Hybrid Wing Flap Actuation for Hydraulic and Electrical Failures

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Solution Overview

Problem

Conventional trailing edge wing flap systems are rendered inoperable by partial or complete failures of hydraulic or electrical systems, leaving aircraft unable to control wing flap positions.

Innovation Solution

The distributed trailing edge wing flap system incorporates a hydromechanical actuator and an electromechanical actuator, coupled by a shaft, with an alternate control unit, allowing operation via pressurized hydraulic fluid, electric motor, or alternate control in case of system failures, ensuring continuous flap control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a single hydraulic or electrical actuator system is used to control wing flaps, then the system structure is simple, but the system becomes inoperable upon partial or complete failures of the hydraulic or electrical systems

Engineering Contradiction:
Improveflap control reliabilityVSAvoidactuator system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The actuator system is segmented into two independent actuator assemblies (first and second actuators), each capable of independently controlling the flight control surface. This segmentation allows the system to maintain functionality even if one actuator fails, as the other actuator can continue to operate the flap control surface.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Each actuator assembly has distinct local qualities - the first actuator is configured for hydraulic actuation while the second actuator is configured for electrical actuation. This local differentiation in actuation mechanisms ensures that a failure in one system (hydraulic or electrical) does not necessarily incapacitate the entire flap control system.

Inventive Principle:
Principle #3Local quality

2Reliability

If redundant actuator assemblies are implemented to ensure continuous operation, then system reliability improves, but device complexity increases

Engineering Contradiction:
Improvecontinuous flap operationVSAvoidactuator assembly redundancy
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Both actuator assemblies are designed to perform the same universal function of controlling the flight control surface, but through different actuation principles (hydraulic and electrical). This multi-functionality allows the system to achieve redundancy without requiring completely different control mechanisms, thereby limiting the increase in complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

A common output mechanism serves as an intermediary that receives actuation from either the first or second actuator assembly and translates it into unified motion of the flight control surface. This intermediary component allows the system to maintain simplicity in the control output while accommodating complexity in the redundant actuation inputs.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If dual actuator systems with different actuation principles are used, then resistance to system failures increases, but manufacturing and system integration becomes more difficult

Engineering Contradiction:
Improvefailure resistanceVSAvoidactuator system integration
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The system dynamically selects which actuator assembly to use based on operational conditions and system status. This dynamic approach allows the system to adapt to failures or maintenance needs by switching between hydraulic and electrical actuation modes, simplifying the integration process as the system can leverage existing infrastructure for either actuation type.

Inventive Principle:
Principle #15Dynamics

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 operation and control of wing flaps even in the event of system failures, maintaining aircraft stability and functionality.

Implementation Method 1

the first actuator is actuatable via pressurized hydraulic fluid to be supplied from a hydraulic system of the aircraft to the first actuator via a hydraulic module operatively coupled to the first actuator

Methodology Applied
Scientific EffectHydraulic fluid pressure: Hydraulic Press

Implementation Method 2

the second actuator is actuatable via an electric motor of the second actuator connected to a first electrical system of the aircraft

Methodology Applied
Scientific EffectElectromagnetic conversion: Electromagnetic Induction

Data Source

PatentEP3549857B1Flap actuator system
Publication Date: 2021.07.14 THE BOEING CO
  • EP3549857B1 patent drawingFigure 1
  • EP3549857B1 patent drawingFigure 2A
  • EP3549857B1 patent drawingFigure 2B~2C

AI summary

Distributed trailing edge wing flap systems are described. An example wing flap system for an aircraft includes a flap, a first actuator, a second actuator, and a shaft. The flap is movable between a deployed position and a retracted position relative to a fixed trailing edge of a wing of the aircraft. The first actuator is to move the flap relative to the fixed trailing edge. The first actuator is actuatable via pressurized hydraulic fluid to be supplied from a hydraulic system of the aircraft to the first actuator via a hydraulic module operatively coupled to the first actuator. The second actuator is to move the flap relative to the fixed trailing edge. The second actuator is actuatable via an electric motor of the second actuator connected to a first electrical system of the aircraft. The shaft operatively couples the first actuator to the second actuator. The first and second actuators are actuatable via the shaft.