Abstract: An axial flux reluctance machine including a rotor formed from a wound tape of paramagnetic material, a first stator formed from a wound tape of paramagnetic material and a similarly constructed second stator, where the first and the second stators define stator poles and wherein the stator poles of the first stator are not completely aligned with the stator poles of the second stator. Also a reluctance machine system for energizing the axial flux reluctance machine and methods for forming the wound tape rotor and stators.

Abstract: In a switched reluctance motor, the projected poles of a rotor have feeble-magnetic portions each having a shape that extends radially inward approximately in the rotational direction from a position relative close to a radially outer end of the projected pole and to an end of the projected pole facing in a counter-rotational direction, that is, a direction opposite to the rotational direction, or a shape that has a side extending radially inward approximately in the rotational direction from a position relatively close to a radially outer end and an counter-rotational direction-facing end of the projected pole and that extends radially inward approximately in the counter-rotational direction. The feeble-magnetic portions are weaker in magnetism than the material of the rotor and reduce the magnetic attraction force occurring at the time of switching of coil energization, thereby reducing noises while ensuring generation of a desired amount of torque.

Abstract: The present invention relates to a squirrel-cage induction motor for frequency converter use, in particular, which squirrel-cage induction motor comprises a stator, a stator winding arranged in its axial grooves, divided into at least two coil groups for each phase of the supplying alternating current and connected to the supplying alternating current in such a manner that the sum of basic frequency groove currents is substantially zero at each moment. In accordance with the invention, one half of the coil groups of each phase is connected to the supplying alternating current at one end of the stator and the other half of the coil groups of each phase at the other end of the stator.

Abstract: A reluctance type synchronous motor comprises: a stator with a plurality of slots placed at an even pitch angle wherein stored inside each slot is a stator winding for creating stator magnetic poles with a predetermined phase alternating current being supplied thereto. A rotor sustained by a shaft and changing magnetic reluctance in its circumferential direction by inclusion inside of a plurality of magnetic isolating portions creates desired magnetic poles. At least one of the central angles between magnetic poles created at the rotor is shifted from the other central angles so that torque ripples during rotation can be reduced.

Abstract: A cooling arrangement for a high speed open rotor reluctance motor/generator apparatus of the type finding combination use in aircraft applications for engine starting and electrical energy generation in both normal and auxiliary power unit operating conditions. The cooling arrangement identifies fluid flow alternatives which include inlet region redirection of coolant fluid to improve its induction into rotor interpolar space, rotor movement-induced centrifugal pressurizing of coolant using simple and more complex structural elements, machine heating of the coolant fluid, kinetic energy extraction from heated moving coolant fluid and combinations of these arrangements in particular machine configurations. Use of the invention under extremes of machine energy levels and self heating in military and commercial aircraft environments are contemplated.

Abstract: A rolling contact bearing with rotational speed measuring device, in particular a wheel bearing for motor vehicles for telemetric transmission of energy and signal between bearing and environment, insensitive to tolerances of the bearing and its surrounding parts, with simple and cost-effective construction and small dimensions. A first telemetry unit is integrated in the inter-ring seal. It comprises pulse transmitter, rotational speed sensor, telemetry electronics and a miniature coil, which is inductively coupled with a further telemetry unit, which is fitted axially outside the bearing, and which supplies the first telemetry unit with energy and receives its signals.

Abstract: A device for determining rotary motions generally includes a signal generator with inwardly directed teeth or inwardly directed projections and a double-sided measuring coil which is arranged within the surface of the signal generator. The measuring coil has a core of permanent magnets and pole shoes. The pole shoes project from both sides of the coil and extend up to the inner surface of the signal generator. The pole shoes are designed, arranged and conformed to one another so that, whenever the end piece of a pole shoe points to a tooth or a projection, the second, diametrically opposite end of the pole shoe is directed to a tooth gap or depression. The measuring coil core is made up of at least two permanent magnets which are magnetized perpendicularly to the coil axis and respectively embedded between two pole shoes.

