Patent attributes
A power extraction system is provided and includes a low-pressure spool of a gas turbine engine, the low-pressure spool being rotatable at an input rotational speed between a first minimum speed and a first maximum speed, downstream components rotatable at an output rotational speed between a second minimum speed and a second maximum speed and a transmission assembly by which rotations of the low-pressure spool at the input rotational speed are transmittable at the output rotational speed to the downstream components. The transmission assembly includes clutches and a controller configured to control openings and closings of the clutches according to an upshifting algorithm whereby a torque applied by the downstream components is used to reduce the output rotational speed to an output speed of a gear into which the transmission assembly is shifting.
