Abstract: Annular rotor disc for, in an axially stacked disc assembly of a plurality of similar rotor discs (22), forming a rotor (16) for an electric motor, in which the discs (22) secure a plurality of axially running permanent bar magnets (28), of substantially rectangular cross-sectional shape, distributed around the circumference of the rotor. The rotor disc (22) has pockets (24, 26) for accommodating and securing the permanent bar magnets (28) in such a way that adjoining bars form an angle to one another. The pockets (24, 26) for adjacent, mutually diverging permanent bar magnets (28), viewed in the radial direction from the centre of the rotor, delimit between them a substantially triangular disc part (32), which is flexibly connected to a radially inner part (36) of the annular rotor disc (22) only by a radially inner web portion (34).

Abstract: The brushless direct current motor comprises a housing 10, a stator 13 and a rotor 11 within the housing, windings on the stator, sensors for sensing the position of the rotor relative to the stator and electronic circuitry for switching the current in the windings in response to outputs from the sensors to cause the rotor to rotate relative to the stator. The sensors and at least a part of the electronic circuitry are encapsulated in an electrically insulating and fuel resistant material in a container within the housing.

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: A rotor portion of a motor includes a rotor core and a plurality of field magnets arranged in a circumferential direction at the rotor core. The rotor core includes at a flux barrier portion thereof arranged between a pair of field magnets of opposite magnetic polarities arranged next to one another a flux barrier hole. The flux barrier hole is independent of a magnet retaining hole in which the field magnet is retained. The magnet retaining hole includes a concave portion extending from a side thereof nearest to the flux barrier hole toward the corresponding flux barrier hole.

Abstract: A metal film 4 is disposed between a permanent magnet 3 and a rotor yoke 1, and the permanent magnet 3 and the rotor yoke 1 are subjected to beam welding. Since the metal film 4 is disposed between the permanent magnet 3 and rotor yoke 1, and the metal film 4 as a laser beam irradiated portion is melted by vacuum beam or laser beam, the metal film 4 has brazing metal function in welding, so that the connection between the permanent magnet 3 and the rotor yoke 1 is strong. Since there is no need of embedding the permanent magnet 3 in the rotor yoke 1 and there is no need to use polymer adhesives, the cost can be reduced.

Abstract: The present invention is a method of compressing lamination stacks for a permanent magnet rotor. The method includes the steps of providing a plurality of stages of lamination stacks and magnet carriers on a rotor shaft to form an assembly; positioning a spacer between each of the lamination stacks of each of the plurality of stages; and fitting a retainer plate with a groove at each end of the assembly. The groove allows a centrifugal force to deflect a top of the retainer plate inward toward the spacers and the spacers are milled to a size that is slightly wider than an axial gap between the lamination stacks of each stage. The groove on the retainer plates has a depth and radial position that determines the extent to which the top of the retainer plate deflects towards the spacers.

Abstract: Apparatus and method for assembling a permanent magnet rotor comprising a rotor fixture configured to slide over a smaller diameter bearing section of the rotor and abutting one end of a center axial section of the rotor and a split compression ring having an inner diameter that is sized to ride over the outer diameter of magnets in magnet carriers assembled on the rotor fixture.

Abstract: In order to provide a less expensive generator, a rotor using nonmagnetic beams is disclosed. The rotor includes a magnetic steel rim connected to a main generator shaft by a hub. The magnetic rim supports the components of the rotor, which includes a plurality of magnets and pole pieces. The pole pieces are connected to the rim with non-magnetic standoffs and nonmagnetic fasteners. The magnets are supported radially by nonmagnetic beams. The magnets are retained tangentially by pole pieces and radially by wedges. The components of the rotor are further retained axially between plates coupled to the rim and a shoulder on the pole pieces.

