Flap Actuation System with Redundant Actuators and Cam Couplers

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Solution Overview

Problem

Existing air vehicle flap actuation systems are prone to skew conditions due to asymmetries in the drive system, which can disrupt airflow control and affect aircraft behavior during takeoff, flight, and landing, especially when one actuator fails, leading to incomplete deployment of control surfaces.

Innovation Solution

A dual drive system with redundant actuators and couplers that selectively couple and decouple to ensure continued operation of the flap even if one actuator fails, using cams and output shafts to isolate the failed actuator and maintain control surface movement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single actuator is used to drive the flap, then the device complexity is reduced, but the reliability deteriorates when the actuator fails

Engineering Contradiction:
Improveactuator system complexityVSAvoidflap actuation reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The actuation system is segmented into two independent actuators (first and second actuators), each capable of independently actuating the flap through separate drive arms and couplers. This segmentation allows the system to maintain functionality even if one actuator fails, thereby improving reliability without significantly increasing overall system complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system is configured with redundant actuators and couplers prepared in advance, so that if one actuator fails, the other is already positioned and configured to take over immediately. The couplers are designed to selectively engage or disengage from drive arms, allowing preliminary preparation for failure scenarios without adding complex control mechanisms.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If redundant actuators are added to improve reliability, then the reliability improves, but the device complexity increases

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

Solution Approach 1:

Both actuators are merged into a single coordinated system that shares common components such as the flap, support structures, and control logic. The actuators work together through a unified control mechanism that can seamlessly switch between them, reducing the effective complexity despite having redundant components.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The system includes self-diagnostic capabilities where sensors monitor actuator performance and automatically detect failures. When a failure is detected, the control system automatically reconfigures to use the remaining functional actuator without requiring complex manual intervention or additional control complexity.

Inventive Principle:
Principle #25Self-service

3Ease of operation

If the cam couples to the drive arm during actuator operation, then the actuation control is improved, but the skew condition worsens when the actuator fails

Engineering Contradiction:
Improveactuation controlVSAvoidflap deployment completeness
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The coupler is designed with dynamic engagement and disengagement capabilities, allowing it to selectively connect or disconnect from the drive arm based on actuator functionality. This dynamic configuration enables smooth actuation control during normal operation while automatically adapting to prevent skew conditions when an actuator fails.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The coupler acts as an intermediary component between the actuator and the drive arm, providing a controlled interface that can engage or disengage as needed. This intermediary mechanism allows precise actuation control when engaged while preventing harmful skew conditions when disengaged due to actuator failure.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP3892536B1Flap actuation systems and related methods
Publication Date: 2024.12.04 THE BOEING CO
  • EP3892536B1 patent drawingFigure 1
  • EP3892536B1 patent drawingFigure 2
  • EP3892536B1 patent drawingFigure 3~4

AI summary

Example flap actuation systems and related methods are disclosed herein. An example flap actuation system (200) includes a first actuator (212), a second actuator (220), a first drive arm (219) coupled to the first actuator (212) and to a flap (202), a second drive arm (225) coupled to the second actuator (220) and to the flap (202), a first cam (506), and a first output shaft (304). The first cam (506) is to couple to the first drive arm (219) to enable the first actuator to actuate the flap via the first drive arm. The example flap actuation system includes a second cam (506) and a second output shaft (304). The first cam is to be uncoupled from the first drive arm in response to a failure of the first actuator. The second actuator is to actuate the flap via the first drive arm and the second drive arm in response to the failure of the first actuator.