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.

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.