Abstract: A drive apparatus having a shortened axial dimension. First and second magnets are each formed into a semi-cylindrical shape and each provided with a magnetized pattern portion. A rotor yoke includes a shaft portion and a magnetic pole portion facing magnetized surfaces of the magnets. First and second stator yokes are each disposed to cooperate with the rotor yoke to sandwich therebetween a part of the first or second magnet where the magnetized pattern portion is formed. First and second coils each magnetize a part of the magnetic pole portion of the rotor yoke which faces the first or second stator yoke.

Abstract: A torque converter device comprises a flywheel rotatable about a first axis, the flywheel including a first body portion having a first radius from a circumferential surface and a first radius of curvature, a first plurality of magnets mounted in the first body portion, each having first ends disposed from the circumferential surface of the first body portion, and each of the first ends of first plurality of magnets having a second radius of curvature similar to the first radius of curvature of the first body portion, a second plurality of magnets mounted in the first body portion, each of the second plurality of magnets being disposed from the circumferential surface of the first body portion, and a generator disk rotatable about a second axis angularly offset with respect to the first axis, the generator disk including a second body portion, and a third plurality of magnets within the second body portion for magnetically coupling to the first and second pluralities of magnets.

Abstract: A driving apparatus includes a magnet that is magnetized to at least two poles in a circumferential direction and fixed to a rotor axis formed with a soft magnetic material, and first and second coils arranged in the same direction as the magnet with respect to the magnet-axis direction and arranged adjacent to an end surface of the magnet in the magnet-axis direction. The first magnetic pole portion is excited by energizing the first coil, and the second magnetic pole portion is excited to a pole opposite to the first magnetic pole portion by energizing the second coil. A yoke portion is formed with a soft magnetic material for supporting the first and second magnetic pole portions. The first magnetic pole portion includes a first coil insertion portion that is inserted to an internal diameter portion of the first coil, and a first magnet facing portion that is arranged to face a magnetized outer circumferential portion of the magnet with a predetermined gap at a predetermined angle.

Abstract: An armature for an electromotive device having a unitary coil and armature is disclosed. The armature may include a coil having inner and outer wave winding portions separated by an insulator, each of the wave winding portions comprising a plurality of sheet metal conductors, and a commutator having a plurality of sheet metal commutator segments each being integrally formed with one of the conductors. The armature may be fabricated from a pair of conductive sheets by forming in each of the conductive sheets a plurality of conductive bands each having first and second conductor portions, shaping the conductive sheets into inner and outer cylinders, positioning the inner cylindrical conductive sheet inside the outer cylindrical conductive sheet, forming a coil from the first conductor portions of the inner and outer cylindrical conductive sheets, and forming a commutator from the second conductor portions of the inner and outer cylindrical conductive sheets.

Abstract: A rotor includes a rotary shaft, a rib provided on the rotary shaft, and a disc-form holding member. The holding member is joined to an axial end face of the rib. The holding member is thereby coupled with the rotary shaft. The holding member is provided with permanent magnets arranged in a circumferential direction. A stator is confronted with the rotor along a central axis of the rotor.

Abstract: A rotary electric machine comprises a rotating shaft rotatably supported by bearings, a rotor attached integrally with the shaft and a stator facing the rotor. The stator includes a plurality of coils arranged substantially in a circular form in a rotating direction of the shaft. The rotor includes a circular-disc rotor yoke made of a ferromagnetic material, such as iron. Depressed and raised portions on a surface of the rotor yoke facing the stator, except for the center portion, are arranged in a circumferential direction of the rotor yoke. N-pole and S-pole magnets are alternately arranged in the depressed portions. Therefore, in addition to torque generated by the magnets, reluctance torque is generated between the raised portions on the rotor yoke side and the teeth on the stator side, thus making it possible to increase the range of rotation speeds of the motor.

Abstract: A magneto-generator, a method of manufacturing the same and a resin molding die for manufacturing the same. In the magneto-generator, a guard ring is omitted with the performance of the magneto-generator being enhanced. The magneto-generator is manufactured by making use of a resin molding die (21) having an outer peripheral surface (21d) to be positioned in opposition to an inner peripheral surface of a flywheel (11) and projections (21a) provided in the outer peripheral surface (21d) for holding a plurality of magnets (12) at predetermined positions, respectively. The magnets (12) are positioned and held stationarily at predetermined positions by the aforementioned projections, respectively, and spaces defined between the resin molding die (21) and the inner peripheral surface of the flywheel (11) are filled with a resin. After hardening of the resin, the resin molding die (21) is detached from the flywheel (11).

