Abstract: A slip ring unit comprises a brush block with multiple brushes rotatable against a module with multiple sliding tracks. A position encoder is connected to the brush block and the module, for detecting the relative position between the brush block and the module. An evaluation unit receives signals from the position encoder and generates a position-dependent signal indicating wear. The evaluation unit has multiple wear counters assigned to multiple positions and/or sections of the slip ring. If a movement is detected within a certain section, the related wear counter is incremented to allow to monitor wear at slip rings that are not continuously rotating.

Abstract: A power tool comprises a housing, a direct current motor arranged in the housing, a speed reduction mechanism coupled to a shaft of the motor, a tool head driven by the speed reduction mechanism, a first direct current power source, and a switching device. The motor comprises a common brush, a high speed brush and a low speed brush which are in sliding contact with a commutator. The switching device is configured to selectively connect the common brush and the high speed brush with the power source to operate the motor in a high speed mode and to connect the common brush and the low speed brush with the power source to operate the motor in a low speed mode.

Abstract: A permanent-magnet electrical machine is disclosed in which the rotor or stator have at least one movable iron segment. A magnetic field of the electric machine is weakened when the movable iron segment is moved a position away from the rotor or stator, respectively. When the movable iron segment is in a first position, such as in contact with the rotor or stator, the field strength is high. When the movable iron segment is in a second position in which the movable iron segment is displaced away from the rotor or stator, the field strength is low. The ability to weaken the field strength causes the constant-power, speed ratio to be increased and thereby increases the utility of the electric machine for applications in which a wide speed range is desired. The electric machine may be used as both a permanent-magnet motor and generator.

Abstract: A permanent-magnet electrical machine is disclosed in which the rotor has a fixed back iron and movable back iron segments. When the movable back iron segments are in a first position, such as in contact with the fixed back iron, the field strength is high. When the movable back iron segments are in a second position in which the movable back iron segments are displaced away from the fixed back iron, the field strength is low. The ability to weaken the field strength causes the constant-power, speed ratio to be increased and thereby increases the utility of the motor for applications in which a wide speed range is desired. The disclosure applies to both permanent-magnet motors and generators. In an alternative embodiment, the stator ring is provided with a fixed portion and at least one movable stator segment.

Abstract: A power tool comprises a housing, a direct current motor arranged in the housing, a speed reduction mechanism coupled to a shaft of the motor, a tool head driven by the speed reduction mechanism, a first direct current power source, and a switching device. The motor comprises a common brush, a high speed brush and a low speed brush which are in sliding contact with a commutator. The switching device is configured to selectively connect the common brush and the high speed brush with the power source to operate the motor in a high speed mode and to connect the common brush and the low speed brush with the power source to operate the motor in a low speed mode.

Abstract: A direct current motor comprising a stator and a rotor. The rotor comprises: a shaft; a rotor core fixed to the shaft; a commutator fixed to the shaft; and rotor windings wound about poles of the rotor core and terminated on the commutator. The motor also has a common brush and at least two selectable brushes in sliding contact with the commutator; at least two direct current power sources; and a switching device configured to connect the common brush and a selected one of the selectable brushes with predetermined combinations of the power sources to operate the motor in different speed modes.

Abstract: Provided are a method, computer-readable medium, and system for automatically determining a proper operational current input to an electric motor. In an exemplary embodiment, a method for determining the proper operational current input includes sending a test signal to an input of an electric motor. A response to the test signal is measured using an output of the electric motor. Based on the measured response, a position of a brush that is capable of conducting current through a commutator of the electric motor is determined. The electric motor is supplied with a first current input if the brush is in a first position and a second current input if the brush is in a second position.

Abstract: A rotating electrical machine, such as an aircraft starter-generator, that may be operated in either a DC motor mode or an AC generator mode. The machine includes a main stator that is selectively configurable as a multi-pole AC stator and a multi-pole DC stator. The machine also includes DC brushes that are selectively moveable into, and out of, electrical contact the main rotor, to thereby electrically couple and decouple a DC power source to and from, respectively, the rotor windings.

