnets forming field magnetic poles and soft magnetic material segments to cover at least stator-facing surfaces of the respective permanent magnets. Each of the soft magnetic materials forms a composite part together with the permanent magnet. The rotor further has a disc-shaped nonmagnetic molded frame molded so as to cover the periphery of the composite part including the permanent magnet and the soft magnetic material segment while leaving a stator-facing surface of the soft magnetic material segment as an exposed surface. The composite part (including the permanent magnet and the soft magnetic material) and the nonmagnetic molded frame are integrated by molding of the molded material.

Abstract: A rotating electrical machine includes a stator core, a rotor core, and permanent magnets. The stator core includes a yoke and tooth portions projecting from the yoke in a radial inward direction. Each tooth portion has a base joined to the yoke and an end opposite to the base. The rotor core includes a boss portion and projections. The projections project from the boss portion in a radial outward direction and spaced in a circumferential direction. Each permanent magnet is located between and spaced from adjacent projections to forma gap in the circumferential direction. A width of the gap is not greater than a width of the end of the tooth portion in the circumferential direction.

Abstract: A brushless motor includes a stator and a rotor. The stator includes an m number of slots spaced apart from one another by a slot angular interval k in a circumferential direction. The rotor includes n magnetic poles. The stator core includes a plurality of core sheets stacked with circumferential positions shifted from one another by a first angle. The first angle is a product of one of a plurality of values of j and the slot angular interval k. The plurality of values of j are values that satisfy (i×n)<(least common multiple of n and m) but do not satisfy (i×n×j×(360/m))=(360×N), where i, j, and N are natural numbers.

Abstract: A brushless motor includes a first rotor core, a second rotor core, and a field magnet member. The first rotor core includes primary projecting pieces arranged along a circumferential direction at equal intervals. The second rotor core has the same shape as the first rotor core, and includes secondary projecting pieces arranged along the circumferential direction at equal intervals. The secondary projecting pieces are positioned between the primary projecting pieces that are adjacent to one another in the circumferential direction. The field magnet member is arranged between the first rotor core and the second rotor core. The field magnet member is magnetized along an axial direction to generate primary magnetic poles in the primary projecting pieces, and generate secondary magnetic poles in the secondary projecting pieces. A rotor includes the first rotor core, the second rotor core, and the field magnet member.

Abstract: Provided is a rotary electric machine, including: a stator; and a rotor provided on the stator so as to be rotatable about a rotation shaft, in which the rotor includes, at an outer circumference thereof, magnetic poles arranged so as to have different polarities alternately, the magnetic poles being formed of a rotor core in which electromagnetic steel plates are stacked, the magnetic poles being excited by permanent magnets which are housed in gaps disposed at an outer circumferential part of the rotor core, and in which the rotor core includes, at an inner circumferential part thereof, in the same stack plane: a short circuit magnetic path connecting magnetic pole pieces which form the magnetic poles; and a protruding portion held in contact with the permanent magnets, which is positioned between magnetic pole pieces which are not connected to the short circuit magnetic path.

Abstract: A permanent magnet motor has a stator and a rotor surrounded by the stator. The stator includes a stator core having twelve teeth and coils wound around the teeth. The rotor includes a shaft and a magnet core group secured to the shaft. The magnet core group includes eight rotor core segments and eight ferrite permanent magnets. Each magnet is sandwiched between adjacent rotor core segments and is polarized in the circumferential direction of the rotor. The magnets are alternately magnetized such that adjacent rotor core segments have opposite polarities.

Abstract: The present invention relates to a rotor for a rotary electric machine, comprising: a hub comprising a stack of sheets, permanent magnets arranged on the surface of the stack of sheets, pole shoes covering the magnets and an attachment means for holding the pole shoes on the hub.

Abstract: Various embodiments relate generally to electrodynamic machines and the like, and more particularly, to rotor assemblies and rotor-stator structures for electrodynamic machines, including, but not limited to, outer rotor assemblies and/or inner rotor assemblies with a corresponding stator assembly. In some embodiments a rotor assembly can include magnetically permeable structures having confronting surfaces oriented at an angle to the axis of rotation. A group of magnetic structures can be interleaved with the magnetically permeable structures. The magnetically permeable structures can also include non-confronting surfaces adjacent to which boost magnets are disposed to enhance flux in a flux path passing through magnetic structures that are interleaved with magnetically permeable structures. Further, the rotor assemblies can include a flux conductor shield disposed adjacent to the boost magnets, the flux conductor shield configured to provide return flux paths.

Abstract: An electric motor has a wound stator and a permanent magnet rotor. The rotor includes a shaft, a hub fixed on the shaft, a plurality of rotor core segments and magnets fixed around the hub. The rotor core segment includes at least two rotor blocks inwardly extending from the innermost portion thereof. The hub includes a plurality of hub blocks equidistantly and outwardly extending from the outer surface thereof. The rotor blocks of each rotor core segment engage with at least one hub block to fix the rotor core segment to the hub. The number of rotor blocks is greater than the number of hub blocks.