Abstract: A motor includes a stator section with a two-phase structure having first and second stator assemblies disposed in an axial direction, and a plurality of pole teeth arranged at an electrical angle of 90 degrees along inner circumferences of the first and second stator assemblies, and a rotor section including a rotation shaft, and first and second permanent magnets that are disposed opposite to and spaced a predetermined gap from the pole teeth and affixed to the rotation shaft with a gap provided between the first and second permanent magnets in the axial direction. Each of the first and second permanent magnets has an effective section at an outer circumference thereof that has multiple poles alternately magnetized with N poles and S poles, and has a protruded section that has a diameter smaller than an outer diameter of the effective section and protrudes in the axial direction.

Abstract: A synchronous AC motor has a stator with stator poles arranged as a plurality of circumferentially extending stator pole groups, with each stator pole group having a pair of corresponding circumferentially extending loop-configuration stator windings disposed adjacent on either side or a single such winding disposed adjacent at one side, adjacent stator pole groups being mutually circumferentially displaced by a fixed amount corresponding to a specific electrical phase angle. A rotating magnetic field is produced by applying respective polyphase AC voltages to the windings, such that currents of mutually opposite direction flow in each pair.

Abstract: A high speed brushless axial gap air core electrical machine includes a rotor mounted for rotation about an axis, and a stationary stator that magnetically interacts with the rotor. The rotor has two discs that are axially spaced apart to form an armature airgap. A stationary air core armature, with windings made of multiple individually insulated strand conductor wire for providing energy conversion, is located in the armature airgap. At least one of the discs carries a circumferential array of multiple alternating axial polarity permanent magnet poles facing the armature airgap. The magnets drive magnetic flux circumferentially through ferromagnetic portions of the discs and axially through the armature airgap. The discs have an integral axially extending circumferentially continuous lip outside of the array of magnet poles.

Abstract: The invention relates to a brushless electric motor comprising a stator, which has pole elements, and a rotor, which is mounted rotatably in relation to the stator and comprises magnet poles of magnetic powder material bonded to form a body and a back yoke body carrying the magnet poles, the magnet poles being formed by at least one molded magnetic body, which is molded with a back yoke side onto the back yoke body.

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: A permanent magnet-excited electric motor with a rotating rotor having permanent magnets disposed with alternating polarities in a ring around its circumference, which magnets cooperate with coils of a stator encompassing the rotor. The permanent magnets, as individual magnets next to one another that are distributed uniformly over the circumference of the rotor, rest on an annular support and are clamped in place at their axial ends by a respective annular frame made of magnetically inactive material.

Abstract: The invention relates to a rotor for an electric machine, especially a synchronous machine with transverse flux, especially a synchronous generator, especially a TFM rotor.

Abstract: The present invention provides a single piece machined rotor comprising a shell having an upper lip and a lower lip, with a pocket formed between the upper lip and the lower lip for mounting magnets therein. The magnets are fixed in place within the inner sidewall of the rotor with an adhesive and spacers. The spacers are positioned between the magnets and are held in place on the shell of the rotor by fasteners. The spacers may be of any type of non-magnetic material that can absorb the heat of the engine. The rotor also preferably includes triggering protrusions and balancing cutouts machined into the shell of the rotor. The cutouts or grooves may be machined into the inner sidewall or the outer sidewall of the rotor. A plurality of timing teeth used for engine speed sensing maybe machined into the single piece rotor assembly. The present invention also contemplates a method of machining the entire rotor out of a single piece of material.

