Abstract: A commutator for an electric motor includes a support ring, a plurality of metal segments arranged around a circumference of the support ring, and a plurality of capacitors arranged between the support ring and the metal segments. Each capacitor is connected between two adjacent metal segments.

Abstract: A core includes a ring body and a plurality of teeth. The teeth extend radially outward form the outer circumference of the ring body. The core is formed by assembling a first core member and a second core member. Each core member has part of the teeth the number of which is half the total number of the teeth. Each tooth includes a tooth body about which the coil is wound, and a magnetism converging portion provided at the distal end of the tooth body. The tooth height of each tooth body gradually increases from a distal section to a proximal section of the tooth body. The tooth width gradually decreases from the distal section to the proximal section. The wire is wound about each of the teeth of the first and second core members. Then, the first and second core members are assembled to form the core. Accordingly, a rotor core having a high coil accommodation efficiency and a high coil space factor is obtained.

Abstract: A rotary transformer has a bus duct assembly that extends through the hollow shaft of a rotary transformer from collector or slip rings positioned above a drive motor for the rotary transformer to end windings of the rotor positioned most remote from the drive motor. By positioning the leads of the bus duct connection with the rotor end windings on the rotor end windings most remote form the drive motor, the shaft strength and integrity is not reduced due to the torque applied by the drive motor. Further, the shaft is formed from two coupled shaft sections and the bus duct assembly comprises two L shaped sections each positioned substantially within a corresponding shaft section. The bus duct sections are interconnected to complete the bus duct assembly making it simpler to remove the first or upper shaft section from the second or lower shaft section during field servicing.

Abstract: The reversible multiphase rotary machine includes a device (3) for supplying current to the windings (12-14) of the stator, which is produced in the form of a mechanical inverter (2) able to be coupled to the aforementioned shaft of the machine and connected to the windings (12-14) of the stator.

Abstract: The invention relates to the construction and a mode of operation of statorless electronically switched DC motors that have two freely turning rotors. The invention also relates to embodiments of the invention regarding the bearings, the circuit design and the mode of operation of machines such as fans and blowers.

Abstract: An electrical current collector system has an electrically conductive slip ring mounted to a rotatable shaft and a fixed conducting ring assembly forming a partially enclosed AC high voltage electrical current conductive ring channel in which slip ring contacting members are mounted. A compartment at ground potential at least partially encloses the slip ring and the fixed conducting ring assembly. A source directs a fluid into the compartment so that the fluid travels through into the conductive ring channel to perform at least one of cooling and cleaning of the slip ring contacting members. A hollow conically shaped insulator has a frustum with a narrower cross-sectional opening connected to the conductive ring channel and a larger diameter cross-sectional portion passing through and connected to the compartment for exhausting the fluid from the current conductive ring channel.

Abstract: The commutator has a cylindrical collector (1), disposed on a motor armature shaft, and electrical-contact means (4, 5), which during one rotation of the collector (1) touch at least two each of a plurality of commutator laminations (3) that are present on the collector (1) and thereby establish an electrical connection between the applicable commutator laminations and external current connections (21, 22).

Abstract: One current passing circuit board is constituted by one metal plate in which a continuous current passing pattern that is to be separated in a plurality of current passing patterns is formed, and molded resin in which the metal plate is inserted. The current passing circuit board is pressed to eliminate the unnecessary portions of the above mentioned current patterns, thereby the one current passing circuit board is formed in a state where the current passing pattern continuously formed is separated in the normal forms.

Abstract: A homopolar machine which exhibits reduced wear and prolonged brush life. Current collectors or brushes are mounted so as to maintain substantially constant contact pressure and so that all of them are polarized negative. Brush holders are provided which facilitate the application of precise and constant contact pressure in a region of very high magnetic forces.

