Abstract: A self-regulating permanent magnet device has a first rotor segment and second rotor segment, each supporting a set of permanent magnets, wherein the position of the second rotor segment relative to the first rotor segment is modified based on the speed of the self-regulating permanent magnet device. By modifying the position of the second rotor segment relative to the first rotor segment, the alignment between their respective sets of permanent magnets, and therefore, the electromotive force (emf) generated in the stator coils is regulated. The position of the second rotor segment is defined by the connection of a torsion spring between the first rotor segment and second rotor segment and a reactionary torque device connected to the second rotor segment. The torsion spring creates a spring force that acts to maintain the alignment between the first rotor segment and the second rotor segment.

Abstract: A dynamoelectric machine comprises a first rotor shaft, a second rotor shaft and a central element. The first rotor shaft rotates about a central axis of the machine and has a first magnetic drive element disposed about an outer circumference of the first rotor shaft. The second rotor shaft rotates about the first rotor shaft and has a second magnetic drive element disposed about an inner circumference of the second rotor shaft. The central element is disposed between the first rotor shaft and the second rotor shaft and is configurable to remain stationary while the first rotor shaft and the second rotor shaft rotate about the central axis. The central element also includes a third magnetic drive element for interacting with the first magnetic drive element, and a fourth magnetic drive element for interacting with the second magnetic drive element.

Abstract: An electric machine that includes a stator core having a stator core length, a first rotor core portion, and second rotor core portion. A spacer is coupled to the first core portion and the second core portion to at least partially define a rotor core. The rotor core has a length that is greater than the stator core length. A permanent magnet is coupled to the rotor core and has a magnet length. The magnet length is greater than the stator core length.

Abstract: A synchronous permanent magnet machine for at least two rotation speeds has a single stator and at least two rotors. For each rotation speed there is provided a separate rotor with a different numbers of poles. The armature windings on the stator extend across all of the rotors and the windings are subjected to a rotating field with the same frequency.

Abstract: A starter/generator mechanically coupled to a gas turbine transmission housing comprises a generator (10) with a rotor forming a field winding and a stator forming an armature, and an energizer (20) with a stator forming a field winding and a rotor forming an armature linked to the field winding of the generator. The rotor (12) of the generator and the rotor (22) of the energizer are mounted on a common shaft (54) together with a gear (86) of the transmission housing, one on each side of this gear.

Abstract: An electrical machine is provided. The electrical machine includes a rotor comprising an inner rotor having a plurality of inner rotor poles and an outer rotor having a plurality of outer rotor poles. The electrical machine further comprises a stator configured to modulate a magnetic flux and to transmit torque to inner rotor and the outer rotor, the stator comprising a stator core interposed concentrically between the inner rotor and the outer rotor; a multiple of stator windings disposed in a plurality of stator slots, the stator windings configured to form a multiple of stator poles. The stator further comprises a plurality of stator teeth interposed between the plurality of stator slots, wherein an arithmetic sum or difference of twice number of stator teeth and a number of the stator poles equals a number of rotor poles.

Abstract: This electric motor of the present invention is formed by an inner circumferential side rotor, an outer circumferential side rotor, and a planetary gear mechanism that are placed coaxially. The planetary gear mechanism is a single pinion type that includes a first planetary gear train and a second planetary gear train that are each single gear train. A first planetary carrier that supports the first planetary gear train is able to pivot around an axis of rotation, and a second planetary carrier that supports the second planetary gear train is fixed to a stator. The electric motor is further provided with an actuator that pivots the first planetary carrier by a predetermined pivot amount around the axis of rotation.

Abstract: A motor includes a stator with an annular stator yoke, a stator core having a plurality of inner and outer teeth projecting from the stator yoke toward inside and outside respectively, a plurality of coils wound on the stator core, and an inner rotor and an outer rotor confronting the inner and outer teeth respectively via an air-gap, and having an permanent magnet respectively. The number of slots “S” and the number of poles “P” establish a relation of S:P=3:2N?1, where N is an integer equal to 1 or more, and a case when 2N?1 becomes a multiple of 3 is excluded.

