Abstract: A permanent magnet motor (and associated rotor and stator) are described. The motor includes: a rotor having: an outer surface disposed radially from a central axis; and a plurality of permanent magnets located on the outer surface of or within pockets located between the outer surface and the central axis of the rotor; a stator having an inner surface in a spaced apart relationship to the outer surface or the plurality of permanent magnets with a gap there between that varies as a function of axial position along the central axis, and a first gap width at a first axial position is different from a second gap width at a second axial position, and the first and second gap widths are sized and configured to reduce the coping torque of the IPM motor as compared to an IPM motor having a constant gap width of the first or second width.

Abstract: The present invention relates to a motor including a motor housing, a stator installed in the motor housing and including a stator core including a plurality of unit stator cores having teeth protruding from a head unit, an insulator, and a coil, a rotor rotatably installed at a center of the stator and including a through hole formed at a center thereof and a magnet module, and a bracket disposed at an upper portion of the motor housing and including a bearing supporting a rotating shaft and a bearing seating unit, wherein the bearing seating unit includes a lateral supporting part supporting a side surface of the bearing and a lower supporting part perpendicularly protruding from the lateral supporting part so that the bearing is seated, and noise reducing groove units are provided on a surface of the lower supporting part.

Abstract: The invention relates to a method and a device for generating a vibration pattern in a person, having a drive which sets a mass in rotation, and at least one sensor device which is coupled to a controller which controls the drive as a function of sensor data over the sensor device. The mass (m) is arranged in a homogeneously concentric fashion around its rotational axis (10), and an interface (20) transmits to the person reaction forces from the mass which arise owing to the change in the rotation.

Abstract: A stator core for an electronically commutated DC motor with an internal rotor having a plurality of radially inwardly directed pole cores which at their periphery are integral with back iron segments and the back iron segments are integral with adjacent back iron segments via webs, wherein the back iron segments alternate with the webs and jointly form a seamless closed one-piece ring. A method of ensuring that in the case of a stator core of this class, upon a reduction of the stator diameter and reduction of the pole distances after winding, a clearly defined end position of the adjoining regions can be assumed, and that for this process, only minimal forces are necessary, in which damage to the stator core is not to be expected, and that at the end of the process only a very small and uniform air gap remains at a lowest possible spring-back.

Abstract: An exemplary heat dissipation fan includes a rotor and a stator. The rotor includes a hub, a central shaft extending down from a top end of the hub, the shaft having a free end far from the top end of the hub. A magnetic element attached to an inner periphery of the hub. The stator includes a stator core consisting layers of yokes, two insulation frames mounted at two opposite ends of the stator core and a coil wound around the insulation frames. An outer surface of the stator faces and is spaced from an inner surface of the magnetic element of the rotor with a clearance defined therebetween. A width of a bottom end of the clearance adjacent to the free end of the shaft being smaller than a width of a top end of the clearance.

Abstract: An arrangement to ensure an air gap in an electrical machine is provided. The electrical machine has a stator arrangement and a rotor arrangement, the rotor arrangement rotating around a longitudinal axis. An air gap is defined by a distance between parts of the rotor arrangement and parts of the stator arrangement, wherein the parts of the stator arrangement are opposite to the parts of the rotor arrangement along a certain length. The stator arrangement includes a lamination stack which is constructed to support a winding of a stator-coil, and the rotor arrangement includes a plurality of permanent magnets. A cross section of the air gap changes along the certain length such that the air gap is not uniform in view to the certain length. The cross section of the air gap is configured by a change in a shape of the lamination stack along the certain length.

Abstract: An arrangement to ensure an air gap in an electrical machine is provided. The electrical machine has a stator arrangement and a rotor arrangement, wherein an air gap is defined by a distance between parts of the rotor arrangement and parts of the stator arrangement. A cross section of the air gap changes along the certain length. The stator arrangement includes a stator support structure and a lamination stack, wherein the stator support structure has support elements for a two-sided support of the lamination stack, the support elements being ring-shaped and connected via a single main bearing to the rotor arrangement. Elements of the ring-shaped support element show different diameters in reference to the longitudinal axis. A first diameter of a first element of the ring-shaped support element is greater than a second diameter of a second element of the ring-shaped support-element.

