Abstract: An inductor alternator having a stator formed from an annular yoke with laminated pole pieces secured to the internal periphery thereof by welding through slots in the yoke. The rectifiers for rectifying the alternating current are located in a detachable compartment at one end of the housing containing the stator. The rotor is journaled within the stator by bearings supported in said detachable compartment.

Abstract: A portable electric motor-driven tool including an electric motor and an electrical control system for controlling the speed of the motor. The control system includes an electric switch for controlling the flow of electrical current to the motor and a composite thyristor and heat sink assembly, with electrical current conducting wires connecting the switch with the assembly. The motor has a fan providing an air stream for cooling the motor. The motor housing has a cavity disposed in the airstream and is configured to receive the thyristor and heat sink assembly and its electrical current conducting wires in quickly detachable relation therein. The heat sink includes an elongated base having laterally extending heat dispersing vanes of various sizes with each vane having a wing portion extending laterally from the vane for added heat dispersement.

Abstract: A brushless D.C. motor has electrical power switched between the phase windings by means of a circuit which includes a plurality of hall effect switches. The hall effect switches are operated by a plurality of arcuate commutating magnets which are radially polarized and are disposed axially adjacent to field magnets which are also radially polarized. Ordinarily, the direction of radial polarization of the commutating magnets and the field magnets will be opposite.

Abstract: A two-pole permanent magnet A.C. machine employs one set of permanent magnets disposed with their magnetic axes parallel to the axis of rotation of the rotor and a second set of permanent magnets disposed so that their magnetic axes are oriented radially. This arrangement allows for significant reduction in flux leakage from the machine rotor and an increase in the power density of the machine.

Abstract: A portable cryogenic helium-filled refrigeration system includes a cold finger evaporator, a compressor connected to the cold finger, a brushless DC motor connected to drive the compressor, and an electronic circuit for switching the stator-armature winding currents of the motor. The motor and compressor and the electronic circuit are all enclosed within a common housing which is charged with helium gas refrigerant under pressure.

Abstract: This disclosure deals with a time delay cut-out circuit for the start winding of an AC electric motor. The circuit includes an electronic switch which is connected in series with the start winding and which may be selectively closed to energize the start winding. Time delay means is provided which in response to current flow therethrough, provides a timing period. An auxiliary coil is wound on the motor stator and supplies current to operate the time delay means. The electronic switch is connected to respond to the time delay means which closes the electronic switch to energize the start winding during the timing period. The components of the circuit, except for the coil, are mounted in a capsule which may be plugged into the motor from the exterior of the stator. The time delay means includes a heat responsive device, and the components are sized and arranged in the capsule to optimize the heat generation and dissipation properties and thereby obtain the desired operating characteristics.

Abstract: A brushless DC motor includes a permanent field magnet secured to a rotor and having a radially directed annular surface, and two phase coil elements in the form of a sectorial loop secured to a stationary stator and disposed in a plane parallel to the annular magnet surface, the loop having circumferentially extending portions which are in inner and outer relation in respect to the center of the annular magnet surface, with the magnet and each coil element being relatively rotatable about the axis of the rotor. The mean radial distance f between the inner and outer circumferentially extending portions of each coil element and the radial width b of the annular surface of the magnet are selected as that the ratio b/f is within the range of 0.8 to 1.2 for maximizing the viscosity factor .mu. of the motor. In addition to providing the above ratio within the stated range or as an alternative thereto, the mechanical viscosity factor .mu. can be maximized by providing a reduced air gap d'=.sqroot.2d/.sqroot.

Abstract: An alternating current generator for charging a battery has a radio noise suppressing capacitor. One terminal of the capacitor element is press-contacted with the bottom of a hollow part formed in a bracket and the other terminal of the capacitor element is press-contacted with a conductive member connected to the output terminal of the generator in the holding of the capacitor. The parts can be decreased and the quality can be improved.

Abstract: A disk-shaped magnet attached to a rotary shaft is circumferentially segmented into a plurality of segments which are magnetized to form driving magnetic poles. A plurality of velocity detecting magnetic poles are also arranged on the disk-shaped magnet concentrically to the driving magnetic poles. The number of the velocity detecting magnetic poles is larger than the number of the driving magnetic poles to increase the frequency of an output signal of a velocity detecting coil which interlinks with the velocity detecting magnetic poles so that a response speed of a velocity control circuit is increased.