Abstract: A vehicle power transfer system and method, and vehicle using the same. The vehicle power transfer system including a differential unit coupled to a half axle, and an electric motor for supplying torque to propel a vehicle. The electric motor is collinear with the differential unit and the half axle.

Abstract: A high voltage, low current electric motor. The motor comprises a drive shaft turned by a sprocket that is driven by an assembly of electromagnets. A carrier supporting permanent magnets travels in a tubular track formed into an endless loop around the sprocket. The carrier preferably comprises a chain formed of interconnected links, each link housing a magnet. The tubular track is non-ferrous and forms a core for a plurality of coils spaced around the tube. A sequencing circuit in the motor sequentially energizes the coils to cause the carrier to circulate around the tube by repelling and attracting the magnets. Teeth on the sprocket engage the chain so that as the chain travels through the tube the sprocket is rotated. Preferably, the coils are double-wound so that a direction control circuit may be included to selectively reverse the direction of the carrier's travel. Speed control also may be included.

Abstract: The present invention relates to a coreless motor including a multi-stage rotor and a driving apparatus having the motor. More particularly, the present invention relates to a coreless motor including magnets and coils arranged, in multiple stages, to be concentric with a rotary central shaft and a driving apparatus having the a motor. According to an aspect of the present invention, a coreless motor including a multi-stage rotor comprises a rotor and a stator. The rotor includes a plurality of cylindrical yokes arranged in multiple stages in a radial direction, and a plurality of magnets fixed to the yokes in the respective stages in such a manner that polarities of the magnets fixed to the yoke in each stage are changed in a circumferential direction of the yoke. Further, the stator includes a plurality of cylindrical armature coil assemblies arranged in multiple stages to face the yokes, and each armature coil assembly includes a plurality of armature coils.

Abstract: Electrical machine, having a stator which bears a winding and having a rotatable rotor, situated at a distance from the stator via an air gap, which includes at least two coaxial rotor sections which are rotatable relative to one another, in which each rotor section bears a system of permanent magnets having polarities which alternately point outward radially, and having an actuating device for rotating the rotor sections relative to one another, the actuating device having a controllable actuator via which the rotor sections may be aligned with one another with a variable rotary offset which is independent of a rotational speed of the rotor. In a method for setting the field and armature of a permanently energized electrical machine for motor vehicles, the rotational speed range of the electrical machine is divided into an armature-setting range, and a freely preselected field suppression is associated with a particular rotational speed of the rotor.

Abstract: A torque converter device includes a first body having a first radius and a first thickness, a first plurality of magnets mounted in the first body, the first plurality of magnets including a plurality of magnet pairs, each of the magnet pairs being axially disposed along a centerline of the first body along the first radius through the first thickness, a second plurality of magnets mounted in the first body, each of the second plurality of magnets being disposed between each of the plurality of magnet pairs, and a second body having a third plurality of magnets within the second body for magnetically coupling to each of the magnet pairs and the second plurality of magnets, wherein rotation of the first body induces rotation of the second body.

Abstract: According to the invention, a tandem alternator includes a rotary shaft, a first and a second field arranged in tandem on the rotary shaft, and a first and a second armature arranged in tandem in the axial direction of the rotary shaft. The first armature is provided on an outer periphery of the first field to constitute a first power generation unit. The second armature is provided on an outer periphery of the second field to constitute a second power generation unit. The first and second fields are arranged to abut each other in the axial direction of the rotary shaft, so as to minimize the axial length of the alternator. The first and second fields are configured to respectively create a first and a second magnetomotive force whose directions are opposite to each other, so as to minimize magnetic leakage between the first and second power generation units.