Abstract: An arrangement to set up and to ensure an air gap in an electrical machine, like a generator, is provided. The electrical machine includes a stator arrangement and a rotor arrangement. The rotor-arrangement rotates around a longitudinal axis. At least parts of the rotor arrangement interact with parts of the stator arrangement to generate electrical power. An air gap is defined by the distance between the parts of the rotor arrangement and the parts of the stator arrangement. The parts of the stator arrangement are opposite to the parts of the rotor arrangement along a certain length. The cross-section of the air gap changes along the certain length, so that the air gap is not uniform in view to the referred certain length.

Abstract: A stator for an electric machine has a circular stator body surrounding a rotor with an air gap therebetween. The stator has radially extending slots that define radially extending stator teeth. Multiple electric windings are located in the slots to define peripherally spaced magnetic poles. Separate coil groups establish multiple phases for the electric machine. Motor torque ripple is attenuated by forming the stator teeth with different widths for a given coil group.

Abstract: This motor includes a stator whereupon a plurality of magnetic poles are arranged at first prescribed intervals on the outer circumference section, and a rotor which is rotatively arranged on the outer circumference of the stator by having a prescribed space in between and has permanent magnets magnetized to different polarities at second prescribed intervals. The magnetic pole of the stator forms an extending section which extends from a magnetic pole base section in a direction parallel to the permanent magnet, and the extending length of the extending section in the direction parallel to the permanent magnet is same as that of the magnetic pole base section in the direction parallel to the permanent magnet or shorter.

Abstract: A generator/motor includes a ring-shaped stator core (20) fixed to a motor housing (10), and a motor rotor (30). The motor rotor (30) includes a ring-shaped rotor yoke (35) which rotates in cooperation with the crankshaft (1) and which is opposed to an inner peripheral surface of the stator core (20) with a predetermined gap therebetween. The motor rotor (30) also includes a rotor flange (31) which fixes and supports the rotor yoke (35) at its outer peripheral surface. The rotor flange (31) is rotatably supported by a support member (51a) of the motor housing (10) through a bearing (60). A cylindrical shaft portion (40) is interposed between the crankshaft (1) and the motor rotor (30), and the crankshaft (1) is spline coupled to the cylindrical shaft portion (40).

Abstract: A vibration motor includes a rotary shaft, an armature core secured to the rotary shaft and having a plurality of salient poles, an armature coil wound around each of the salient poles except at least one salient pole, a frame serving as an outside cover, a plurality of magnets secured to the frame and having respective different polarities, and a weight adapted to rotate together with the rotary shaft and disposed eccentrically, wherein the weight is disposed inside the frame and secured to the armature core in such a manner that at least a part of the weight is inserted in a hollow provided in at least the one salient pole having no armature coil.

Abstract: The invention relates to a direct drive for large-scale drives, comprising a stator (1) which is configured, when seen from the peripheral direction, by a plurality of segments (3, 4, 5, 6), each having a self-contained winding arrangement, and a rotor which is configured from segments. The segments of the rotor are located on working elements that rotate with the rotor, and interact electromagnetically with a winding system of the stator (1). The inventive drive is especially suitable for ring motors and tube mill drives.

Abstract: A rotor for an electric machine includes a shaft that is rotatable about an axis and defines a first diameter normal to the axis. A first core portion defines a first aperture having a first aperture diameter that is larger than the first diameter. The first core portion is positioned adjacent the shaft to define a first space. A second core portion defines a second aperture having a second aperture diameter that is larger than the first diameter. The second core portion is positioned adjacent the shaft to define a second space. A damping member is positioned in the first space and the second space. The damping member at least partially interconnects the shaft, the first core portion, and the second core portion.

Abstract: In an electromagnet switch, a stationary iron core is composed mainly of a base part and a disk part. The base part is faced to a plunger and the disk part is forcedly inserted and fixed to a boss part formed in the base part. The disk part is composed of a metal plate of ferromagnetic substance (iron plate) and another substance plate (made of resin or rubber and the like, for example,) of a smaller spring constant or a larger damping coefficient than that of the metal plate. The metal plate and another substance plate are laminated. Another substance plate absorbs or reduces the impact force when the plunger is electromagnetically attracted toward and collides with the base part. The propagation of a large impact noise or crashing sound is thereby suppressed, and as a result the impact noise can be reduced.

Abstract: A rotor of a BLDC motor includes: a rotor divided into a north pole and a south pole on the basis of a magnetic pole separating line; and a stator at which the rotor is disposed with an air gap, the stator having a first pole shoe, a second pole shoe and a pair of detent grooves at its inner surface, wherein an air gap forming portion for enlarging an air gap between the rotor and the detent grooves is formed at both end portions of the rotor where the magnetic pole separating line passes, so that the rotor can maintain the motor performance and reduce resonance noise by reducing only higher degree of cogging torque from cogging torque generated when the motor is driven.