Abstract: A motor using Hall effect elements is disclosed, in which a disk-shaped multi-pole magnet which is circumferentially divided into a plurality of magnetic poles each magnetized in an opposite polarity to its adjacent magnetic poles is attached to a rotary shaft and a magnetic circuit is constituted by the multi-pole magnet and a yoke plate disposed to face the multi-pole magnet. A pair of Hall effect elements are disposed within a magnetic field of the multi-pole magnet to detect positions of the respective magnetic poles of the multi-pole magnet. Output voltages from the pair of Hall effect elements are supplied to a pair of drive coils, respectively, to generate driving magnetic fluxes therein. A pair of pole pieces are mounted on the yoke plate to face the pair of Hall effect elements, respectively.

Abstract: An electrical generator comprises a stationary permanent magnet for establishing a magnetic field, one or more sensing coils responsive to the magnetic field, and a diamagnetic blocking element movable between the magnet and the sensing coils for periodically interrupting the magnetic field to produce electrical energy in the coils. A preferred embodiment includes a pair of semi-circular coils arranged side-by-side in the magnetic field and a rotatable blocking disc interposed between the magnet and the coils. The disc includes a semi-circular portion of superconductive material rendered impermeable to the magnetic field at temeperatures near absolute zero and a semi-circular portion of magnetically inert material to alternately block and pass the magnetic field to the coils upon rotation of the disc.This is a continuation, of application Ser. No. 566,090, filed Apr. 8, 1975 now abandoned.

Abstract: A stepping motor of the homopolar design with a step angle of 3.6.degree. and having a generally cubic form is disclosed. The motor includes a generally square, single-section laminated stator which has only four stator poles extending radially inwardly from the middle regions of the straight sides, and a concentric rotor secured to a shaft journaled in a pair of bearing bells fixed to the stator at the opposite faces thereof and having the same generally square configuration. The rotor includes a disc-shaped permanent magnet of high remanent energy density (B.times.H).sub.max .gtoreq.10.times.10.sup.6 GOe, and a pair of annular steel rotor elements provided at the working air gap with identical numbers Z.sub.r of rotor teeth of pitch .tau..sub.r =360.degree./Z.sub.r. Each stator pole is provided at the working air gap with four or five stator pole teeth of pitch .tau..sub.s =360.degree./Z.sub.s, where Z.sub.

Abstract: A flux sensor is provided for measuring magnetic flux in laminated cores, and especially for measuring the axial flux in the end regions of the stator cores of large generators. The sensor comprises a flat, multi-turn coil of fine wire enclosed in an insulating enclosure which includes a pressure-supporting member of greater thickness than the coil. The sensor is thin enough to be placed between the laminations of a generator core and the high clamping pressure is carried by the pressure-supporting member which protects the coil. The leads are flat conductors brought out between the laminations to the periphery of the core. Such a sensor can remain permanently embedded in the core since it does not effect the core structure.

Abstract: In a brushless DC motor, the rotor has a rotor shaft with a rotor yoke attached thereto and an annular rotor magnet mounted on the rotor yoke, the stator has a stator yoke with stator coils disposed on the stator yoke so as to face the rotor magnet, and two magnetic field sensing elements, such as, Hall elements, are provided for detecting the rotational position of the rotor. A printed wiring board and the stator coils are arranged on the same surface of the stator yoke so as to make the motor flat. The printed wiring board also serves as a thrust pad for the rotor shaft and provides a ground for the latter.

Abstract: An electric motor is disclosed having stator and magnetic field gradients that taper from strong to weak. The stator is divided into north and south pole sections which each define half of a cylindrical cavity for axially receiving the rotor. The stator magnetic field gradient is established by north and south pole stator sections each having an axial cross section defined by first and second overlapping circles. The first circle is centered on the axial centerline of the motor. The second circle is centered on the vertical centerline of the motor and is provided with a radius approximately equal to the diameter of the first circle. The first and second circles intersect at a common tangent to define the weakest of the north and south pole sections of the stator. A tangent of the first circle spaced 180.degree. from the common tangent of the first and second circles intersects the second circle to define the strongest of the north and south pole sections of the stator.

Abstract: A centrifugal actuator for an electric motor starting switch which is rotatable with the rotor shaft of the motor and which is movable axially with respect to the rotor shaft. A spring biases the centrifugal actuator into engagement with a fixed stop carried by the housing of the electric motor so that the position of the centrifugal actuator with respect to the motor starting switch remains fixed and is not affected by axial movement of the rotor shaft within the electric motor housing.

