Abstract: An electrical machine of the reluctance or permanent magnet type includes one or more pawns of high permeance material which are relatively moveable along a plurality of C-shaped stators which are regularly spaced at a predetermined stator pitch dimension. The pawn or pawns are of a length equal to or exceeding the stator pitch dimension such that as the pawn is pulled into the air gap of a stator which is energized, the magnetic field induced in the pawn or provided by a permanent magnet is coupled to a following stator which is not yet energized to avoid reverse acceleration of the pawn and reduce vibration. The field coupled to the following stator also reduces the power required to establish a desired level of magnetic flux in the following stator when the following stator is energized. The cross-section of the air gap of the stator and the pawn are closely matched to maintain a minimum air gap when the pawn passes through the air gap of each stator.

Abstract: A DC compound motor of the type having a series winding and a shunt field winding includes an auxiliary generator driven by the motor for supplying power to the shunt field winding. The generator can be chosen, or a control circuit added, to control the current supply to the shunt field winding based on the speed of the motor.

Abstract: A commutator employs superconducting switches to commutate currents in the field stator of a dc machine. The switches couple the machine's stator windings to a DC link. The switches are exposed to magnetic fields of alternating strengths, turning on and off in a sequence that maintains a constant torque angle between the stator's mmf vector and the flux vector of the machine's rotor or that rectifies a current induced into the stator by the machine's rotor.

Abstract: A rotor magnet of the type including a plurality of circumferentially arranged magnets of alternately opposite polarities, wherein each of the magnets has a magnetizing pattern such that the magnetic force is minimum at predetermined portions near opposite ends of the magnet and gradually increases from the predetermined portions toward the center of the magnet and also from the predetermined portions toward the opposite ends of the magnet. With this magnetizing pattern, the rotor magnet has a substantially sinusoidal waveform-like magnetic flux density distribution pattern when the motor is rotating. As a consequence, the magnetic polarity changes smoothly and the motor can, therefore, operate at a low operation noise.

Abstract: A magnetic pole position detecting device is coupled with a brushless dc motor by determining the angular positional relationship between an input shaft of a rotor, a detecting device body, and a locating mark formed on a detecting device casing by outputting absolute values indicative of the angular position of the rotor, coupling an output shaft of the brushless dc motor with the rotor of the detecting device, driving the dc motor externally, and forming another locating mark on the motor casing in alignment with the locating mark formed on the detecting device casing, under a condition in which the angular positional relationship between the motor casing and the detecting device casing is so determined that motor induced voltage is in phase with waveform of the absolute values output. Therefore, it is possible to easily replace the magnetic pole position detecting device with a new one in a short time at any job site, independently from the motor.

Abstract: A DC brushless motor comprising a rotor shaft, and rotor assembly mounted on the rotor shaft. The rotor assembly includes a permanent magnet rotor and a plurality of sequentially stacked rotor laminations positioned between the rotor magnet and the rotor shaft. The permanent magnet rotor is magnetized with N number of rotor poles. A stator assembly in magnetic flux relationship with the rotor assembly is provided. The stator assembly includes plurality of sequentially stacked stator laminations with each stator lamination having N number of stator poles. The stator laminations are juxtaposed to the permanent magnet rotor such that each stator pole is of a different polarity from the corresponding rotor pole. The distance between the stator and rotor poles forms an air gap. Each of the stator poles are slightly skewed with respect to each of the corresponding rotor poles such that the air gap is asymmetrical. Electrical windings are provided for energizing the stator poles to operate the rotor.

Abstract: A three-phase direct-current motor has a field magnet having P field poles positioned as a circular array at angularly equally spaced intervals, and an armature having cores providing N slots with three-phase coils disposed therein, either the field magnet or the armature being rotatable with respect to the other. P and N are defined by P=2(4n+3) and N=3(2n+1) where n is an integer of 1 or more, and being selected such that the least common multiple of N and P is equal to N.times.P. Alternatively, P and N are defined by P=2(3n.+-.1) and N=6n where n is an integer of 2 or more.

Abstract: In a d.c. motor, the stator may form the armature and has its windings inserted in slots in its cylindrical surface and the rotor may comprise a permanent magnet or be provided with d.c. windings. Switching means operate in synchronism with rotation of the rotor to connect a d.c. source to the armature windings so that a rotating field is produced in arrears of the rotor field to exert a repelling force on the rotor poles. Because the rotor and stator fields are in opposition, rather than in mutual assistance, less energy is needed to energize the windings to produce a given torque. Also the current in each winding is very low when commutation occurs and sparking avoided.

