Abstract: A starter-generator system is configured to be operable at multiple variable frequencies. The starter-generator includes a rotor and a stator. The rotor is configured to rotate and has a single main field winding wound thereon. The stator has at least a first stator winding set and second stator winding set independently wound thereon. Upon electrical excitation and rotation of the rotor the starter-generator supplies electrical power from each of the stator winding sets at different frequencies. Also, upon electrically exciting one or both of the stator winding sets with appropriate AC power, the rotor will rotate and generate a starting torque.

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 conventionally wound main stator that is selectively configurable as a multi-pole AC stator and a multi-pole DC stator. The machine also includes rotor windings that are configured to be selectively coupled to either an exciter or a plurality of commutator segments, and DC brushes that are selectively moveable into, and out of, electrical contact with the commutator segments, to thereby electrically couple and decouple a DC power source to and from, respectively, the rotor windings.

Abstract: A starter-generator system supplies a controllable torque to a gas turbine engine, to thereby assist in starting the gas turbine engine, by independently controlling excitation frequency and/or voltage magnitude. The starter-generator includes a multi-phase exciter stator, a rotationally mounted multi-phase exciter rotor, a multi-phase main stator, a rotationally mounted multi-phase main rotor, and an exciter controller. The rotationally mounted multi-phase exciter rotor has a plurality of exciter rotor windings wound thereon that, upon excitation thereof with a rotating electromagnetic exciter flux generated by the exciter stator, have non-rectified excitation currents induced therein.

Abstract: A high speed, high power generator has its main stator and main rotor configured to provide enhanced cooling capability. The generator includes a generator housing, a stator, a shaft, and a rotor. The stator is mounted within the generator housing. The shaft is rotationally mounted within the generator housing, and includes an inner surface that defines an internal fluid flow passage, an outer surface, and a plurality of interlamination cooling supply orifices extending between the shaft inner and outer surfaces. The rotor is mounted on the shaft and includes a plurality of poles formed from laminations, and one or more interlamination disks. Each interlamination disk is disposed between at least two of the laminations and includes a plurality of interlamination flow passages that receive a cooling medium from the shaft and direct the cooling medium, via centrifugal force, through the rotor and onto the stator.

Abstract: A starter-generator system supplies a controllable torque to a gas turbine engine, to thereby assist in starting the gas turbine engine, by independently controlling excitation frequency and/or voltage magnitude. The starter-generator includes a multi-phase exciter stator, a rotationally mounted multi-phase exciter rotor, a multi-phase main stator, a rotationally mounted multi-phase main rotor, and an exciter controller. The rotationally mounted multi-phase exciter rotor has a plurality of exciter rotor windings wound thereon that, upon excitation thereof with a rotating electromagnetic exciter flux generated by the exciter stator, have non-rectified excitation currents induced therein.

Abstract: A high speed, high power generator has its main stator configured with one or more reduced-diameter sections. The generator includes a generator housing, a main rotor, and a main stator. The generator housing has a main stator cooling flow passage formed therein that is configured to receive a flow of a cooling medium. The main rotor is rotationally mounted in the generator housing. The main stator is mounted within the generator housing and surrounds at least a portion of the main rotor. The main stator includes a stator core coupled to the generator housing adjacent the main stator cooling flow passage, and includes two or more nominal-diameter sections and one or more reduced-diameter sections. The nominal-diameter sections each have a first outer diameter, and the reduced-diameter sections, each have a second outer diameter that is less than the first diameter.

Abstract: A system is provided for cooling a stator coil of a rotating machine. In one embodiment, and by way of example only, the system includes a stator core, a radial core opening, and a sleeve. The stator core has an axially extending slot formed therein, an outer circumferential surface, and an inner circumferential surface. The radial core opening extends from the stator core outer circumferential surface to the axially extending slot. The sleeve is disposed within the axial slot and configured to surround the stator coil. The sleeve has a cooling fluid supply port formed therein that is aligned with the radial core opening.

Abstract: One embodiment of the invention relates to a low profile electric generator having a short axial length. A cylindrical rotor body defines an interior cavity and is coupled to a driveshaft along the axis of the cylindrical body. A first rotor assembly is coupled to the inner surface of the cylindrical body, the first rotor assembly defining a space to receive a first stator that is independent from the cylindrical body. A second rotor assembly is coupled to the outer surface of the cylindrical body and electrically coupled to the first rotor assembly. A second stator is arranged around the second rotor assembly, independent from the cylindrical body, and radially positioned about the axis of the cylindrical body. By arranging the generator components in such configuration, the axial length of the generator is reduced in comparison to a conventional generator.