Abstract: A connection terminal construction for connecting a driving coil terminal of an electro-mechanical converter such as a step motor or the like of electronic timepieces to an output terminal of a wiring circuit is disclosed. The construction comprises a terminal base formed of a flexible print substrate and provided at least one of upper and lower surfaces thereof with connection patterns. The terminal base is extended toward a circuit substrate substantially in alignment therewith and secured thereto by means of a screw.

Abstract: An external-rotor brushless direct-current motor has a pair of rotor plates spaced axially apart and connected together for joint rotation about an upright axis. One of these plates carries an annular multipolar axially polarized magnet. A fixed stator plate extends between the two rotor plates and carries a plurality of angularly equispaced sequentially activatable windings. In addition a flux-return element of soft iron is carried on this stator plate and has an outer periphery formed with projections extending into the flux region of the magnet. These projections may simply be the corners or points of a polygonal flux-conducting element, or may be formed between recesses cut into the periphery of this element.

Abstract: A one piece, elongated strip of electrically conductive material is provided with electrical connection means at each end thereof. Preferably, each connection means is bent approximately ninety degrees from the plane of the material strip. The strip serves as a jumper means finding application in dynamoelectric machines employing switch assemblies for connecting the dynamoelectric machine to a source of electrical energy, and speeds interconnection of the switch assembly during motor manufacture.

Abstract: An auxiliary field winding for a superconductive AC electrical machine. The auxiliary field winding is adapted to provide a controlled and rapidly varying magnetic field to an armature winding in addition to that produced by the main field winding for improving the dynamic stability of the machine. The main field winding is superconductive and is adapted to provide a substantially steady-state magnetic field to the armature. The two windings permit the machine to rapidly accommodate changes in the load made on the machine during operation.

Abstract: A cup-shaped shell with a re-entrant bearing member surrounds the rotor on the bottom side and has a rim which is substantially flush with the top of the rotor. On a balcony or shoulder in the outer portion of the shell, the coils of an iron-less stator winding are affixed by means of an adhesive so that they extend self-supportingly inwards into an air gap between two parts of the rotor that are spaced by a separator piece resisting the magnetic forces tending to attract the two parts of the rotor to each other, which member is mounted on the rotor shaft and surrounds, with an intermediate clearance, the re-entrant bushing of the casing.

Abstract: A frame member for the voltage regulator spaces the latter from the stator core and from an insulating plate on the bearing cover which also supports the voltage regulator, so as to maintain an air space between the stator core and the frame member which serves as a window for the intake of cooling air into the generator. The cooling air cools the regulator, as well as the stator core and winding, and the air gap reduces the heat transfer from the stator core and winding to the regulator.

Abstract: A rectifier and brush assembly for an alternator has a rectifier comprising two parallel spaced phase plates carrying respective sets of diodes. The terminals of respective diodes of the sets are soldered to respective connectors. One terminal of each of a set of field diodes is also soldered to each connector while the other terminal of each field diode is soldered to a connector common to all the field diodes. This common connector has an integral apertured flange which is secured by a screw against a conductive plate carried by a housing for the brushes. The conductive plate is electrically connected with one of the brushes in the brush housing. The brush housing also carries a voltage regulator of which a lead is crimped to an apertured electrical connector secured by the screw to the conductive plate.

Abstract: In an electromagnetic driving device for example for an electric clock, a driving polar rotor arranged in the magnetic field of a coreless field coil drives a rotatable following polar rotor so that in their static states the poles of the rotors are shifted at a definite angle in the direction of the magnetic field of the coil. The driving polar rotor is rotatably supported within a bobbin on which the coil is wound and is retained in the bobbin by a rotor retaining part which is held in place by a printed circuit plate which controls the current flowing through the coil.

Abstract: Iron or other ferromagnetic material is utilized in the rotor core of a dynamoelectric machine having a superconductive field winding. A parallel connection arrangement of the winding in combination with a plurality of current dividing resistance elements provides a sinusoidal distribution of current density across the circumference of the rotor. The magnetic field associated with the sinusoidal current distribution is reduced in critical interior regions of the winding by the demagnetizing field produced by the magnetic poles of the ferromagnetic core, thereby allowing a larger current to flow in the winding without destroying superconductivity. The two fields add in regions exterior to the winding, thereby providing a net increase in the useful external field obtained from a given amount of superconductive material.

