Abstract: Provided is a generator in which straight rod magnets have been heated to form curved ones, with the identical polarity ends of the magnets having been forcibly butted together by diamagnetic connecting devices to form a field element ring. The field element ring is arranged through three Y-shaped sets (evenly spaced apart) of one inner and two outer roller devices set on a base steel sheet. Rotary drive force is applied from the centrally placed drive motor to one of the inner and outer roller devices to rotate the field element ring. Between, and in line with, the three sets of inner and outer roller devices are arranged three segments of an armature coil that is wound around the field element ring. In turn, the armature coil is encased within three segments of an armature core that are set on the base steel sheet.

Abstract: In the laws of magnet, apart from those of repelling and attracting terms, there's a third position hitherto unnoticed, that of rotating terms, when they are angular. It is this 3rd aspect that's been utilized to turn a wheel or cause a motion in a body. The speed from the wheel is multiplied through a set of gear-wheels in order to turn an armature inside a coil. This generates electricity energy that can be applied as required. Also, the spinning magnets that prompts the generation, or the electricity energy generated, when applied to run engines for vehicles, or supply homes and industries with power, does not leave an after-burn that can pollute the environment, the way the burning of fossil fuels does. So, more importantly, it helps in redressing of global warming and attainment of a cleaner and greener world environment.

Abstract: The present invention relates to a permanent magnet for a motor, to be buried in a permanent magnet motor, including: a plurality of sheet magnets for lamination, and an insulating layer arranged between the plurality of sheet magnets for lamination. Since the invention has the above-mentioned constitution, the permanent magnets are free from the problems of temperature elevation and coercive force depression, therefore making it possible to provide a high-power small-sized motor. Furthermore, it is unnecessary to perform the conventional correcting processing after sintering, which can simplify the production steps, and therefore, it becomes possible to mold the permanent magnet with a high degree of dimension accuracy.

Abstract: A periodic magnetic field generation device is provided with a field pole of a Halbach array structure in which main pole permanent magnets magnetized in a direction of a generated field and sub pole permanent magnets magnetized in a direction opposite to the direction of magnetic poles of the main pole permanent magnets are alternately disposed linearly or circularly so as to be adjacent to each other. A part of each of the main pole permanent magnets on a side on which the magnetic field is generated is replaced by a soft magnetic member, and a relation between a length A of the soft magnetic member on the side of the generated field along a moving direction and a length B of each main pole permanent magnet on a side of a back yoke along the moving direction is A<B.

Abstract: A hybrid magnet motor that utilizes two reciprocating magnet head pistons that are 180 (degrees) out of sync., in which acts against a rotating dual polarity magnet wheel (5) which causes a repulsion for the first 180 (degrees) of rotation, then an attraction for the second 180 (degrees) of rotation, when the magnet head piston reaches about 67.5 (degrees) Before-top-dead-center. A timing disk (15) triggers on the appropriate sensor, in which activates or energizes that particular electromagnetic coil, and causes the magnet head piston in question to rotate past the pistons stall out point, which is when the magnet head piston is at its Top-dead-center, or its magnet head piston is closest to the magnet wheel (5). This is the cylinders closest and strongest point of attraction. As the magnet head piston is caused to rotate further After-top-dead-center to about 22.

Abstract: A generator includes a coil of conductive material. A stationary magnetic field source applies a stationary magnetic field to the coil. An internal magnetic field source is disposed within a cavity of the coil to apply a moving magnetic field to the coil. The stationary magnetic field interacts with the moving magnetic field to generate an electrical energy in the coil.

Abstract: A generator includes a coil disposed about a core. A first stationary magnetic field source may be disposed on a first end portion of the core and a second stationary magnetic field source may be disposed on a second end portion of core. The first and second stationary magnetic field sources apply a stationary magnetic field to the coil. An external magnetic field source may be disposed outside the coil to apply a moving magnetic field to the coil. Electrical energy is generated in response to an interaction between the coil, the moving magnetic field, and the stationary magnetic field.

