Abstract: A stator assembly for an axial-flow fan motor for cooling electronic components consisting of a base, a stator, and insulating pins for connecting the base to the stator. The stator consists of a core covered by an insulating coating and a winding formed thereon from magnet wire. The stator also includes mounting holes formed in the core. The winding is electrically connected to the base through free ends of the magnet wire forming the winding. Each insulating pin has a first conductive end which is mounted to the base and a second non-conductive end which is received in one of the mounting holes on the stator. In the preferred embodiment, the base consists of a printed circuit board which includes circuitry for operating the motor within which the stator assembly is mounted. The method of securing the stator to the base is also disclosed.

Abstract: A positioning device for a miniature fan includes a coil seat including a number of annularly spaced poles each having a radially extending stem and a circumferential arcuate section. Each stem has a winding wound therearound, and each arcuate section has a first end edge and a second end edge. A circuit board is securely connected to the coil seat and includes a sensor element mounted thereon. The sensor element is located on a vertical line extending from one of the first end edge and the second end edge of one of the poles.

Abstract: A brushless motor which includes an arrangement to prevent dielectric breakdown of electronic parts mounted on a control board. The breakdown is caused by a heat sink which becomes electrostatically charged. The potential at the heat sink, which contacts switching devices (for instance, FETS) of the brushless motor, is equalized with the potential at one side of a source line for a drive circuit formed on the control board that includes the switching device. As a result, when the heat sink becomes electrostatically charged, the charge at the heat sink can be discharged to the source line, thereby eliminating the above problem.

Abstract: An elevator motor (2) employing permanent magnets (30) attached in a circle on the surface (36) of the rotor disc (12). The rotor disc (12) forms part of both the magnetic circuit and the supporting structure of the rotor (13). The permanent magnets (30) are placed in a separate cavity formed in the stator disc and having one side open, said cavity also housing the stator windings (17). The outer cavity wall directed towards the rotor disc (12) is provided with a sealing member to close the cavity.

Abstract: An inside out electric motor includes a rotor having an interior surface defining an interior space and a magnetic element mounted on the rotor. The motor also includes a stator having a bobbin. The bobbin has a bearing positioned at a central axis of the bobbin. The bearing rotatably engages the rotor to permit the rotor to freely rotate with respect to the stator. The bobbin also has a pole member molded into the bobbin so that an end of the pole member is spaced radially inward from and at least partially aligned with the magnetic element, and a winding wound around the bobbin so that the winding passes adjacent the pole member.

Abstract: An electrical machine, such as an electric motor, generator or torquer-generator, includes a relatively rotatable cylindrical armature and magnetic pole structure separated by an annular gap into which a surrounding fluid may flow during operation of the machine. In order to prevent the build-up of deposited solid material in the gap between the components, one of the components is provided at its surface with a narrow elongate projection which extends helically along and around the surface. The height of the projection is slightly less than the gap between the components so that it remains out of contact with the surface of the other component so as not to frictionally engage it and interfere with relative rotation between the components.

Abstract: A godet for guiding and advancing a yarn with a rotating godet jacket. The godet jacket is mounted to a rotor shaft, which is driven by means of a three-phase motor. The three-phase motor is controlled via a frequency inverter, which is mounted in a housing, whose interior accommodates the electronic subassemblies of the frequency inverter in a stationary and heat transferring manner. The housing of the frequency inverter is firmly connected to the housing of the three-phase motor.

Abstract: A starter has a housing formed with a fitting part and a flange on the outer periphery thereof. The fitting part is in circular shape when viewed in the axial direction and is press-fitted, in the socket-and-spigot joint manner, into a fitting hole of an engine-side body with the flange being in abutment with a fitting plane of the engine-side body. The outer diameter Ho of the fitting part is set larger than the axial length of the center of gravity of an armature of a starter motor from a fitting plane of the flange.

Abstract: In a motor, a rotor made of a permanent magnet which is equally divided in the circumferential direction to be alternately magnetized to different poles is formed into a cylindrical shape. The first coil, the rotor, and the second coil are sequentially arranged in the axial direction of the rotor. The first outer and inner magnetic poles excited by the first coil are set to oppose the outer and inner circumferential surfaces, respectively, of the rotor, and the second outer and inner magnetic poles excited by the second coil are set to oppose the outer and inner circumferential surfaces, respectively, of the rotor. An electric element is arranged at a position to oppose, across a predetermined gap, the circumferential surface of the permanent magnet not covered with the first or second outer magnetic pole. Alternatively, an electric element and a circuit pattern are formed on a connection member that connects the first and second outer magnetic poles to each other.

