Retractable Aircraft Landing Gear With Integrated Actuator Locking

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Solution Overview

Problem

Current retractable aircraft landing gear assemblies are complex, expensive, heavy, and require inefficient and difficult assembly due to tight clearances and precise motion paths, leading to technical difficulties during installation and maintenance.

Innovation Solution

A retractable landing gear assembly with a main strut and sidestay system that uses a two-point attachment to the aircraft, featuring an actuator that controls the strut's retraction and extension, allowing pre-assembly adjustments on a jig to ensure precise kinematics, reducing the need for additional locks and hydraulic actuators.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If multiple attachment points and complex kinematics are used to ensure precise motion paths and tight clearances, then the reliability and performance of the landing gear assembly is improved, but the device complexity and difficulty of installation increase significantly

Engineering Contradiction:
ImprovereliabilityVSAvoidcomplexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The landing gear assembly is divided into modular components including the main strut assembly, sidestay assembly, and actuator system. Each module can be independently assembled, tested, and installed, reducing overall system complexity while maintaining reliability through standardized interfaces and attachment points.

Inventive Principle:
Principle #1Segmentation

2Manufacturing precision

If multiple attachment points and complex rigging are used to accommodate precise motion paths, then the manufacturing precision and performance are improved, but the ease of manufacture and installation deteriorate

Engineering Contradiction:
ImproveprecisionVSAvoidease of manufacture
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The actuator is pre-assembled and pre-rigged to the main strut assembly before installation on the aircraft. This preliminary action allows for precise adjustment and alignment to be completed during manufacturing rather than during complex field installation, improving both precision and ease of manufacture.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The actuator mounting and rigging operations are extracted from the aircraft installation process and performed separately during landing gear assembly. This separation allows the actuator to be pre-positioned and pre-adjusted on the ground, simplifying the actual aircraft installation while maintaining precise motion paths.

Inventive Principle:
Principle #2Taking out (Extraction)

3Reliability

If traditional landing gear designs with multiple components are used, then the reliability and locking capability are improved, but the weight and cost increase

Engineering Contradiction:
ImprovereliabilityVSAvoidweight
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

The actuator serves multiple functions simultaneously: it provides both the retraction force and the locking mechanism through its dual-position operation. By merging the actuation and locking functions into a single component rather than using separate systems, weight is reduced while maintaining reliability through the integrated design.

Inventive Principle:
Principle #5Merging (Combining)

4Stability of the object's composition

If traditional landing gear designs with multiple attachment points are used, then the structural stability is improved, but the productivity and installation efficiency decrease

Engineering Contradiction:
ImprovestabilityVSAvoidproductivity
Core Design Contradiction:
Stability of the object's compositionVSProductivity

Solution Approach 1:

The complex rigging and adjustment operations are extracted from the aircraft installation process and performed in advance during landing gear assembly. This allows the actual aircraft installation to be completed quickly with minimal adjustments, improving productivity while maintaining structural stability through pre-verifying the kinematics on a jig.

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentEP4282752B1Aircraft landing gear assembly
Publication Date: 2025.10.29 AIRBUS OPERATIONS LTD
  • EP4282752B1 patent drawingFigure 1
  • EP4282752B1 patent drawingFigure 2
  • EP4282752B1 patent drawingFigure 3

AI summary

A retractable landing gear assembly for an aircraft has a main strut (210) arranged to pivot between a retracted position and an extended position, and a sidestay (220) having an unfolded position and a folded position. A telescopic actuator (250) is coupled between the main strut (210) and the sidestay (220), so that when the actuator (250) has a first length the sidestay (220) locks the main strut (210) in the extended position, and when the actuator (250) has a second length the sidestay (220) is in the folded position and the main strut (210) is in the retracted position.