Abstract: A coreless motor comprises a motor housing having a bearing, a rotor mounted within the housing, rotatably supported within the bearing and having a plurality of coils constituting a pancake coil, a permanent magnet stator mounted within the housing and disposed opposite to the rotor, in which the stator is arranged opposite to an effective coil section of the pancake coil and thus the rotor, and an annular spacing is formed opposite to an outer peripheral portion other than the effective coil section of the rotor so that a balance adjusting member for the rotor as well as an electrical part associated with the coreless motor can be provided in the annular spacing within the motor housing.

Abstract: Measurement of the current flowing in the rotor of an electrical machine and especially an a.c. exciter with external poles for excitation of a synchronous machine by way of a rectifier mounted on the rotor is accomplished without the use of sliprings by means of at least one pair of contra-wound coils extending in the axial direction of the rotor, the coils being connected in series and mounted in a slotted support of insulation material secured to the underface of a pole shoe in the gap between shoe and a toothed rotor. A voltage proportional to the rotor current is induced in the pair of coils by the stray flux generated by the current carrying conductors in the rotor slots. The width of each coil approximates the width of one tooth on the rotor and the spacing between the axes of the coils approximates the size of the rotor slot pitch.

Abstract: A method and apparatus are provided for detecting rotor faults in large dynamoelectric machines, such as turbine generators. Faults in the rotor windings of such machines may occur as shorted turns or as ground faults, and in either case even harmonics are produced in the field flux waveform in the air gap of the machine. The occurrence of such faults, therefore, can be detected by monitoring the flux waveform in the air gap to detect the presence of even harmonics. This may be done by means of a search coil or coils properly disposed in the air gap of the machine.

Abstract: A miniature electric motor is disclosed wherein a synthetic bobbin or frame has a rotor inside of a central cylindrical cavity, the rotor being supported in bearings which include large diameter flanges bonded to the bobbin. The windings are disposed around the bearing flanges and in grooves whose bottom surfaces are tangential to the cylindrical cavity. The windings thus assist in holding the bearing flanges to the bobbin and form part of the motor framework. The angular bottom surfaces effect increase in the number of turns in the windings and effects an increase in the rotor diameter and thus in the motor torque.A ring yoke of high permeability and low remanence surrounds and is bonded to the bobbin. Attached to the inside wall of the yoke are two diametrically opposed soft iron pins located at an angle to the normal of axis of the field created by the windings to create poles for stopping the rotor at a predetermined position.

Abstract: An electric motor having a rotor consisting of a disk-shaped multi-polar magnet circumferentially sectioned to have a plurality of magnetic poles, a stator consisting of a pair of superimposed star-shaped flat driving coils, said driving coils being disposed facing said magnet, said driving coils being arranged to be supplied with respective alternating currents having a phase differential of 90.degree. thereby to drive the disk-shaped magnet, said motor further comprising a speed detecting coil having a plurality of radially disposed generating wire elements, said generating wire elements being disposed within a magnetic field of said magnet and being connected in series, whereby a signal having a frequency corresponding to the revolution speed of said disk-shaped magnet is induced in said speed detecting coil.

Abstract: To prevent connecting difficulties in the manufacture of automotive-type alternators of the claw pole generator type, resilient spring compression terminals, or contacts are formed, respectively, on a terminal board or on a voltage regulator terminal for engagement with a spring terminal element connected to the fieldwinding so that mere placement of the terminal board or a voltage regulator, respectively, against the springy terminal connections will effect electrical connection and not requiring any internal connecting steps within the alternator and especially at locations of impaired accessibility since they are hidden behind the terminal board, or voltage regulator, respectively.

Abstract: A slug is disposed adjacent a rotor of an induction type motor. The slug is of a "ferrous" material such that the attraction between it and the magnetic poles of the rotor creates at least side and preferably both side and end loading of opposed ends of the rotor shaft within its supporting bearings. The slug, disposed stationarily in spaced relation to the rotor, is of a length approximately equal to the length of a chord through adjacent magnetic poles. The action of the slug is to reduce bearing rattle in a rotating member.

Abstract: An exciter current lead-through bolt which is passed through a radial bore in the rotor shaft of a dynamo-electric machine, especially a turbo-generator, and screwed into an exciter-current lead-in conductor bar which lies in a longitudinally extending bore within the shaft. The radially outer part of the lead-through bolt is mechanically and electrically connected with a terminal conductor bar leading to the exciter winding located on the rotor. In order to reinforce the lead-through bolt and minimize the danger of breakage, a radially inwardly directed resilient force is applied to the outer end of the bolt. Provision is also made for internal as well as external cooling of the through-bolt by air which is taken in by respective air pick-up devices located on the surface of the shaft.