Abstract: A motor actuator has a housing, an output gearwheel rotated by a motor, a pattern board provided on one side of the output gearwheel, and a conducting unit. The conducting unit is formed integrally with brushes contacting the pattern board and connector pins corresponding to each of the brushes and electrically connecting the brushes to other electrical components. The brushes and connector pins are fixed by an insulating resin so as to maintain the structure when link portions unneeded for electrical connection are cut.

Abstract: A brushless DC motor and drive package is disclosed, including modular subassemblies which are integrated into a single unit. The drive includes power electronic circuitry and related control circuitry which is supported on a circuit board within the package. The circuit board is supported on an end cap of the motor and is housed within the package housing. The end cap supporting the circuit board preferably forms a bearing support recess for receiving a shaft bearing. The resulting package is extremely compact, and reduces or eliminates the need for separate drive circuitry and related support hardware.

Abstract: A bicycle dynamo with a rotary-current generator having a stator and a rotor which can be rotated relative to the stator. The stator or the rotor has radially extending pole fingers which are wound individually with one surrounding magnetic coil winding respectively. The ratio of the number of poles of the rotor to the number of poles of the stator is a non-integer value, and the ratio of the number of poles of the stator to the number of poles of the rotor is a non-integer value. This permits the implementation of a bicycle dynamo of a high efficiency even at a relatively low riding speed, which may be used, for example, to power bicycle lighting systems.

Abstract: An integral brushless DC motor and drive package is disclosed that includes the brushless DC motor and drive circuitry supported by one of the motor end caps. The drive circuitry includes power electronic devices for converting input power to pulsed power for the motor. The power switching components extend from a circuit board and are received within recesses of the end cap. The switching components are electrically insulated from the end cap, but are thermally conductive to the end cap within the recesses to dissipate heat during operation. The switching components are preferably disposed in radially equally spaced positions on the circuit board to provide even heat loading to the end cap.

Abstract: A correcting signal generator 42 stores the quantitative relation of the magnetic interference between the rotation angle .theta.3 of a resolver 23 and the detected values A3, B3 of a resolver 22, and outputs the correcting values A8, B8 for the magnetic interference according to the rotation angle .theta.3. An adder 41 calculates and outputs the corrected detection values A4, B4 by adding the correcting values A8, B8 to the detected values A3, B3 of the resolver 22 output from a latch circuit 14. A resolver rotation angle calculation circuit 47 calculates and outputs an angle .theta.2 by taking an arc tangent of the quotient A4/B4 of the corrected detection values A4, B4. In the same way, a correcting signal generator 44 calculates and outputs the angle .theta.3.

Abstract: Electromagnetic shielding apparatus is provided for a motor having a rotor and a stator wherein the shielding apparatus is characterized by the absence of an electromagnetic shield in the stator of the motor.

Abstract: An in-hub brushless permanent magnet DC motor has a radial working gap but uses coils wound in the axial direction of the motor. The coils generate fields that interact with the permanent magnet fields across the radial gap. The stator includes a plurality of angularly spaced stator teeth that have faces radially spaced across the gap from the permanent magnet. The stator teeth are connected to the base and extend axially into a cavity within the hub. The permanent magnet is a magnetically-segmented ring magnet located on an outer rim of the hub radially outwardly from the stator teeth. The magnetic flux from the permanent magnet is directed radially across the gap and into the stator teeth. Each stator tooth has an axially oriented post around which is wound a coil that generates an axial field. The axially-oriented part of each coil forms part of the magnetic circuit. The magnetic flux directed radially into each stator tooth is turned axially into the post and through the coil.

Abstract: A method and apparatus for real-time electric motor diagnostics and condition monitoring. While the motor is energized, dynamic operating parameters are determined and a notification signed is generated if predetermined criterion are satisfied. The diagnostic apparatus is integrated with the motor and includes a set of sensors, a processing unit, a memory and an output interface for communicating alarms, warnings and calculated operating parameter values or the like to a display device and to an external supervisor having wireless paging capability to alert a remote operator or maintenance personnel. In a normal operating mode, the processing unit calculates a general class of derived motor operating parameters such as over-temperature, over-voltage, over-current, excessive vibration, and phase imbalance.

Abstract: A stator structure for miniaturized DC brushless motor is disclosed.

