Abstract: A dry vacuum pump is provided, including two shafts, respectively supporting at least one pumping rotor being configured to synchronously rotate in reverse in order to convey a gas to be pumped from an intake of the dry vacuum pump to an outlet; and a synchronous motor configured to rotate one shaft of the two shafts, the synchronous motor including a rotor coupled to the shaft, a first stator with windings arranged around the rotor, and at least one second stator with windings arranged around the rotor, the windings of the stators being configured to be supplied individually or simultaneously in order to adapt a power of the synchronous motor to a pumping load. A method for controlling a synchronous motor of a vacuum pump is also provided.

Abstract: A device for detecting a holding state of an object. The device includes a housing for the object that has a shape that can be held by an operator and a piezoelectric sensor attached to the housing. Moreover, a detecting unit can detects a holding state of the housing by using a fluctuation amount of an output voltage of the piezoelectric sensor. The housing has a shape having a hollow space and the piezoelectric sensor has a flat film shape and is disposed in contact with an inner wall surface of the housing. The piezoelectric film produces charges when stretched and contracted in response to a displacement of the housing that are outputted as a voltage to the detecting unit. When detecting that the output voltage significantly fluctuates, the detecting unit identifies that the object is being held.

Abstract: A vibration wave drive device includes an annular piezoelectric element including a piezoelectric material and multiple electrodes provided sandwiching the piezoelectric material, the annular piezoelectric element being configured to vibrate by a traveling wave of a wavelength ?; and a power feeding member including at least an electric wire for supplying electric power to the element, the feeding member being provided at a first surface of the element. The element includes at least two driving regions, and a non-driving region arranged between two of the at least two driving regions and having an average annular length of n?/4, n being an odd number. At least one electrode provided on the first surface is arranged across the driving region and the non-driving region, and is electrically connected to the feeding member only in the non-driving region.

Abstract: An electrical machine is provided comprising a first rotor (121), wherein the first rotor includes a support structure (163), a second rotor (131), a stator (141) and, wherein the first rotor, second rotor and stator are arranged concentrically about a shaft (50), and at least one of the second rotor and the stator is adapted to accommodate the support structure. An electrical machine is also provided comprising a shaft (50) having an axis, at least one first rotor (321), at least one second rotor (331), at least two stators (341a), (341b) and, wherein the first rotor, second rotor and stators are arranged axially along the shaft and extend from the axis.

Abstract: A stator module and a motor including the stator module are provided. The motor includes a stator and a stator module. The rotor includes a rotor core and a plurality of rotor poles arranged around a circumference of the rotor core, each generating a magnetic flux. The stator module includes a first stator and a second stator disposed coaxially with each other, each being rotatable in a circumferential direction and each having a coil wound thereon, and a rotation driving unit which controls a rotation of the first stator and the second stator through the same angle in opposite directions, thereby controlling a flux linkage of a rotor according to the rotational angle of each of the first stator and the second stator.

Abstract: A stepping motor includes a stator, a rotor which is rotatable to the stator, a rotor-side position regulation part which is fixed to the rotor and is rotated together with the rotor, and a stator-side position regulation part which is fixed to the stator. The rotor includes a rotary shaft, and a rotor magnet which is mounted on an outer periphery of the rotary shaft. The rotary shaft is integrally formed with the rotor magnet by resin. The stator-side position regulation part includes a first stator-side position regulation part which contacts the rotor-side position regulation part at a first position to regulate a rotation of the rotor in one direction, and a second stator-side position regulation part which contacts the rotor-side position regulation part at a second position different from the first position to regulate a rotation of the rotor in an opposite direction to the one direction.

Abstract: The actuator system has a external rotor motor having: (i) an internal armature configured as a stator having a set of coils wrapped around a set of arms, and (ii) an external permanent magnet rotor having a set of poles configured to rotate less than 90 degrees around the stator. The actuator system has a drive shaft configured to be rotated by the external rotor motor. The actuator system has a drive train connecting the external permanent magnet rotor to the drive shaft, and configured to provide gear ratio to the drive shaft.

Abstract: A method and controller for controlling electric vehicles wherein an output level to an output device is determined on the basis of timing information of input timing data. In one embodiment the timing data is provided on the basis of the duration of one or more user input device, such as one or more buttons. Different algorithms may be applied depending upon the duration of activation of the input device. An electric vehicle including the controller is also disclosed.