Abstract: A motor including a stator assembly and a rotor assembly. The stator assembly includes a stator core and a winding; the stator core includes a yoke and a plurality of teeth protruding inwards from the yoke; between two adjacent teeth formed is a winding slot; the winding is arranged in the winding slot, and winded on the teeth. The rotor assembly includes a rotor core and a permanent magnet. The rotor core includes an annular ring having a central axial bore and a plurality of magnetic induction blocks protruding outwards from an outer side of the annular ring. Between two adjacent magnetic induction blocks formed is a radial recess for mounting the permanent magnet. The magnetic induction blocks at both sides of an opening of the radial recess protrude with a hook block. The thickness of the rotor core is larger than that of the stator core.

Abstract: A rotor core has installation portions in which first magnets, which are permanent magnets, are arranged. The installation portions are larger than the first magnets. The first magnets are divided into a first group and a second group. The first magnets in the first group are fixed to the installation portions to be offset in the positive rotational direction of the rotor toward the pseudo magnetic poles or the different magnetic poles. The permanent magnets in the second group are fixed to the installation portions to be offset in the inverse rotational direction of the rotor toward the pseudo magnetic poles or the different magnetic poles.

Abstract: A rotor for a modulated pole machine, the rotor being configured to generate a rotor magnetic field for interaction with a stator magnetic field of a stator of the modulated pole machine, wherein said rotor includes: a tubular support structure defining a circumferential mounting surface, the tubular support structure including a plurality of elongated recesses in the mounting surface, and a plurality of permanent magnets arranged at the mounting surface of the tubular support structure and magnetised in the circumferential direction of said rotor so as to generate the rotor magnetic field, the permanent magnets being separated from each other in the circumferential direction of the rotor by axially extending rotor pole sections for directing the rotor magnetic field generated by said permanent magnets in a radial direction, wherein at least one permanent magnet or one rotor pole section extends at least partly into one of the recesses.

Abstract: An electric machine (1), particularly used as an electric motor, has a rotor (2) comprising a plurality of disks (4). A disk (4) of the rotor (2) is divided in a circumferential direction (5) into a plurality of disk sectors (6, 7, 8) between which magnetic pockets (9, 10) are designed. Furthermore, the disk (4) has an inner fastening collar (15) and connecting members (20, 23, 24) connecting the disk sectors (6, 7, 8) to the fastening collar (15). Such a connecting member (20) comprises a main web (21), a side arm (30) branching off the main rib (21) in the circumferential direction (5), and a side arm (31) branching off the main web (21) opposite to the circumferential direction (5). High mechanical stability of the disk (4) can thus be ensured, wherein magnetic flow losses are reduced.

Abstract: In an arrangement in accordance with the invention for attaching a permanent magnet to an electrical machine's rotor, the rotor comprises at least two magnetic poles, and there is a pole gap between two magnetic poles. Permanent magnets are installable on the surface of the magnetic core. A pole piece is installable on the permanent magnet side facing the air gap. There is fixing means on the sides of the pole piece facing the pole gap for attaching the pole piece to the rotor using the locking parts, and the fixing means are connected to the pole piece through an articulated joint.

Abstract: A motor including a stator and a rotor. The stator includes teeth and windings. Each tooth has a distal portion defined by a radially inward side of the stator. The rotor, which is arranged inward in the radial direction from the stator, includes a rotor core, magnets, and salient poles. Each salient pole is separated by a void from the magnet that is adjacent in the circumferential direction. The distal portion of each tooth is longer than a radially outward side of each magnet.

Abstract: A permanent magnet rotor arrangement that is particularly suitable for low-speed large-diameter electrical generators includes a rotor 2 having a radially outer rim 4. A circumferential array of magnet carriers 12 is non-releasably 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 magnet pole portion 31 is made up of an integral magnet 44 into which are integrated a main permanent magnet piece 41 which is magnetized in the direction of a rotational axis, a pair of auxiliary permanent magnet pieces 42, 42 which are disposed at circumferential sides on one side of the main permanent magnet piece 41 with respect to the direction of the rotational axis, which are each magnetized in the direction of the rotational axis and a direction which is at right angles to a radial direction and on which magnetic poles face each other which are the same as a magnetic pole on the one side of the main permanent magnet piece 41 with respect to the direction of the rotational axis, and a pair of auxiliary magnet pieces 43, 43 which are disposed at circumferential sides on the other side of the main permanent magnet piece 41 with respect to the direction of the rotational axis, which are each magnetized in the direction of the rotational axis and a direction which is at right angles to a radial direction

Abstract: A motor including a stator, a rotor, and a current supply unit. The stator includes a stator core, which has a plurality of teeth, and a plurality of coils, which are wound around the teeth. The rotor includes a plurality of magnets, which function as first magnetic poles, and salient poles, which function as second magnetic poles. Each of the salient poles is arranged between adjacent magnets spaced apart by a clearance from the magnets. When P represents the number of poles in the rotor and S represents the number of coils, a ratio P/S of the pole number P and the coil number S is represented by (4n?2)/3m (where n and m are integers that are greater than or equal to 2). The plurality of coils includes a plurality of coil groups including coils for three phases. The current supply unit executes a different current control for each coil groups.