Abstract: A reluctance machine including a plurality of phase windings where each phase winding comprises a plurality of fractional-pitched coils. The reluctance machine may be coupled to a drive that can energize one, two or more of the phase windings to provide output torque that is derived from: (i) the self-inductances of the phase windings; (ii) a combination of the self inductances of the phase windings and the mutual inductances between the phase windings; or (iii) the mutual inductances between the phase windings.

Abstract: This invention relates to a switched reluctance rotator according to which a rotor can be rotated at a high speed without generating electromagnetic vibration at a rotating shaft and in which a current for generating of torque and a current for generating a radial force are passed through windings on the protruding poles of the stator or a winding for generating torque, and a winding for generating a radial force are wound on the protruding poles of the stator.

Abstract: A micro-turbo generator device (10) includes a housing (12), a rotor (14), a plurality of stator cores (16), and coils (18) encircling the stator cores. The housing (12) includes a shaft (34) which has an axis (11). The rotor (14) is rotatably mounted onto the shaft (34) and includes a perimeter (32) and a plurality of rotor poles (24) extending generally radially about the axis (11). Each rotor pole (24) includes a magnetizable tip (30) and a concave fluid impact surface (26). The stator cores (16) are disposed about the rotor (14) and include first pole face (15) and second pole face (17) facing the perimeter (32) of the rotor (14) and spaced apart therefrom. The coils (18) helically encircle the stator cores (16) and conduct electrical current to magnetize the stator cores (16) to magnetize the tips (30) and to alternately conduct induced electrical current generated in response to changes in magnetic flux between the first and second pole faces (15, 17) and the magnetizable tips (30).

Abstract: A capacitive sensor includes a rotor and a stator. The rotor includes at least one rotor sector, and the stator plate includes a plurality of stator sector plates. A dielectric is located between the stator and the rotor. The rotor sector plate, the plurality of stator sector plates and the dielectric form a plurality of capacitors when the rotor plate is in a plurality of positions. The plurality of stator sector plates are coupled to an external multiple voltage source which applies multi-phase voltage signals to each of the stator sector plates in which each multi-phase voltage has a different phase. The multi-phase voltage signal is coupled from the rotor to the stator through the formed capacitors so that the coupled signal through the capacitors is indicative of the angular position of the rotor. A second sensor comprises a movable plate assembly and a non-movable plate assembly that form a plurality of capacitors when the movable plate assembly is in a plurality of positions.

Abstract: A reluctance machine system including a reluctance machine having a rotor and a stator including at least one phase winding and a full pitch auxiliary filed winding where constant currents are established in the auxiliary field winding to assist in the establishment of a magnetic field in the machine so as to improve the machine's performance. Alternate embodiments are disclosed wherein the auxiliary field winding is positioned in a conventionally-shaped stator with phase windings of different types (e.g., short-pitched and fractional-pitched).

Abstract: A switched reluctance motor is provided with a rotor position detecting apparatus for detecting a rotor position wherein the apparatus comprises a rotor position-sensing mechanism removably mounted in a ventilator hole formed in a side wall of a motor housing for enabling an easy replacement of printed circuit boards and photo-interrupters when they need to be repaired and maintained. The sensing mechanism includes a fixing member having spaced slots for receiving respective circuit boards.

Abstract: A variable reluctance motor is disclosed including a stator having a plurality of radially inwardly extending poles. A coil of foil wire is mounted about each of the stator poles. Flats are formed in the inner surface of the stator adjacent to the sides of each of the stator poles so that the coils of foil wire can lie flat thereagainst. A pair of rigid cylindrical retainers are provided for retaining the coils of foil wire on the poles. A rotor assembly is disposed within the stator. The rotor assembly includes a shaft having a rotor secured thereto. A plurality of radially outwardly extending poles are formed on the outer surface of the rotor. Electrical current is selectively passed through each of the coils of foil wire to cause the rotor assembly to rotate relative to the stator. Each of the coils of foil wire is wound beginning with a start winding and ending with a finish winding.

