Thrust Reverser Actuation With Bi-Directional Pumps
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Solution Overview
Problem
Conventional thrust reverser actuation systems for jet propulsion engines are inefficient due to high power requirements, complex synchronization systems, and excessive weight, leading to power wastage, construction costs, and potential damage during actuator jams.
Innovation Solution
A thrust reverser actuation system utilizing bi-directional electrically-driven pumps to power hydraulically-driven actuators, eliminating the need for high-pressure hydraulic circuits and complex synchronization systems, and incorporating a simplified control mechanism with pressure relief valves and make-up/spill valves to manage fluid flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a main hydraulic circuit is used to power the thrust reverser actuation system, then the system can operate with high power availability, but significant power wastage occurs and components require heavy-duty construction
Solution Approach 1:
The system divides the hydraulic power supply into separate actuator-level pumps rather than using a centralized high-pressure hydraulic circuit. Each actuator has its own pump that generates hydraulic pressure locally, eliminating the need to continuously maintain high pressure in a main hydraulic circuit and reducing overall power consumption.
Solution Approach 2:
The system changes the pressure parameter from continuously high (main hydraulic circuit) to on-demand variable pressure (actuator-level pumps). The pumps generate hydraulic pressure only when actuators need to move, and at the specific pressure required for that moment, rather than maintaining constant high pressure throughout the system.
2Stability of the object's composition
If a mechanical synchronisation system is used to coordinate actuators, then actuator synchronization is achieved, but system weight increases and damaging loads can be transferred during jams
Solution Approach 1:
The system replaces the mechanical synchronisation system (worm wheels, threaded sections, flex shafts) with an electronically-controlled pump system. Each actuator's pump is controlled by a control system that coordinates their operation, eliminating heavy mechanical linkages while achieving synchronization through electronic control signals.
3Reliability
If electric motors with high inertia are used in the actuation system, then reliable actuation is achieved, but the system requires very strong construction adding weight and cost
Solution Approach 1:
The system replaces high-inertia electric motors with low-inertia bi-directional pumps. These pumps provide reliable actuation through hydraulic force multiplication while having minimal inertia, eliminating the need for overly strong mechanical construction to handle motor inertia during jams or unexpected scenarios.
4Reliability
If complex control systems are used to manage actuator acceleration and deceleration, then actuator damage is prevented, but system complexity increases
Solution Approach 1:
The bi-directional pumps provide inherent soft start and stop characteristics due to their hydraulic nature. The hydraulic fluid's compressibility and flow characteristics naturally limit acceleration and deceleration rates, providing actuator protection without requiring complex electronic control systems for acceleration/deceleration management.
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 system reduces weight, simplifies control, and minimizes the risk of actuator damage by using bi-directional pumps to manage hydraulic fluid flow, reducing the demand on the aircraft's hydraulic system and eliminating the need for heavy-duty construction, thus enhancing efficiency and reliability.
Implementation Method 1
a bi-directional electrically-driven pump configured to pump hydraulic fluid through the hydraulic circuit
Data Source
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AI summary
A thrust reverser actuation system 100 for a jet propulsion engine for a vehicle, the thrust reverser actuation system 100 comprising: a plurality of hydraulically-driven thrust reverser actuators 150 for actuating one or more thrust reverser components 2 of the jet propulsion engine, each actuator 150 comprising: a hydraulic circuit 160; and a bi-directional electrically-driven pump 190 configured to pump hydraulic fluid through the hydraulic circuit 160, wherein the hydraulic circuit 160 and the pump 190 are configured such that the direction of the pump 190 dictates the direction of the actuation of the actuator 150.