Abstract: An interface system is presented, which prevents operational interference between a vehicle power door and a ramp of an access system by interrupting power to the motors and actuators responsible for operating the door. The interface system includes a relay system that does not interrupt, read, signal, or otherwise interfere with the communication lines between a body control unit, door control unit, or remote control transmitter or receiver. Thus, the interface system functions without the need to receive and transmit signals on the vehicle's communication bus. The interface system enables the ramp controller of the access system to be a separate module, which controls the ramp and kneel functions, because the only input the ramp controller provides to the power door system is to a ground signal that mimics that of a switch included in the vehicle.

Abstract: A method for monitoring a fan comprises measuring power usage of the fan, determining a derivative of the measured fan power usage, tracking the derivative over time, and predicting impending fan failure based on the tracked fan power usage derivative.

Abstract: A position sensor generates a signal representative of the angular position and, if desired, angular velocity of a rotating object using only a single circular track and plural brushes that ride on the track when the object rotates. The single circular track can have plural segments, and the sensor can generate more than one signal cycle per revolution.

Abstract: A motor system includes four brushes electrically connected to a rotor. A stator includes two magnetic poles. A circuit selectively rotates the rotor at a first speed by applying a first voltage to a first of the brushes and a second voltage to a second of the brushes. The circuit selectively rotates the rotor at a second speed by applying the first voltage to the first brush or the second brush, and applying the second voltage to a third of the brushes and/or a fourth of the brushes.

Abstract: In order to design as inexpensively as possible a control device for DC motors which are provided with a commutator for feeding their motor windings which has at least four sliding contacts, this device comprising a modulation stage which generates at least one control signal modulated as to pulse width with a clock frequency substantially above the motor speed and a control circuit which is controlled by the at least one control signal and has at least one load branch which feeds the commutator and is provided with an electronic switch controlled by the control signal modulated as to pulse width, it is suggested that the sliding contacts be combined to form at least two control groups, that the sliding contacts be combined within each control group to form pairs of sliding contacts and that each control group have its own load branch associated with it.

Abstract: A direct-current motor is provided with an armature, which includes a core and coils, a commutator, which has segments, a first, second, and third brushes, and a pair of magnets. The core includes teeth, which form teeth groups. The tooth located at the most advancing end in a teeth group in the rotation direction of the armature is the most advancing tooth. Each coil is wound about one of the teeth groups. One of the magnets includes a reverse flux portion. When the third brush starts to establish a short circuit between an adjacent pair of the segments during the rotation of the armature, the most advancing end of the most advancing tooth in the teeth group that corresponds to the coil connected to the pair of the segments starts circumferentially overlapping the reverse flux portion. This suppresses the interference caused by a short circuit established by the third brush.

Abstract: The known arrangements have at least one rotor coil (RS) arranged on the rotor and at least one stator coil (SS) arranged on the stator. The rotor coil (RS) and the stator coil (SS) respectively have at least one winding (WI) and there is a magnetic coupling between the rotor coil (RS) and the stator coil (SS). With an arrangement of this sort, it is possible for example to transmit measurement signals of a measurement pickup (MA) arranged on the rotor (RO) for the contactless measurement of torques. The additional acquisition of the respective angular position and/or of the respective angular speed (.omega.

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 motor-assisted power steering apparatus includes a DC motor which is fixed to a heat conductive frame, a torque sensor for detecting steering torque and a control circuit for controlling current supplied to the motor. The control circuit includes a first unit disposed in a space defined by the frame and a commutator of the motor and a second unit disposed outside the motor. The first unit includes multiple switching elements connected to the motor, and the second unit includes a microprocessor for setting motor current, a current detecting unit for detecting current supplied to the motor, a current control unit for providing duty ratio signals and a gate driving circuit for driving the switching elements according to the duty ratio signals.

Abstract: In an ordinary DC motor in a windshield wiper, operating speed tends to increase as the motor brushes become seated. The invention counteracts this tendency by providing a brush geometry which causes the effective angular position of a brush to change during seating. The change is in a direction which tends to reduce speed.