Abstract: A transmission system with continuously variable transmission ratio includes an input shaft (2), an output shaft (4) and preferably also a differential gearset comprising at least three parallel shafts (2, 4, 12). The system also includes first and second motor/generators comprising first and second rotors (16, 32) and first and second stators (20, 26; 36, 26), respectively. The first and second rotors (16, 32) are connected to respective shafts. The electrical connections of the first and second stators are connected together. A controller (45) is arranged to control the flow of electrical power between the first and second stators. At least a portion (26) of the first stator is connected to at least a portion (26) of the second stator.

Abstract: The disclosure is directed to a motor/generator including a magnetic circuit that is created between a rotor and stator through a first air gap and a second air gap so that a magnetic field (magnetic flux) passes through two parts of the edges of multiple stator teeth parts. A first protruding end part and a second protruding end part of the stator teeth parts which face each air gap may contain different shapes with regard to the circumferential direction of the rotor. These shapes and orientation of the first and second protruding end parts may reduce the cogging torque of the motor/generator.

Abstract: A polyphasic multi-coil generator includes a drive shaft, at least first and second rotors rigidly mounted on the drive shaft so as to simultaneously synchronously rotate with rotation of the drive shaft, and at least one stator sandwiched between the first and second rotors. A stator array on the stator has an array of electrically conductive coils mounted to the stator in a first angular orientation about the drive shaft. The rotors each have an array of magnets which are circumferentially equally spaced around the rotor and located at the same radially spacing with respect to the centre of the rotor and the drive shaft at a first angular orientation relative to the drive shaft. The arrays of magnets on adjacent rotors are off-set by an angular offset relative to one another.

Abstract: A hybrid induction motor includes a motor casing; a rotational shaft rotatably coupled with the motor casing; an induction rotor rotated by being integrally coupled with the rotational shaft and having a rotor core and a conductor bar inserted in the rotor core; a stator having a hollow into which the induction rotor is inserted and installed with a certain length in a direction of the rotational shaft; a first magnetic rotor inserted between the stator and the induction rotor and coupled with the rotational shaft so as to be freely rotatable; a second magnetic rotor inserted between the stator and the induction rotor so as to be symmetrical with the first magnetic rotor and coupled with the rotational shaft so as to be freely rotatable; and a magnetic spacer inserted between the first and second magnetic rotors.

Abstract: A permanent magnet electric generator includes a housing, and a stator and a rotor assembly disposed inside the housing. The rotor assembly has annular inner and outer rings concentric with the axis of rotation. A plurality of permanent magnets is distributed on the inner surface of the outer ring. The stator assembly includes a plurality of stator blocks configured to form an annular ring-shaped stator member. The stator member is concentric with the axis of rotation and is interposed between the inner and outer rings such that the outer ring circumferentially encircles the stator member. The stator member is wound with a three-phase winding for a three-phase voltage output.

Abstract: A hybrid step motor has axially spaced first and second sets of rotor sections (or alternatively different sets of stator sections) characterized by different tooth widths. The rotor/stator tooth width ratio in one set is optimized for one-phase ON operation while the rotor/stator tooth width ratio for the other set is optimized for two-phase ON operation. More generally, the two sets are optimized together for near sinusoidal, torque profile and substantially equal microsteps.

Abstract: A stepping motor comprises first to third coil portions and first to second rotors. The first rotor has a cylindrical shape and a circumferential surface thereof is magnetically-polarized so as to alternately arrange south poles and north poles. The first rotor is disposed inside the first and second coil portions, and is rotated by magnetic fields generated at a time when the first and second coil portions are energized. The second rotor has a disk shape and a surface thereof is magnetically polarized so as to alternately arrange south poles and north poles. The second rotor is disposed such that edge areas of both surfaces thereof are interposed between the second and third coil portions. The second rotor is rotated by magnetic fields generated at a time when the second and third coil portions are energized.

Abstract: The invention includes an electric machine having a rotor, stator and at least one winding in the stator adapted to conduct a current, and a secondary winding, electrically isolated from the first winding and inductively coupled to the first winding, which may be used to control at least one of the output voltage and current of the first winding.