Abstract: A number of embodiments of rotating electrical machines using permanent magnets wherein the cogging torque is substantially reduced as are vibrations caused by magnetic flux variations. This is accomplished by disposing the coil windings in equal circumferential spacing and disposing the associated permanent magnets in non-symmetrical relationship so that the gaps between some of the magnets are different. In addition, the coil windings are such that no two coils of any phase are immediately adjacent each other in a circumferential direction. A method for calculating the optimum spacing is also disclosed.

Abstract: A plurality of motors are assembled. A plurality of part-sized stators are provided. Each of the part-sized stators is a split portion of a full-sized stator which has been previously split. The full-sized stator includes a printed circuit board with a plurality of coils. Each part-sized stator is inserted into a respective motor.

Abstract: Slots are formed at a nonuniform pitch at a ratio of two slots per phase per pole. An X-phase winding phase portion constituting a stator winding is constructed by connecting in series an a-phase winding phase sub-portion and a d-phase winding phase sub-portion having a phase difference corresponding to an electrical angle of 34 degrees, a Y-phase winding phase portion is constructed by connecting in series a b-phase winding phase sub-portion and an e-phase winding phase sub-portion having a phase difference corresponding to an electrical angle of 34 degrees, and a Z-phase winding phase portion is constructed by connecting in series a c-phase winding phase sub-portion and an f-phase winding phase sub-portion having a phase difference corresponding to an electrical angle of 34 degrees.

Abstract: A torque motor may include a rotor having at least two magnets disposed thereon, and a stator having a core and at least one coil. The magnets are arranged and constructed so that the outer surfaces thereof alternately have a N pole and a S pole. The magnets cover the rotor over an angle of less than 360 degrees. The core has a first and second magnetic pole elements. The magnetic pole elements are arranged and constructed such that an angle defined between a first straight line passing through a center of the first magnetic element and a center of rotation of the rotor and a second straight line passing through a center of the second magnetic element and the center of rotation of the rotor is less than 180 degrees.

Abstract: In order to achieve high machine utilization with the magnetic fields having an approximately sinusoidal profile, an electrical synchronous machine is proposed having the following features: a stator and a rotor with the stator having a three-phase winding (3) and the rotor being fitted with permanent magnets, the three-phase winding (3) is arranged in slots in the stator, the slots in the stator are formed by essentially axially running teeth (7, 8) which have at least two different tooth pitch widths ?zb and which are arranged alternately in the circumferential direction of the stator, with their number in each case being identical, only the teeth (7) with a tooth pitch width which is greater than other teeth (8) are at least partially surrounded by a winding (3).

Abstract: A DC motor apparatus includes a motor housing assembly which includes an outer liquid-tight coolant chamber and an inner, armature-reception chamber portion. Pairs of permanent magnet stator magnet modules are housed within the liquid-tight coolant chamber, and shunt members are housed within the liquid-tight coolant chamber between the stator magnet modules. An armature is centrally located in the inner, armature-reception chamber portion. The armature includes at least one pair of armature pole portions which are wound with same-directional windings. A commutator is connected to the armature, and the commutator includes commutator contacts. An adjustable brush advance/retard mechanism includes roller brushes for contacting the commutator contacts. A liquid cooling system includes a coolant pump and a coolant fluid radiator for circulating liquid coolant through the liquid-tight coolant chamber for cooling the stator magnet modules and the shunt members.

Abstract: A motor having a rotor with a plurality of magnetic poles arranged in an arch or circular shape and a stator in which coils are disposed on the magnetic teeth of a stator core having a plurality of the magnetic teeth disposed opposite to the rotor, wherein a magnetic pole part for cancelling a cogging torque is disposed around the rotor.

Abstract: A motor employing vector motion principles to Convert magnetic forces into rotary motion has a rotor with a shaft and a plurality of magnets connected to the shaft by bent supports having a particular bend angle. The rotor is positioned within a stator having a plurality of stator magnets opposing the rotor magnets. Magnetic force, such as a repelling or attracting force between the rotor and stator is formed in a non-radial direction due to the orientation of the rotor magnets mounted on bent supports and their opposing stator magnets. One segment of the bent support receives an action force from the magnetic force between the stator magnet and the rotor magnet. Another segment of the bent support exhibits a reaction force opposing the action force. The vectors of the action force and the reaction force combine into a resultant vector having a direction that induces rotor rotation.

