Performance envelope extension device for a gas turbine engine
AssigneeCEF Industries, Inc.
InventorsNeil M. Nelson, William A. Sponzilli, Quitman W. Lott
Life of this patent
Estimating the term…
Abstract
The present invention relates to a device for extending the performance life of a gas turbine engine by rotating the turbine after shutdown to achieve uniform cooling. The apparatus includes a motor, a high ratio gearset engaged with the motor, an overridable coupling means engaging the gearset with an accessory shaft of the turbine, and a logic circuit. The circuit determines when the engine has been shut down and continues to rotate the turbine for a predetermined period of time. If an external force interferes with the post-shutdown turning, the circuit will sense that force and compensate for it.
Claims15
An apparatus for controlled uniform cooling of a gas turbine engine having a spool, comprising:
- a motor;
- a gearset engaged with said motor;
- overridable coupling means engaging said gearset with a turbine accessory shaft which is connected to the spool;
- means for sensing engine operation;
- means for sensing when the engine has been shutdown;
- means for controlling the motor to rotate the spool for a predetermined period after the sensing means determines that the engine has been shutdown;
- a housing for containing the apparatus;
- and
- means for detachably attaching the housing to an engine accessory pad of a gas turbine engine.
The apparatus according to claim 6, further comprising:
- means for determining if the external force ceases to rotate the spool within the predetermined period;
- and
- means for restarting the motor to rotate the spool if the external force ceases to rotate the turbine prior to the elapsing of the predetermined time period.
An apparatus for controlled uniform cooling of a gas turbine engine having a spool, comprising:
- a motor;
- a gearset engaged with said motor;
- overridable coupling means engaging said gearset with a turbine accessory shaft which is connected to the spool;
- means for sensing engine operation;
- means for sensing when the engine has been shutdown;
- means for starting the motor to rotate the spool for a predetermined period after the sensing means determines that the engine has been shutdown;
- means for sensing the speed of the spool during the predetermined period;
- means for comparing the sensed speed to predetermined values;
- and
- means for controlling the motor in response to output from the comparing means.
An apparatus for controlled uniform cooling of a gas turbine engine having a spool, comprising:
- a motor;
- a gearset engaged with said motor;
- means for engaging the gearset with a turbine accessory shaft that is connected to the spool;
- override means for allowing engined operation without turning the motor and gearset;
- means for sensing the rotational speed of the turbine accessory shaft;
- logic means for activating the motor when the rotation of the turbine accessory shaft has exceeded a first predetermined speed and then slowed below a second predetermined speed;
- and
- logic means for deactivating the motor when a predetermined time period has elapsed since the activation of the motor.
The apparatus according to claim 16, further comprising:
- logic means for reactivating the motor if both the motor has been deactivated because the rotational speed became zero or less and if the predetermined time period has not yet elapsed.
Dependencies are inferred from the claim text.