Abstract: A dc motor wherein a driving force thereof can be used effectively with a simple and compact mechanical construction and a motor controlling system which can control such a dc motor to be driven efficiently. The motor comprises at least two coils, and change-over means for changing electric connection of the coils to change over the motor, when power is selectively supplied to the coils, between a first mode in which the torque produced is relatively high and the rotational frequency is relatively low and a second mode in which the torque is relatively low and the rotational frequency is relatively high. The motor controlling system includes selecting means for automatically selecting one of the first and second modes to control the change-over means in response to a given condition of the motor.

Abstract: A bidirectional DC motor comprising a commutator (6) which can be connected to a constant voltage source by a first and a second brush. The second brush is disposed opposite one side of the first brush in a spaced disposition with respect to the periphery of the commutator, which spacing correlates with a desired motor characteristic to provide a relatively convenient arrangement for switching the direction of rotation of a DC motor. In addition to the second brush (8) provided for one direction of rotation, the commutator (6) also has a third brush (9) for the counter-direction of rotation and is disposed in a spaced disposition with respect to the periphery of the commutator (6), which spacing correlates with the desired motor characteristic for the counter-direction of rotation. The first brush (7) is connected to one pole (+) of the constant voltage source (10) and the two other brushes (8, 9) are connected to the other pole (-) of the constant voltage source (10) by a switch (S1, S2) respectively.

Abstract: A rotary scanner having a mirror with a plurality of deflecting facets for deflecting a light beam and a motor for rotating the mirror. The motor has a plurality of commutator segments and brushes, and at least one commutation position can be seen from outside. Further, the commutation positions are located at corresponding points with borders among the deflecting facets of the mirror.

Abstract: A regulator and brush holder assembly having a regulator assembly attachable to an alternator adjacent to the alternator's slip rings and a housing attached to the regulator assembly. The housing has a brush holder portion and a regulator compartment enclosing the regulator circuit of the regulator assembly. The brush holder portion has a pair of spatially separated brush holder compartments and a pigtail chamber associated with each brush holder. The associated brush holder compartments and the associated pigtail chambers have an open end and a closed end and are connected by a slot. Brush terminals are attached to the housing and extend into the open end of the pigtail chambers. A carbon brush is slidably received in each brush holder cavity and its pigtail connection is connected to the associated brush terminal through the slot.

Abstract: An apparatus for controlling a load lifting implement of a work vehicle in response to the condition of a motor brush is provided. The vehicle has a frame and the load lifting implement is connected to the frame and elevationally moveable relative to the frame between first and second directions. A brush wear indicator senses the wear of the motor brush and produces a warning signal in response to a predetermined amount of wear of the motor brush. A control system receives the warning signal and responsively controllably inhibits the elevational movement of the load lifting implement in at least one of the first and second directions.

Abstract: It is proposed to obtain a switching device for the electrical switching (i.e. switching on and off or reversing the direction of rotation) of electric tools, especially electric hand tools such as drills, grinders and the like, by mounting a rotatable setting ring on the outer cylindrical housing of the electric tool and positioning it opposite the end shield at the B-end of the electric motor inside the housing in such a manner that inwardly pointing projections of the setting ring will grip a plate or switching ring on the electric motor and will cause the said plate or switching ring to perform a slave motion for switching the electric motor on and off or reversing its direction of rotation whenever the external setting ring is subjected to a manual rotation.

Abstract: This invention relates to a speed changing device, giving at least two motor speeds, for an electric motor supplied with direct current. It is applicable to motorized ventilating fan units designed for the air cooling of heat engines, mainly for automobiles.The speed changing device is characterized in that it includes a contactor having at least two positions whereby, in the first position of the contactor, not more than three of the brushes are supplied with electrical current so as to obtain a first motor speed (low speed), while in the second position of the contactor, all of the brushes are supplied with electrical current so as to obtain the greater motor speed (high speed).