Abstract: A homopolar machine produces an axial counter force on the rotating shaft to compensate for the load on the shaft's thrust bearing to reduce wear and noise and prolong bearing life. The counter force is produced through magnetic interaction between the shaft and the machine's field coils and is created by changing the current excitation of the field coils, which results in a magnetic flux asymmetry in an inner flux return coupled to the shaft. The homopolar machine may also have a configuration that uses current collectors that maintain substantially constant contact pressure in the presence of high magnetic fields to improve current collector performance. The current collectors are flexible and may be made from either electrically conductive fibers or stacked strips such that they bear up against the armature so that the pressure is maintained by the spring constant of the current collector material.

Abstract: A very simple and reliable rotor (4) for a (brushless) exciter to be used to energise the field winding of a rotor of a generator, is proposed which can be used for high-speed rotation and for the generation of high currents for energising the field winding of the rotor of the generator. The rotor (4) comprises at least two conducting bars (6) aligned substantially parallel to the axis (8) of the rotor (4), wherein the bars (6) are connected on their first axial end to a collecting ring (13) and wherein on their second axial end the bars (6) are connected individually to two rings (14, 15) by means of diodes (16) with reversed polarity such that alternating current induced in the conducting bars (6) due to a static field (7) is converted into a direct current (DC) in the two rings (14, 15).

Abstract: An electric motor includes a stator which carries permanent magnets, and a rotor which carries electromagnets. A particular arrangement of connecting up the windings of the electromagnets to the distributing collector and the selection of the ratio of stator magnets to rotor electromagnets enable higher torque to be achieved. The main field of application is in motor-wheels of vehicles.

Abstract: A rotor with wedges and a method of retaining wedges in a rotor are disclosed. The rotor includes a shaft, first and second poles extending radially from the shaft, and first and second coils of windings respectively wrapped around the first and second poles. Each coil includes a respective outer face including two end portions and two side portions, and a respective inward-facing edge including two end sections and two side sections. The rotor further includes a first outer wedge positioned between neighboring side portions of the first and second coils, and a first inner wedge positioned between neighboring side sections of the first and second coils. The first inner wedge is coupled to the first outer wedge so that the first outer wedge is at least partly retained from moving radially outward away from the shaft.

Abstract: A rotary transformer system (20) comprises a rotatable shaft (28) having at least one and preferably plural electrically conductive slip rings (27) mounted thereon. The slip rings (27) of the phase planes are electrically connected to their respective windings on rotor assembly (22) by the bus conductors (80). The bus conductors (80) extend through respective phase isolated bus ducts (82) formed interiorly in rotatable shaft (28). The bus ducts (82) have a buffer (146) provided therebetween so that the bus ducts (82) are not in physical contact, but are spaced apart and separated. A mouth (160) and annulus (162) of each bus duct (82) extend through a cover plate (164). The cover plate (164) is secured by fasteners (166) through insulated spacers (167) and is held slight aloft above the circumference of rotatable shaft (28), thereby insulating cover plate (164) from rotatable shaft (28). The cover plates (164) of adjacent bus ducts (82) are electrically connected by a flux plate (170).

Abstract: An improved flat or cylindrical mechanical electric commutator with neutral segments (4) between the current carrying segments which allow the current carrying carbon brushes (11, 12, 13, 14) in a brush holder (7) to pass from a negative current carrying segment to a positive current carrying segment or the opposite charge current in the base of the commutator without allowing the face or any part of the carbon brush to touch both the negative and positive segments in the base of the commutator at the same time, resulting in the switching of the electric current to an energized coil of an electric motor, electrical generator or electric apparatus or device, at predetermined intervals and times to suit the design requirements of the energized coil, electric motor of the stepper, brushless DC and switched design, electric generator or electric apparatus or device, while the commutator can accommodate single phase electrical circuits, double phase electrical circuits, three phase electrical circuits or any numbe

Abstract: A sulfidation-resistant current-carrying member, such as a commutator, suitable for a direct-current motor in a fuel pump is provided. The current-carrying member for a direct-current motor in a fuel pump includes a commutator composed of a carbon layer having carbon as a principal component and forming a sliding surface at one end, and a metal carbon layer fixedly bound with the carbon layer at the other end and comprising 55 to 90 wt % of metal having brass as a principal component and a remaining portion having carbon as a principal component. By using brass as a primary metal component in the metal carbon layer, it is possible to achieve a commutator with superior resistance to sulfidation.