Abstract: A high-torque electric motor having a rotor supported by an elongated torque arm comprising a pair of frustoconical-shaped support members. The rotor has a spherical-shaped outer surface and a complementarily shaped stator cavity. The spherical magnetic elements and the conical support members cooperate to brace the rotor against deflection along its rotational axis.

Abstract: A brushless rotary electric machine includes a stator having an annular armature core with first radial teeth at the outer periphery thereof and second radial teeth at the inner periphery thereof and an armature winding wound between the teeth, a rotor having a pair of first and second rotary cores disposed tandem in the axial direction thereof, and a field coil. Each of the first and second rotary cores has a pair of coaxial outer and inner cylindrical pole members respectively facing the first and second radial teeth, a center core and a disk member magnetically connecting the pair of coaxial cylindrical pole members and the center core. The stator is accommodated by a first space defined by the outer and inner cylindrical members of the pair of first and second rotary cores. The field coil is accommodated by a second space defined by the inner cylindrical pole member and the center core of the first and second rotary cores.

Abstract: This invention relates to an arrangement for detecting the driven state of a vibration wave actuator apparatus and provides an apparatus in which a waveform signal having an amplitude corresponding to a vibration state is generated by a monitor circuit, and this waveform signal is level-detected by a comparing circuit having a predetermined threshold so as to form a signal having a pulse width corresponding to the amplitude of the waveform signal, thereby detecting a vibration state from the pulse width.

Abstract: A combined power driven device is made up of three layers, each of the three layers forming an electromechanical structure such as a stator or an armature. One of the three layers serves as a common magnetic structure for interaction with the electromechanical structures formed by the other two layers and the three layers may be mechanically coupled with each other, a load, and/or an active power source to provide either generator or motor functions, or a combination of generator and motor functions.

Abstract: A disk drive has a sleeve-bearing spindle motor having a rotor for rotating the disk of removable data storage cartridge. A retainer which is compliant in the direction of axial movement of the rotor stops the axial movement. The retainer is mounted on a moveable platform which mounts the disk cartridge as it is inserted into the drive. The retainer includes a cantilevered beam which is compliant in the direction of axial movement.

Abstract: In prior art multi-phase electric machines in which conductor parts are interlace to form conductor lanes for various phases, the connection points are on the winding end, thus permitting only a very limited local possibility for welding of the conductor ends. In addition, the manufacturing cost is increased with an odd number of phases, since the design is asymmetrical and a number of different formers necessary is relatively high. The invention calls for prefabricated conductor parts (17) to be welded or soldered in the zones which will subsequently be located in the soft magnetic body. Divided bars with a high conductor cross-sectional area are connected before the insertion of soft magnetic segments, connection zones which are large relative to the conductor cross-sectional area are realized, and problems with the insulation are avoided.

Abstract: A motor vehicle power steering gear has a proportional control valve with first and second valve members connected by a torsion spring and defining a center position with zero torque in the torsion spring. Electromagnetic apparatus for varying the magnitude of the effective restoring torque of the torsion spring comprises a stationary exciting coil, a circular permanent magnet member connected to one of the first and second valve members for rotation therewith and comprising a plurality (n) of permanent magnets of alternating radial polarity, and a pole piece connected to the other of the first and second valve members for rotation therewith, magnetically coupled to the exciting coil, and having a pair of magnetic flux conducting rings each defining a plurality (n/2) of pole teeth facing the permanent magnet member and opposing the pole teeth of the other to define pole tooth pairs each having a region of circumferential overlap.

Abstract: A synchronous motor/generator is modified by mounting the conventional rotor on a sleeve that rotates freely on the main shaft rather than being fixedly mounted on the shaft. Limits to this rotation are incorporated in the design such that the maximum angular rotation of the rotor on the shaft equals half the stator advance that occurs during a complete full cycle of the AC stator winding voltage. In addition to smoothing transients, this configuration permits the machine to smoothly drop into the correct stator/rotor flux phase when it changes from a motor to a generator, and back into the correct phase for a motor, when the AC power is interrupted, and subsequently resumes, resulting in dropping a single cycle.