Abstract: The invention relates to an electric synchronous machine. There is a need for a dual rotor electric synchronous machine which has a mechanism for adjusting the rotor relative angular displacement while the machine is running in order to reduce back emf. There is a need for such an adjusting mechanism which can carry high torque loads. An electric synchronous machine is provided with a housing, first and second shafts rotatably supported in the housing, each with a corresponding rotor fixed thereon, both having permanent magnet field poles. Each rotor is surrounded by a corresponding annular stator, and stator coils are wound through both stators. A planetary transmission is coupled between the first and second shafts and operable during rotation of the first and second shafts to adjust an angular orientation of the second shaft with respect to the first shaft.

Abstract: An energy conversion system that converts electrical energy to mechanical energy, and with certain power supplies can convert solar energy into mechanical energy. It operates on a timed direct current pulse and its configuration causes a magnetic field to align with a rotational shaft, two rotors, and one or more stationary field pieces each having a coil. One rotor has a spherical configuration and the second rotor mounted on the same shaft has an arcuate configuration with truncated ends. A coil can be mounted between the two rotors. The offset position of field coils allows for higher torque in low to high rpm ranges. The spherical rotor shape was chosen for ease of construction, mass in a condensed space, less gyroscopic effects than flat flywheels, and positive effects of placement in magnetic circuit. Since there is only one major moving part, the present invention is simple, long-lasting, and virtually problem-free.

Abstract: An apparatus for converting between mechanical and electrical energy, particularly suited for use as a compact high power alternator for automotive use and “remove and replace” retrofitting of existing vehicles. Various aspects of the invention provide a means of significantly increasing the output of permanent magnet alternators while addressing the issues of radial loading applied to a permanent magnet alternator rotor. Another aspect of the invention allows for the production of power in two discrete voltages. An aspect of this invention allows for a marked increase in output capability without increasing axial length through the use of magnetic fringing. One aspect of the invention offers an effective means of mounting a skewed stack that eliminates or reduces cogging that is present in a permanent magnet machine without negatively impacting airflow. Another aspect of the invention reduces cogging by radially offsetting opposing magnets of a dual rotor permanent magnet machine.

Abstract: According to the invention, a tandem alternator includes a rotary shaft, a first and a second power generation unit arranged in tandem in the axial direction of the rotary shaft, a housing accommodating the power generation units and having a plurality of air holes formed through a front end wall thereof, a pulley provided on a front end portion of the rotary shaft which protrudes outside from the first end wall of the housing, and a first and a second rectifier working to respectively rectify AC powers output from the first and second power generation units. The first rectifier is so fixed to the outer surface of the front end wall of the housing as to be located on the radially outside of the pulley and cover only part of the air holes. The second rectifier is fixed to the outer surface of a rear end wall of the housing.

Abstract: An electric motor comprising an inner periphery side rotor provided with inner peripheral permanent magnets with unlike poles, which are disposed alternately along a circumferential direction of the inner periphery side rotor, an outer periphery side rotor provided with outer peripheral permanent magnets with unlike poles, which are disposed alternately along a circumferential direction of the outer periphery side rotor, and a rotating device that varies a relative phase between the inner periphery side rotor and the outer periphery side rotor by rotating at least the inner periphery side rotor or the outer periphery side rotor around the rotational axis. The outer peripheral side rotor is arranged such that a rotational axis thereof is coaxial with a rotational axis of the inner periphery side rotor. The rotating device sets a variable width of the relative phase between the inner periphery side rotor and the outer periphery side rotor within a range of an electrical angle of below 180°.

Abstract: The vehicle-use tandem electric rotating machine includes a first stator-rotor pair, a second stator-rotor pair, and a controller individually controlling a first field current flowing into a first field coil of the first stator-rotor pair and a second field current flowing into a second field coil of the second stator-rotor pair. The first stator-rotor pair is configured to generate electric power to be supplied to essential electric loads, and the second stator-rotor pair is configured to generate electric power to be supplied to non-essential electric loads. The controller is configured to restrict the second field current from flowing into the second field coil when rotational speed of a vehicle engine driving the tandem electric rotating machine is lower than a predetermined threshold speed set above an idle speed of the vehicle engine.