Abstract: An electric machine having a rotor carrying a field coil has a fan and slip ring assembly. The slip ring assembly is axially remote from the fan portion, the slip ring assembly being electrically connected to the field coil. The point of connection between the slip ring assembly and the field coil is secured to the fan by a thermoplastic retaining member that is ultrasonically welded to the surface of the fan.

Abstract: A homopolar machine produces an axial counterforce on the rotating shaft to compensate for the load on the shaft's thrust bearing to reduce wear and noise and prolong bearing life. The counterforce is produced through magnetic interaction between the shaft and the machine's field coils and is created by changing the current excitation of the field coils, which results in a magnetic flux asymmetry in an inner flux return coupled to the shaft. The homopolar machine may also have a configuration that uses current collectors that maintain substantially constant contact pressure in the presence of high magnetic fields to improve current collector performance. The current collectors are flexible and may be made from either electrically conductive fibers or stacked strips such that they bear up against the armature so that the pressure is maintained by the spring constant of the current collector material.

Abstract: A choke 10, for suppressing radio-frequency interference of a brush-type motor, includes a single wire having a portion 15 wound about a coil axis A to define a plurality of coils 14 including two outermost coils 16 and 18. An attaching structure 20 extends from each outermost coil and is disposed generally transverse with respect to the coil axis. Each attaching structure is constructed and arranged to be inserted through an associated opening in a supporting structure and to be bent so as secure the choke to the supporting structure. An elongated end portion 22 extends from each attaching structure so as to be spaced from and generally parallel to the coil axis. The elongated end portions extend in opposite directions. One of the elongated end portions is constructed and arranged to be directly electrically connected to an electrical connector of a motor and the other of the elongated end portions is constructed and arranged to be in electrical connection with a brush of the motor.

Abstract: A choke 10, for suppressing radio-frequency interference of a brush-type motor, includes a single wire having a portion 15 wound about a coil axis A to define a plurality of coils 14 including two outermost coils 16 and 18. An attaching structure 20 extends from each outermost coil and is disposed generally transverse with respect to the coil axis. Each attaching structure is constructed and arranged to be inserted through an associated opening in a supporting structure and to be bent so as secure the choke to the supporting structure. An elongated end portion 22 extends from each attaching structure so as to be spaced from and generally parallel to the coil axis. The elongated end portions extend in opposite directions. One of the elongated end portions is constructed and arranged to be directly electrically connected to an electrical connector of a motor and the other of the elongated end portions is constructed and arranged to be in electrical connection with a brush of the motor.

Abstract: A contact assembly of an alternator including an interior chamber, which houses a first end of a rotor shaft having an axis of rotation, first and second bearing assemblies coaxially aligned with the rotor shaft and electrically isolated from one another; and at least one spring member coaxially positioned with respect to the rotor shaft within the chamber. The spring member(s) exerts resistive forces into at least one of the first and second bearing assemblies and support structures within the interior chamber in order to compressively sandwich the first and second bearing assemblies within the interior chamber. The contact assembly may also include capacitors electrically connected to the bearing assemblies.

Abstract: The invention relates to the construction and a mode of operation of statorless electronically switched DC motors that have two freely turning rotors. The invention also relates to embodiments of the invention regarding the bearings, the circuit design and the mode of operation of machines such as fans and blowers.