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: An index signal is used for assuring media for use in a floppy disk drive to be exchangeable with each other. While the signal is output once for each rotation of a spindle motor, since the signal generation is carried out in a non-contact manner with rotating members including the medium, a hole sensor or the like has been previously used. However, such a hole sensor is expensive and fragile under temperature and mechanical stress. A pulse generator has been proposed, in which the rotor magnet is provided with magnets having unequally allocated angles and disposed all along a circumference and a stator coil and is disposed so as to match with the rotor magnet to have a pulse generated once for each rotation. However, the generated signal has, been poor in its S/N characteristic. It is an object of the invention to overcome the difficulties and provide a pulse generator that is highly reliable and excellent in the S/N characteristic with the manner of allocation of angles for the rotor magnet improved.

Abstract: A dynamo-electric machine such as a switched reluctance motor (10). A stator (14) has a central bore (16) and a plurality of inwardly salient poles (18A-18D) extending into the bore. A rotor (22) is mounted on a shaft (24) for rotation relative to the stator. The rotor has a plurality of outwardly salient poles (26A, 26B) extending into the bore. Stator windings (20, 21) are bifilar windings which produce an electromagnetic field when a phase is energized. The bifilar windings return energy to the voltage source when the phase is de-energized. An auxiliary winding (28) is also installed on the stator. The auxiliary winding is energized, when the machine is off, to produce a magnetic field which causes rotation of the rotor to a preferred aligned position relative to the stator poles. This facilitates subsequent starting of the machine. An electrical circuit (30) energizes the auxiliary winding, when the machine is off; and then energizes the stator windings when the machine is started.

Abstract: A switched reluctance motor includes a stator defining a plurality of radially-inwardly-extending poles and a rotor defining a plurality of radially-outwardly-extending poles. The poles of the stator define a shape in radial cross-section characterized by a generally rectangular body portion, and a tip portion which tapers at an angle no greater than 40.degree. relative to the sides of the rectangular body portion. The nominal width of the rectangular body portion of each stator pole is at least 1.3 times the nominal (chordal) dimension across the arcuate, radially-innermost surface on the tip portion thereof.

Abstract: A reluctance machine including a stator defining a plurality of stator poles and a plurality of stator slots, a rotor positioned to rotate with respect to the stator, and a plurality of phase windings, where each phase winding comprises a plurality of coils, where each coil is wound about more than one stator pole, where each coil comprises two coils sides, and where only one coil side is positioned in each stator slot, wherein the self-inductance of each phase winding varies as a function of the angular position of the rotor with respect to the stator. Also a reluctance machine similar to that described above where each of the phase windings is magnetic uni-polar.

Abstract: A rotor for a two-pole synchronous reluctance or a switched reluctance motor can be constructed from a stack of flat, planar laminations of grain-oriented materials. To enhance the necessary anisotropy of reluctance, slots are provided in the lamination along the magnetic flux lines in the preferred grain direction. The laminations may be provided with an essentially circular outer perimeter, and slots for a squirrel cage winding provided. A complete, efficient squirrel cage winding can thus be provided for a two-pole synchronous reluctance motor for starting purposes.

Abstract: A magnetic rotor (5) is provided inside a stator armature (1) of a reluctance motor with an air gap between them. Two salient poles (5a, 5b), each having a width that is 2.5 times each of angular intervals among adjacent slots (1a, 1b, . . . , 1h) of the stator armature (1), are arranged on the outer peripheral portion of the rotor (5). Magnetic fluxes generated by energizing armature coils (2h, 2d) of magnetic poles (4h, 4d) that are not situated at positions where torque is produced are added to magnetic fluxes generated by energizing armature coils (2a, 2e) of magnetic poles (4a. 4e) that are situated at-positions where torque is produced in a direction indicated by arrow R. As a result, leakage fluxes Fa, Fb between the magnetic poles (4a, 4e) and the salients (5a, 5b) of the rotor (5) increase, causing the torque to increase.

