Abstract: A wound stator for a permanent magnet electric machine has an array of coils on the outer rim of a generally cylindrical stator body. The stator coils are wound directly on the stator body by providing the stator body with a plurality of mutually circumferentially-spaced, coil-retaining and forming members around which the ends of the stator coils are coursed so that the coil sides project in a direction parallel to the center axis of the stator. Wire connections are formed between coils of a phase, and wire loops are formed between the last wound coil of one phase and the first wound coil of a subsequently wound phase. Mechanisms are provided for clamping the stator start wires and for temporarily retaining the wire loops.

Abstract: A first input signal has successive zero amplitude crossings. A first comparator generates a first bilevel output signal responsive to the first input signal. The first comparator has a hysteresis characteristic which is switched on at each said zero crossing of the first input signal and switched off prior to each occurrence of the next following zero crossing. A second input signal has successive zero amplitude crossings and is displaced in phase relative to the first input signal. A second comparator generates a second bilevel output signal responsive to the second input signal. The hysteresis characteristic is switched on by level transitions of the first bilevel output signal and switched off by level transitions of the second bilevel output signal. The first and second input signals may be sinusoidal. The hysteresis characteristic may controlled by first and second flip/flops, which are set by the first bilevel output signal and reset by the second bilevel output signal.

Abstract: An electronically commutated motor for dust exhausters with a stator with excitation windings and with a rotor positioned to rotate in an air gap. The rotor has bundled laminations and permanent magnets around its circumference corresponding to the number of poles of the stator. A fan rotor of a ventilator is also provided on the rotor shaft, with the fan rotor connected downstream from the motor in the intake direction of the cooling air. The rotor shaft is connected with a turbine for generation of an intake air current, wherein the fan rotor is positioned in the upper bearing plate of the turbine. The bearing plate is designed in one piece in immediate vicinity of the turbine rotor and has indentations and cutouts in a radially outward direction, whereby air currents of the fan rotor and the turbine rotor flow each from its respective side, with the exit slots for cooling air from the fan rotor and the outlets for the exhaust from the turbine going out from the bearing plate.

Abstract: This invention discloses a magnetic bearing device comprising a rotary member rotatably supported on a supporting member through a magnetic bearing, a free oscillating member which is oscillatable almost coaxially with the rotary member and disposed at a position not being in contact with both supporting member and rotary member, magnetic coupling member for oscillating the free oscillating member and the rotary member together, and a damping member disposed between the free oscillating member and the supporting member.

Abstract: A motor housing for a string trimmer having a vibration damper disposed between the housing member and the motor. The motor housing has transverse motor support ribs fixedly supporting the motor. A damper chamber is formed in the housing between and end face and an adjacent transverse motor support rib. Stiffner ribs disposed between the end face and the adjacent transverse motor support rib form radial seats on diametrically opposite sides of the motor. A resilient linear vibration damper member is compressively received in each of the damper chambers between the electric motor and the radial seats.

Abstract: In a switch mode power supply a voltage developed in an isolating transformer is rectified via a first diode and coupled via a feedback path to a control terminal of a regulator. The voltage is also rectified via a second diode and coupled to a supply terminal of the regulator. A pair of diodes are coupled in series between the supply and control terminals. During normal operation, the pair of diodes are non-conductive. When, under a fault condition, the first diode is disconnected, the pair of diodes provide a redundant or alternative feedback path in a manner to prevent excessive output level of the power supply.

Abstract: A current source delivering a constant current despite sudden voltage fluctuations which may be applied on its output. This current source includes two branches in parallel, a generating branch and a reference branch. The output current is kept constant by keeping the potential difference across the terminals of the resistors in the generating branch constant, by using a differential amplifier. All the transistors are of the NPN type.

Abstract: There is presented an electric motor having a drive shaft, an armature and a commutator fixed on the drive shaft, a housing disposed around the armature, magnets disposed between the armature and the housing, and an endframe fixed to the housing. The endframe has therein a journal for retaining the drive shaft, brushes for contact with the commutator, and shunts and terminals connected to the brushes. In the endframe are brush tubes for slidably retaining the brushes and coil springs for urging the brushes into engagement with the commutator. Each brush tube has one of the coil springs therein, an outer end, side, front and rear walls sufficiently closed to prevent egress of the coil spring, and an open inner end through which one of the brushes engages the commutator. An internal wall of the brush tube is provided with a barb integral therewith and extending inwardly of the brush tubes to overlie a portion of the coil spring proximate the brush tube outer end.

Abstract: A parallel running control apparatus for PWM inverters controls the parallel running of a plurality of unit inverters controlled in pulse width modulation to supply AC power to a load, output terminals of the unit inverters being connected to each other via interphase reactors. The parallel running control apparatus comprises a current detector, a compensating unit and a control unit. Since a secondary magnetic flux, a slip frequency, and other control variables can be calculated without taking account of any element of disturbance, stable control ensues.

Abstract: A compound structure for increasing brush resistance while reducing brush face short-circuit current loss includes multi-piece single-material, multi-piece different-material, or multi-piece graduated permeation material brushes arranged to reduce circulation losses.