Abstract: A motor vehicle power steering gear having a proportional control valve and an electromagnetic apparatus for varying the effective restoring torque of a torsion bar of the proportional control valve. The electromagnetic apparatus includes a cylindrical ring attached to a valve spool of the proportional control valve having "n" permanent magnets thereon with alternating radial polarity, a pole piece rigidly attached to a valve body of the proportional control valve having n/2 homopolar outer pole teeth outside of the magnet ring and n/2 homopolar inner pole teeth inside of the magnet ring in radial alignment with the outer pole teeth, and a stationary exciting coil magnetically coupled to the pole teeth. The pole teeth are grouped in n/4 symmetrically arrayed pairs. A first angle between radial centerlines of the permanent magnets is 360/n. A second angle between radial centerlines of the pole teeth in each pair is greater than the first angle (360/n) and less than two times the first angle (2(360/n)).

Abstract: Proximity switches and circumferentially movable stator windings allow a motor-generator to simultaneously sense and switch from a synchronous motor position to a synchronous generator position. This mechanism replaces the conventional separate sensing and switching of motor-generator functions. Automatic rotational repositioning of the stator maintains constant voltage and prevents the generation of transient voltages or harmonics. The stator flux leads the rotor magnetic flux slightly in an import power or motor position, creating a torque on the rotor and a counter torque on the stator reacted by the fixed casing of the apparatus. As the stator field weakens due to a failure of the normal power supply, the counter torque also weakens and the stator windings are biased to begin to turn with the rotor until the rotor and stator fields are in step, i.e., when virtually no current is generated or consumed or until a full export power or generator position is reached.

Abstract: Proximity switches and circumferentially movable stator windings allow a motor-generator to simultaneously sense and switch from a synchronous motor position to a synchronous generator position. This mechanism replaces the conventional separate sensing and switching of motor-generator functions. Automatic rotational repositioning of the stator maintains constant voltage and prevents the generation of transient voltages or harmonics. The stator flux leads the rotor magnetic flux slightly in an import power or motor position, creating a torque on the rotor and a counter torque on the stator reacted by the fixed casing of the apparatus. As the stator field weakens due to a failure of the normal power supply, the counter torque also weakens and the stator windings is biased to begin to turn with the rotor until the rotor and stator fields are in step, i.e., when virtually no current is generated or consumed or until a full export power or generator position is reached.

Abstract: A rotary transformer having a rotor assembly mounted on a shaft and a plurality of associated cooperative stators rotatably mounted about the rotor assembly. The stators are angularly adjustable, relative to each other, about the axis of the shaft. Electrical power is delivered to one of the stators (the primary stator), which functions as a primary of the transformer. The remaining stators (secondary stators) function as a secondary of the transformer. The relative angular orientation between the secondary stators determines the magnitude of the output voltage from the secondary stators.

Abstract: A permanent magnet generator having a plurality of permanent magnet generator units which produce a controlled output potential by mutual magnetic flux linkage between the permanent magnet generator units to produce the controlled output potential in accordance with the invention includes a plurality of permanent magnet rotors (20 and 22) mounted on a drive shaft (26) with at least one of the rotors being rotatable with respect to the drive shaft to vary an angular position of the at least one of the rotors relative to the shaft to produce a mutual variable magnitude magnetic axial field extending parallel to the drive shaft; at least one stator (26, 28, 72) disposed at a position axially offset from the plurality of rotors which is magnetically coupled to the variable magnitude permanent magnet axially field; and a mechanism (46, 48) responsive to a stator fault for angularly positioning the rotors relative to each other so that the permanent magnetic field coupled to the at least one stator is zero.

Abstract: A vibration wave motor in which a signal for suppressing unnecessary vibration engendered during the driving of the vibration wave motor, besides the driving signal of the motor, is applied to the motor to suppress the unnecessary vibration.

Abstract: In a preferred embodiment, an oscillating stepping motor having only one stator phase. What would otherwise be a second stator phase is a magnet fixedly disposed with respect to the rotor to produce a detent position of the rotor. When the stator is energized, the field of the fixed magnet is at least partially overcome and the rotor steps to a first predetermined position. When the stator is de-energized, the rotor returns to the detent position. Alternately energizing and de-energizing the stator causes the rotor to oscillate between the two positions. Alternatively, an angle of oscillation twice that produced above may be provided by reversing the stator field to oscillate the rotor between the first predetermined position and a second predetermined position produced by reversing the stator field.

