Abstract: A stator includes an annular stator core that is comprised of a plurality of stator core segments, an outer ring that is fitted on the radially outer surfaces of the stator core segments so as to fasten them together, and a stator coil mounted on the stator core. Each of the stator core segments is formed of a plurality of stator core sheets that are laminated in the axial direction of the stator core. Each of the stator core sheets has a reinforcement portion that includes a recess formed in one of the major surfaces of the stator core sheet and a protrusion formed on the other major surface. The stator core sheets are laminated so that for each adjoining pair of the stator core sheets, the protrusion of one of the stator core sheets is fitted in the recess of the other stator core sheet.

Abstract: Line-start permanent-magnet (LSPM) rotors, rotor components, and machines using LSPM rotors, where the PM rotors have PM bulks in W-like shapes, vent openings between PM bulks, and/or air gaps at ends of PM bulks in the W-like shapes.

Abstract: A production method for a rotor for a permanent magnet-type rotary electric machine, includes the step (S01, S02) of forming a magnet piece that has a plurality of groove portions that are provided on at least one of end surfaces of the magnet piece in a predetermined direction, the step (S03) of stacking a plurality of formed magnet pieces so that adjacent magnet pieces contact each other and the plurality of groove portions of one of the adjacent magnet pieces cross with the plurality of groove portions of another one of the adjacent magnet pieces, and the step (S04) of inserting and disposing the plurality of stacked magnet pieces into a hole formed in a rotor core.

Abstract: A rotor includes a rotor frame having a plurality of ribs which are disposed at predetermined intervals in a circumferential direction and which extend in a radial direction, and a shaft portion and a rim portion which are provided at inside diameter sides and outside diameter sides of the plurality of ribs, respectively, main magnet portions which are disposed individually between the ribs which are adjacent to each other in the circumferential direction, and a plurality of sub-magnet portions which are disposed on at least one sides of the ribs in the rotational axis direction, and wherein a rigid portion is formed in an area where the sub-magnet portions are projected in the radial direction relative to an area where the rib is projected in the radial direction in a cross section of the rim portion taken along the rotational axis direction.

Abstract: An object of the present invention is to provide a rotor magnet that is capable of adjusting attraction of magnet that is mounted in a spindle motor, a spindle motor including the same, a recording and reproducing apparatus, and a jig for manufacturing the same, with a simple configuration. A rotor magnet is an approximately annular member that is attached to a rotor hub rotating around a shaft forming a part of a spindle motor. The rotor magnet is magnetized such that magnetization properties of axially top and bottom surfaces of the rotor magnet are different from each other.

Abstract: An electrical generator includes a rotary disk that is made of plastic injection molding in which a plurality of coils each having an exposed contact is embedded. Two stationary disks are arranged on opposite sides of the rotary disk and each has an inside surface that opposes the rotary disk and carries two semi-circular magnets. The rotary disk is fixed to a shaft having opposite ends fit into bearings that are received in central bores defined in the stationary disks. The coils are each formed by winding a wire in at least one turn in the form of a circle or an ellipse, the turns being coincident with each other or partially offset with respect to each other. Or alternatively, the coils are formed concentric with respect to each other and the rotary disk.

Abstract: An axial gap motor including a rotor and stators, wherein: the rotor is provided with a plurality of primary magnet portions, a plurality of auxiliary magnet portions, and a rotor frame; the rotor frame is provided with a plurality of ribs that extend in the radial direction of the rotor frame, and a shaft portion and a rim portion that are integrally connected with each other via the ribs, and the rotor frame houses the primary magnet portions and the auxiliary magnet portions; the primary magnet portions are provided with primary permanent magnet pieces; the auxiliary magnet portions are provided with auxiliary permanent magnet pieces; and each of cross-sectional areas of the ribs which is perpendicular to the radial direction increases from the rim portion side towards the shaft portion side in the radial direction.