Abstract: A power train assembly for delivering electrical power to a driven device such as a motor is constructed of an IMS board and a PCB. A considerably smaller and standardized IMS board is obtained by limiting the components on the IMS board to include only inverter transistors, input rectifiers and a thermistor. The only other component is a connector for effecting a simple vertical connection to the overhead printed circuit board which contains the device control and drive components. The power train assembly realizes surface board savings on the order of between 40% to 50% in the IMS. The height of the IMS is also reduced, which makes it possible to replace the usual potting compound with a thin surface coating.

Abstract: An electronic component cooling apparatus capable of permitting a sufficient amount of air to be fed to an electronic component to be cooled. An impeller which includes a plurality of blades for sucking air from one side in an axial direction of a revolving shaft of a motor is fixed on a rotor of the motor. A casing having a cylindrical cavity defined therein in which the motor and impeller are received is constructed of a peripheral wall arranged so as to surround the impeller and a closing wall for closing an end of the cavity on the other side in the axial direction. The peripheral wall is formed at a portion thereof in proximity to an end thereof on the one side with a lateral discharge port through which air suckedly introduced into the cavity is discharged so that a surrounding portion for surrounding a whole circumference of the impeller is left at a portion of the peripheral wall in proximity to an end on the other side.

Abstract: In a starter, a power supply terminal connected to a solenoid coil of a magnet switch and connectable to a starter external circuit is provided on an end cover. The power supply terminal includes a terminal metal member, a bimetal which interrupts electric conduction between the solenoid coil and the terminal metal member at the time of temperature rise above a predetermined temperature, and a casing contacting a foot part of the terminal metal member and encasing the bimetal therein. The bimetal responds to each of the excessive heating of the terminal metal member and excessive energization current to interrupt the conduction. In case of a single axis-type starter, the power supply terminal is provided on a recess so that the terminal metal member does not extend axially beyond the rear end face of the end cover.

Abstract: The asynchronous discoidal electric motor has stator (1A, 1B) windings (13) and radial rotor bars (2) embedded in notches (11, 22) opened by a very narrow slit (11, 21). These slits (11, 21) and notches (12, 22) may be machined electrochemically using a wire. Application to asynchronous discoidal electric motors with winding embedded in the stator and with a cartwheel structure on the rotor.

Abstract: An electric motor has back-to-back zener diodes across each winding to short the reactance current over the threshold voltage upon polarity reversal, to serve the dual functions of reducing communtator arcing and increasing torque output by delaying the decay of the reactance current until the reversed current begins to surge after reversal. A resistor may be added in series with the series connected back-to-back zener diodes.

Abstract: An electric motor input circuit including a leadless capacitor which reliably and efficiently provides the highest possible level of RFI suppression and the greatest reduction in conducted voltage transients. The assembly includes a capacitor having no solid lead wires and no epoxy coating which is snap-fit into the motor power circuit so that one of the capacitor plates is in pressing engagement with one of the input terminals and the other of the capacitor plates is in pressing engagement with a conducting tab. The conducting tab is formed on the other of the input terminals, and the capacitor is, therefore, connected between the terminals without the use of solid capacitor leads.

Abstract: A rolling contact bearing with rotational speed measuring device, in particular a wheel bearing for motor vehicles for telemetric transmission of energy and signal between bearing and environment, insensitive to tolerances of the bearing and its surrounding parts, with simple and cost-effective construction and small dimensions. A first telemetry unit is integrated in the inter-ring seal. It comprises pulse transmitter, rotational speed sensor, telemetry electronics and a miniature coil, which is inductively coupled with a further telemetry unit, which is fitted axially outside the bearing, and which supplies the first telemetry unit with energy and receives its signals.

Abstract: A dynamoelectric machine has a stator end cap mounted on a stator core, which attaches a control circuit board directly onto the stator. The end cap has integrally formed fingers which permit snap on connection of the circuit board. Guide pins make certain the circuit board is oriented properly upon connection to the end cap. The end cap also has wire fixtures which hold winding leads of a winding and permit insulation displacement terminals on the circuit board to plug into the winding leads and achieve electrical contact at the same time the circuit board is mounted on the end cap. Hall devices mounted onto the circuit board are guided into pockets formed on teeth of the stator end cap for precise location. The end cap is constructed to shield the winding from contact with the motor shell. In addition, backward curved fans are employed to reduce mechanical noise in the direction of high speed rotation.