Abstract: A rotor for a switched reluctance or synchronous reluctance machine includes a central member from each end of which extends a rotor pole. The rotor is made up of continuous laminations which each define a plane parallel to the axis of rotation of the rotor. A reluctance machine is also disclosed in which the rotor is used. The rotor has radially inner pole faces which cooperate with the pole faces of an inner stator.

Abstract: A permanent magnet machine combines both principles of variable reluctance machines and permanent magnets, and comprises a rotor with salient rotor poles and a stator with salient stator poles. A pair of ferrite arched permanent magnets are embedded in the stator yoke beneath respective stator poles and are arranged symmetrically around the central axis of the machine. A field winding for boosting or weakening the primary flux generated by the permanent magnets is wound in a special arrangement.

Abstract: A new class of doubly-salient motors which incorporate a specific stator/rotor pole arrangement and stationary permanent magnets mounted in the stator to provide a linearly increasing flux linkage over the entire area of pole overlap. The new motors provide greater output torque, higher efficiency, quicker response, and a simpler structure in comparison to conventional reluctance motors.

Abstract: A linear motor having a plurality of stator pieces rather than a ring-shaped stator. Accordingly, production costs are reduced and controllability can be improved. By coupling directly two sets of rotors and stators with a pulsator and spinning tub, an extra power transfer device can is unnecessary.

Abstract: An apparatus and method for starting a single-phase variable reluctance motor defined by a stator having one or more pairs of projecting poles defining a principal axis and a rotor mounted on a rotatable shaft co-axial with the principal axis of the stator is provided. The apparatus includes a device for preventing the rotor from being halted in a position of zero-developed torque thereby enabling reliable starting of the motor. The device includes a vane defined by a ferromagnetic disk having alternating mark regions and space regions which is mounted to the rotatable shaft and may form part of a rotor position transducer. A permanent magnet is positioned so as to move the vane into a position at which starting torque of the desired direction will be developed when the motor is energized. A further embodiment combines the magnet with a Hall-effect sensor so that, in conjunction with the vane, a rotor position transducer is formed.

Abstract: An open stator axial flux asynchronous induction electric motor has an open stator having two spaced insulating supports with a slot extending from a periphery of each of the supports to an inner location. A plurality of poles extend between and are secured to the supports. The stator has either distributed winding or salient phase pole windings associated with at least some of the poles with an opening between adjacent poles in the regions of the slots in the supports. The motor has a rotor with a shaft extending through the slots and at right angles to the supports. Two spaced rotor discs are present on the shaft and are located at either side of the stator. Each disc is made of a magnetically permeable material and has either an inner face of electrically conductive material or an inner face with conductive paths which function as rotor windings.

Abstract: In a thin type flexible disk drive motor, in order to improve undesirable jittering of rotation, an inertia ring of larger diameter than that of the rotor frame is fixed immediately under the rotor. The inertia ring consists of a short cylinder part of the larger diameter to be fixed under the rotor frame and a flange part of the diameter not smaller than that of FG (frequency generation) magnet part. The disk drive motor also has a drive pin engaging assembly that allows a drive pin to be secured within a hub of the flexible disk while stabilizing the drive pin and after disk chucking.

Abstract: A reluctance machine system including a reluctance machine having a rotor and a stator including at least one phase winding and a full pitch auxiliary filed winding where constant currents are established in the auxiliary field winding to assist in the establishment of a magnetic field in the machine so as to improve the machine's performance.

Abstract: A switched reluctance electric motor is disclosed that includes a stator portion having a plurality of stator poles. Adjacent stator poles are wound with energizing windings and which are connected in-series to form a respective one of a plurality of motor phases of the electric motor. A rotor portion of the electric motor is also disclosed, and is supported for rotation relative to the stator, and which also includes a plurality of rotor poles. An electrical conductor having first and second ends is disposed about the adjacent stator poles for each one of the plurality of motor phases. The first and second ends of each electrical conductor are shorted together to thereby minimize induced flux linkages in non-energized motor phases when one of the motor phases is energized.

