Synchronized Hydraulic Flap Actuation with Position Hold Backup

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Solution Overview

Problem

Existing flight control actuation systems for aircraft rely on hydraulic actuators, which can be inefficient and lack precise control, especially when hydraulic pressure is unavailable, leading to inconsistent movement and potential loss of control.

Innovation Solution

The system employs synchronized hydraulic actuators with meshing worm gears and gears, along with brakes and motors, to ensure consistent movement and positioning of flight control members, using an actuation control unit to manage hydraulic fluid flow and adjust valves based on sensor signals, allowing for independent control of inboard and outboard flight control members.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If hydraulic actuators are used for flight control members, then the actuation system can provide sufficient force for control surface movement, but the system lacks precise control and consistency when hydraulic pressure is unavailable

Engineering Contradiction:
Improvecontrol consistencyVSAvoidprecise control
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent combines hydraulic actuators with electrical motors in a hybrid actuation system. Each flight control member has both a hydraulic actuator and an electric motor that can independently or simultaneously provide actuation force. This merging ensures reliable control consistency through hydraulic power while maintaining precise control capability through electric motor control, resolving the contradiction between reliability and ease of operation.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The system changes the actuation parameter from purely hydraulic pressure-dependent to a dual-mode system that can operate in hydraulic mode, electric mode, or hybrid mode. The control system dynamically selects the appropriate actuation parameter based on available hydraulic pressure and control precision requirements, ensuring both reliability and precise control across different operating conditions.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If individual control of flight control members is implemented, then differential operation for optimizing wing loading is achieved, but the system complexity increases

Engineering Contradiction:
Improvedifferential operation capabilityVSAvoidactuation system complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent divides the actuation system into independent modular units, with each flight control member having its own hybrid actuator assembly. This segmentation allows each control surface to be independently controlled with its own hydraulic actuator and electric motor, enabling differential operation for optimizing wing loading while keeping each module's complexity manageable and standardized.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The hybrid actuator design provides multi-functionality by enabling each flight control member to be actuated independently through either hydraulic or electric means. This universal actuation capability allows the system to achieve differential operation for various flight conditions while using standardized components, reducing overall system complexity despite the increased adaptability.

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

3Manufacturing precision

If synchronization members are added to coordinate actuator movement, then consistent positioning is achieved, but the device complexity increases

Engineering Contradiction:
Improvepositioning precisionVSAvoidactuation system complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent incorporates feedback control mechanisms where sensors monitor the position of flight control members and provide real-time data to the control system. The control system processes this feedback and adjusts the actuation commands to both hydraulic actuators and electric motors to ensure they reach and maintain the desired synchronized position, achieving precise positioning without overly complex mechanical synchronization linkages.

Inventive Principle:
Principle #23Feedback

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

This solution provides consistent and precise control of flight control members, maintaining position even when hydraulic pressure is unavailable, and allows for differential operation of inboard and outboard flight control members, optimizing wing loading during flight.

Implementation Method 1

The slave hydraulic actuator includes meshing first and second worm gears

Methodology Applied
Scientific EffectWorm gear mechanism: Worm Drive

Implementation Method 2

A pump moves the hydraulic fluid through the supply and to the actuators. The hydraulic fluid then is directed into different sections of the hydraulic actuators to move the hydraulic actuator

Methodology Applied
Scientific EffectHydraulic pressure: Hydraulic Press

Implementation Method 3

the pacing hydraulic actuator including meshing first and second gears with a same efficiency in both operating directions

Methodology Applied
Scientific EffectGear meshing: Gear

Data Source

PatentEP3626977B1Distributed linear hydraulic high lift actuation system with synchronization members
Publication Date: 2021.12.29 THE BOEING CO
  • EP3626977B1 patent drawingFigure 1
  • EP3626977B1 patent drawingFigure 2
  • EP3626977B1 patent drawingFigure 3

AI summary

An actuation system for controlling flight control members of a vehicle. Each flight control member (101) is controlled by two or more linear hydraulic actuators (20). Synchronization members (40) extend between the hydraulic actuators (20) on the same flight control members (101) to synchronize the movements of the hydraulic actuators (20) for consistent movement across the length of the flight control members (101). Brakes (50) can maintain the positions of the synchronization members (40) and thus the flight control members. Motors (60) can provide for moving the synchronization members to control the positioning of the hydraulic actuators (20) and flight control members.