Abstract: A permanent magnet motor operated by the magnetic interaction between two or more permanent magnets, and a control system therefor, is provided. The permanent magnet motor may be a piston motor having a magnetic piston assembly mounted on a crank shaft, and a rotatable cam shaft having a cam magnet corresponding to the piston assembly. When the cam shaft rotates about an axis, the poles of the cam magnet alternatingly face the adjacent magnetic pole of the corresponding piston magnet. The magnetic field interactions between the piston magnet and the cam magnet cause the piston to reciprocate within the cylinder. The permanent magnet motor may also be a rotary motor comprising a rotor having a plurality of rotor magnets, and a stator having a stator magnet. A stator motor drives the stator causing the rotor to rotate in response to alternating interactions between magnetic fields of the stator magnet and rotor magnets. A vehicle comprising a permanent magnet motor is also disclosed.

Abstract: The present invention has an object to provide a rotating mechanism with a very high rotation efficiency in which rotation resistance is reduced and rotation is encouraged. It comprises a fixed member having bearings and a rotary member including a rotary shaft journalled by the bearings and a disk member fixed on the rotary shaft. A plurality of coils is mounted on the fixed member and arranged at regular intervals on a circle centered on the rotary shaft, and first permanent magnets are mounted on the disk member, arranged at regular intervals on a circle centered on the rotary shaft and arranged to face the coils.

Abstract: A transverse flux machine (TFM) includes a stator assembly that provides a plurality of U-shaped magnetic circuits placed circumferentially around a rotor assembly. The plurality of U-shaped magnetic circuits being comprised of a first stator segment, a second stator segment, and a plurality of stator yokes. The first stator segment and the second stator segment each have a plurality of poles spaced around a first circumference and a plurality of slots spaced around a second circumference opposite each of the plurality of poles. The plurality of stator yokes each have a first end sized to fit within one of the slots associated with the first stator segment and a second end sized to fit in one of the slots associated with the second stator segment.

Abstract: The present invention relates generally to a motor that may generate torque and produce energy. The motor comprises a drive shaft configured to rotate about an axis, a first flywheel coupled to the drive shaft, a force transmission device coupled to the drive shaft, and a first shielding device coupled to the drive shaft and positioned between the first flywheel and the force transmission device. A first piston dolly is coupled to the force transmission device, the first piston dolly configured to move laterally along the axis of the drive shaft. A first magnetic device is coupled to the first piston dolly. In addition, a second piston dolly is also coupled to the force transmission device, the second piston dolly configured to move laterally along the axis of the drive shaft. A second magnetic device is coupled to the second piston dolly.

Abstract: A dual motor has a shaft and a first motor connected to the shaft. The first motor is a standard electrical motor receiving voltage steps. The first motor provides a rotational force to the shaft when the voltage is applied. A second motor is also connected to the shaft, and the second motor is a permanent magnet motor comprising a flexible member connected to the shaft at a flexible member inside end. The permanent magnet motor also has an inside magnet mounted to a flexible member outside end, and the inside magnet moves relative to the shaft. The permanent magnet motor also has an outside housing. An outside magnet is mounted to the outside housing, and stepped voltage application flexes the flexible member. Optionally, stepped voltage application flexes the flexible member so that the outside magnet rotates relative to the inside magnet.

Abstract: An electrical machine is disclosed. The electrical machine comprises a first discontinuous volume comprising a high resistivity soft magnetic material.

Abstract: There is provided a magnetic field generator for MRI 10 applicable to a variety of magnetic field generators, and capable of preventing separation of permanent magnets 20 which constitute permanent magnet groups 14a, 14b. The magnetic field generator for MRI 10 includes a pair of permanent magnet groups 14a, 14b. The pair of permanent magnet groups 14a, 14b each including a plurality of permanent magnets 20 bonded to each other, are opposed to each other with a space in between. The permanent magnet groups 14a, 14b have projections 18 projecting more outward than the area of contact with respective pole pieces 16a, 16b. A flange-shaped member 34 is attached to each outer circumferential surface of the pole pieces 16a, 16b, covering a space-facing surface 18a of the projection 18.

Abstract: A fault tolerant synchronous permanent magnet machine is disclosed that reduces rotor losses by limiting eddy-current losses in the retaining sleeve. The machine limits eddy-current loss by any one or combination of axially segmenting the retaining sleeve, providing a highly electrically conductive non-magnetic shield to the retaining sleeve, and by configuring stator teeth width, stator teeth tip width, and slot distribution of the stator.

