Abstract: Systems and method for mixing the output of a vehicle alternator throughout any operating temperature range include a first temperature sensor for measuring a first temperature and a second temperature sensor for measuring a first temperature. A first temperature module compares the first temperature with a first temperature reference to determine a first temperature error, and to calculate a first duty cycle reference based on the first temperature error. A second temperature module compares the second temperature with a second temperature reference based on the second temperature error, and to calculate a second duty cycle reference based on the second temperature error. A duty cycle selection module selects the lesser of the first duty cycle reference or the second duty cycle reference as a maximum system duty cycle. A duty cycle control module regulates a field current of the vehicle alternator based on the maximum system duty cycle.

Abstract: Torque generating apparatus and method for automotive applications. A brushless DC motor is design optimized to operate at a design voltage, Vs, along an optimal speed/torque profile. A DC/DC converter is provided for supplying power at an alternate voltage, Va, to enable motor operation at speed/torque combinations not on the optimal profile. A switch is provided to enable the motor to be operated selectively at either of the two voltages.

Abstract: A segmented stator for a permanent magnet motor. The stator includes a plurality of stator segments forming an annular stator yoke and a plurality of stator teeth extending from an edge of the stator yoke. At least one coupling is between adjacent stator segments and shaped to allow movement of adjacent teeth in a so-called loose tooth design. Slot wedges are located between adjacent teeth to prevent the conductive windings from moving out of the slots through the slot openings. The slot wedges also prevent movement of adjacent teeth with respect to one another. The segmented stator can comprise an annular yoke with a plurality of discrete teeth or a plurality of assemblies including a rim section and a tooth section. The slot wedges can be keyed wedges that maintain their position through interlocking and/or can be integrated with a stator bobbin.

Abstract: Torque generating apparatus and method for automotive applications. A brushless DC motor is design optimized to operate at a design voltage, Vs, along an optimal speed/torque profile. A DC/DC converter is provided for supplying power at an alternate voltage, Va, to enable motor operation at speed/torque combinations not on the optimal profile. A switch is provided to enable the motor to be operated selectively at either of the two voltages.

Abstract: An automotive steering assist system having an electric motor provided with poles organized into 2 groups. The motor has means for detecting shorts in the poles and means for disabling all poles in a pole group whenever a short is detected in a pole of that group.

Abstract: A segmented stator for a permanent magnet motor. The stator includes a plurality of stator segments forming an annular stator yoke and a plurality of stator teeth extending from an edge of the stator yoke. At least one coupling is between adjacent stator segments and shaped to allow movement of adjacent teeth in a so-called loose tooth design. Slot wedges are located between adjacent teeth to prevent the, conductive windings from moving out of the slots through the slot openings. The slot wedges also prevent movement of adjacent teeth with respect to one another. The segmented stator can comprise an annular yoke with a plurality of discrete teeth or a plurality of assemblies including a rim section and a tooth section. The slot wedges can be keyed wedges that maintain their position through interlocking and/or can be integrated with a stator bobbin.

Abstract: A rotor for a permanent magnet motor with a rotor yoke and a permanent magnet ring mounted on the rotor yoke, the magnet ring having a plurality of circumferentially spaced poles. One of the rotor yoke and the permanent magnet ring is an annular member including depressed portions along a peripheral edge located around a midpoint between each pole. The depressed portions are shaped so the motor produces a sinusoidal flux density. The other of the rotor yoke and the permanent magnet ring is an annular ring. In another aspect, the rotor has a rotor yoke and a permanent magnet ring mounted on the rotor yoke. The permanent magnet ring includes a plurality of circumferentially spaced poles. One of the rotor yoke and the permanent magnet ring includes a plurality of depressions along an outer peripheral edge shaped so the motor produces a sinusoidal flux density during operation. Each of the plurality of depressions is located around a junction defined by two poles.

Abstract: A stator tooth design for a stator core of a permanent magnet motor. The tooth surface comprises a plurality of surface segments, wherein each surface segment of the plurality of surface segments joins an adjacent surface segment of the plurality of surface segments at an obtuse angle, preferably between 160 and 170 degrees. Alternatively, the tooth surface comprises a single essentially straight surface segment. Each of the plurality of surface segments has a starting edge and an ending edge. Preferably, the starting edge of a surface segment lies along a first circumferential path a predetermined radial distance from the outside edge of the stator core and the ending edge of the surface segment lies along a second circumferential path either closer to or further from the outside edge. The first circumferential path and the second circumferential path can be concentric to the outside edge of the stator core.

