Abstract: The motor comprises a stator formed in one piece and having an opening formed therein, a yoke of high magnetic permeability and a coil wound round the yoke. The rotor comprises a shaft and a bar magnet. The opening has a first part all points of which are disposed at a first distance from the rotation axis of the rotor and a second part the points of which are disposed at second distances, different from the first distance, from that rotation axis. The invention is applicable particularly to stepping motors having a low consumption of electric current, e.g. for time pieces.

Abstract: Dynamoelectric motors, particularly, a brush and brush holder assembly which comprises two semi-circular motor casing elements manufactured of non-insulating material. The semi-circular casing elements may be snap-fitted together, so as to support the individual brushes in contact with a commutator. The brush holder is characterized by its structural simplicity and ease of assembly.

Abstract: An electromagnetic rotary motor including a stator means, a rotor means and an electronic control means for inducing an electromagnetic field. The stator means includes a permanent magnet means having pole faces that define a gap between them with a generally uniform magnet flux density thereacross. The gap has an entrance section, an exit section and a generally curved longitudinal path extending from the entrance section to the exit section around a transverse axis. The magnetic flux density changes as one moves from the entrance section to the exit section as a function of arc degree position around the transverse axis. The rotor means includes a predetermined number of permanent magnets disposed radially outwardly from the rotor axis. These rotor magnets are disposed substantially within the gap and the magnetic field of each rotor magnet interacts with the magnetic field of the stator magnets through repulsion or attraction.

Abstract: Difficulties in sensing the temperature of end turns in dynamoelectric machines are avoided through the use of an envelope containing a temperature sensor disposed between abutting sets of end turns in such machine. The envelope has two insulating plies formed of insulating material sandwiching a ply formed of metal having excellent thermal conductivity. The latter is bonded to the former such that an exposed edge of the insulating plies exists by which the envelope may be closed to totally encapsulate the metal ply.

Abstract: A rotary rectifier assembly including a shaft adapted to be rotated. Three equally angularly spaced phase conductors are disposed about the shaft and insulated with respect to each other and with respect to the shaft and each has opposed, axially opening recesses. Diode wafers are received in each of the recesses and each recess further receives an electrically conductive load shoe. A pair of end conductors sandwich the phase conductors, wafers and load shoes and each end conductor has three equally angularly spaced curved recesses for matingly receiving the curved portion of the corresponding ones of the load shoes. A single biasing device is employed to bias one end conductor towards the other to thereby establish good electrical contact between the various components while occupying a minimum of space and minimizing the overall weight of the assembly.

Abstract: A magnetic drive unit includes a magnetic circuit composed of a yoke and a magnet which define a magnetic gap therebetween, and a voice coil movably disposed in the magnetic gap for moving a driven member, the voice coil comprising turns formed by helically cutting a tubular conductive body, the turns being spaced at pitches which are larger within the magnetic gap and become progressively smaller in directions away from the magnetic gap. The turns are of a rectangular cross section and insulated by a mass of resin coated on their surfaces.

Abstract: The present invention relates to a kinetic wheel arrangement comprising a stator, a rotor and a magnetic suspension, wherein said rotor comprises a central recess about said axis of rotation; there is disposed in said central recess of the rotor a pressure system provided with a screw which is connected to the stator and of which the axis merges with said axis of rotation of the rotor, this pressure system being adapted to take a first position for which said rotor is free to rotate about its axis of rotation while being suspended by its magnetic suspension, and a second position for which it presses said rotor against said stator to immobilize it; and remotely-controlled means are provided to cut said screw between said stator and said rotor. The invention is particularly applicable to the caging of the rotor in phases during which the kinetic wheel arrangement undergoes considerable mechanical stresses.

Abstract: A brushless DC motor of the kind that includes a relatively large rotor permanent magnet magnetized radially in segments around its circumference to provide alternate segments oppositely magnetized has a stator magnetic structure with two dissimilar pole pieces in flux conducting relation to a pair of windings. A first of the pole pieces presents a face to the outer surface of the annular magnet across an air gap. A second pole piece, which may be somewhat further from the outer surface of the annular magnet, at the opposite end of the windings, presents only a narrow edge surface facing generally in the direction of the magnet. The modified pole piece is L-shaped or U-shaped, having one or two legs respectively, projecting from the coil support structure generally circumferentially with respect to the magnet.

Abstract: A holder arrangement for the reciprocating rod of an electromagnetic reciprocator includes a reciprocating rod capable of reciprocating axially by magnetic action or the alternate combination of magnetic and spring actions, thereby effecting movement of a working member or members mounted at one end or both ends of said rod over a given stroke. In this arrangement, a flexible rod holder is disposed at a suitable position of a base to which an electromagnet is attached, said holder being provided with a flexible tongue piece for holding said reciprocating rod.

Abstract: A permanent magnet type stepping motor is provided. The rotor is made of a cylindrical laminated iron core whose outer periphery is toothed at an equal pitch, and the number of teeth is Nr. The stator is made of a laminated iron core whose inner periphery is formed so as to face the rotor at an air gap between the rotor and the stator. Thin plate permanent magnets are attached on the surface of the stator teeth facing the air gap. The permanent magnets are disposed at an equal pitch and polarized such that the polarities of adjacent pole pieces differ from each other. The number of pole pieces is Ns, and has a relation Ns=2(Nr.+-.Np), where Np is an integer more than 1. The stator grooves are half opened or closed and have multiphase 2 Np pole distributed windings.