Abstract: An energy module utilizing permanent magnets arranged on a moveable inner shaft (33) which interact with an arrangement of permanent magnets on a rotating outer shaft (32) thereby producing torque. By moving the inner shaft (33) in and out of the rotating outer shaft (32) magnets, a continuous rotation is achieved which is similar in function to an electric motor while mainly using the power of permanent magnets. A magnetic energy advantage is created since the power to move the moveable inner shaft (33) is less than the power output of the torque generated on the rotating outer shaft (32).

Abstract: The magnetic drive for electrical generation is a magnetically driven mechanical device in which two opposing arrays of permanent magnets are set in electromagnetic fields arranged with their positive polarity ends facing each other and that are set at an angle relative to the exterior of an interior shaft with a gap between the two opposing arrays necessary to allow for the rotation of the arrays. The exterior magnetic array is fixed, while the interior magnetic array is connected to a rotating shaft. The exterior magnetic forces work to push against the interior magnets causing the interior magnetic array to rotate. The interior shaft is inserted through and connected to an electric generator, converting the mechanical rotation into electrical power.

Abstract: An arrangement of magnets or magnetically charged materials incorporated in a fan like machinery that provides rotational driving force and further assists the electric generation, based only on the repulsion or attraction forces between magnetic fields. This system can be implemented in both horizontal axis systems as well as vertical axis systems to assist in the rotational driving forces as well as in any other oriented type of axis.

Abstract: A device for inducing the rotation of a plurality of rotors by use of magnetically charged materials includes at least a pair of rotors rotatably mounted. Each rotor includes at least one outwardly extending element having magnetic material attached to the opposing ends of the element. The elements of the two rotors are positioned co-planarly with respect to one another, such that each element of one rotor is paired with a corresponding co-planarly positioned element of the other rotor. The elements are positioned sufficiently proximate to one another such that the polarity of one element's end may interact with the polarity of its paired element of the other rotor to induce a rotation of one or both of the two rotors.

Abstract: A magnet motor comprises a first ferromagnetic member and a second ferromagnetic member reciprocated in working direction relative to the first ferromagnetic member. A controller displaces a permanent magnet between an engaged position adjacent to the ferromagnetic members with the flux being perpendicular to the working direction and a disengaged position spaced from the first and second ferromagnetic members. The controller also displaces the second ferromagnetic member towards the first ferromagnetic member when the permanent magnet is in the disengaged position and captures energy from the resulting displacement of the first ferromagnetic member away from the second ferromagnetic member when the permanent magnet is in the engaged position.

Abstract: A dual motor has a shaft and a first motor connected to the shaft. The first motor is a standard electrical motor receiving voltage steps. The first motor provides a rotational force to the shaft when the voltage is applied. A second motor is also connected to the shaft, and the second motor is a permanent magnet motor comprising a flexible member connected to the shaft at a flexible member inside end. The permanent magnet motor also has an inside magnet mounted to a flexible member outside end, and the inside magnet moves relative to the shaft. The permanent magnet motor also has an outside housing. An outside magnet is mounted to the outside housing, and stepped voltage application flexes the flexible member. Optionally, stepped voltage application flexes the flexible member so that the outside magnet rotates relative to the inside magnet.

Abstract: The present disclosure relates to a magnetic motor including a drive magnet, a motion magnet, and an acceleration field. The drive magnet includes magnetic shielding, typically on a portion thereof, altering the magnetic field of the drive magnet. In some embodiments, the motion magnet has a cross-section that is generally in the shape of a ‘V’ or ‘A’. The acceleration field is created by the interaction between the drive magnet and the motion magnet as the motion magnet is passed through the altered magnetic field of the drive magnet. The altered magnetic field of the drive magnet may often be near a first end of the drive magnet. In further embodiments, the motion magnet can be operably coupled to an output shaft and rotate around the central axis of the output shaft. The present disclosure, also relates to a device, including the magnetic motor, for generating energy from a turbine.

Abstract: A magnetic piston includes a housing having a tapered bore extending along an axis thereof and a piston having a tapered outside wall mating with the tapered bore of the housing for providing radial and longitudinal movement within the tapered bore about a rotational axis of the piston. A shaft is connected to the piston for movement along its longitudinal axis thereof, wherein the axes of the tapered bore and piston are generally aligned along the longitudinal axis. A first set of magnets is embedded within the outside wall of the piston and a second set of magnets is embedded within a surface of a wall forming the bore of the housing. The polarity for each of the magnets within the sets provides attracting and repelling forces causing rotation of the piston relative to the housing and a linear movement of the shaft along the longitudinal axis.