Abstract: A motor unit having a drive motor, a control portion, and a base made of an aluminum die-casting product. The motor unit is fixed to a fixing stand of a sewing machine for driving a drive shaft thereof. The base has a pair of supporting brackets connected to the fixing stand for suspendingly fixing the base to the fixing stand. The base has a plate-like portion. The drive motor is fixed to one surface of the plate-like portion, and the control portion is fixed to an opposite surface thereof. A motor cover made of a synthetic resin is mounted on the one surface for covering the drive motor, and a protection cover made of a synthetic resin is mounted on the opposite surface for covering the control portion. The control portion includes a plurality of electronic components including heat generating elements. The heat generating elements are directly mounted on the base to release heat from the base.

Abstract: An alternator, in particular for a motor vehicle, comprises half-shells to which stator windings are fixed and which rotatably receive a rotor shaft, and a rectifier circuit made up of power diodes each comprising body and a lead extending axially from said body. The bodies of some of the diodes are connected to ground while the bodies of the other diodes are connected to an output terminal of the alternator. The diode bodies are fixed on or in the back half-shell of the alternator on or in a dissipating support which is generally in the form of a plate that is insulated from the half-shell and that is outside it. According to the invention, the distance between the dissipating support and the back half-shell, and the positions of the said other diodes on the dissipating support are such that the leads of said other diodes project into openings formed in the back half-shell.

Abstract: A drive device with an electric motor with permanent magnets and a pole top more particularly for use with servo drives in motor vehicles. A relay is provided for switching the motor current with at least one electromagnet, which contains a relay coil and a relay armature, and with at least one relay contact. The relay is mounted in the pole top of the electric motor and the magnetic field lines of the electromagnets are closed through the permanent magnets and the pole top of the electric motor.

Abstract: A micro-turbo generator device (10) includes a housing (12), a rotor (14), a plurality of stator cores (16), and coils (18) encircling the stator cores. The housing (12) includes a shaft (34) which has an axis (11). The rotor (14) is rotatably mounted onto the shaft (34) and includes a perimeter (32) and a plurality of rotor poles (24) extending generally radially about the axis (11). Each rotor pole (24) includes a magnetizable tip (30) and a concave fluid impact surface (26). The stator cores (16) are disposed about the rotor (14) and include first pole face (15) and second pole face (17) facing the perimeter (32) of the rotor (14) and spaced apart therefrom. The coils (18) helically encircle the stator cores (16) and conduct electrical current to magnetize the stator cores (16) to magnetize the tips (30) and to alternately conduct induced electrical current generated in response to changes in magnetic flux between the first and second pole faces (15, 17) and the magnetizable tips (30).

Abstract: A terminal and capacitor box is provided for mounting directly onto a generally cylindrical surface of an electric induction motor housing. The terminal box includes a generally rectangular body member adapted to receive a pair of capacitors therein. The body member includes a substantially planar deck surface, a first pair of substantially rectangular opposing sidewalls, and a second pair of opposing sidewalls. The second pair of sidewalls have a curved bottom edge preselectively contoured to conform to the curved surface of the electric motor housing. In addition to the above, the terminal box includes a torsional spring member for engaging the pair of capacitors and holding the pair of capacitors in place against the planar deck surface of the rectangular body member and between the sidewalls regardless of the orientation of the terminal box. Thus facilitating the manufacturing process by rendering the box less sensitive to rough handling and more ameanable to processing as a subassembly.

Abstract: A drive for rotating equipment that does not require internal or external mechanical seals and obviates the necessity to have internal shaft and bearings, eliminating internal lubrication problems and can be used with different types of prime movers is provided. A driven rotor, connected to the prime mover, with mounted horizontal stop rings, vertical stop rings, permanent magnet for floating rotor position, and permanent rotor drive magnet is driven by a driver rotor mounted with strain gauge and permanent magnet, electromagnet for driven rotor position and drive, strain gauges signal transmission rings, and electromagnet current transmission rings. The driver rotor, by using the signal generated by the strain gauges, varies current to the electromagnets controlling magnetic field forces to float the driven rotor. When the unit is shutdown the driven rotor rests on the vertical stop rings uncoupled.

Abstract: Systems employing passive magnetic bearing elements having minimal power losses are provided. Improved stabilizing elements are shown, employing periodic magnet arrays and inductively loaded circuits, but with improved characteristics compared to the elements disclosed in U.S. Patent No. 5,495,221 entitled "Dynamically Stable Magnetic Suspension/Bearing System." The improvements relate to increasing the magnitude of the force derivative, while at the same time reducing the power dissipated during the normal operation of the bearing system, to provide a passive bearing system that has virtually no losses under equilibrium conditions, that is, when the supported system is not subject to any accelerations except those of gravity.