Abstract: A contact assembly of an alternator comprising an interior chamber, which houses a first end of a rotor shaft having an axis of rotation, first and second bearing assemblies coaxially aligned with the rotor shaft and electrically isolated from one another; and at least one spring member coaxially positioned with respect to the rotor shaft within the chamber. The spring member(s) exerts resistive forces into at least one of the first and second bearing assemblies and support structures within the interior chamber in order to compressively sandwich the first and second bearing assemblies within the interior chamber. The contact assembly may also comprise capacitors electrically connected to the bearing assemblies.

Abstract: An alternator adapted for use with a motor vehicle includes rotor assembly and a stator assembly, which may be like the rotor and state assemblies of brush-type alternators, and also a contact assembly that includes two relatively low-friction, electrically conductive, ball bearing assemblies that are adapted to conduct the DC exciting current for the alternator and that are electrically isolated from each other. Each ball bearing assemblies include inner and outer races that are electrically connected to each other by a plurality of bearing balls and by electrically conductive grease which is packed about the balls. The inner race of each ball bearing is rotatably secured to the rotary shaft of the rotor assembly and is connected to electrical leads which, in turn, are connected with the rotor assembly. The outer race of each ball bearing is fixed relative to the rotary shaft and is connected with a storage battery.

Abstract: To present a motor brush structure capable of decreasing the current ripple and torque ripple substantially while minimizing the cost increase, and, by using the same motor, a motor-driven power steering device capable of suppressing generation of working sound, magnetostriction sound, radio noise, and cogging feel during steering operation. In a motor-driven power steering device used as a steering device for turning wheels such as front wheels of an automobile, a pair of shunt brushes for shunting are added to a pair of main brushes, these shunt brushes are disposed at positions for geometrically inverting the brush contact positions with segments, and it is composed so that the waveforms of the current flowing in the main brushes 11 from each segment of a commutator to each coil, the current into the shunt brushes, and the shunted current may be mutually inverted in phase to cancel each other.

Abstract: An electrical current collector system (20) comprises a rotatable shaft (28) having at least one and preferably plural electrically conductive slip rings (27) mounted thereon. For each phase, a slip ring is paired with a fixed conducting ring assembly (44). The fixed conducting ring assembly forms an envelope within which slip ring-contacting members are situated. The slip ring-contacting members can take many forms, including brushes (240) or rollers (404). The fixed conducting ring assembly comprises a first conducting plate (200T) and a second conducting plate (200B) positioned parallel to one another to form a conductive ring channel (220) therebetween. The slip ring-contacting members (240, 404) are mounted in the conductive ring channel. An at least partially transparent wall (200W) extends between the first conductive plate and the second conductive plate of the fixed conducting ring assembly to further define the conductive ring channel and permit visual inspection of the slip ring-contacting members.

Abstract: An electrical current collector system includes a rotatable shaft (28); an electrically conductive slip ring (27); and a slip ring support assembly (42). The slip ring support assembly (42) comprises plural post insulators (102) spaced radially about the rotatable shaft for attaching the conductive slip ring to the rotatable shaft. The post insulators facilitate adjusting of the position of the slip ring relative to the rotatable shaft, e.g., to provide concentric positioning. The post insulators comprise an attachment/adjustment assembly (106) for connecting to the slip ring. In one embodiment, the attachment/adjustment assembly comprises a spring plate (134) which is adjustably biased to provide a preloading displacement that absorbs differential movement due to temperature changes of the slip ring an the rotatable shaft. In one example deployment, the current collector system is provided as part of a rotary transformer system (20) which, e.g.

Abstract: An electrical current collector system (20) comprises an electrically conductive slip ring (27) mounted to a rotatable shaft (28), as well as a fixed conducting ring assembly (44) having slip ring-contacting members (240, 404) mounted thereon. The slip ring (27) and fixed conducting ring assembly (44) are mounted to have an annular gap (48) formed therebetween. A slip ring support assembly (42) comprising plural post insulators (102) spaced radially about the rotatable shaft attaches the conductive slip ring to the rotatable shaft. The slip ring and fixed conducting ring assembly are at least partially enclosed in a compartment (57), to which a source (302) applies a cooling/cleaning fluid. In accordance with the structure and method of the invention, the source directs the fluid over at least some of the post insulators for cleaning of the post insulators.