Abstract: There is provided a magnetic field generator for MRI 10 applicable to a variety of magnetic field generators, and capable of preventing separation of permanent magnets 20 which constitute permanent magnet groups 14a, 14b. The magnetic field generator for MRI 10 includes a pair of permanent magnet groups 14a, 14b. The pair of permanent magnet groups 14a, 14b each including a plurality of permanent magnets 20 bonded to each other, are opposed to each other with a space in between. The permanent magnet groups 14a, 14b have projections 18 projecting more outward than the area of contact with respective pole pieces 16a, 16b. A flange-shaped member 34 is attached to each outer circumferential surface of the pole pieces 16a, 16b, covering a space-facing surface 18a of the projection 18.

Abstract: A composite rotor of a step motor and a method for producing the same are disclosed. The composite rotor comprises a positioning member having a positioning protrusion, a first magnetic conductive member, at least one magnet and a second magnetic conductive member. The first magnetic conductive member, the magnet and the second magnetic conductive member are successively mounted on the positioning member and limited by the positioning protrusion. One end of the first magnetic conductive member and one end of the second magnetic conductive member abut against two opposite ends of the magnet, respectively.

Abstract: A stator of a motor includes a stator core formed of a plurality of teeth and an annular yoke connecting the teeth to each other, and windings wound on the teeth. A rotor of the motor confronts the stator while supported rotatably, and includes a rotor magnet, a rotor core, and a position sensing magnet. The motor further includes a position sensor for sensing a rotational position of the rotor and a circuit board for supplying an electric current to the windings in response to the rotational position of the rotor. The rotor magnet, the rotor core, and the position sensing magnet are integrated into one unit, which is mounted on a shaft of the rotor.

Abstract: A repulsive force conversion drive system for centrifugal force conversion to drive a load. A movable load to be driven by movement and provide external power due to movement of the movable load. A rotary repulsive force conversion drive connected to the movable load, such that the movable load moves in a first linear direction due to centrifugal force of rotating mass of the rotary repulsive force conversion drive. A linear repulsive force conversion drive connected to the movable load, the linear repulsive force conversion drive connected to the movable load such that the movable load moves is a second linear direction that is opposite the first linear direction on command from the linear repulsive force conversion drive.

Abstract: In at least one aspect, a second multi-axis vacuum motor assembly is provided. The second multi-axis vacuum motor assembly includes (1) a first rotor; (2) a first stator adapted to commutate so as to rotate the first rotor across a vacuum barrier and control rotation of a first axis of a robot arm within a vacuum chamber; (3) a second rotor below the first rotor; (4) a second stator below the first stator and adapted to commutate so as to rotate the second rotor across the vacuum barrier and control rotation of a second axis of the robot arm within the vacuum chamber; (5) a first feedback device adapted to monitor rotation of the first axis of the robot arm; and (6) a second feedback device adapted to monitor rotation of the second axis of the robot arm. Numerous other aspects are provided.

Abstract: A magnetic drive system and method are provided wherein magnets on a stator interact with a magnet on the rotor to create repulsion and attraction forces that produce axial shaft rotation. More particularly, a magnet is pivotally attached to a carriage that processes about an annular magnet. The resultant magnetic forces interact with a magnet on the rotor shaft and cause the rotor shaft to turn.

Abstract: To provide a quantum motor capable of reliably carrying out rotation. A quantum motor includes a rotor containing a functional material of which quantum characteristic is externally controllable, an N pole permanent magnet and an S pole permanent magnet applying magnetic field to the rotor, and a light source varying the quantum characteristic of the rotor. The light source varies the quantum characteristic of the rotor, so that rotation force is generated in the rotor and the rotor rotates.

Abstract: New design of generator and or generators, which creates electricity. Using a sphere shape design compared to the traditional generator designs already in use today. Using a sphere shape design for the placements of the magnets and coils. The gears will allow for multiple layers to be used for rotation, dependent on power needs.

Abstract: New design of generator and or generators, which creates electricity. Using a sphere shape design compared to the traditional generator designs already in use today. Using a sphere shape design for the placements of the magnets and coils. The gears will allow for multiple layers to be used for rotation, dependent on power needs.

Abstract: The present invention relates to rotary motors in which the rotational motion of the motor is provided by the attractive (or repulsive) forces between a pair of cooperating magnets in response to tilting of the motor axle.