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 conventionally wound main stator that is selectively configurable as a multi-pole AC stator and a multi-pole DC stator. The machine also includes rotor windings that are configured to be selectively coupled to either an exciter or a plurality of commutator segments, and DC brushes that are selectively moveable into, and out of, electrical contact with the commutator segments, to thereby electrically couple and decouple a DC power source to and from, respectively, the rotor windings.

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 conventionally wound main stator that is selectively configurable as a multi-pole AC stator and a multi-pole DC stator. The machine also includes rotor windings that are configured to be selectively coupled to either an exciter or a plurality of commutator segments, and DC brushes that are selectively moveable into, and out of, electrical contact with the commutator segments, to thereby electrically couple and decouple a DC power source to and from, respectively, the rotor windings.

Abstract: A starter-generator includes redundant motor/generator sets disposed within a common housing. Each motor/generator set is electrically and mechanically independent of one another, with the exception of a common input/output gear. The starter-generator is configured such that if one of the motor/generator sets experiences a predetermined torsional load, it will decouple from the input/output gear, allowing the other motor/generator set to continue operation uninterrupted.

Abstract: A generator system is configured to supply relatively constant frequency AC power when driven by a variable speed prime mover, by independently controlling the main rotor flux rotational speed. The generator system includes an exciter stator that induces current in the exciter rotor windings at a desired frequency and phasing. The exciter rotor windings are electrically connected to the main rotor windings, and are thus electrically excited at the same frequency and phasing. Excitation is supplied to the exciter stator from an exciter controller, which controls the frequency and phasing of the exciter excitation, based on the rotational speed of the generator, to maintain a constant output frequency.

Abstract: A rotor for a high speed generator is constructed of a plurality of laminations and interlamination disks, which are disposed between each of the laminations. A coil support assembly is disposed within each of the rotor interpole regions and is secured to the interlamination disks.

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 conventionally wound main stator that is selectively configurable as a multi-pole AC stator and a multi-pole DC stator. The machine also includes rotor windings that are configured to be selectively coupled to either an exciter or a plurality of commutator segments, and DC brushes that are selectively moveable into, and out of, electrical contact with the commutator segments, to thereby electrically couple and decouple a DC power source to and from, respectively, the rotor windings.

Abstract: A rotating electrical machine, such as an aircraft starter-generator, that may be operated in either a motor mode or an generator mode. The machine includes a main rotor that is selectively configurable as an M-pole rotor or an N-pole rotor. The machine can also include 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: A rotating electrical machine, such as an aircraft starter-generator, that includes an exciter that has its stator windings supplied with electrical power from a power supply. One or more switches are electrically coupled between the exciter stator winding and the power supply and are configured and controlled so that a capacitance may be selectively placed electrically in series with the exciter stator windings.

Abstract: A rotating electrical machine, such as an aircraft starter-generator, that includes an exciter that has its stator windings supplied with electrical power from a power supply. One or more switches are electrically coupled between the exciter stator winding and the power supply and are configured and controlled so that a capacitance may be selectively placed electrically in series with the exciter stator windings.

Abstract: One embodiment of the invention relates to a low profile electric generator having a short axial length. A cylindrical rotor body defines an interior cavity and is coupled to a driveshaft along the axis of the cylindrical body. A first rotor assembly is coupled to the inner surface of the cylindrical body, the first rotor assembly defining a space to receive a first stator that is independent from the cylindrical body. A second rotor assembly is coupled to the outer surface of the cylindrical body and electrically coupled to the first rotor assembly. A second stator is arranged around the second rotor assembly, independent from the cylindrical body, and radially positioned about the axis of the cylindrical body. By arranging the generator components in such configuration, the axial length of the generator is reduced in comparison to a conventional generator.

Abstract: A rotating electrical machine, such as an aircraft starter-generator, that may be operated in either a motor mode or an generator mode. The machine includes a main rotor that is selectively configurable as an M-pole rotor or an N-pole rotor. The machine can also include 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: A rotating electrical machine, such as an aircraft starter-generator, that includes an exciter that has its stator windings supplied with electrical power from a power supply. One or more switches are electrically coupled between the exciter stator winding and the power supply and are configured and controlled so that a capacitance may be selectively placed electrically in series with the exciter stator windings.