Abstract: The invention relates to a sliding contact device for transmitting electrical signals or power between at least two units located opposite one another, whereby at least one unit comprises slideways, which are arranged along the trajectory of motion and which are made of electrically conductive material, and a second unit comprises sliding contacts that are in electrical contact with said slideways of the first unit. The invention is characterized in that, in the second unit, several carbon holders are arranged on a supporting plate with conductor tracks for contacting the carbon.

Abstract: Devices for the management of contact spots, partly consisting of surface plating, partly of surface polishing and partly of substrate surface profiling in the form of parallel grooves stretched out in the direction of sliding and/or of isolated asperities. The management of the contact spots is designed to generate, at electrical brush interfaces, a large number of contact spots of pre-determined shapes and distribution that promote low electrical contact resistance and long wear life. Preferably, the substrate is coated with a hard, highly conductive coating that is resistant to wear and chemical attack. The invention is similarly applicable also to electrical switches wherein it will assure reduction of interfacial resistance as well as of sticking forces. Finally, it may also be used for the efficient transfer of heat across interfaces.

Abstract: When winding an armature coil, start S of a winding is entwined around a riser R1, the wire is wound via a riser R4 around a salient pole P1 adjacent to the riser R4 and an opposed salient pole P2 to the salient pole P1 in order, and leads from a riser R3 through an opposed riser R6 to an adjacent salient pole P3 and an opposed salient pole P4. Next, the wire is passed to a riser R5 and is wound around an opposed riser R2, an adjacent salient pole P5, and a salient pole P6, then ends with the riser R4. A varistor 18 is inserted and three electrodes 19 are soldered to the corresponding risers R2, R4, and R6.

Abstract: An assembly for transferring current comprises at least one electrically conductive slip ring; at least one electrically conductive brush for supplying current to the at least one slip ring; and an electric or pressure actuator driven vibration source for changing the position of the brush with respect to the slip ring. If desired, brush current can shared by using inductance variations or by selective coupling of rotor windings to the slip rings.

Abstract: Proposed is a commutation device for a direct-current motor, designed to improve the ripples in the signal course (40, 50) for the commutation current, so as to obtain reliably and error-free speed information with the aid of an electronic circuit. With the commutation device design according to the invention, the longitudinal edges of the collector bars (11, 21, 31) form an angle (&agr;) of more than zero degrees with the front longitudinal edge (18, 28, 38) of the contact face (16, 26, 36). On the one hand, this results in a reduction of the brush noise (airborne sound) and, on the other hand, in a lowering of the noise development (structure-born sound).

Abstract: When winding an armature coil start S of a winding is entwined around a riser R1, the wire is wound via a riser R4 around a salient pole P1 adjacent to the riser R4 and an opposed salient pole P2 to the salient pole P1 in order and leads from a riser R3 through an opposed riser R6 to an adjacent salient pole P3 and an opposed salient pole P4. Next, it is passed to a riser R5 and is wound around an opposed riser R2, an adjacent salient pole P5, and a salient pole P6, then ends with the riser R4. A varistor 18 is inserted and three electrodes 19 are soldered to the corresponding risers R2, R4, and R6.

Abstract: A coaxial drive employs a base member which is secured to a housing and is open to atmosphere and mounts rotatably an interior drive shaft about said base member so that rotation of the drive member in either direction in a full 360° circle. An electrical slip ring is provided between the base and the drive member with a ferrofluidic seal disposed proximate the lower end of the interior drive shaft such that atmospheric pressure passing through the base member and through the electrical slip ring is blocked by the ferrofluidic seal which has an opposite end disposed to the vacuum in the central processing apparatus.