Abstract: A drive mechanism for windshield wiper systems on motor vehicles comprises a d.c. motor to be driven in at least two different speeds of operation. The motor includes a collector, a first and a second carbon brush substantially resting against the collector diametrically opposite each other, and a third carbon brush which rests against the collector between the first and the second carbon brush. The third carbon brush is set off at a particular angle relative to the second carbon brush. When the d.c. motor is operated in the first speed of operation the first and the second carbon brush is connected to the voltage source and when the d.c. motor is operated in the second speed of operation the first and the third carbon brush is connected to a voltage source.

Abstract: A direct current machine construction in which the rotor includes a permanent magnet with the stator including winding energizable from a direct current source. In a first embodiment first and second stationary slip rings are connected to an external direct current source. Coupled for rotation with the shaft are to first and second brush assemblies with brushes which are spring biased and protrude radially outwardly from the rotor shaft. The commutator for the windings is stationary relative to the housing and includes a plurality of commutator segments positioned intermediate the slip rings and in a cylindrical manner facing inwardly toward, and for contact with, the commutator brushes. The windings are on the stator with the winding leads being accessible externally of the stator for enabling switching devices to be utilized for changing of the number of turns of the stator windings for thereby varying the motor characteristics, as needed.

Abstract: A two-speed permanent magnet D.C. electric motor has a housing, permanent magnets carried by the housing, and an armature assembly installed in the housing. The armature assembly has a shaft rotatably mounted in the housing, first coil windings, a first commutator connected to the first coil windings, second coil windings and second commutator connected to the second coil windings. A first set of brushes is carried by the housing and engages the first commutator for applying a D.C. voltage to the first coil windings to cause rotation of the armature assembly at a first speed. A second set of brushes is carried by the housing and engages the second commutator for applying the same D.C. voltage to at least the second coil windings to cause rotation of the armature assembly at a second speed.

Abstract: A silent, high torque, impulse actuator system for low average power devices. The system incorporates a typical small three pole D.C. motor which has been modified to allow quick electrical conversion, with unipolar switching circuitry, from conventional rotation, to silent magnetic braking at a stop position; and then to a normally OFF condition.The high efficiency of this intermittent drive system is enhanced by the unique combination of being normally off between actuations; the high efficiency of the D.C. motor during start conditions; and the use of a round cam to provide a cosine power stroke that utilizes the inertia of the motor rotor to maximum mechanical advantage.

Abstract: A conventional three pole D.C. motor has a third placed at an acute angle of 60 degrees to one of the normal brushes and positioned to contact the commutator plates. A motor energizing circuit is normally off and is capable of energizing the normal brush and, alternately, the third brush which is displaced 60 degrees from the normal brush. A single intermittent rotation begins with the normal brush being energized, and continues in a conventional manner until a rotation sensor at approximately 300 degrees cuts off the normal brush and energizes the third brush for a specific period, during which time all armature poles are of opposite polarity to the adjacent field poles; which causes the motor to be magnetically braked at the 360 degree full rotation point. At the end of the braking period, all power is removed until the next intermittent cycle.

Abstract: A turbine-driven apparatus and method for generating and linearly controlling periodic bipolar drive signals to drive an electromechanical device, such as a DC motor, in response to an input command signal. The apparatus comprises a rotatable cylindrical commutator driven by a gas turbine, the commutator having two matched half-cylinder conductive sections separated by insulation at the common joints. The turbine also drives an alternator to produce AC power which in turn is rectified to produce DC power. Two pairs of diametrically opposing brushes are held in contact with the rotating commutator. The first pair of brushes connected to the DC power source, is fixed in position. The second pair, connected across the electromechanical load, is adjustable in rotational position relative to the first pair through coupling to a stepper motor.

Abstract: The commutator of a DC motor is uniquely constructed to include at least one dead segment at least as wide as the associated brush (brushes). A silicon controlled rectifier (SCR) is arrranged in the circuit between the voltage source and said brush (brushes) to provide a switching means to automatically cut off current flow therethrough each time a brush passes over the dead segment. The current is reestablished by way of a gating means, which in the preferred embodiment is a variable frequency pulse generator.

