Patent ID: 7105937

Claim:
A starter/generator system for starting a gas turbine engine for aeronautical applications comprising: an alternating current dynamoelectric machine; a torque converter with an input shaft coupled to a drive shaft of the dynamoelectric machine; a first rotation-speed selective coupling with an input shaft coupled to an output shaft of the torque converter and an output shaft coupled to a drive shaft of the engine, wherein the first coupling transfers power from its input shaft to its output shaft so long as the input shaft rotates at least as fast as the output shaft for coupling the dynamoelectric machine through the torque converter to the engine in a starting mode; an adjustable speed transmission with an input shaft coupled to the drive shaft of the engine; a second rotation-speed selective coupling with an input shaft coupled to an output shaft of the adjustable speed transmission and an output shaft coupled to the drive shaft of the dynamoelectric machine, wherein the second coupling transfers power from its input shaft to its output shaft so long as the input shaft rotates at least as fast as the output shaft for coupling the engine through the adjustable speed transmission in a generating mode; a hydraulic fluid source for selectively filling the torque converter with hydraulic fluid to transfer rotational power from the dynamoelectric machine to the engine during the starting mode; and a control unit for switching the dynamoelectric machine from a starting mode to a generating mode when the engine reaches a self-sustaining rotational speed, coupling the hydraulic source to the torque converter in the starting mode and adjusting the ratio of the adjustable speed transmission to change the frequency of power generated by the dynamoelectric machine in the generating mode.