Abstract: A device for generating forces that are variable and controllable in amplitude, in direction, and in frequency, the device includes two unbalanced rotors (18, 20, 35 to 38) mounted coaxially in a casing (11). The device further includes electromagnetic drive elements for driving a first of the two rotors in rotation relative to the second of the two rotors, and brake elements (43 to 45) for braking the second rotor (20, 36, 38) relative to the casing.

Abstract: A continuously variable transmission has a drive shaft, a power takeoff shaft and a power branching device disposed therebetween and has a continuously variable power branch containing a variator, and a mechanical power branch parallel thereto. To provide a large adjustment range and a high level of efficiency in conjunction with a simple and space-saving configuration, the variator is an electromagnetic transmission with a rotatably mounted drive rotor connected to an input shaft, a rotatably mounted power takeoff rotor connected to an output shaft, and a stator connected fixed in terms of rotation and mounted axially displaceably. The rotors have permanent magnets which are each distributed circumferentially axially adjacent to one another and have alternating polarity. The stator has at least one short-circuit winding disposed radially adjacent to the permanent magnets and the effective transmission ratio being adjustable by axial displacement of the stator relative to the rotors.

Abstract: This electric motor includes first permanent magnets secured integrally to an outer periphery side rotor and second permanent magnets secured integrally to an inner periphery side rotor. The first permanent magnets and the second permanent magnets are arranged so as to offset the relative torque produced between the outer periphery side rotor and the inner periphery side rotor based on the magnetic flux of the inner peripheral permanent magnets and the outer peripheral permanent magnets.

Abstract: An electrical machine comprising a rotor and a stator is provided. The stator includes a plurality of stator tooth modules configured for radial magnetic flux flow. The stator tooth modules include at least one end plate, and the end plates have extensions for mounting onto a stator frame. The stator is concentrically disposed in relation to the rotor of the electrical machine.

Abstract: An electromagnetic coupler for a motor vehicle. The coupler includes a first electric machine having an axis and including a first stator bearing a first coil, an input rotor and a first part of an output rotor, and a second electric machine including a second stator bearing a second coil and a second part of the output rotor. The input rotor includes an inner drum spaced apart from the first part of the output rotor and from the first yoke, while the second yoke is spaced apart from the second part of the output rotor by an air gap. The first coil is wound onto the yoke of the first stator around the axis of the first electric machine.

Abstract: A variable speed power generator system, includes a primary power induction generator (12), a secondary control induction (14), each of the induction generators having a rotor (22, 24) mounted so as to be rotated by a common shaft (16) of a variable speed prime mover (20), an inverter (50) connected to the stator (15) of the secondary control induction generator, a controller (30) connected to the inverter controls the output of the inverter, output of the primary induction generator is connected to the grid (51), controller provides output signal to the inverter based on selected inputs to the controller so that the output of the primary induction generator matches the active and reactive power requirements of the grid. An induction machine which includes a rotor having laminations and insulated cage bars, the bars being electrically isolated from on another as well as electrically insulated from the laminations.

Abstract: A three-phase opposite rotating motor of a fan comprises a stator having a three-phase coil set without a core, a first rotor and a second rotor. The number of the poles of the first rotor is unequal to the number of the poles of the second rotor. The ratio of the number of solenoids of the three-phase coil set and the number of the first poles of the first rotor is 3:4, and the ratio of the number of solenoids of the three-phase coil set and the number of the second poles of the second rotor is 3:2, to ensure the motor works normally in an opposite rotating operation.

Abstract: A hybrid vehicle implements a required traveling condition by generating a required driving force necessary to drive the vehicle even in the case where a supply source of a working fluid develops a malfunction. The hybrid vehicle is equipped with a motor which changes the phase difference between two rotors and an engaging/disengaging device which turns on/off the supply of a driving force of an internal combustion engine, the motor and the engaging/disengaging device being driven by a working fluid.