Abstract: A vacuum cleaner assembly includes a motor having a rotor and a stator for providing motive power to the assembly. The rotor and stator each include armatures having tips. In one aspect, the widths of the rotor and stator tips are different. In another aspect, the rotor armatures have a non-constant width. Another aspect discloses the motor being a two-phase brushless motor having an even number (N) of stator armatures and N+2 rotor armatures. In another aspect, a rotor armature includes an aperture. In another aspect, each rotor armature includes a plurality of layers laminated together, with one layer being dimensionally different than the other layers. In another embodiment of the present invention, a control circuit energizes the windings of the stator so as to toggle the rotor in a first direction before alternately energizing the windings to drive the rotor in a second direction.

Abstract: A drive unit with a drive and an electric machine, the drive being equipped with a drive shaft and the electric machine with a stator and a rotor. The rotor is coaxial to the stator and connected to the drive shaft for the transmission of torque, where the stator and the rotor interact with each other across an air gap, and where the drive shaft causes the rotor to execute a wobbling motion. In a cross section parallel to the drive shaft, the geometric course of at least one of the two surfaces forming the boundaries of the air gap, i.e., the surface of the rotor or the surface of the stator, is designed so that it at least approximates the geometric slowing curve (VR) described by the wobbling motion of the rotor.

Abstract: A motor employing vector motion principles to convert magnetic forces into rotary motion has a rotor with a shaft and a plurality of magnets connected to the shaft by bent supports having a particular bend angle. The rotor is positioned within a stator having a plurality of stator magnets opposing the rotor magnets. Magnetic force, such as a repelling or attracting force between the rotor and stator is formed in a non-radial direction due to the orientation of the rotor magnets mounted on bent supports and their opposing stator magnets. One segment of the bent support receives an action force from the magnetic force between the stator magnet and the rotor magnet. Another segment of the bent support exhibits a reaction force opposing the action force. The vectors of the action force and the reaction force combine into a resultant vector having a direction that induces rotor rotation.

Abstract: An alternator includes a stator having a stator core formed with a number of slots extending longitudinally on an inner circumference thereof, and two sets of three-phase stator coils installed in the slots, and a rotor rotably disposed inside the stator, the rotor having a field coil for generating magnetic flux on passage of electric current, and pole cores covering the field coil, a number of claw-shaped magnetic poles being formed in the pole cores by the magnetic flux, a total number of slots in the alternator being one per pole per phase per set, the slots being formed such that radial center lines of adjacent openings of the slots have nonuniform pitch in a circumferential direction.

Abstract: A method for assembling an inside out motor includes the step of stacking a plurality of laminations together to form a pole member. A stator is molded around the pole member so that an end of the pole member is located adjacent an exterior surface of the molded stator. An electrically conductive magnet wire is wound around the molded stator adjacent the pole member to form a winding of the motor.

Abstract: An electric motor includes a rotor and a stator including a plurality of unit cores each of which has two ends. The unit cores are disposed so that the ends of each unit core are adjacent to the ends of the neighboring unit cores respectively. Each unit core includes a yoke section and a plurality of salient poles which are integral with the yoke section and on which windings are wound respectively. Adjacent portions of the unit cores are selected so that magnetic fluxes passing through the respective adjacent portions are substantially the same.

Abstract: A permanent magnet generator is so thin as to be incorporated in a 3.5″ diskette. The generator having so low cogging torque that can be rotated smoothly even by a low torque driving source as a 3.5″ FDD to generate stable output is disclosed. It has stator magnetic poles facing via a magnetic gap an outer circumferential surface of the stator permanent magnet having a plurality of magnetic poles on it. One to six of the stator magnetic poles are removed and instead of the removed magnetic poles provided is a soft magnetic piece to face the rotor magnetic poles. Grooves are preferably provided on the soft magnetic piece, facing the rotor magnetic poles. A notch is provided on the permanent magnet generator to avoid interference with an input/output terminal and/or a card contact terminal of the diskette for inserting a memory card.

Abstract: A permanent magnet motor includes a rotor having a permanent magnet and a stator core having circumferential teeth the number of which is 2n where n is an integer equal to or larger than 2, the teeth including first teeth the number of which is n and second teeth the number of which is n, the first and second teeth being circumferentially regularly disposed alternately. Each first tooth has a head with an end face opposed to the rotor and formed generally into the shape of an arc about a center of rotation of the rotor so that an air gap defined between said end face and a surface of the rotor opposed to said end face is circumferentially uniform. Each second tooth has a head with an end face opposed to the rotor and shaped so as to be gradually departed farther away from an opposite surface of the rotor as the head extends from its circumferentially central portion toward both circumferential ends.