Abstract: The invention is directed to the method of utilizing unbalanced non-equilibrium magnetic fields to induce a rotational motion in a rotor, the rotor moves with respect to the armature and stator. The invention, a three (3) tier device (armature, rotor, and stator) has the armature and stator being fixed in position with the rotor allowed to move freely between the armature and stator. To induce a rotational motion, the rotor, in its concave side uses unbalanced non-equilibrium magnetic fields created by having multiple magnets held in a fixed position by ferritic or like materials to act upon the magnets imbedded in the armature. The rotor, in its convex side has additional unbalanced non-equilibrium magnets and additional pole pair magnets to create a magnetic flux that moves with the moving fixed position fields to cut across closely bonded coils of wire in the stator to induce a voltage and current that is used to generate electrical power.

Abstract: A rotor includes: a magnet having a circular cylinder shape and having a hole formed through its axial center, wherein the hole has in axial cross section a regular polygonal shape having flat portions and angle portions, and wherein a recess having a truncated cone shape is disposed at an axial end of the magnet such that the recess has its maximum diameter portion located at the axial end and has its minimum diameter portion communicating with the hole; and a shaft fitted in the hole of the magnet, wherein the outer circumference of the shaft makes contact with the flat portions of the hole of the magnet thereby forming a plurality of gaps between the outer circumference of the shaft and the angle portions of the hole of the magnet, and adhesive is filled in the gaps.

Abstract: This invention relates to the field of engines. More particularly, the present invention relates to devices and methods used in the field of energy generation. Embodiments of the present invention provide environmentally friendly piston engines and/or the capability of retrofitting existing combustion engines to provide engines that run using no or little fuel.

Abstract: Rotor formed by groups of materials (4) that orientate the magnetic field and magnets (2) in spiral lines, with the two magnetic poles of each magnet (2) facing the stator (3). Close to a magnetic pole of the end of the group, the material (4) that orientates the magnetic field protrudes towards the stator (3). This configuration enables to vary the field of each magnetic pole of the rotor which is projected to the stator; in this way, one end of the group of magnets (2) concentrates a very close magnetic pole in order to interact with the stator (3) and the opposite magnetic pole moves away gradually in order to decrease the interaction with the stator (3). The application is for magnetic motors.

Abstract: The MagnaForce Generator is an energy producing device using magnetic force in a way that allows continuous movement to produce energy. The device described above where one or more of the magnets are attached to a device which moves the magnet(s) to maximize the free flow of the movement created by the magnetic fields. Most likely magnets in a circle with a spinning magnet on a shaft in the middle The device described incorporates piston(s) which retreats into a cylinder to avoid opposing forces from or related to the primary rotational device that do not complement the production of energy and that emerge to assist in the production. The device incorporates materials that redirect the magnetic fields to maximize the production of energy. The device described might incorporate any pre-existing braking device. The device described might incorporate a pre-existing generating device. The device described might incorporate a locomotive device.

Abstract: Disclosed is a spindle motor comprising: an integral turntable including: a table on which a rotating body to be installed, and an inner side wall and an outer side wall formed to be recessed upwards at a portion therebetween on a lower surface of the table so that a predetermined hollow is formed, a surface of thereof being formed slant; a ball cover for covering a ball inserted into the hollow and the hollow; a rotation shaft an upper portion of which is inserted into a center of the integral turntable; a bearing supporting a lower portion of the rotation shaft; a coil formed on an outside of the rotation shaft; and a magnet formed on an outside of the coil.

Abstract: A hybrid-electric vehicle is provided having a respective electrical machine in each wheel thereof. Each electrical machine is of the axial-flux type, having a rotor sandwiched axially between two parts of a stator. Each electrical machine is fitted to the respective wheel such that the rotor takes the place of a disc of a disc brake system, and the stator is mounted in place of a calliper of the disc brake system.

Abstract: The invention relates to an actuator device comprising a headpiece (1) with an adjuster mechanism for an actuating arm mounted to pivot on the headpiece into the actuated and open position and a housing (7) supporting the headpiece (1) with an interior for housing a linearly adjustable control rod connected to the adjuster mechanism (3) and connected to the actuator arranged in the housing (7). According to the invention, the housing (7) is in the form of an extrusion moulded hollow profile (8), the interior of which has a constant inner cross-section over the entire length thereof.