Abstract: A motor capable of generating an electric signal having a particular and precise frequency may be used in a rotary magnetic head apparatus for a video tape recorder. A wiring pattern for generating the signal is disposed on a stator opposite a rotor. Alternating magnetic flux provided by movement of the rotor produces the signal. Gaps in the wiring pattern allow the wiring pattern and wiring for iron core assemblies also disposed on the stator to be disposed on a single circuit board. A toroidal coupling line and a loop coupling line close the loop without crossing the gaps.

Abstract: This invention provides a two-phase motor which is applicable to a field where high rotation precision is required as in an FDD spindle motor, which requires a low cost, and which can maintain stable characteristics free from magnetic balance fluctuation between the two phases due to assembly. This motor has a ferromagnetic stator having N stator salient poles and a rotor magnet having M poles. N and M are selected to be both even numbers so a relation N:M=2:2n-1 (n is a natural number) holds. The N stator salient poles are divided into first and second salient pole groups of N/2 stator salient poles on which windings are concentratedly wound. The stator salient poles belonging to the first and second salient pole groups are alternately arranged in the circumferential direction of the stator. The phases of the windings of the stator salient poles belonging to the first and second salient pole groups are sequentially opposite to each other in the circumferential direction in units of groups.

Abstract: Apparatus for the bidirectional transfer of information comprises in each case: at least one rotating component (1); a further component (2); receivers (4, 5) on the respective components (1, 2), said receivers facing one another in groups on the axis of rotation (6) of the rotating component (1); and transmitters (7, 8) fitted on the components (1, 2) eccentrically with regard to the axis of rotation and directed towards the corresponding receivers (4, 5).

Abstract: A magnetic rotor (5) is provided inside a stator armature (1) of a reluctance motor with an air gap between them. Two salient poles (5a, 5b), each having a width that is 2.5 times each of angular intervals among adjacent slots (1a, 1b, . . . , 1h) of the stator armature (1), are arranged on the outer peripheral portion of the rotor (5). Magnetic fluxes generated by energizing armature coils (2h, 2d) of magnetic poles (4h, 4d) that are not situated at positions where torque is produced are added to magnetic fluxes generated by energizing armature coils (2a, 2e) of magnetic poles (4a. 4e) that are situated at-positions where torque is produced in a direction indicated by arrow R. As a result, leakage fluxes Fa, Fb between the magnetic poles (4a, 4e) and the salients (5a, 5b) of the rotor (5) increase, causing the torque to increase.

Abstract: A drive package for a dynamoelectric machine mounts a printed wire board in cantilever fashion from a wall of a drive package housing. Potting material in the housing provides mechanical support for the printed wire board away from the heat sink. Heat generating components on the first printed wire board have tubes of electrically insulating, thermally conductive material inserted over them and are clamped against the heat sink. The heat sink is mounted directly to the housing and is electrically grounded by the housing.

Abstract: A spindle motor comprises a stationary shaft, a rotor hub rotatably mounted by ball bearings to the stationary shaft, and annular sealing members disposed between the outer surface of the stationary shaft and the inner side of the rotor hub axially outwardly of the ball bearings. The sealing member is directly fitted onto the outer race of the corresponding ball bearing. The outer race of each ball bearing is high precision finished so that the sealing member is definitely coaxial with the stationary shaft regardless of the finishing accuracy on the inner side of the rotor hub. Accordingly, the radial distance between the inner side of the sealing member and the outer surface of the stationary shaft can be minimized with high precision offering an excellent labyrinth effect.

Abstract: Power supply is accomplished via two rails, which are arranged in one plane and which in each case have lugs, which can be bent out from the rail plane. In this case, contact arm of at least one lug is run away over a rail. In this way, a system which is quick to install and which, moveover, is quickly extended in the axial direction is produced.

Abstract: An electrostatic shielding system is provided for an AC motor to eliminate generation of destructive motor bearing currents. Conductive end turn shields are layered over the stator coil end turns at each end of the stator. Conductive grounding clips mechanically and electrically engage the end turn shields at one end of the clip, and electrically and mechanically engage the slotted openings in the stator at the other end. Conductive strips extend longitudinally along the stator slotted openings.

Abstract: Electric motor coils are electrically connected to a power device in an inverter. A conductor for supplying a drive current to the motor coils includes a heat radiating area or other heat radiating member in the wiring path. Thus, the heat from the electric motor is radiated from the conductor in the wiring path. The power device and other components of the inverter can be prevented from being thermally damaged or degraded by the heat transmitted from the motor coils to the inverter through the conductor having higher heat conductivity.

