Auxiliary Oil Pump Control for Geared Turbine Lubrication Loss
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Gas turbine engines with gear reductions require reliable lubrication under various flight conditions, including extreme conditions where the main oil supply system may fail or be inadequate.
Innovation Solution
An auxiliary oil supply system that includes a rotation sensor, a control unit, an auxiliary oil pump, and a main supply sensor to detect rotation and inadequate oil supply from the main system, thereby providing supplemental lubrication to the gear reduction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a gear reduction is added between the fan drive turbine and the fan rotor to allow the fan to rotate at slower speeds, then efficiency is improved, but the system becomes more complex and requires additional lubrication systems
Solution Approach 1:
The oil supply system is segmented into a main oil supply system and an auxiliary oil supply system. The auxiliary system includes a separate auxiliary oil pump, auxiliary oil tank, and associated sensors and controls, dividing the lubrication function into independent subsystems that can operate autonomously when needed.
Solution Approach 2:
The auxiliary oil supply system is pre-configured with an auxiliary oil pump, auxiliary oil tank, and control system that can activate before main system failure. The system includes preliminary protective measures such as sensors and control logic ready to engage the auxiliary pump when main oil supply pressure drops or rotation is detected.
2Device complexity
If the main oil supply system is used alone, then the system is simpler, but it may fail to provide adequate lubrication under extreme flight conditions
Solution Approach 1:
The auxiliary oil supply system serves as a pre-prepared backup or cushion against main system failure. The auxiliary oil tank stores reserve oil, and the auxiliary pump is positioned to immediately engage when main supply pressure drops or when rotation is detected, providing a safety buffer during extreme conditions.
Solution Approach 2:
The auxiliary oil supply system acts as an intermediary backup system between the main oil supply failure and complete gear lubrication failure. The control system mediates between the main system status (monitored by pressure sensors) and the auxiliary system activation, ensuring seamless transition when needed.
3Reliability
If an auxiliary oil supply system is added to ensure continuous lubrication, then reliability is improved, but the device complexity increases
Solution Approach 1:
The auxiliary oil supply system is designed to activate automatically without manual intervention. Rotation sensors detect fan rotor rotation and trigger the auxiliary pump through the control system, while pressure sensors monitor main oil supply status. The system self-regulates based on sensor inputs, reducing the need for complex manual control mechanisms.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Ensures continuous lubrication for at least 30 seconds at high power operation and allows the engine to operate under windmill conditions for extended periods, including 90 minutes in the air and indefinitely on the ground with appropriate wind speeds, while maintaining functionality under negative gravity conditions.
Implementation Method 1
The rotation sensor is an optical sensor
Implementation Method 2
the main supply sensor senses a pressure of the main oil supply system
Implementation Method 3
an auxiliary oil pump, and a main supply sensor for sensing operation of the main oil supply system. The control is programmed to supply oil from the auxiliary oil pump to the gear reduction
Data Source
AI summary
A gas turbine engine includes a fan drive turbine, a fan rotor, and a gear reduction driven by the fan drive turbine and, in turn, to drive the fan rotor. A main oil supply system supplies oil to components within the gear reduction, and an auxiliary oil supply system. The auxiliary oil supply system includes a rotation sensor for sensing rotation of a component that will rotate with the fan rotor, a control, an auxiliary oil pump, and a main supply sensor for sensing operation of the main oil supply system. The control is programmed to supply oil from the auxiliary oil pump to the gear reduction when the rotation sensor senses the component is rotating. A determination is made that inadequate oil is being supplied from the main oil supply system based upon information from the main supply sensor.