Abstract: A motor includes a stator, a first rotor and a second rotor. The stator has a plurality of outer teeth projecting outward from an annular stator yoke, a plurality of inner teeth projecting inward from the stator yoke, and windings wound on both of the teeth. Instead of providing both of the teeth with the windings, toroidal windings can be wound on the stator yoke at each section sandwiched between the slots, which stator yoke is disposed between each one of the inner slots and corresponding each one of the outer slots. This motor is structured such that the phases of cogging torque and torque ripple existing between the stator and the second rotor can be reversed with respect to the phases of cogging torque and torque ripple existing between the stator and the first rotor.

Abstract: A hybrid induction motor comprises a stator fixedly installed in a casing, an induction rotor rotatably inserted into a center of the stator and having a shaft at a center thereof, a first synchronous rotor slid in a longitudinal direction of the shaft between the stator and the induction rotor and free-rotatably installed in a circumferential direction of the shaft, and a second synchronous rotor facing the first synchronous rotor, slid in a longitudinal direction of the shaft between the stator and the induction rotor, and free-rotatably installed in a circumferential direction of the shaft.

Abstract: Embodiments of the present invention include a composite electromechanical machine which can operate as a motor or a generator (including dynamo or alternator). In an aspect, the present composite electromechanical machine comprises at least two rotating elements (rotor) and one stationary element (stator) where the two rotating elements are coupled through a gear mechanism. The gear mechanism can combine the torque of the inner and the outer rotor, preferably using helical gears which have lower noise level and higher contact area. The gear mechanism can also act as a locking mechanism to keep the outer rotor in place. The gear mechanism can comprise a first gear coupled to the inner rotor and a second gear coupled to the outer rotor. In an embodiment, the first and second gears are coupled together to connect the inner and the outer rotors. The gear mechanism can further comprise a third gear coupled to the double-sided stator.

Abstract: A multi-redundant motor may be used to implement a relatively small, lightweight redundant actuator assembly package. The motor is implemented as a brushless DC motor and includes N-number of stators and M-number of rotors. Each stator has a plurality of independent stator coils disposed thereon, and N is an integer greater than two. Each permanent magnet rotor is disposed between, and is spaced axially apart from, two of the stators. Each rotor has a plurality of magnetic dipoles disposed thereon, and M is an integer equal to (N?1).

Abstract: A compact arrangement features a fan (42?), a fluid pump (134), and an electric drive motor (106). The latter has a stator (22) having a stator winding (118) that is configured to generate a rotating field. The stator (22) has associated with it a permanent-magnet external rotor (106) for driving the fan (42?), and a permanent-magnet internal rotor (140) for driving the fluid pump (134). The stator winding (118) thus drives not only the rotor (106) of the drive motor and hence the fan (42?), but also the internal rotor (140) and hence the fluid pump (134). The arrangement is very well suited for combination with a fluid cooler (90).

Abstract: The present invention is a direct current generating machine that eliminates the need for brushes or other mechanical commutators. A pair of opposed, spaced apart rotatable rotors, each carrying a plurality of bar magnets, are synchronously rotated about a common axis of rotation. A stationary electrically conducting wire extends through the axis of rotation, and radially outwardly therefrom, between the rotating magnetic field. In another embodiment the bar magnets are replaced by pieces of steel which interrupt a unidirectional, magnetic field created by a magnet. The magnet used to create the unidirectional, magnetic field may be an electromagnet. The resultant electrical signal generated in the conductor is unidirectional. The present invention may be used to create brushless DC electrical signals, brushless three-phase DC electrical signals, or a plurality of DC and/or inverted DC signals.

Abstract: A clean engine for transportation, generators, and other applications. It comprises a series of alternating support wheel assemblies and magnet wheel assemblies that are propelled in a consistent pattern by battery powered electromagnets. The engine comprises at least one support wheel assembly and at least one magnet wheel assembly. The support wheel assemblies and magnet wheel assemblies are aligned in a specific pattern along a main shaft that is supported on each end by sealed bearings mounted in a nonmagnetic housing.