Abstract: A motor with positive torque parking positions. The motor includes a rotor which is rotatable about an axis of rotation and a stator in magnetic coupling relation with the rotor. The stator includes a plurality of teeth each having a radially extending shaft and an axially extending face. The faces of the stator teeth define an aperture for receiving the rotor and the faces of the stator teeth and the rotor define an air gap therebetween. Each stator tooth has a notch in its face that is approximately at least as wide as the shaft of the stator tooth so that the stator has a magnetic configuration relative to the rotor for parking the rotor in a rest position corresponding to a positive torque starting position. The motor also includes a winding on the shafts of the stator teeth and a control circuit for controlling current in the winding whereby an electromagnetic field is produced for rotating the rotor at a desired speed or torque during operation of the motor.

Abstract: A stator wound resolver comprising: a stator and a rotor aligned on an axis; the stator having a plurality of teeth with input and output windings disposed on some or all of the teeth, the input and output windings exhibiting a mutual inductance characteristic that varies as a function of position of the rotor about the axis; the input winding being connectable to a drive signal and the output windings being disposed on the teeth such that output signals induced in the output windings correspond to position of the rotor; the rotor being attachable to a position changing means, the rotor comprising at least two axially spaced rotor pieces that are offset from each other by a stagger angle such that a portion of harmonic distortion produced by one of the rotor pieces is reduced by complementary harmonic distortion produced by another of the rotor pieces.

Abstract: A switched reluctance motor has a rotor disposed in an annular stator and formed mainly of a stack of iron plates. The rotor has pole protrusions that face the stator. The pole protrusions have weak magnetic portions provided therein. Each weak magnetic portion has a shape elongated from a leading outer point to a tailing inner point, or a shape that has a base side extending a leading outer point to a tailing inner point and that extends from the base side in the rotational direction and in the inward radial direction. The weak magnetic portions are formed of a material that has a weaker magnetism than the materials forming the other portions of the rotor.

Abstract: The sensor 20a has first and second permanent magnets 31, 32, stator 33 and coil 24. The first and second permanent magnets 31, 32 has an inner peripheral face formed with south and north poles circumferentially and alternately with a uniform space therebetween. Holes 17a, 17b are formed circumferentially with a uniform space therebetween in the tone wheel 13. At the moment when all the south poles in the first permanent magnet 31 are opposed to the holes 17a, all the north poles of the second permanent magnets 32 are opposed to the holes 17b, resulting in that the alternating magnetic flux flows in the stator 33 and the electric voltage is generated alternately in opposite directions in the coil 24 as the tone wheel 13 rotates.

Abstract: A switched reluctance machine capable of improved operation under fault conditions. The machine includes a controller which responds to a fault in a phase winding by cutting off current to the phase windings of all stator poles that are aligned with a rotor pole at the time the stator pole having the phase winding with the fault therein aligned with a rotor pole. Consequently, there is no magnetic flux in the stator or rotor at such time. Therefore, no current is induced in the faulted phase winding. This avoids generation of a counter torque, as well as avoiding potential catastrophic failure of the SR machine.

Abstract: A variable reluctance electric motor includes a stator having a plurality of radially inwardly extending poles which are divided into a plurality of longitudinal sections. The cross sectional shapes of the first stator pole sections are different from the cross sectional shapes of the second stator pole sections. A rotor is supported within the stator for relative rotational movement and includes a plurality of radially outwardly extending poles which are divided into a plurality of longitudinal sections. The cross sectional shapes of the first rotor pole sections are different from the cross sectional shapes of the second rotor pole sections. The first rotor poles are longitudinally aligned with the first stator poles so as to interact therewith when electrical current is supplied to windings provided on the stator poles.