Abstract: A reluctance type rotating machine includes a stator having armature windings arranged on an inner periphery of the stator, a rotor having projection portion forming magnetic poles, and a plurality of permanent magnets arranged on both side faces of the projection portions. Owing to the provision of the permanent magnets, it is possible to restrain magnetic fluxes of the armature windings of the stator from leaking toward interpole portions between the magnetic poles. The power output of the machine can be improved by increased effective fluxes.

Abstract: A switched reluctance motor driven by a two-phase source, includes a stator having an even number of evenly-spaced, like stator poles defining a gap between each stator pole; windings for each of the two phases of the motor wound about stator poles that are circumferentially separated by a winding and an associated stator pole of a different phase; and a rotor mounted for rotation relative to the stator, the rotor having an even number of rotor poles, the rotor poles being dimensioned such that when the phases are alternately energized, the rotor poles operatively interact with the stator poles such that the motor advances sequentially to a first state wherein one-third of the rotor poles are magnetically coupled to a like number of the stator poles, to a second state wherein two-thirds of the rotor poles are magnetically coupled to a like number of stator poles and to a third state wherein all of the rotor poles are magnetically coupled to a like number of stator poles.

Abstract: A switched reluctance machine includes a first element having a plurality of uniform poles and a second element having a first pole and a second pole. The first pole has a wide face and the second pole has a narrow pole face. The first and second elements are disposed for movement relative to each other such that the wide and narrow poles are moveable in spaced relation to the plurality of uniform poles.

Abstract: A substantial saving of material cost and weight is obtained in an induction motor by a rotor including two sets of differently punched laminations. The laminations in one of the two groups each weigh less than 95% of the laminations in the other one of the two groups. Such laminations can be automatically produced on a computer-controlled die press by providing a separate punch pattern that is capable of being programmed for selected laminations. The lighter laminations can be used to counterbalance a crank without requiring additional counterbalancing weight to be added outside the motor.

Abstract: A permanent magnet rotor type electric motor is formed of a stator core generating a rotation magnetic field, and a rotor core rotationally situated inside the stator core. The rotor core includes a first core member for generating a magnet torque, permanent magnets embedded in the first core member for forming magnetic poles, and a second core member for generating a reluctance torque without having a permanent magnet therein. The second core member is coaxially united with the first core member so that the rotor core is divided into the first core member for generating the magnet torque and the second core member for generating the reluctance torque.

Abstract: A miniature motor with a two-pole stator, and a rotor having three or more salient poles each having a core with flanges extending toward both sides thereof and a winding. The rotor is adapted to simulate a two-pole construction by cutting off at least the tip of a flange on either side on a part or all the salient rotor pole cores, thereby limiting the spontaneous-stop angular positions of the rotor to two. One insulating spacer is provided between a plurality of commutator segments of the commutator in such a positional relationship as to come in contact with one of the two brushes when the rotor is at a spontaneous-stop angular position. The motor is prevented from burning and restarting suddenly after a stop since the motor has a self-inactivating function by interrupting current supply at spontaneous-stop angular positions while maintaining motor torque by minimizing the angle of non-conduction to the rotor.

Abstract: A stepping motor is equipped with a rotor, a supporting member that rotatably support the rotor, and stators that have multiple stator teeth and that face each other across the diameter of the rotor, wherein said multiple stator teeth are positioned such that they are apart from each other. Using the construction described above, it is possible to make the rotor diameter smaller than the conventional model, thereby reducing the overall size of the stepping motor. Therefore, it is possible to make the outer diameter of lens barrel smaller than the conventional model without changing the lens diameter, which in turn makes the overall size of the camera more compact.

Abstract: An inside out electric motor includes a rotor having an interior surface defining an interior space and a magnetic element mounted on the rotor. The motor also includes a stator having a bobbin. The bobbin has a bearing positioned at a central axis of the bobbin. The bearing rotatably engages the rotor to permit the rotor to freely rotate with respect to the stator. The bobbin also has a pole member molded into the bobbin so that an end of the pole member is spaced radially inward from and at least partially aligned with the magnetic element, and a winding wound around the bobbin so that the winding passes adjacent the pole member.