Abstract: A switch and terminal assembly adapted to be mounted to a structural component of a dynamoelectric machine by an electrical conductive mounting member. The assembly has a casing, and receiving means is provided through the casing for accommodating the mounting member. A grounding device is disposed in the casing for connecting the dynamoelectric machine to ground, and the grounding device includes means associated with the receiving means for engagement with the mounting means upon the mounting thereby of the assembly to the dynamoelectric machine structural component.

Abstract: An overspeed switching mechanism for a motor has an electrically conductive rotor driven by the motor, a movable drag mechanism having a permanent magnet structure linked magnetically with the rotor for movement of the mechanism through electromagnetic interaction between the magnet structure and the rotor, a latching mechanism linked with the drag mechanism by means of another permanent magnet structure for restraining movement of the drag mechanism until the rotor attains a preset speed at which the latching mechanism releases the drag mechanism and allows limited movement thereof, a switch, and an actuator operatively linked with the drag mechanism and the switch for translating movement of the drag mechanism into switching of the switch.

Abstract: In order to provide an electrically insulated and fluid-tight assembly for securing a current transformer to the inside of a dynamoelectric machine housing, a screw is inserted through an aperture in the machine's housing to secure the current transformer to a portion of the inner surface of the housing wherein a first insulating material is used to insulate the current transformer from the housing; a second insulator is used to insulate the screw from the housing; and an insulating cap is secured over the top of the screw. An O-ring provides a fluid-tight seal between the cap and the machine housing and a retaining ring is utilized to secure the cap over the screw's head within the machine housing. Secured to the lower part of the current transformer is a soft iron magnetic shield which is threaded to engage the screw and serves to support the current transformer.

Abstract: Apparatus for overvoltage protection of the field winding of a synchronous dynamoelectric machine. A protective spark gap device is electrically connected in parallel across the field winding of the machine and is designed to weld itself into a short-circuit when the voltage across the field winding increases to an unacceptable value. The weldable spark gap provides a positive indication of problems in the field circuit and at the same time protects the field circuit from damage from continued operation. The protective spark gap is not self-restoring and therefore must be removed and replaced before operation is resumed.

Abstract: An ac generator for a vehicle in which a stator frame having a stator core fixed thereto and supporting a rotary shaft therein is composed of a pair of end covers of steel plate and a cylindrical casing of steel plate, and the end covers, cylindrical casing and stator core are integrally connected together by welding so as to ensure a high mechanical strength.

Abstract: A homopolar motor-battery combination having axially magnetized elements alternating with conductive disks attached to a motor shaft. The conductive disks and an electrochemically active shroud member around the disk rims act as battery electrodes to send current through the disks. The current reacts with the axial magnetic field to produce rotation of the disks and shaft when immersed in an electrolyte.

Abstract: To provide for even running and uniform torque output of pulse-energized motors, elements having soft-iron characteristics are located outside of the air gap, but within the stray, or leakage field emanating from the poles of a permanent magnet rotor, the elements being shaped and located with respect to the windings to exert a braking torque on the rotor when the rotor is in a position with respect to the coils of the motor for efficient energization of the coils, the magnet elements interacting with the field from the rotor during the gaps of energization to release the stored energy therein. The magnet elements may be yoke elements located adjacent, or outside of the air gap, soft-iron sheet metal strips, adjustably positioned on the stator, or the like.

Abstract: An arrangement for the rotating thyristor excitation [RT excitation] in a turbogenerator which is suited for very high centrifugal force loadings in which the carrier discs of the rectifiers wheels are designed in the form of hubs mounted about the shaft secure against turning and having hollow-cylindrical projections extending axially in two directions to form with the shaft recesses into which the semiconductors including their cooling elements and their protective external components as well as the electronic driver units are disposed along the inside diameter of the cylindrical projection on the hubs.

Abstract: An integral servomechanism is shown that mounts a synchro receiver in the form of a control transformer, a torque motor, an isolation transformer and associated electronic circuitry integrally within a housing wherein the transformer permits the utilization of integrated circuits by providing voltages stepped down from the line voltage while isolating the control transformer from the line voltage.