Abstract: The stator electromagnets (80', 82', 84', 86', 88', 90') face inward about the rotor cavity (12) of the motor. Spaced horseshoe magnets (70) with spaced apart, opposite poles face outward about the periphery (22) of the rotor (20). The stator electromagnets are in two arrays. Each array is aligned with one pole of the rotor set of horseshoe magnets and has a pulling electromagnet (80' or 86') of a pole opposite to the pole of the rotor magnet. Each array also includes two pushing electromagnets (82', 84' or 88', 90') circumferentially offset from the pulling electromagnet, which are of a magnetic pole the same as the pole of the rotor magnet. Optical sensors (173, 175), which are axially aligned with the electromagnets, sense the position of rotor with regard to points on the stator. Switches on a circuit card associated with each array of electromagnets connect to the corresponding optical sensor for alternatively passing or blocking current to the electromagnets.

Abstract: In a d.c. motor, the stator may form the armature and has its windings inserted in slots in its cylindrical surface and the rotor may comprise a permanent magnet or be provided with d.c. windings. Switching means operate in synchronism with rotation of the rotor to connect a d.c. source to the armature windings so that a rotating field is produced in arrears of the rotor field to exert a repelling force on the rotor poles. Because the rotor and stator fields are in opposition, rather than in mutual assistance, less energy is needed to energize the windings to produce a given torque. Also the current in each winding is very low when commutation occurs, and sparking avoided.

Abstract: A commutator machine, in particular a small direct-current motor, has at least one pair of permanent magnets (11) retained on a magnetic short-circuit element (10), the permanent magnets being of a single-substance ferrite material or a multi-substance material having portions of high coercivity and high remanence along the periphery of an armature (15) rotating inside the stator (12). By selecting suitable ferrite materials, depending on the required excitation field intensity or the required demagnetization stability, and by the proposed dimensioning of armature diameter (d.sub.A), magnet thickness (D.sub.M) and thickness of the short-circuit element (D.sub.R), an optimal configuration of the motor is obtained by attaining the maximum possible capacity with the lowest possible weight.

Abstract: A brushless D.C. motor, suitable for use as a hand-held surgical tool, includes a field of self-supporting coils arranged between a pair of impregnated fiberglass epoxy sheets situated in an air gap formed by a rotatable shaft having an even-number plurality of magnets formed thereon, and a non-electrically conductive housing. The individual magnets abut one another upon the shaft to prevent a magnetic return path from the substantially unidirectional field produced thereby, and are formed in relationship to the coils such that a single rotor pole will never be under a single coil, in order to minimize induced shorted currents.

Abstract: The invention generally concerns a DC motor with an armature, several poles and with field coils surrounding said poles. According to the instant invention, each pole includes two pole halves which are displaced from each other in the peripheral sense by a given distance. Pole halves belonging to a given pair are connected to each other by a common pole shoe so that each pole is approximately U-shaped in its radial cross-section with the legs of the U (the pole halves) pointing outwardly. Each pole half is individually surrounded by its own field coil. In general, the principle of the invention is that the pole of a classic DC motor is split in two and that the thus obtained pole halves are displaced symmetrically relative ends of the pole shoe. In this manner, a shorter yoke length Lj.sub.8, together with lower magnetomotive force in ampere-windings than in a classic DC motor are made possible. Furthermore, a lower coil resistance is obtained, i.e.

Abstract: A dc brushless electromagnetic rotary machine, such as a dc electric motor or a dc electrical generator, includes a rotor having a permanent magnet which has the entirety of its cylindrical outer peripheral surface magnetized in the same polarity. The outer surface faces an annular armature core fixed on the inner cylindrical surface of a casing frame forming a stator of the machine. In the structure, the magnetic flux emanating from the rotor magnet passes the armature core and returns to the magnet from a position other than the armature core. The armature core is provided with coil windings on its cylindrical inner surface facing substantially the one surface portion of the permanent magnet. A portion of the coil windings is covered with a shielding member in which portion current is conducted which induces magnetic flux in a direction opposite to that of the magnetic flux generated from the permanent magnet.

Abstract: A brushless DC micromotor made up of a stator coil and a rotor housed inside thereof with magnet poles formed therein, which micromotor is characterized in that the stator coil is formed by coaxially winding more than one coil sheet formed on an insulating sheet, on which coil sheet a plurality of coil patterns are continuously provided in series in the direction of winding. The motor of the present invention can be made smaller, thinner and lighter than the conventional counterpart made by the use of a wound copper wire coil.

