Patent attributes
A power extraction system for a gas turbine engine may comprise a high spool transmission, a low spool transmission, and an accessory gearbox. The accessory gearbox may comprise a starter-generator, a low spool starter-generator gear, a high spool gear, and a clutch configured to selectively engage and disengage the low spool starter-generator gear and the high spool gear. The low spool starter-generator gear may be configured to transfer torque between the starter-generator and the low spool transmission for accessory power generation. The high spool gear may be configured to transfer torque to the high spool transmission for engine starting. The clutch may be controlled by a variable transmission and may allow accessories to be driven by the low spool after starting.
