Single Actuator Landing Gear with Misalignment Rod

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing aircraft landing gear with a breaker strut and alignment stabilizer member require two actuators to move between deployed and retracted positions, as the lifting actuator cannot misalign the stabilizing member's rods, preventing movement.

Innovation Solution

A method involving a rotary actuator coupled to a rod of the stabilizing member, allowing continuous movement and misalignment of the rods, enabling the undercarriage to be lifted with a single actuator by pivoting against the locking member, ensuring kinematic linkage for rotation and displacement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a lifting actuator is coupled to one of the strut rods to lift the undercarriage, then the undercarriage can be raised, but the rods of the stabilizing member cannot be misaligned, which prevents any movement of the undercarriage

Engineering Contradiction:
Improveundercarriage lifting capabilityVSAvoidactuator configuration complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

A separate misalignment actuator is introduced as an intermediary device that specifically targets the stabilizing member's locking mechanism. This dedicated intermediary component releases the alignment constraint before the lifting actuator can effectively move the undercarriage, resolving the contradiction between lifting capability and movement prevention.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The misalignment actuator performs a preliminary action by releasing the locking member and allowing rod misalignment before the lifting actuator initiates undercarriage movement. This sequential preliminary action eliminates the constraint that would otherwise prevent lifting, enabling the main lifting operation to proceed without interference.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If two actuators are used to maneuver the undercarriage (one for misalignment, one for lifting), then the undercarriage can be properly deployed and retracted, but the mechanical complexity and number of components increase

Engineering Contradiction:
Improveundercarriage maneuvering reliabilityVSAvoidnumber of actuators
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The misalignment actuator and lifting actuator are merged into a single integrated actuator system. This unified actuator performs both functions sequentially: first misaligning the stabilizing member rods by acting against the locking member, then lifting the undercarriage. The merging eliminates the need for two separate actuators while maintaining full maneuvering capability and reliability.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The single actuator is designed with multi-functionality, capable of performing both the misalignment function (by acting on the locking member) and the lifting function (by acting on the strut rod). This universal actuator replaces two specialized actuators, reducing component count while maintaining the reliability of both misalignment and lifting operations.

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

Data Source

PatentEP2437978B1Method for operating a landing gear assembly with a breaker strut
Publication Date: 2021.06.02 SAFRAN LANDING SYSTEMS
  • EP2437978B1 patent drawingFigure 1~4
  • EP2437978B1 patent drawingFigure 5

AI summary

The invention relates to a method for operating between an extended position and a retracted position an aircraft landing gear assembly comprising a leg hinged to the aircraft, the leg being stabilized in the extended position by a breaker strut with two hinged links, the strut being held in the aligned position by a stabilizing member comprising two hinged rods kept in line by a locking member, said method being characterized in that it comprises the steps of arranging the strut (2; 102) and the stabilizing member (4; 104) in such a way that at least one of the rods (4a; 104a) of the stabilizing member exhibits a continuous movement as the leg moves from the extended position to the retracted position; and attaching an operating actuator 10; 110) to this rod to pivot the rod in opposition to the locking member and exert a force on the latter such as to tend to move the leg.