Abstract: A binded carbon brush includes a brush main portion formed mainly of carbon, and an electric conductor formed by a material, such as a copper powder, having an electric resistivity lower than that of the brush main portion and extending along a main current direction of the brush. In the cross section of the brush perpendicular to the main current direction, the diameter or the vertical and horizontal sizes of the conductor is so set as to be smaller than both the vertical and horizontal sizes of the brush main portion.

Abstract: A counterweighted rotor for use in a compressor assembly, the counterweighted rotor including a core assembly, an end ring defining a first end of the rotor, an end ring defining a second end of the rotor, each end ring having a plurality of coining lugs integrally cast thereto, the coining lugs sized for securing weights to the rotor, a plurality of counterweights for balancing the rotor, each of the counterweights including a body formed from powdered metal, the body having an aperture on its radial edge for engaging a coining lug, and a lip integrally formed on the counterweight porprotioned for contour fitting with the inside diameter of the rotor end ring. A method of forming counterbalanced rotor employs forming weights from powdered metal, the counterweights attaching to the rotor by coining over a coining lug of the rotor end ring through an aperature in the counterweight body.

Abstract: There is disclosed a magnetic bearing cell of rotationally symmetrical construction, which includes a rotor having two rotating permanent ring magnets and a stator having a damping disk that projects into a first gap between the permanent ring magnets of the rotor. In order to improve the radial stability of the cell an additional permanent ring magnet is secured to the shaft and is spaced apart from one of the rotating permanent ring magnets to define a second gap therebetween. A ring disk that is secured to the stator projects into the second gap, the ring disk carrying an axially magnetized stator permanent ring magnet in the vicinity of the rotating permanent ring magnets of the rotor.

Abstract: A planar carbon segment commutator has contact members, with terminals, attached to the front surface of an insulating base member by means of overmoulded carbon segments formed integral with anchor pieces disposed within apertures in the base member. Each aperture has a second part disposed rearwardly of a first part having a smaller cross-section than the second part and the anchor piece disposed within the aperture has a locking portion which fills the second part of the aperture to thereby resist withdrawal of the anchor piece from the aperture. The contact members are embedded in the carbon segments and have holes filled with carbon segment material to increase interlocking between the contact members and the segments.

Abstract: In order to be able to completely eliminate the axial play of an armature spindle of an electric motor, especially for a windshield wiping system of a motor vehicle, even though conditions change over time, a prestressing member acted upon by a spring leg continuously presses against the end of the armature spindle. The prestressing member does not necessarily have to abut directly on the end of the armature spindle, but rather a cap is inserted onto the end of the armature spindle and non-rotatably fixed to the motor housing or a gear housing. An eccentric formed as the housing of the prestressing member abuts on the outside of the bottom of the cap. In an alternative embodiment, a mushroom shaped prestressing member having a mushroom head presses against the end of the armature spindle.

Abstract: A miniature motor includes a case made of metallic material and formed into a bottomed hollow cylindrical shape and having a permanent magnet fixedly fitted to the inner circumferential surface thereof. A rotor is provided with an armature and a commutator. A case cap is fitted to an open end of the case and has brushes making sliding contact with the commutator. Input terminals are electrically connected to the brushes directly or via other electrically conductive material. The rotor is rotatably supported by bearings provided on the case bottom and the case cap. Through holes formed into a T shape in cross-sectional profile are provided on the case cap made of a resin material. The input terminals each having a stopper on the lower end thereof and a lanced and raised piece on the central part thereof are passed in the through holes, the lanced and raised pieces are bent to almost right angles with the input terminal surface to fixedly fit the input terminals to the case cap.

Abstract: A brushless DC drive motor with an external rotor has three pole shoes on a substantially ring-shaped stator for each two poles on the rotor. The stator winding is commutated by a three-phase commutation network in such a fashion that first, second and third networks in the stator winding are cyclically connected to an external DC source in accordance with rotor position. Each of the networks comprises at least one stator coil wrapped around a neck of a single corresponding one of the pole shoes.

Abstract: An asynchronous motor is disclosed with stator and rotor windings placed in respective grooves, at least one of the windings being a cast winding. The grooves on the stator and those on the rotor are so inclined relative to each other that the groove inclination is approximately 60 to 90% of the pole pitch. In addition, to enhance the effect of the groove inclination, the stator and/or rotor is subjected, after the casting of the windings, to a heat treatment process in which the stator and/or rotor is heated to a high temperature and then cooled. The invention facilitates construction of an asynchronous motor having a reduced magnitude of generator torque of the motor and a changed rotational speed at which it occurs in relation to a conventional asynchronous motor.

Abstract: A stator core for supporting an electrical coil includes a plurality of groups of circumferentially abutting flat laminations which collectively form a bore and perimeter. A plurality of wedges are interposed between the groups, with each wedge having an inner edge and a thicker outer edge. The wedge outer edges abut adjacent ones of the groups to provide a continuous path around the perimeter.

Abstract: A collector terminal and hydrogen seal assembly for insertion within a radial hole in a generator rotor and connectable to a conductor bar located within an axial bore formed in the rotor, the seal assembly comprising a substantially cylindrical terminal stud portion having threaded upper and lower sections and a smooth intermediate section; insulation wrapped about the intermediate section; a spacer block located between the seal elements and defining an annular space surrounding the insulation; and a conduit in the terminal stud adapted to introduce compressed air from outside the generator rotor to the annular space for testing the integrity of the seal elements.