Abstract: A generator includes a rotatable housing carrying permanent magnets for creating a magnetic field, an armature carrying electrical coils and a gear set for simultaneously rotating the housing and magnetic-field-creating permanent magnets in a direction opposite to the direction of rotation of the armature coils. The armature or field can be rotated separately by a clutch or transmission.

Abstract: A homopolar actuator has a permanent magnet disk element rotatably positioned between a pair of toothed pole pieces with mutually offset teeth, an electromagnetic coil and pole elements coupling the coil flux to the pole pieces. The pole pieces may themselves be rotatable or stationary. The permanent magnet circuit attempts to center the disk element relative to the pole pieces, and the electromagnetic circuit, depending on the direction of current in the coil, either reinforces the centering action or overcomes the centering force to displace the elements from center position. The device is used as a two or three position actuator or as an actuator or magnetic spring operating against an external force and seeking a position as a function of current.

Abstract: A limited angle torque actuator produces a substantially constant torque over an excursion angle of 90 degrees or more. The actuator uses a core made from a highly permeable magnetic material such as soft iron. In a preferred embodiment, one or more permanent magnets are attached to the outer surface of the cylindrical core. In another embodiment, the permanent magnets are spaced apart from a stationary core to create an air gap therebetween. When current flows through a coil wound on the stator, first and second stator poles are created which interact with the permanent magnets to rotate the rotor assembly.

Abstract: An actuator has a permanent magnet ring with a plurality of radially magnetized poles rotatably positioned between a pair of toothed pole pieces with interdigitated teeth, an electromagnetic coil and pole elements coupling the coil flux to the pole pieces. The pole pieces may themselves be rotatable or stationary. The permanent magnet circuit attempts to move the magnet ring to a first position relative to the pole pieces, and the electromagnetic circuit, depending on the direction of current in the coil, torques the magnet in one direction or another toward stable positions on either side of the first position. The device is used as a two or three position actuator or as an actuator operating against an external force and seeking a position as a function of current.

Abstract: A variable speed controllable induction motor comprises a single rotor formed in one-piece having different sets of rotor conductive members effective respectively at different speed ranges, that is, at least a set of first conductive members specifically effective for a lower speed range and a set of second conductive members specifically effective for a higher speed ranges; a plurality of stators disposed side by side surrounding and facing respective portions of said rotor; and a phase shifting apparatus for producing phase differences on the respective portions of the rotor conductive members. The motor can achieve an overall wide range speed control due to the combined effects of the characteristics obtained respectively from the different set of the rotor conductive members.

Abstract: A squirrel-cage induction motor having a sectional stator comprising a first stator fixedly held on a frame, and a second stator circumferentially movably supported on the frame beside the first stator. The second stator is displaced relative to the first stator through a gear mechanism by a control motor through an angle meeting operating conditions of the squirrel-cage motor required by the load. Thus, the squirrel-cage induction motor has satisfactory response characteristics, and the second stator can manually be turned in case the component of the mechanism for driving the second stator, for example, the control motor, malfunctions.

Abstract: The present invention relates to a 3-position rotational actuator which obtains three stable points by two pairs of field poles, in which the magnetic flux to a rotor due to one pair of field poles of a stator for maintaining the rotor at the first stable point is substantially equal to the magnetic flux to the rotor due to the other pair of field poles of the stator for rotating the rotor from the first stable point. The magnetic flux density of the other pair of field poles of the stator applied to the rotor is set to be smaller than the magnetic flux density of the one pair of field poles of the stator. Therefore, the detention torque can be maintained to the same degree and the drive torque can be improved.

Abstract: A rolling rotor motor/compressor is made with a stator and both an inner and an outer rotor which serve to mechanically balance the device. The device can be configured to be a single compressor, two compressors, staged compressors as well as functioning as a motor. In the preferred embodiment the rotors are restricted to an orbiting movement.

