Rotary Actuator Integration for Thinner Aircraft Control Surfaces

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Solution Overview

Problem

Aircraft control surface systems face limitations in reducing wing thickness and achieving optimal aerodynamic performance due to the spatial requirements and aerodynamic penalties of linear actuators, which necessitate a more efficient and compact solution for controlling control surfaces.

Innovation Solution

An electronically controlled rotary actuator system is integrated within the aerodynamic aircraft structure, utilizing a hydraulic pump and electric motor system to move control surfaces with variable pressure, reducing the need for external space and enhancing aerodynamic performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If linear actuators are used to control control surfaces, then the control surface can be moved to desired positions, but the wing thickness cannot be reduced and aerodynamic performance is penalized due to the space required for the actuator

Engineering Contradiction:
Improvewing thicknessVSAvoidcontrol surface positioning capability
Core Design Contradiction:
Volume of moving objectVSReliability

Solution Approach 1:

The patent replaces the traditional linear actuator mechanical system with a rotary actuator system that uses hydraulic or electric rotation to achieve control surface movement. This substitution eliminates the need for a linear mechanical push-pull mechanism, allowing the actuator to be mounted in a rotary configuration that occupies less space within the wing structure, thereby enabling reduced wing thickness while maintaining control surface positioning capability

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent transitions from linear actuation (one-dimensional movement) to rotary actuation (rotational movement around an axis). This dimensional change allows the actuator to be integrated into the wing structure in a different spatial orientation, reducing the volume required along the wing thickness dimension while preserving the ability to move the control surface through mechanical linkage

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Manufacturing precision

If linear actuators are used in aircraft, then control surfaces can be positioned accurately, but non-value-added structural space is required for spatial integration of system equipment

Engineering Contradiction:
Improvecontrol surface position accuracyVSAvoidspace for actuator integration
Core Design Contradiction:
Manufacturing precisionVSVolume of stationary object

Solution Approach 1:

The patent replaces the space-intensive linear actuator mechanical system with a compact rotary actuator system. The rotary mechanism, driven by hydraulic motors or electric motors with gear reductions, achieves the same control surface positioning accuracy through rotational motion converted to linear motion at the control surface hinge, thereby reducing the volume required for actuator integration within the aircraft structure

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent integrates the rotary actuator components (motor, gear train, shafts) in a nested or compact arrangement within the wing or fuselage structure. The counterbalancing mechanism and drive train are arranged in a space-efficient configuration that fits within the existing structural envelope, minimizing the non-value-added space required while maintaining positioning accuracy

Inventive Principle:
Principle #7Nested doll (Nesting)

3Ease of operation

If linear actuators are used, then control surface movement is achieved, but aerodynamic performance is penalized

Engineering Contradiction:
Improvecontrol surface movement capabilityVSAvoidaerodynamic penalty
Core Design Contradiction:
Ease of operationVSObject-generated harmful factors

Solution Approach 1:

The patent replaces linear actuators with rotary actuators that can be positioned more optimally within the wing structure. This substitution allows for better aerodynamic fairing of the actuator housing and surrounding structures, reducing drag and improving airflow over the wing. The rotary actuator configuration enables cleaner integration with the aerodynamic surface, eliminating the need for protruding linear actuator components that create aerodynamic penalties

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 allows for thinner wing designs with improved aerodynamic performance, reduced drag, and increased safety through dual-energy actuation, enabling efficient control surface movement and backup functionality in case of hydraulic system failure.

Implementation Method 1

A hydraulic pump sends hydraulic fluid into the rotary actuator at variable pressure

Methodology Applied
Scientific EffectHydraulic pressure: Hydraulic Press

Implementation Method 2

An electric motor system operates to cause the hydraulic pump to send the hydraulic fluid into the rotary actuator

Methodology Applied
Scientific EffectElectromagnetic conversion: Electromagnetic Induction

Data Source

PatentEP3272649B1Electronically controlled rotary actuator for an aircraft control surface
Publication Date: 2023.07.05 THE BOEING CO
  • EP3272649B1 patent drawingFigure 1
  • EP3272649B1 patent drawingFigure 2
  • EP3272649B1 patent drawingFigure 3

AI summary

A method and apparatus for positioning a control surface (210). A desired position (320) for the control surface (210) associated with an aerodynamic aircraft structure (212) is identified. The control surface (210) is moved to the desired position (320) using an electronically controlled rotary actuator system (208) located inside of the aerodynamic aircraft structure (212), wherein a shape (216) of the aerodynamic aircraft structure (212) with the electronically controlled rotary actuator system (208) has a desired aerodynamic performance (220).