Abstract: A variable reluctance electric motor includes a hollow cylindrical stator having a plurality of radially inwardly extending poles. Each of the stator poles is generally rectangular in cross sectional shape and is bifurcated into two stator teeth at its radially innermost end by a central, longitudinally extending slot. The outer circumferential edges of the stator pole teeth are beveled at their respective junctions with the sides of the stator pole. A stator pole gap width is defined between adjacent stator poles. A slot width is defined within each of the stator poles between the adjacent longitudinally extending edges of the slot. The ratio of the stator pole gap width to the stator pole slot width is in the range of from about 1.8 to about 2.3. A cylindrical rotor is co-axially supported within the stator for relative rotational movement. The rotor has a plurality of radially outwardly extending poles formed thereon. Each of the rotor poles is generally rectangular in cross sectional shape.

Abstract: A switched reluctance motor drive includes a noise reduction circuit configured to control the decay of current when a motor phase is switched from active to inactive. The current decay is controlled to occur in two stages: a first portion and a second portion. The first portion is controlled by alternately activating and deactivating one of the two switches in the two switch drive topology to obtain a current profile conforming to a predetermined profile. The current decay in the second portion of the inactive interval occurs by keeping both switches off so that it decays naturally. The duration of the first portion of the inactive interval is different for each motor phase, as is the duty cycle of the switch gating signal driving the switch that is alternately activated and deactivated. The scheme reduces the acoustic noise generated during operation of the motor.

Abstract: A motor vehicle clutch includes an axis of rotation, a pressure plate, a cover, an apply spring, a release bearing, a stator housing, a stator, a rotor, a rotor housing and a plurality of cam followers. The pressure plate is concentric with the axis of rotation. The cover extends radially over the pressure plate. The apply spring is disposed between the cover and the pressure plate and biases the pressure plate away from the cover. The release bearing is concentric with and axially displaceable along the axis of rotation and is connected to the apply spring for selectively deflecting the spring with axial movement. The stator housing is stationary and is concentric with the axis of rotation. The stator is fixed within the stator housing and has a plurality of poles with windings there about. The rotor is also concentric to the axis of rotation and is operably excited by the stator. The rotor housing is fixed to the rotor. The rotor housing has a plurality of cam ramps arcuately disposed about the axis.

Abstract: A method and circuit for controlling a switched reluctance motor are provided. The method includes the steps of controlling a current in a phase coil of a motor phase of the motor during an active stage of the motor phase and controlling the current in the phase coil during an inactive stage of the motor phase. The latter step includes the substep of increasing the level of current in the phase coil for a predetermined period of time during the inactive stage of the motor phase. By increasing the current level during the inactive stage, the rate of current dissipation is reduced, thereby reducing acoustic noise. A circuit in accordance with the present invention includes a pair of one-shot circuits connected together in series and responsive to the end of the active stage of the motor phase. The second one-shot circuit generates an output signal that closes a switch connected to a phase coil of a motor phase of the motor for a predetermined period of time during the inactive stage of the motor phase.

Abstract: An apparatus for controlling a switched reluctance machine changes the operating modes between a single-phase operating mode, and a multi-phase operating mode. The switched reluctance motor includes a rotatable rotor, a stator, and a plurality of stator windings defining a corresponding plurality of machine phases. When in the multi-phase mode, all of the plurality of stator windings corresponding to the plurality of machine phases are energized. When in the single-phase mode, stator windings corresponding to a single, selected machine phase are energized. The apparatus includes a logic circuit for sensing a speed of the rotor and generating a speed signal in response thereto, and a comparator circuit.

Abstract: A switched reluctance motor includes a stator defining a plurality of radially-inwardly-extending poles and a rotor defining a plurality of radially-outwardly-extending poles. The poles of the stator define a shape in radial cross-section characterized by a generally rectangular body portion, and a tip portion which tapers at an angle no greater than 40.degree. relative to the sides of the rectangular body portion. The nominal width of the rectangular body portion of each stator pole is at least 1.3 times the nominal (chordal) dimension across the arcuate, radially-innermost surface on the tip portion thereof.

Abstract: A switched reluctance motor includes a stator defining a plurality of radially-inwardly-extending poles and a rotor defining a plurality of radially-outwardly-extending poles. The poles of the stator and the rotor are respectively divided into at least two longitudinal sections, with each pole section featuring a different shape when viewed in radial cross-section. The shape of one rotor pole section is such as to subdivide the pole into three teeth, namely, a central tooth flanked on either side by a side tooth, further characterized in that the shape of the central and side teeth are symmetric relative to a radius bisecting the central tooth. In a preferred embodiment, the circumferential spacing between the central tooth and each side tooth of one rotor pole is less than the circumferential spacing between the opposed side teeth of adjacent rotor poles.