Abstract: A permanent magnet electric motor including a rotor having an annular arrangement of field magnets for rotation around an axis relative to a stator. An annular FG magnet arrangement affixed to an end of the rotor cooperates with an adjacent FG coil to produce a signal indicative of the rotor speed. A shunt washer of magnetically permeable material is interposed between the field magnet arrangement and the FG magnet arrangement.

Abstract: An improved reluctance machine is provided wherein auxiliary flux paths are provided such that the leakage flux of the machine is directed through the auxiliary flux paths and not through the excited stator poles to reduce the impact of stator pole saturation on the machine's performance.

Abstract: A rotational velocity sensor ring comprising a circular cylindrical body with a radially interior cylindrical surface, a radially exterior cylindrical surface and first and second cylinder ends, a plurality of substantially equally spaced, substantially equal length fingers extending from the first cylinder end, and on each of the fingers, a substantially 180.degree. bend proximate to the first cylinder end, wherein each finger is radially exterior of the circular cylindrical body, wherein each finger has a finger end extending toward a second cylinder end opposite the first cylinder end, wherein each finger is proximate to the radially exterior cylindrical surface and parallel to a cylinder axis of the circular cylindrical body, wherein the fingers comprise a set of teeth of the rotational velocity sensor ring.

Abstract: A new class of doubly-salient machines which incorporates a specific stator/rotor pole arrangement to provide a linearly increasing flux linkage over the entire area of pole overlap, and either (1) stationary permanent magnets mounted in the stator, or (2) one or more auxiliary field windings coiled about the stator or (3) a combination of stationary permanent magnets and auxiliary field windings. In each of the three cases, the permanent magnets or auxiliary winding(s) generate the primary flux and block and thereby limit flux in the ordinary path of the secondary flux (due to the stator windings) through the stator. The altered magnetic structure utilizing four stator and six rotor poles increases efficiency when operated as a generator, and provides greater output torque when operated as a motor.

Abstract: A single-phase permanent magnet motor (10). A stator assembly (12) includes a stator (14) having a central bore (and a plurality of salient poles (18a-18d) extending into the bore. A rotor (13) is positioned within the bore and is rotatable relative to the stator. Stator windings (17) are used to energize the motor. A magnet (22) installed on the rotor is used to position the rotor in a stable detent or parked position to facilitate starting the motor. The magnet is a ring magnet formed on the rotor and the magnet has a plurality of magnetic ring segments (24a-24d) extending circumferentially about the ring. Each ring segment is shaped to provide a constant level of flux across the ring segment. Each stator has an indentation (36) at one end for aligning the rotor with the stator in its parked position. The result is the availability of more starting torque to start the motor than is available in other motor constructions.

Abstract: A pulse generating wheel, combined with a radial shaft sealing ring, for a machine element that can rotate about an axis. The pulse generating wheel has a cylindrical sleeve that can be slid onto the machine element. The radial shaft sealing ring is provided with a sealing lip, made of polymer material, that is delimited on the side facing the atmosphere by a conical surface. In a first axial position of the cylindrical sleeve, the conical surface is contacted by the cylindrical sleeve and can be expanded in the radial direction. The cylindrical sleeve can be displaced out of the first axial position into a second axial position in which the sealing lip moves into direct contact with the machine element, and the cylindrical sleeve is at an axial distance from the conical surface.

Abstract: A reluctance machine comprises a rotor, defining rotor poles and a stator defining stator poles. Each stator pole pair, creating a flux path through the rotor includes only one winding mounted on one of the stator poles. The invention is particularly applicable to a machine having a four-pole field pattern and an odd number of phases. The coils are placed on alternate stator poles such that the space between stator poles can be used exclusively for a single winding. The single winding is made larger to compensate for the lack of a winding on its associated pole.