Abstract: A stepping motor has a stator and a rotor disposed to surround the stator. The rotor has an annular magnet which has a plurality of magnetic poles formed along a circumference thereof, and a comb-teeth-shaped back yoke which is disposed to surround the magnet and has a plurality of comb teeth, the comb teeth facing boundary positions of adjacent magnetic poles.

Abstract: A rotor for an electrical machine that comprises two parallel magnet wheels, each of which comprises axial teeth so that each tooth on a wheel is situated in the space existing between two consecutive teeth on the other wheel, and that comprises magnetic elements, each arranged between two adjacent teeth and partly received in a groove produced in each of the opposite lateral faces of the two adjacent teeth In one embodiment, each of the two adjacent teeth comprises one groove at a maximum, which emerges at the base of the first tooth.

Abstract: An electric rotating machine includes a stator having a stator core provided with a teeth unit and a coil wound around each tooth in the teeth unit in a concentrated fashion and a rotor rotatably supported with air gap against the teeth unit of the stator, the rotor having a rotor core and a plurality of permanent magnets held by the rotor core, wherein the permanent magnet is a rare earth magnet made of rare earth magnetic particles bound with SiO2. Also disclosed is an automobile that includes the electric rotating machine in which the permanent magnet in the rotor is a rare earth magnet made of rare earth magnetic particles bound with SiO2, and the stator in the electric rotating machine has a stator core provided with a teeth unit and a coil wound around each tooth in the teeth unit in a concentrated fashion.

Abstract: First and second magnet holding apertures are disposed through first and second permanent magnet holding seats that are disposed so as to protrude from first and second yoke portions so as to have aperture centers that are oriented in an axial direction. Cylindrical resin first and second magnet loading portions are disposed so as to project integrally on first and second fans such that central axes thereof are oriented in the axial direction, and first and second permanent magnets are insert-molded into the first and second magnet loading portions. The first and second fans are fixed to first and second pole cores by fitting the first and second magnet loading portions together with the first and second magnet holding apertures.

Abstract: A multi pole electrical machine includes an armature and a stator. The armature is movable in a direction of armature motion with regard to said stator and includes armature pole pairs. These armature pole pairs follow each other in the direction of armature motion. Each armature pole pair corresponds to one magnetic period. The stator includes a differing fixed number of stator poles per armature pole pair to reduce a cogging force of the electrical machine. An arrangement of the stator poles, with regard to both electrical and magnetic aspects, includes at least two identical sub-arrangements of stator poles. These sub-arrangements of stator poles follow each other in the direction of armature motion. Each of the sub-arrangements of stator poles is associated with one or more armature pole pairs and includes more than three of stator poles.

Abstract: A brushless DC motor has a stator and a rotor. An angle ?0 between an edge section of the flux barrier on a magnetic pole center side and an edge section on a side for coming in contact with the rib of adjacent flux barrier, with respect to the rotor center, is determined to be equal to or greater than an angle satisfying a following relationship ?0=180°*m/(Pn*f/f0) (provided 2?0??r<90°) wherein, a frequency of vibration which is to be reduced is represented with f, a pole pair number is represented with Pn, an electrical frequency is represented with f0=Pn*N, a motor revolution is represented with N, m=1, 3, 5, . . . , an angle of the rib with respect to the rotor center is represented with ?r, therefore making of motor highly effective and decreasing of the motor acoustic noise are coped with.

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: An actuator according to the present invention includes: a rotor that includes a magnet that has a cylindrical shape, and an outer peripheral surface alternately magnetized into different poles in a peripheral direction, and a soft magnetic member that is fixed to an inner diameter portion of the magnet; a coil that is concentric with the magnet, and arranged adjacently to the magnet in an axial direction thereof; and a stator that has a magnetic pole portion opposed to the outer peripheral surface of the magnet, in which the soft magnetic member composing the rotor and the stator are excited by the coil.

Abstract: A spindle motor is provided, which includes a stationary sleeve supported from a base, rotating shaft disposed through the sleeve, a fluid dynamic bearing between the sleeve and the shaft, a hub supported proximate a first end of the shaft, a stator supported from the base, a magnet supported from the hub and offset axially relative to the stator, and a steel ring supported from the base and positioned beneath the magnet.

Abstract: Provided are a super-high speed permanent magnet type synchronous motor which causes less loss in a rotor even though it is driven by an inverter adapted to be operated with a fundamental frequency around 1 kHz, and an air compressor. The air compressor having a super-high speed permanent magnet type synchronous motor which is composed of a stator in which armature windings are wound in a plurality of slots formed in a stator core, and a rotor including a shaft made of a conductive magnetic material, a conductive permanent magnet laid around the outer periphery of the shaft, and a reinforcing member made of carbon fibers and laid around the outer periphery of the permanent magnet, wherein a laminated electromagnetic steel sheet is interposed between the shaft and the permanent magnet, and the laminated electromagnetic steel sheet has a high tensile strength higher than 70 kg/mm2.