Abstract: A rotary-type electromagnetic actuator for a toy includes a cylindrical magnetic stator fixedly mounted within a housing, a rotor arranged concentrically within the stator and rotatably supported by a shaft within the housing, a coil wound on the rotor for causing the rotor to rotate back and forth by being energized and deenergized, a commutator fixedly secured to the shaft of the rotor for supplying current to the coil, a rotor position-correcting member turnably provided inside the housing in opposition to the commutator and in concentric relation with respect to the housing, and a pair of current feeding brushes embracing the commutator from both sides thereof, each of the current brushes having one end secured to the position-correcting member and another end in pressing contact with a respective commutator bar of the commutator. The coil is energized by dc power supplied through the brushes and commutator.

Abstract: A method of driving an ultrasonic motor having a rotation body (6) which is rotated by travelling waves generated in a vibrator body (3), whereby the drive frequency of the motor is controlled in accordance with the value of an operating parameter such as phase difference between drive current and voltage, such as to maintain the drive frequency at a value which is lower than the antiresonance frequency of the vibrator body (3) and higher than a highest resonance frequency of the vibrator body (3) in a hysteresis loop exhibited by a resonance frequency characteristic of the vibrator body (3). Continuous stable operation is attained, irrespective of the effects of temperature and load changes upon the motor operating characteristics.

Abstract: Limited angle torque motor includes a rotor assembly having one or more permanent magnets which are magnetized in the diametrical direction and a stator assembly including a pair of circumferentially spaced stator magnetic pole pieces, each having a stator pole flange at the opposite end thereof. Each stator pole piece has a greater circumferential width in the region of the respective stator pole flanges to increase the amount of magnetic material in such region where the flux density is the highest. Surrounding the stator assembly is a magnetic housing which desirably effectively has no air gap therein.

Abstract: An encoder motor comprising: an encoder incorporated in the encoder motor, for carrying out positional detection and having an encoder code wheel fitted to a motor rotary shaft of the encoder motor; a coil formed as a moving coil movable together with the motor rotary shaft; a magnet operative with respect to the moving coil; and a bobbin in the form of cylinder on which the moving coil is disposed. The bobbin is arranged concentrically with respect to the motor rotary shaft and directly fixed to the code wheel of the encoder.

Abstract: A variable speed controlled induction motor has a rotor (8) formed in one piece and a plurality of stators (24,25), the rotor having a plurality of rotor cores (2,3) and a plurality of conductive members (5) interconnected and the stators having respective stator windings (22,23). The stator windings (22,23) are connected in series, the rotor conductive members (5) are short-circuited by connecting members (r) at an air space or a non-magnetic core portion disposed between the rotor cores (2,3), and at least one of the plurality of stators (24,25) is associated with a phase shifter (38;47;50;51) providing the voltage of a given phase to the stator windings, whereby the rotational speed can be controlled easily over a wide range with excellent torque characteristics and efficiency.

Abstract: An electric motor attachable to a photographic camera for shutter rewind and film transport. The output shaft of the motor acts on the main shaft of the camera and has no further operational connection with the camera shutter. The electric motor (8) proper is rotatably supported in the housing (7) so that the stator of the motor rotates oppositely to the direction of rotation of the rotor when the rotor is locked into position at the end of the shutter rewind and film transport. A switch for the motor circuit is actuated by the backward moving stator.

Abstract: A drive system for causing a relatively massive scanning element, such as a mirror, to rotate back and forth about a scan axis, with minimum disturbance of the space vehicle which carries it, includes a counterbalance which oscillates about an axis parallel to axis of the element in the opposite direction and 180.degree. out of phase so that the net angular momentum of the system is zero. One or more buffer springs attached to the element encounter limit stops on the counterbalance, or vice versa, at the ends of the scan to stop and reverse the motions of both the element and counterbalance without reaction on the supporting members. For a given rate of scan, the energy of the system remains substantially constant but changes twice per cycle from kinetic energy during the coasting period (i.e., between contacts with the springs) to potential energy stored in the springs during reversal. Proper attention to the design of the bearings and of the springs and stops ensures minimum loss of energy.

Abstract: An automatic circuit breaker senses the remaining charge in series connected batteries driving a motor whose rotor shaft bearing and stator are rotatably supported by a fixed member, sensing the reaction torque of the motor. The power circuit is broken when the reaction torque drops below a predetermined value indicating that at least one of the batteries has discharged beyond a certain point to prevent reverse charging of the discharged battery.