Abstract: The present invention relates to the field of electric motors, and more particularly to a motor driven by permanent magnets. The magnetic motor of the invention comprises a main rotor and auxiliary rotors, as well as a plurality of novel magnetic barriers allowing the magnets to actuate only when the direction of the force created by said magnets is coincident with the movement.

Abstract: A high-efficiency motor is disclosed. The motor includes two sets of permanent magnets and further includes electromagnets incorporated to be energized by a control system to provide a variable-speed motor that produces high torque.

Abstract: A motion transfer system comprising stator magnets (24-27) and rotor magnets (22-23) adapted to be displaced relative to each other on a linear or rotating path. The stator magnets (24-27) are reciprocally movable on a direction inclined to the direction of relative movement between stator and rotor magnets. Auxiliary magnets (29), fixed to the stator, are arranged such that the magnetic force between stator magnets (24-27) and rotor magnets (22-23) at least partially cancels the magnetic force between stator magnets (24-27) and rotor magnets (22-23) when the rotor magnets (22-23) are at least partially between stator magnets (24-27) and auxiliary magnets (29).

Abstract: Electromechanical systems utilizing suspended conducting nanometer-scale beams are provided and may be used in applications, such as, motors, generators, pumps, fans, compressors, propulsion systems, transmitters, receivers, heat engines, heat pumps, magnetic field sensors, kinetic energy storage devices and accelerometers. Such nanometer-scale beams may be provided as, for example, single molecules, single crystal filaments, or nanotubes. When suspended by both ends, these nanometer-scale beams may be caused to rotate about their line of suspension, similar to the motion of a jumprope (or a rotating whip), via electromagnetic or electrostatic forces. This motion may be used, for example, to accelerate molecules of a working substance in a preferred direction, generate electricity from the motion of a working substance molecules, or generate electromagnetic signals. Means of transmitting and controlling currents through these beams are also described.

Abstract: Devices of the invention include a rotor with magnets and a stator with two magnet zones. The end zone of the stator toward which the rotor magnet first approaches has two preferred variants: it can be formed either of one magnet or of a high magnetic permeability material. The other end of the stator is preferably formed of thick magnets.

Abstract: A power generator using a permanent magnet is provided, which includes a fan having a magnetic property of generating a repulsive force when identical polarities approach between magnetic bodies, and a permanent magnet plate which is located in opposition to one side of the fan and axially combined with the fan on an identical shaft. In this case, the polarity of one surface of the fan equals that of the facing surface of the permanent magnet plate facing the fan. Thus, since a repulsive force is generated between the fan and the permanent magnet plate, the fan continuously rotates to thereby generate power.

Abstract: An inner rotor brushless motor is miniaturized, flattened and made lighter without reducing motor performance. A rotor and a stator are enclosed inside a sealed case (i.e., a sealed space) assembled by covering an attachment base with a cup-shaped bracket. A motor substrate on which a motor driving circuit is formed is provided in a gap formed in an axial direction between (i) the rotor and the stator and (ii) a base portion inside a bracket opening of the bracket.

Abstract: The present invention has an object to provide a rotating mechanism with a very high rotation efficiency in which rotation resistance is reduced and rotation is encouraged. It comprises a fixed member (1) having bearings (16, 18); a rotary member (2) including a rotary shaft (21) journalled by the bearings and a disk member (22) fixed on the rotary shaft; a plurality of coils (3) which are mounted on the fixed member (1) and arranged at regular intervals on a circle centered on the rotary shaft (21); and a first permanent magnet (4) mounted on the disk member (22), wherein first permanent magnets (4) are arranged at regular intervals on a circle centered on the rotary shaft (21) and arranged to face the coils (3).

Abstract: A motor-pump assembly for household appliances (1) such as dishwashers and washing machines, in particular for discharging water, of unusual structural simplicity, comprises a pump equipped with an impeller (2A) and a single-phase synchronous electric motor (7) with mechanical start-up equipped with a stator (5) and with a rotor (3) mutually separated by an air gap (4). The rotor (3) is of the type using permanent magnets (2B); the stator (5) is of the diapason type and is equipped with a pack core of laminations and with a pair of pole pieces (5C) that wrap coaxially around the rotor (3). The length (s) of the pole pieces (5C) of the stator (5) is at least 15% less than the length (r) of the rotor (3).