Abstract: A single-phase variable reluctance motor is disclosed. The motor includes a stator having a pair of projecting poles defining a principal axis and a rotor mounted on a rotatable shaft co-axial with the principal axis of the stator. The stator may have inwardly extending poles that terminate in a central bore and the rotor may be rotatably disposed in the central bore. In such an embodiment, the stator poles are arranged generally diametrically opposed to one another. The rotor is mounted on a shaft and has a pair of poles generally diametrically opposed from each other. The stator and rotor may be formed from laminations of a ferromagnetic material. Energizing coils are wound around one or more of the stator poles. When energized, the energizing coil(s) impart a torque on the rotor causing it to rotate. One or more permanent magnets are inserted into the winding(s) forming the energizing coil(s) to park the rotor in a preferred starting position when the motor is turned off.

Abstract: In the case of a stator-excited starter-generator, a permanent magnet arrangement, which is magnetized in the opposite direction to the winding excitation, and has yoke overhangs which are radial with respect to the adjacent sector stator elements, is arranged in the axial separating space of two sector stator elements, which are arranged axially one behind the other each stator element is winding-excited by an excitation winding part of opposite polarity.

Abstract: A variable reluctance sensor for sensing the rotational speed of a target wheel having teeth, separated by slots, angularly positioned along its periphery is comprised of an elongated core interposed between two permanent magnets which generate additive magnetic flux passing longitudinally through the elongated core. This additive flux is, however, opposed by a longitudinal flux developed by the opposing ends of the permanent magnets. In the absence of surrounding ferromagnetic material, the magnitudes of the opposing longitudinal flux components are essentially equal, resulting in no net longitudinal component of magnetic flux. The elongated core and permanent magnets are encircled by a multi-turn electrical coil which is wound transversely about a longitudinal dimension. A portion of the elongated core and permanent magnets extending beyond the electrical coil are positioned adjacent the periphery of the target wheel and define an air gap therebetween.

Abstract: A tone wheel made by press-forming a magnetic metal plate, has an annular portion and a plurality of fingers which are arranged in comb teeth fashion on an outer peripheral rim of the annular portion, and formed by bending beck the magnetic metal plate through 180 degrees so as to be overlapped as two layers, so that there is a large change in magnetic flux density as the tone wheel rotates past an opposing sensor, thereby increasing the amount of change in the sensor output signal.

Abstract: A switched reluctance motor has groups of adjacent poles of the same polarity. A starting magnet is fitted to one side of one or more of the poles in one or more of the groups. The polarity of the magnet can be the same as that of its host pole. The starting magnet influences the rest position of the rotor when it is not being driven so that the rotor will not be in an orientation such that it will not start when the stator poles are energized.

Abstract: A wheel speed sensor having a simple construction outputs a signal used for measuring the rotational speed of a wheel without noise due to displacement of rotating members. A housing is provided on a carrier member of a suspension mechanism, the carrier member carrying a bearing rotatably supporting a wheel shaft of the wheel. At least one fixed tooth is protrusively formed on an inner surface of the housing. An annular coil is arranged inside the housing. A rotatable yoke member is accommodated in the housing and is rotatable together with the wheel shaft. The rotatable yoke member comprises a shaft inserted into a center hole of the annular coil and an extending member extending in a radial direction. The shaft extends through the center hole of the annular coil so that a first gap is formed between an end of the shaft and a wall of the housing. At least one rotatable tooth is formed on an outer periphery of the extending member so that a second gap is formed between the rotatable tooth and the fixed tooth.

Abstract: A variable reluctance rotation sensor comprising a flux member having a ferromagnetic pole piece formed of a cylindrical center portion interposed between a first and second end portion. Each of the end portions have a respective surface which contains elongated teeth, similarly separated by slots as teeth on the periphery of a toothed wheel. The cylindrical center portion is positioned with respect to the toothed wheel such that the toothed surfaces of the first and second end portions are positioned adjacent the periphery of the toothed wheel comprising the teeth and slots, the magnetic flux member and toothed wheel defining an air gap. The sensor further comprises permanent magnets which establish main flux loops traversing the air gap, and leakage flux loops linking an electrical coil wound about the cylindrical center portion. As the toothed wheel is rotated, the magnitude of the main flux loops vary in relation to the varying air gap.