Abstract: In a permanent magnet rotor type electric motor having a stator core generating a rotation magnetic field and provided therein with a rotor core in which each magnetic pole is formed by a permanent magnet, the rotor core is fabricated by coaxially and unitedly joining a first core member and a second core member, in which a first permanent magnet of a predetermined cross-section shape is embedded per magnetic pole in the first core member, and a second permanent magnet which is made of a different material and has a different cross-section shape from those of the first permanent magnet is embedded per magnetic pole in the second core member, thereby achieving the permanent magnet rotor type electric motor having the performance and size appropriate for the intended use.

Abstract: A switched reluctance machine includes a first element having a plurality of uniform poles and a second element having a first pole and a second pole. The first pole has a wide face and the second pole has a narrow pole face. The first and second elements are disposed for movement relative to each other such that the wide and narrow poles are moveable in spaced relation to the plurality of uniform poles.

Abstract: A flat vibration generating apparatus wherein a flat coreless eccentric vibrator armature generates an eccentric vibration desired from the aspect of body feel. An air-core armature coil group thereof consists of m pieces (where m is an integer of 3 or more) of armature coils disposed in superposition with one another in m phases in an arrangement such that they are eccentric and with their phases deviated in a circumferential direction, and that they do not describe a complete disc-like shape as viewed from the axial direction.

Abstract: A substantial saving of material cost and weight is obtained in an induction motor by a rotor including two sets of differently punched laminations. The laminations in one of the two groups each weigh less than 95% of the laminations in the other one of the two groups. Such laminations can be automatically produced on a computer-controlled die press by providing a separate punch pattern that is capable of being programmed for selected laminations. The lighter laminations can be used to counterbalance a crank without requiring additional counterbalancing weight to be added outside the motor.

Abstract: An electric machine uses materials with hysteresis characteristics (such as cast steel) to form the field poles and magnetic flux to align with the magnetic flux in the armature excited by the inclined angle of the brushes for use as a one directional rotational electric motor, or for a generator power output if there is a mechanical work input. By utilizing the armature winding offset angle for excitation and control to eliminate the field exciting components, the machine is an improved design that has a simple structure and low cost.

Abstract: A DC motor magnetic circuit configuration having reduced flux leakage and improved flux density that leads to greater motor efficiency and a higher motor constant. In one embodiment of the invention, and improved permanent magnet DC motor is provided that has a stator frame supporting a plurality of pole pieces in proximity to a rotor rotatably accommodated therein. The improvement comprises at least one of the pole pieces having a pole face lying in a plane that intersects both isotropic and anisotropic planes of the pole piece.

Abstract: A pulse generator includes a rotor assembly which is formed by circularly arranged magnetic poles, and a stator assembly which is disposed coaxial with the rotor assembly and is formed by stator coils arranged circularly. Index angles defined by the circumferential ends of the magnetic poles are made unequal to each other. Pitches defined by angular intervals between adjacent stator coils are selected to allow the stator coils to electromagnetically match the corresponding magnet poles only once per revolution of the rotor assembly.

Abstract: An optical apparatus having a light-quantity control device includes:a) a rotating member having a plurality of magnetic poles;b) a stator having a plurality of magnetic pole sections opposed to the rotating member;c) a coil for exciting the stator;d) an input device for inputting driving speed information as the driving speed of the rotating member;e) an output device for outputting to the coil a driving signal for rotatably driving the rotating member less than one full rotation thereof on the basis of the driving speed information;f) a detecting device for directly detecting a movement state of the rotating member and outputting a detection signal which varies approximately linearly with the position of the rotating member representing movement state information;g) a forming device for forming rotating speed information of the rotating member from the detection signal;h) a correcting device for correcting the driving speed information by the use of the rotating speed information, the correcting device prov

Abstract: A width of polar teeth is made smaller at a region close to a gate portion 20 than a width of the polar teeth at the other region or a part of the polar teeth is eliminated at the region close to the gate portion 20 and the gap between the polar teeth is thereby increased so as to provide such a cavity as to facilitate the flow of a resin in an axial direction between the polar teeth, whereby the flow of the resin is facilitated.

Abstract: A permanent magnet excited motor is provided with a plurality of low circumferential hump-like protrusions on the face of each stator pole to partially decrease the air gap between the stator and rotor and act as so-called magnetic cams to exert a force on the rotor to smooth an otherwise uneven parasitic slot torque that occurs between the interaction of slot openings of the stator poles and the gaps between the permanent magnet poles of the rotor.