Abstract: The invention proceeds from a geared motor, specifically a windshield wiper motor for a vehicle, with an electric motor enclosed by a motor housing, with a gear located on the drive shaft of the electric motor enclosed by a gear housing and with a brush mounting plate to hold brushes, where there is at least one ground brush connected to ground. The invention is characterized by the presence of a connector element at the brush mounting plate, which has at least one brush locator to accept an electrical connection with the ground brush and at least one ground locator to accept an element connected to ground.

Abstract: A linear motor for controlling motions of thread being woven on a weaving machine is disclosed. The linear motor contains a stator (1) which produces a magnetic field, an armature (2) which is arranged in the magnetic field, and two flexible mounting parts (3) which are arranged parallel to one another in such a manner that the armature which is connected to the mounting parts is movable relative to the stator. The linear motor drives a member that can contact the thread and thereby influence its motion.

Abstract: When winding an armature coil start S of a winding is entwined around a riser R1, the wire is wound via a riser R4 around a salient pole P1 adjacent to the riser R4 and an opposed salient pole P2 to the salient pole P1 in order, and leads from a riser R3 through an opposed riser R6 to an adjacent salient pole P3 and an opposed salient pole P4. Next, it is passed to a riser R5 and is wound around an opposed riser R2, an adjacent salient pole P5, and a salient pole P6, then ends with the riser R4. A varistor 18 is inserted and three electrodes 19 are soldered to the corresponding risers R2, R4, and R6.

Abstract: An electromechanical machine includes a stator fixed with respect to a housing structure and a rotor fixed with respect to a driven shaft. The stator includes a magnetically permeable core having a plurality of parallel winding slots containing conductive windings. Coilheads are located at opposite axial ends of the magnetically permeable core where the windings turn to extend down a parallel winding slot. The motor is equipped with electrostatic shield arrangements in the winding slots and coilheads to reduce capacitive coupling between the stator and rotor during operation.

Abstract: A collector ring for transferring electrical current between a non-rotatable member and a rotatable member. The collector ring comprises a first support which is fixed to the non-rotatable member and which has at least one conductive metal ring member mounted thereon which is electrically insulated from the non-rotatable member. An input terminal is electrically connected to each of the ring members for connection to a source of electrical energy. A second support is rotatably mounted on the first support with the second support being adapted to operatively mechanically connected to the rotatable member whereby rotation of the rotatable member with respect to the non-rotatable member will cause the second support to rotate with respect to the first support.

Abstract: A method and circuit is disclosed for soft-commutation of a direct current (DC) motor. An attenuation circuit is connected through auxiliary brushes A, A', B and B' to the commutator (16) to drain circuit from successive armature coils (15) before the main brushes (27, 28) disconnects from each of the coils (15). This prevents the spark generation that normally occurs in conventional DC motors. The attenuation circuit may also be connected before energization of the coil (15) for a soft turning on operation.

Abstract: A brushless slip ring includes a housing, a plurality of annular spaces disposed in the housing and spaced apart along a common longitudinal axis, and a cageless assembly of electrically conductive spherical balls freely rotatably disposed in each of the spaces. Each of the spaces is formed between radially inner and outer electrically conductive surfaces of a rotor and stator, respectively, and a pair of axially spaced retainer rings. The spherical balls conduct electrical current between the outer and inner surfaces. The balls are rigid and harder than the inner and outer surfaces and are arranged in an annular row. The balls occupy substantially the entire circumference of the space and are freely circumferentially movable relative to one another within the space for making contact with one another.

Abstract: A galvano mirror is held by a mirror holder. The mirror holder is rotatable about a rotation axis and supported in a stator. A center pins (made of conductive material) are provided to the stator. A pair of receive members (made of conductive material) are provided to the mirror holder. Each of the receive member receiving respective center pin. A pair of coils are provided to opposing ends of the mirror holder, the movable parts being connected to the receive members. The center pins and the receive members constitute a electrical feeding path for feeding electricity to the coils.