Abstract: A motor for a hybrid vehicle is provided in which miniaturization of the drive system and transmission system can be achieved while maintaining driving performance. A drive plate 23 which connects a crank shaft 2 of an engine 1 to a transmission 3, is provided with a rotor base section 3 orthogonal to an axis C of the crank shaft 2, and a plurality of magnets 21 having pole faces facing in a direction along the axis C, are mounted on the rotor base section 3 to form a rotor 30, and there is provided a stator 32 with a plurality of conductive coils 22 arranged so as to face the magnets 21 of the rotor 30 in a direction along the axis C.

Abstract: A plurality of grooves 25 are formed in an outer peripheral surface of a cylindrical rubber magnet 17. The grooves 25 extend in a direction in which the cylindrical rubber magnet 17 is inserted into a yoke 3. The grooves 25 are open on both ends in the direction of insertion and are also open outwardly in a radial direction of the cylindrical rubber magnet 17. The grooves are formed at predetermined intervals in a peripheral direction of the cylindrical rubber magnet 17. When the cylindrical rubber magnet 17 is inserted into the yoke 3, an adhesive 15 gets into the grooves 25 without being pushed out of a lower end surface 21 of the cylindrical rubber magnet 17. The adhesive located between adjacent grooves also readily gets into the grooves 25. By presence of the adhesive got into the grooves 25, a necessary and sufficient amount of the adhesive can be uniformly interposed between a peripheral wall section 11 of the yoke 3 and the cylindrical rubber magnet 17.

Abstract: A magnet cradle for supporting a permanent magnet in an overhung recessed slot on the surface of a permanent magnet rotor having an axis of rotation. The cradle is non-magnetic and comprises a top and bottom wall abutting the permanent magnet. The cradle is sized to hold the permanent magnet within the overhung slots. Axial end walls generally perpendicular to the axis of rotation have circumferential edges configured to directly abut overhung portions of the slots. The total axial length of the top and bottom walls of the cradles in the axial direction are greater that the total axial length of the magnet, thereby permitting a magnet to fit between the axial end walls of the cradle without the cradle in the magnetic flux path of the magnet.

Abstract: A rotor of a motor is attached to a rotor axis slidably both in axial direction and rotational direction, each of elastic bodies is attached to each of side faces of the rotor, and the rotor is fastened to the rotor axis through the elastic body, mechanically by applying pressure on each of the side faces of the rotor in the axial direction through the elastic body, or chemically by bonding the rotor axis and each of the elastic bodies as well as each of the elastic bodies and each of the corresponding side faces of the rotor.

Abstract: An alternator for a vehicle comprises two pole pieces having interlaced poles (10) and magnets, the poles exhibiting grooves profiled along an axis (21) and accommodating the magnets, the profile completely preventing the magnets escaping from the grooves in a plane perpendicular to the axis (21). It has, for each magnet (20), a strip (24) interposed between one face (25, 27) of the magnet and at least one of the grooves (18), the strip (24) being produced from a material which is less hard than the magnet.

Abstract: A rotary electric machine including a flux-concentrating rotor with permanent magnets disposed between pole pieces, and a stator with teeth having a free end deprived of pole swellings and a concentrated winding. The pole pieces and the magnets are configured so as to minimize the difference Ld?Lq where Ld is inductance on a forward axis and Lq is inductance on a quadrature axis.

Abstract: A magnetic flux shield extending substantially the entire width of a magnetic disk drive spindle motor magnet is mounted between the magnet and the disk drive's base frame and rotates with the magnet. The flux shield is formed of a magnetic material to capture any stray magnetic flux from the motor magnet that may produce power draining eddy currents in the base frame.

Abstract: A rotor core, rotating in the vicinity of a generating coil, comprises a balance weight section and a pair of magnetic poles, provided on opposite sides of the balance weight section 2 with respect to a center of rotation O of the rotor core 1 to sandwich a magnet, and confronting through a magnetic gap G. A magnet holding section 9 for preventing the magnet 5 flying out through the magnetic gap G due to centrifugal force, is provided integrally contiguous to each of the magnetic poles so as to connect between the two magnetic poles.