Abstract: The first and second interpole compensation windings are disposed on the commutation starting side and the commutation ending side of the interpole cores, respectively. The current flowing through the first and second interpole compensation windings are controlled in response to the first and second voltages detected by the first and second brushes disposed on the commutation starting side and the commutation ending side of the brushes.

Abstract: Commutator apparatus for electric motors includes electrical conductors making electrical contact with brushes through substantially three hundred sixty degrees of rotation of the commutator to provide current paths during time periods of current flow to prevent arcing. The commutator apparatus further includes cylindrical portions and blade portions which overlap and on which brushes are positioned to make the electrical contacts.

Abstract: A motor with a commutator, for example a traction motor, comprising brush-holders mounted on a ring adapted to rotate to bring them one by one opposite an inspection gate. The connection between these brush-holders and the fixed circuits is ensured by a system of split rings contacting on a blade, these rings being of clearly different diameters so that they are separated from one another except at their point of fixation. The supports of the brush-holders, the rings and the blades are identical and comprise a flat metal core with insulating coating working solely in compression.

Abstract: A four pole d.c. motor speed control is provided by connecting two of the opposed brushes together to ground and the intermediate brushes to separate terminals of a switch means which in energized positions connects a grounded power supply to at least one of the brushes. The switch means supplies various combinations including direct connection of the power supply to one or both of the brushes. Connection of the power supply through resistance means, connection of the other brush to provide a closed circuit across the windings or to provide a resistance in series with those windings.

Abstract: The commutator or commutators of a DC motor are uniquely arranged with a plurality of peripherally spaced, current carrying segments separated by relatively large, electrically dead, non-conducting spaces, each of the dead spaces being at least as wide in a peripheral direction as the corresponding width dimension of the brushes positioned adjacent thereto. A silicon controlled rectifier (SCR) is arranged in the circuit between the negative pole of the voltage source and the commutator input terminal and acts as a switch to automatically cut off current flow therethrough each time a brush leaves a commutator segment. The current is not re-established until the SCR is again gated, which time may be varied by a variable resistor/capacitor gating circuit.To prevent stoppage of the motor with the brushes of the commutator in a dead space a plurality of commutators are provided with the segments thereof staggered with relation to the first.

Abstract: An electrically energizable device of the type that may be selectively rotated through first and second angles of rotation in respective opposite directions in response to the electrical energization thereof in respective opposite senses supports and oscillates a disc member having two discrete circumferentially disposed electrically conductive areas separated by two discrete electrically insulating areas. This device is mounted upon the housing of an electrical motor in such a manner that the disc member is in axial alignment with the motor armature with a surface of each of the motor brushes being in sliding engagement with a surface of the disc member and in contact with a respective one of the electrically insulating areas when the disc member is in a neutral position. Electrical energization of the motor armature may be effected in respective opposite senses in response to the operation of the disc member through the first angle of rotation and through the second angle of rotation.

Abstract: An apparatus and a method is described for smoothing the acceleration and deceleration of an electric motor. This is accomplished by using a pair of brush springs (strong and weak) for each brush of an electric motor. At low speeds, the strong spring is retracted so that the force with which the brush is applied to the motor commutator is greatly reduced. This reduced frictional force improves the smoothness of the acceleration and deceleration characteristics of the motor at low speeds.

Abstract: A direct current motor which includes a stator for producing a fixed magnetic field and a plurality of armature windings. The motor is caused to rotate by applying current to each winding only while that winding is passing through a zone in a given orientation relative to the stator field. The direction of rotation is changed without changing the direction of the current applied to the windings, by changing the orientation of the zone relative to the stator field, to reverse the direction of the rotational force applied to the armature. Because the current does not reverse through the armature windings, the control circuit can be simple and in a preferred embodiment includes only two gate-turn-off silicon controlled rectifiers, a switch, and a resistor.