Abstract: A knitted glass fiber tube is everted, or turned inside out to convert the usual outward flare which develops at the cut end thereof into a purse mouth which tends to urge the cut end inward against the peripheral surface of a conductor bar passing therethrough. The intimate contact between the cut end of the everted knitted glass fiber tube and the conductor bar resists deposition of conductive contaminants which may otherwise reduce the insulation provided by the everted knitted glass fiber tube.

Abstract: A dc brushless electromagnetic rotary machine, such as a dc electric motor, a dc electrical generator, includes a rotor having a permanent magnet which is cylindrical outer peripheral surface magnetized in the same polarity. The outer surface faces armature cores fixed on the inner cylindrical surface of a casing frame forming a stator of the machine. In the structure, the magnetic flux emanating from the rotor magnet passes the armature cores and returns to the magnet from a position other than the armature cores. The armature core is provided with coil windings wound thereon in such a manner that a portion of the windings is included in the air gap formed between the rotor magnet and the cores. Additional magnetic flux induced in response to current flowing over the armature windings causes the main magnetic flux generated from the rotor magnet to be turned in the same way irrespective of the angular position of the rotor.

Abstract: In a permanent magnet commutator type D.C. servomotor having a wound iron core armature and a permanent magnet stator, the stator includes a uniquely formed annular yoke. The unique yoke includes a central opening and a plurality of permanent magnet pole pieces, which are securely held to arcuate magnetic material projecting into the opening and which are spaced equally from and about the axis of the yoke. The magnets and arcuate magnetic material form boundaries to accommodate the armature and also form a relieved area between the magnets designed for reduced field distortion. The radial thickness of the magnet pole pieces, the arcuate members of magnetic material and the radial thickness of the yoke are proportioned relative to each other and to the I.D. of the pole pieces at prescribed values to maximize the motor performance.

Abstract: Homopolar generators are provided with a helical field coil disposed around a rotor, wound coaxially with the rotor, and connected in series with sliding electrical contacts on the rotor. The coil of a single rotor machine includes two sections wound so as to increase magnetic flux through the rotor when current is allowed to flow through an external circuit and through the coil and brushes. For a dual counterrotating rotor machine, a single section coil is used to perform the same function.

Abstract: An electromechanical device comprised of a battery energized motor having widely separated poles and requiring momentum for operation applied by inertia from a lost motion fly-weight accelerated by the motor during commutation which momentarily starts and stops the motor for an extended dwell time and which subsequently restarts the motor for continued operation, there being primary sensory effects as a result of motor operation subject to speed change by the control of extraneous motion, there being a first motor commutated circuit energizing sensory effects, and there being a second cam switched circuit energizing sensory effects adjusted to long and short dwell modes, the motor operation and effects being synchronous at variable angular velocity within 180.degree. and 360.degree. of rotation.

Abstract: The stator of the motor comprises a series of stator rings arranged in cylindrical fashion. Each stator ring is made up of a circular row of electromagnetic components, each component comprising a U-shaped core having two outwardly projecting poles and individual coils for each of the poles. The stator rings are positioned so that their electromagnetic components are offset rotationally from one ring to the next. The rotor is mounted to rotate outside the stator and comprises a plurality of longitudinally arranged magnetic elements circumferentially spaced around the stator. In operation, the stator rings are energized sequentially by suitable switching means to generate a torque in the rotor. The motor has capacity for variable speed and variable torque.

Abstract: A dynamoelectric machine, of the direct current type, with a circumferentially segmented stationary magnetic field structure providing magnetic poles including diametrically opposed pairs of north and south poles, with intervening poles of alternating polarity; rotor conductors extending longitudinally and selectively interconnected in sets providing a plurality of series current paths each traversing a plurality of stator active pole regions; and a pair of brushes for current collection at one or both machine ends.

Abstract: The rotor of an electric direct current rotating machine has at least one winding which cooperates with a stationary magnetic circuit. The winding is formed of several sections connected in series. The respective opposite ends of each section are connected to adjacent segments of a commutator associated with the winding. The sections are arranged on the rotor in such a manner that portions of different adjacent sections are disposed concurrently in the commutation zone so that currents flow through these portions in opposite directions. The invention finds application in particular to direct current motors and to motor-generators.