Abstract: A brushless motor with a rotor having a magnet and a magnetic return, the magnet and magnetic return being arranged to form a gap therebetween, and a stator having a coil disposed in the gap.

Abstract: An inductive coil for an electromotive device includes a pair of concentric conductive sheet metal winding portions each comprising a plurality of axially extending conductive bands each being separated from an adjacent conductive band by a space, each of the conductive bands of one of the winding portions being coupled to one of the conductive bands of the other winding portion, the winding portions being encapsulated in a material that extends through at least one of the spaces from an exterior portion of the induction coil to an interior portion of the induction coil.

Abstract: A limited rotation torque motor is disclosed that includes a rotor and a stator. The rotor includes a plurality of pairs of magnetic poles and the stator includes a plurality of pairs of stator coils. Each stator coils extends along a longitudinal length of the motor.

Abstract: A claw-pole permanent-magnet stepping motor includes a pair of cases containing two or more inductors in symmetrical arrangement with multiple claw poles. The case unit has an oval shape having thin flat side walls or thin stepped side walls and connecting thick arcuate surfaces operating to resist external flux leakage from the motor and eliminating magnetic circuit obstructions. The cases, side walls, and inductors allow the motor to have a width to length ratio from about one to one to about one to two thus allowing a reduction in size and a low profile design while retaining available output torque.

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: A rotor assembly for a brushless motor includes a core circumferentially affixed about a longitudinal surface of a shaft. A rotor magnet covers the entire outer surface of the core to seal the core within the magnet and to prevent exposure of the core to ambient conditions. The rotor magnet has a plurality of portions of alternating magnetic polarity and is formed of a plastic mixed with neodymium-iron-boron particles.

Abstract: A rotor assembly for an alternator includes an electrical wire defining an excitation winding. A first pole piece and a second pole piece each have a generally circular body defining an axis of rotation and an outer radial periphery. A plurality of pole fingers are spaced radially about and extend axially from the outer radial periphery of each pole piece parallel to the axis of rotation. Each pole piece includes a plurality of mounting surfaces spaced radially about the outer radial periphery between the pole fingers. A plurality of permanent magnets are positioned on the mounting surfaces. A plurality of covers include tabs extending therefrom and are adapted to substantially encase one of the permanent magnets. The mounting surfaces of the first and second pole pieces include ribs which are adapted to engage the tabs to secure the covers to the mounting surfaces.

Abstract: Disclosed is a brushless vibration motor having a driving circuit therein, which is capable of operating like a typical DC motor. The brushless vibration motor comprises an eccentric rotor R having an eccentric weight 5b, a rotor case 5 and a magnet 6 which has a plurality of magnetic poles arranged in the rotor case; a shaft 2 for supporting the eccentric rotor, a housing H for supporting the shaft, a stator S which is disposed around the shaft on a stator base 1 constructing a part of the housing and which consists of armature coils to drive the rotor, and a driving circuit member 1c which is mounted in a space K corresponding to an area of at least one armature coil.

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 into 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 rotor for an electric rotary machine having signal generating inductor magnetic poles provided on a periphery thereof comprising a cup-like rotor yoke having a peripheral wall and a bottom wall and an inductor forming member mounted on the peripheral wall of the cup-like yoke and including a ring-like portion fitted onto the peripheral wall of the rotor yoke and having the inductor magnetic poles formed thereon and securely mounted on the rotor yoke by forcing protrusions formed on the peripheral wall of the rotor yoke against the both axial ends of the ring-like portion.

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: A synchronous induction motor features improved assemblability of a rotor, significantly reduced production cost, and improved operation performance of the motor. A plurality of die-cast secondary conductors is provided around a rotor yoke constituting the rotor of the synchronous induction motor. End rings are die-cast integrally with the secondary conductors on the peripheral portions of both end surfaces of the rotor yoke. Permanent magnets are inserted into slots formed such that they penetrate the rotor yoke. The openings of both ends of the slots are closed by a pair of end surface members formed of a non-magnetic constituent. One of the end surface members is secured to the rotor yoke by one of the end rings when the secondary conductors and the end rings are formed. The other end surface member is secured to the rotor yoke by a fixture.