Abstract: A low inertia, speed variable induction motor with a stator, a yoke, and a rotor mounted on an output shaft being accommodated in the interior of a frame, wherein the stator is fixedly provided inside the frame, the yoke is rotatably mounted inside the frame in a manner to oppose the stator with a small gap between them, and a cup-shaped rotor is inserted into the small gap between the yoke and the stator, thereby reducing the size and weight of the driving body including the cup-shaped rotor, and improving its high speed response property.

Abstract: A homopolar generator includes a stator producing a magnetic field and a rotor which rotates in the stator magnetic field to generate electrical discharge current. The current is available from a slip ring surface defined on the rotor, and a plurality of brush mechanisms are provided to collect and transfer the discharge current from the rotor slip ring. Each brush mechanism includes a brush pad for contacting the rotor slip ring. The brush pad is attached to one end of a laminated trailing arm brush strap. A brush actuator forces the brush pad into contact with the rotor slip ring against the yieldable brush lifting force of the brush strap. To compensate for the reaction between adjacent brush straps due to the magnetic fields set up by the discharge current being transferred by each, a conductor strap is electrically connected to the end of the brush strap opposite the attached brush.

Abstract: A reciprocating electric motor employs plural motor stator modules each including a group of coils selectively energized in subgroups to produce a magnetic field sweeping from one end of the group to the other and then repetitively from the same one end to the other always in the same direction until a number of ferromagnetic non-ferromagnetic armature sections each equal in length to the length of the stator modules and equal in number to the stroke of the motor divided by the length of each section has passed the stator module and thereafter the sequence of energization is reversed to move the armature a like distance in the opposite direction, the several coils of each group being electrically connected in a set each of which has its own power supply, the power supplies being collectively controlled by a microprocessor.

Abstract: A linear DC motor adapted for driving a positioning table having a frame and a table displaceable in a linear direction has a toothed assembly affixed to one element thereof and an array of permanent magnets facing the toothed assembly mounted on the other element. Coils wound around the teeth of the toothed assembly and appropriately energized by DC produce a linear force which is effective to displace the table in a desired direction. When used with a position sensor and an appropriate control system, the table is controllable to a desired position. A set of brush members depending from the table contact a developed linear slip ring track for energizing the coils and for switching polarity of voltage to the coils at appropriate locations. In an embodiment where the coils are stationary on the frame and the magnets are disposed on the table, a power pickup arrangement movable with the brush members is incorporated into the brush and developed slip ring apparatus.

Abstract: An electric linear drive comprises a housing in which an external rotor electric motor is mounted. The motor has its stator fixedly mounted on said housing while on the other hand the rotor of the motor has a male screw thread thereon on which a bush is screwed. The bush is joined to a thrust rod and there are means for guiding the bush axially in the housing so that it may be moved into and out of the housing with a telescoping effect. This guiding means is furthermore designed for limiting the axial stroke of the thrust rod.

Abstract: In an electric motor, for example as used in audio or video apparatus, the rotor comprises a disk-shaped carrier of synthetic resin in which coils are accommodated. In order to stimulate a uniform running of the motor the mass of the rotor is increased by manufacturing the carrier from a synthetic resin filled with a filler having a high specific mass.

Abstract: The present invention provides a micro stepping motor for more accurately stepping and positioning a magnetic head in a magnetic disc system. The stepping motor has a permanent magnet type rotor and a stator encircling the rotor, the rotor having a plurality of pole teeth formed therein with a fine pitch and the stator also having a plurality of pole teeth formed therein with a fine pitch and disposed opposed to the pole teeth in the rotor, the stator pole teeth being divided into at least one pair of pole tooth groups which are out of phase relative to each other by an electrical angle of 180 degrees. A single common stator coil is provided to the pair of stator pole tooth groups. Thus, the stepping pitch of the rotor is determined by the pitch in the pole tooth groups, whereby the rotor can steppingly be driven with higher density even by the reduced number of stator coils.

Abstract: A solenoid assembly comprising a magnetic plunger, an electric coil for generating a magnetic flux in a direction along an axis of the magnetic plunger, a main yoke composed of at least two separate members for defining a magnetic flux passage around the electric coil, and a pair of yoke end members held in engagement respectively with opposite ends of the main yoke, an outer casing. The yoke end members have recesses extending substantially normally to the axis of the magnetic plunger, and the main yoke has projections fitted respectively in the recesses to maintain the main yoke and the yoke end members in engaging relationship. The outer casing has an inner wall keeping the main yoke held in engagement with the yoke end members. A leaf spring acts on the main yoke to hold the latter securely in place in the outer casing. The yoke end members have cylindrical projections supporting thereon the electric coil between the projections of the main yoke.

Abstract: A linear motor comprising a moveable coil, a stationary core in which the coil moves, and a drive member including a shaft and a bearing, the shaft moveable in the bearing and passing through the core. In the preferred embodiment, the drive member includes a pair of circular plates connected by three shafts that slide in bearings passing through the motor core, with the coil attached to the periphery of one of the plates. Springs having varying coil spacing are seated between the plates and the motor core to damp the motor's motion, with the strongest damping at the ends of its reciprocating stroke.

Abstract: A variable-frequency feeder control using a single oscillator to develop signals for moving materials in either one of two directions. An output signal from the oscillator is applied to a first timing circuit which develops signal pulses for driving a horizontal electromagnetic drive coil. The first timing circuit controls the duration of the signal pulses which determine the amplitude of power to drive the horizontal coil. The output signal from the oscillator is applied to a second timing circuit which developes a phase shifted signal to control the phase between the power applied to the horizontal coil and the power applied to a vertical drive coil. A third timing circuit uses the phase shifted signal to develop signal pulses for driving the vertical coil and controls the duration of the drive pulses.