Abstract: An inner rotor (21) is arranged as a motor field, including permanent magnets (25) embedded in an inner rotor core (24) and an inner rotor shaft (26) coupled with the inner rotor core. An outer rotor (22) is arranged as a motor armature, including a hollow armature core (36), plurality of windings (37), two side flanges (38, 39), and an outer rotor shaft (40) coupled with one of the side flanges. The inner rotor is rotatably supported inside the outer rotor, and both rotors are rotatably supported inside a stationary motor enclosure (23). Electric current is conducted to the windings of the armature via brushes (58) and sliprings (59). The interaction between a revolving electromagnetic field of the outer rotor and the permanent magnetic field of the inner rotor propels both rotors to rotate in opposite directions.

Abstract: An electro-magnetic circular engine in which the motive force is electro-magnetism. The electro-magnetic circular engine comprises a hub assembly, first and second electro-magnetic wheels, electro-magnetic means, and electrical means. The electro-magnetic circular engine includes the rotation of the hub assembly in a predetermined direction continuously after the initial activation of the hub assembly by assembly of applying a short period of the external force, such as from a starter. At least three alternators are connected to the rotating shaft and work at a minimum of 35 amps to over 600 amps each and recharge batteries.

Abstract: A variable speed isosychronized motor includes two annular stators conformed for variable angular alignment relative to each other and a common rotor extending a plurality of isolated loops to cross-induce power between stators once such are angularly displaced. In this form of losses, attendant to speed variation through stator phasing are reduced. Electrical compensation may be inserted between each terminal pair. Potentiometers in parallel with capacitors and may be inserted between the respective terminals to expand the operating range of the device.

Abstract: The hybrid induction motor includes a housing; a stator installed in the housing and having a stator core portion and a stator coil portion; a rotor coupling body having a rotary shaft rotatably installed in at the housing, a cage rotor portion rotating integrally with the rotary shaft, and a permanent magnet rotor portion coupled to a circumference of the cage rotor portion with a certain air gap so as to rotate freely with respect to the rotary shaft; and a reverse rotation preventing switch, when the rotary shaft rotates reversibly, coming in contact with the permanent magnet rotor portion which is moved along the shaft by thrust generated by the rotor coupling body and cutting off power being supplied to the stator coil portion.

Abstract: An induction motor having a reverse-rotation preventing function, comprises: a stator provided with a winding coil generating flux by a current; an induction rotor provided with a cage and rotatably inserted in the stator, wherein a rotary shaft is coupled to its inside; a synchronous rotor provided with a permanent magnet and rotatably coupled between the stator and the induction rotor; an induction-force generating unit generating a force for moving the synchronous rotor in an axial direction; and a rotation preventing unit preventing a reverse rotation by fixing the synchronous rotor moved by the induction-force generating unit at the time of reverse rotation of the synchronous rotor.

Abstract: A electric motor is disclosed in which torque ripple is reduced. The electric motor includes a single motor shaft. Rotors are disposed so as to be mutually offset in phase, and the rotors are secured to the motor shaft. Stators are arranged so as to individually correspond to the rotors, and the stators are disposed so as to be matched in phase. The phases of torque ripple generated in each motor unit, which is comprised of a combination of a single rotor and a single stator, are offset.

Abstract: A rotary drive mechanism is disclosed comprising a housing (10), a first motor (12) having a first rotor (38) and a first stator (32) connected to the housing and a second motor (50) having a second rotor (52) and a second stator (54) connected to the housing characterised in that the second motor is mechanically independent of the first motor whereby acceleration torques of the first motor are at least partially inertia balanced by the second motor. The balancing may be effected by equal and opposite rotation of the second motor. Control means may be provided to provide the second motor with a current which is proportional to that supplied to the first motor. Also disclosed is a positioning device and a probe having the rotary drive mechanism.