Abstract: A rotor assembly for an alternator includes an electrical wire defining an excitation winding. A first pole piece and a second pole piece each have a generally circular body defining an axis of rotation and an outer radial periphery. A plurality of pole fingers are spaced radially about and extend axially from the outer radial periphery of each pole piece parallel to the axis of rotation. Each pole piece includes a plurality of mounting surfaces spaced radially about the outer radial periphery between the pole fingers. A plurality of permanent magnets are positioned on the mounting surfaces. A plurality of straps include tabs extending there from which are fastened to the pole pieces to secure the permanent magnets to the mounting surfaces.

Abstract: An energy conversion magnetic circuit is constituted with magnet pole pieces of magnets or armatures which are in parallel with respect to the shaft to obtain a dynamic force or an electromotive force. The magnetic circuit for a generator or an electric motor has a rotating shaft, a plurality of supporters fixedly mounted in a perpendicular direction to the circumference of the rotating shaft, a plurality of rotors arranged in parallel with respect to the shaft on each end of the plurality of supporters to be rotated by attraction force and repulsion force of a magnetic field, and a plurality of armatures having a coil wound on the body thereof. The coil is mounted at an interval outside the rotors and receives induced alternate magnetic flux of the rotors to generate a rectangular wave electromotive force or to obtain a high torque with input of electrical energy.

Abstract: A magnetic material fixing structure of motor rotor including multiple overlapping silicon steel plates. An outer circumference of each silicon steel plate is recessed to form multiple receptacles at equal intervals. A magnetic material is disposed in each receptacle. The receptacle has two lateral faces, a bottom face and an opening opposite to the bottom face. Each of adjoining sections of the two lateral faces and the bottom face is formed with a dented section dividing the lateral faces and bottom face of each receptacle into multiple resilient plates. When inlaying the magnetic material into the receptacle, the resilient plates are deformed to resiliently tightly clamp the magnetic material.

Abstract: A direct current electric motor having a reduced inertia rotor includes a stator affixed to a housing wherein the stator comprises a plurality of electrically conductive windings. The stator further defines a central cavity in which is mounted a rotor. The rotor comprises a shaft, at least two magnets affixed in a radially spaced manner from the shaft, and a rotor core between the shaft and magnets that is rotationally de-coupled from the shaft and the magnets.

Abstract: An interior permanent magnet machine including a rotor stack defining at least two adjacent magnet retention slots and a plurality of permanent magnets positioned within the interior of the rotor, wherein the radial thickness of the rotor that is above a given magnet retention slot transitions from a first radial thickness to a bridge region having a second radial thickness that is less than the first radial thickness. The bridge region is positioned between the two magnet retention slots and the transition to the bridge region occurs within an area falling within a defined angular expanse.

Abstract: An interior permanent magnet machine is disclosed that, in one exemplary embodiment, includes a stator defining a number of stator poles, a rotor, a number of permanent magnets positioned within the interior of the rotor and at least two impedance reduction slits associated with each permanent magnet where the impedance reduction slits are positioned radially outward of the permanent magnets. In further embodiments, each impedance reduction slit is positioned such that at least a portion of the slit is within a defined region.

Abstract: A rotor (10) for a miniature electric motor includes a magnet (12) having a rotation axis (14) and a shaft (16) fixed concentrically to the magnet. The magnet (12) includes a through hole (20) extending coaxially with the rotation axis (14). The shaft (16) includes a portion (24) fitted in the through hole (20). The portion (24) has an axial interengagement length (t1) shorter than an axial length (T1) of the through hole (20). The rotor (10) also includes reinforcing means provided at least inside the through hole (20). The magnet (12) comprises an annular magnet material (18), and a coating (22) formed on a surface of the magnet material and arranged at least inside the through hole (20). The reinforcing means is formed as the coating (22) of the magnet (12), and acts to ensure a fixing force to securely hold the shaft (16) in a predetermined position on the magnet.