Unidirectional Compounding Drive to Prevent Turbo Back-Driving
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Solution Overview
Problem
Existing compounded internal combustion engines face efficiency losses and reliability issues due to parasitic drag when operating in modes where exhaust energy is insufficient to power the turbo-compressor, leading to potential damage and reduced performance.
Innovation Solution
Incorporation of an over-running clutch in the compounding drive to ensure unidirectional mechanical rotation, preventing back-driving of the turbo-compressor and limiting hydraulic flow, thereby maintaining efficiency and preventing damage during low-energy exhaust conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a compounding drive is used to recover energy from exhaust gases, then engine efficiency is improved, but parasitic drag increases when exhaust energy is insufficient to power the turbo-compressor
Solution Approach 1:
The uncoupler module extracts the turbo-compressor from the compounding drive when exhaust energy is insufficient, preventing it from being driven backward by the engine. This separation eliminates the parasitic drag on the engine while maintaining the compounding drive's energy recovery capability when conditions are favorable
Solution Approach 2:
The uncoupler module acts as an intermediary between the engine and the turbo-compressor, controlling the mechanical connection based on operating conditions. It allows the turbo-compressor to be coupled to the compounding drive when exhaust energy is sufficient, and decoupled when energy is insufficient, thereby managing parasitic drag
2Use of energy by moving object
If a compounding drive is used to recover energy from exhaust gases, then engine efficiency is improved, but reliability decreases due to potential damage from back-driving
Solution Approach 1:
The uncoupler module applies preliminary anti-action by preventing the engine from driving the turbo-compressor backward in the first place. This proactive protection mechanism stops the harmful back-driving before it can cause damage to the turbo-compressor components
Solution Approach 2:
The uncoupler module removes the turbo-compressor from the compounding drive when exhaust energy is insufficient, isolating it from the engine's rotational force. This extraction prevents the engine from imposing damaging reverse torque on the turbo-compressor, thereby improving reliability
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
The solution effectively reduces parasitic drag and prevents damage by ensuring unidirectional operation, enhancing the reliability and efficiency of the engine, especially during flight-idle modes or other low-energy operating regimes.
Implementation Method 1
the uncoupler module can include an overrunning clutch, simplifying the arrangement of the turbo-compressor to provide unidirectional operation when exhaust flow through the turbo-compressor is insufficient to drive the turbo-compressor
Implementation Method 2
Turbochargers compress air prior to admission to the engine for combustion, generally using residual energy recovered from the exhaust gases issued by the engine during operation
Implementation Method 3
a turbine configured to extract work from a flow of exhaust fluid
Data Source
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AI summary
A compounding drive (100) includes an input member (108), an epicyclical gear arrangement (212) connected to the input member, an output member (106) connected to the epicyclical gear arrangement, and a hydraulic pump/motor set. The hydraulic pump/motor set connects the epicyclical gear arrangement to the output member through an overrunning clutch for unidirectional communication of mechanical rotation between the input member and the output member. Engine arrangements, aircraft, and methods of compounding internal combustion engines are also described.