Abstract: A module and method are disclosed for adding an electrical device such as a timer to an existing electric motor such as that found in a whirlpool bath system for driving a water pump. The module includes an input connector configured for mating with a connector on a power cable, an output connector configured for mating with a power connector on the electric motor, and a timer electrically connected between the input and output connectors. The method of adding an electrical device to an existing electric motor using the module comprises the steps of removing the power cable connector from the motor power connector, connecting the module output connector to the motor power connector, and connecting the power cable connector to the module input connector. In this manner, an electrical device which is prewired between the module connectors can be coupled to an existing electric motor without the use of tools, without the aid of an electrician, and without any risk of serious electrical shock.

Abstract: The present invention concerns a motor for generating torques around more than one axis with respect to an object that can be rotated and revolved around only one point. Only one mechanism is necessary to maintain a prescribed position or to produce changes in position around one or more axes (X, Y, or Z).The permanent-magnet excited synchronous machine comprises stator shells (10 & 10.1), multiple-phase windings (11 & 11.1), and a rotor (12) with permanent magnets (13 & 13.1), whereby the annular and spherical surfaces (14) of the rotor are more extensive than the annular and spherical surfaces (15) of the shells.All the spherical surfaces share the same center (M) of curvature, which simultaneously constitutes the origin of the coordinate systems, and the center of rotation. The shaft (17) is supported only at the center of curvature and such as to ensure freedom of motion throughout the reference coordinate system (21).

Abstract: An adaptable rotating rectifier and suppression resistor assembly is designed to fit and mate with state-of-the-art, two-pole generators with maximum flexibility to accept a variety of known possible diode configurations and a relatively large suppression resistor in a cost effective manner. A tubular housing of the assembly has an axially extending internal cavity with a plurality of bus bars arranged in fixed, spaced relation in a radially outer portion of the internal cavity so as to extend axially along the internal cavity. A plurality of diodes of any one of at least three significantly different configuration diodes and a suppression resistor are arranged in line along the axis of the internal cavity with radially outwardly extending spring contact plates electrically connecting the diodes and suppression resistor with the bus bars. A desired preload force is provided on these components between an end cap at one end of the housing and a retainer at the other.

Abstract: In a brushless motor, its magnet unit is formed by laying on each other a first magnet made of a flexible bond magnet material which is anisotropic and a second magnet made of a flexible bond magnet material which is isotropic, and the second magnet is smaller in wall thickness than the first magnet, and is confronted with the stator and the magneto-electric conversion element.

Abstract: Systems and apparatus for integrating an air switch and a power cord into an electric motor, and methods for assembling an electric motor including an integral air switch and an integral power cord, are described. In one embodiment, an air switch and a power cord are incorporated into an electric motor. No additional removable cover is required for the switch and cord. To eliminate the motor centrifugal switch, an air switch is provided to control energization and de-energization of the motor windings. The air switch includes a snap action switch to cut-out the start winding used for ensuring that the rotor has sufficient starting torque.

Abstract: The invention relates to a high precision axial and radial aerostatic and aerodynamic bearing for a motor. The bearing surfaces of the stator and the rotor are of a toroidal shape.

Abstract: An electric motor-generator has a rotor (1), a stator including soft ferromagnetic cores (3, 5) and coils (4, 6), permanent magnets (2) having pole axes in a plane radial to an axis of rotation of the rotor, means for mounting the magnets, the cores and coils to the rotor and stator, and means for energizing the coils. The rotor is caused to rotate by attraction of the magnets to the cores (5) as the magnets and cores approach one another, an opposite attraction force between the magnets and the cores being neutralizeable by energizing the coils (6) as the magnets and cores move apart. The cores are C-shaped and a magnetic circuit is formed when the magnets and cores are in proximate alignment.

Abstract: A brushless dc external-rotor motor having a hollow cylindrical heat sink fastened to the peripheral border region of a printed circuit board. Power semiconductors are arranged on an inner cylinder wall of the heat sink in a heat conducting manner, and the cylinder wall forms part of the peripheral border of the stator flange in the motor. A connector fastens Hall generator(s) on the circuit board and provides the electrical connection with the circuit board. The connector can be soldered along with all other electronic components in a joint soldering process, wherein a subassembly of a preassembled circuit board and a heat sink fastened to its periphery and carrying the power semiconductors passes through a solder bath to solder all components in a single soldering process. It is subsequently necessary only to plug the Hall generator or generators onto the connector or connectors soldered onto the circuit board.