Abstract: A grounding system for an AC or DC motor or other rotating apparatus comprising a conductive brush in resilient contact with a contamination-free conductive member removably secured onto a rotating part such as a motor shaft or tachometer shaft. The contacting surface is preferably formed of brass and is shielded from contamination from motor bearings and the like, for reliably shunting the shaft to the frame of the machine so as to avoid high voltage transients across bearings as would otherwise result in bearing damage or destruction. A brush housing or holding means positions the brush in juxtaposition with the rotating conductive member and cooperates to substantially enclose the region of contact between the brush and the conductive member.

Abstract: A grounding system for an AC or DC motor or other rotating apparatus employs a conductive brush in resilient contact with a contamination free conductive member removably secured onto a rotating part such as a motor shaft or tachometer shaft. The contacting surface is preferably formed of brass and is shielded from contamination from motor bearings and the like, for reliably shunting the shaft to the frame of the machine so as to avoid high voltage transients across bearings as would otherwise result in bearing damage or destruction.

Abstract: An apparatus reducing capacitive coupling between the stator and the rotor of an electromagnetic machine. The apparatus includes an electrically connective shield positionable between the stator and the rotor, the shield electrically separated from both the stator windings and the rotor when so positioned. A grounder electrically connects the shielder to ground thus substantially reducing capacitive coupling between the stator and the rotor.

Abstract: An electric variable speed drive includes a hub member, a driven member, a magnetic coupler, and a rotary electrical connector. The hub member is mounted for rotating with the shaft of a prime mover. The driven member is rotatably supported on the hub member by bearings, and includes a mechanical output portion such as a pulley. The magnetic coupler includes an electric coil and magnetic poles which are mounted for rotating with one of the hub and the driven members. An armature is mounted to the other of the hub and driven members. An electric current is passed through the electric coil to magnetically couple the hub member to the driven member. The extent of the magnetic coupling between the hub and driven members is determined by the electric current passing through the electric coil.

Abstract: For electric motor collectors with lamella inner cross members, which serve for anchoring the individual lamellas, protrude inwards running at least predominantly parallel to the collector axis and are provided with undercut surfaces, which are to be grasped from behind by reinforcing rings. Reinforcing rings are proposed which, aside from a metallic clamping ring, comprise a supporting ring, which is fitted positively into the metallic clamping ring and forms a double body with the clamping ring and is formed from a material, which is resistant to compression and insulating even at high operating temperatures. With this, reinforcing rings are produced from two partial rings, which are easily manufactured and easy to press together, or by the supporting ring which is brought into the clamping ring by injection molding. The reinforcing rings form a unit which can withstand extremely high thermal and mechanical stresses and imparts the collector with very high stability under load and fatigue endurance.

Abstract: An electric motor has a tubular housing part, permanent magnets arranged inside the housing part, a rotatable motor armature with a collector having a running surface, a plurality of sliding brushes having sliding surfaces abutting against the running surface of the collector, and an element for loading the motor armature in direction of its rotary axis toward the sliding brushes so that the running surface of the collector which in its projection is formed as an annular surface abuts against the sliding surfaces of the sliding brushes.

Abstract: Ceramics material are not resistant to tensile force, though they are resistant to compression force. Therefore, ceramics materials, when used as the material of a commutator of an electric rotary machine, tends to be cracked and broken due to tensile stress generated in the inner peripheral portion of the commutator when the latter is press-fitted on the rotor shaft of the machine. The invention is aimed at obviating the above-described problem, so as to make it possible to produce a sliding current collector of an electric rotary machine from a ceramics material. To this end, according to the invention, an annular gap is formed between the inner peripheral surface of the ceramics commutator and the other peripheral surface of the rotary shaft and the gap is filled with a resin such as a thermosetting resin which is then thermally set to form a resin layer by which the commutator is bonded to the rotor shaft.