Abstract: A synchronous motor includes a stator, a rotor and permanent magnets. The rotor includes a rotor iron core rotatable relative to the stator, and a plurality of conductor bars accommodated within corresponding slots in the rotor iron core. The conductor bars have their opposite ends shortcircuited by respective shortcircuit rings to form a starter cage conductor. The rotor also has a plurality of magnet retaining slots defined therein at a location on an inner side of the conductor bars, in which hole permanent magnets are embedded.

Abstract: An electrical machine includes first and second magnetically permeable parallel cores. Each core is elongated to thereby define a lengthwise direction and first and second core profiles transverse to the lengthwise direction. First coils are wound about the first core profile and sequentially disposed along the length of the first core. Second coils are wound about the second core profile and sequentially disposed along the length of the second core. A multi-pole elongated permanent magnet is parallel with the cores and located between them. The magnet is movable, relative to the cores, in the lengthwise direction.

Abstract: A single phase line start permanent magnet synchronous motor is started by an interaction between magnetic fields of the coil and of the secondary conductor, and an normal operation can be performed using only the permanent magnet and the operating condenser of small capacity, only the main coil, or only the operating condenser when the synchronous rotating speed is reached and the rotation is started, and therefore an additional direct current supplying device for supplying the direct current and the position sensor for sensing the rotational position of the rotor can be excluded, the structure can be made compactly by constructing the driving circuit simply, and manufacturing cost can be reduced.

Abstract: A circumferential confronting type motor includes an armature core that has drive coils wound around its plurality of poles, and a drive magnet positioned opposite to the armature core in the radial direction. The drive magnet has a plurality of divided magnetized sections, each with a magnetic center, formed separated from each other in the axial direction by a non-magnetized section. The magnetic centers of the respective plurality of divided magnetized sections are provided in symmetrical positions with respect to a magnetic center in the axial direction of the armature core. Further, electromagnetic action between the drive magnet and the armature core causes the two to rotate relatively, while magnetic action between the plurality of divided magnetized sections and the armature core regulates their relative movements in the axial direction.

Abstract: An embedded permanent magnet type induction motor has a rotor that is a lamination of a plurality of rotor core plates (10). The rotor core plate is provided with a plurality of rotor slots (12) each inclined by an angle &agr; with respect to a radial direction of the rotor core plate. The rotor has the axial length L being made of laminations divided into at least two equal portions with respect to its central axis. The divided laminations are combined with one another so that one of the divided laminations is opposed to another in inclination of the angle &agr; and the plurality of rotor slots of one of the divided laminations are respectively superposed on the rotor slots of another at at least their ends closer to the central axis of the rotor to form a skew angle &bgr;.

Abstract: A DC motor of the present invention includes a rotor unit which is rotatably arranged within the motor and has a cylindrical field magnet fixed to an outer surface of a holder into which a rotating shaft is press-fitted at a center thereof, said cylindrical field magnet being magnetized such that S and N poles alternate with each other in a circuferential direction thereof, and a stator unit which is circumferentially arranged around the rotor unit and is comprised of a plurality of stator yokes so arranged as to oppose the field magnet with a small gap, each of the stator yokes being formed by circumferentially stacking a large number of thin plates, each consisting a salient pole, and a plurality of coil units, each being formed by winding a magnet wire on a bobbin and mounted on each of the stator yokes. Thus, each of the S and N poles has a plurality of stages formed in an axial direction and shifted from each other in the circumferential direction of said field magnet with a predetermined shift amount.

Abstract: A rotary electrical machine comprising a stator (10) and at least one rotor (12) having a plurality of permanent magnets (14). The rotor consists of a rotor disc, at the outer edge of which the permanent magnets are mounted. The rotor disc (12) is provided with airgap varying means (19) which are angled towards the stator (10) and mounted on the rotor hub (24) for rotation therewith. When the rotor is stationary, the airgap (30) between the magnets (14) and the stator (10) is at a minimum. In operation, as the speed of rotation of the rotor (12) increases, a centrifugal force is generated which acts to bend the airgap varying means (19) and, therefore, the rotor disc (12) back, away from the stator (10), thereby drawing the magnets (14) away from the stator and increasing the size of the airgap (30). The increase in size of the airgap results in a corresponding decrease in flux and therefore a decrease in the maximum output voltage for that rotor speed.