Aircraft Landing Gear Truck Beam Positioner

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Solution Overview

Problem

Existing truck beam positioners for aircraft landing gear add weight, cost, complexity, and maintenance requirements, while also being less reliable compared to the disclosed technology.

Innovation Solution

A simplified, lightweight passive truck beam positioner is introduced, utilizing a shock strut with a rotatable truck beam and a link assembly with a limiter joint to maintain the truck beam's position relative to the shock strut, reducing the need for active actuators and complex mechanisms.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If active truck beam positioners with hydraulic actuators are used, then the truck beam position can be controlled, but the weight, cost, and complexity of the landing gear increase

Engineering Contradiction:
Improvetruck beam position controlVSAvoidpositioner mechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent removes the hydraulic actuator and control system from the truck beam positioner, extracting the active control function entirely. The truck beam position is now maintained passively through the mechanical linkage between the shock strut and truck beam, eliminating the need for complex active positioning mechanisms while maintaining functional reliability.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The truck beam positioner now serves itself through passive mechanical means. The linkage automatically maintains the correct position through the geometric relationship between the shock strut movement and truck beam orientation, without requiring external control systems or energy input.

Inventive Principle:
Principle #25Self-service

2Reliability

If active truck beam positioners with hydraulic actuators are used, then the truck beam position can be controlled, but the weight of the landing gear increases

Engineering Contradiction:
Improvetruck beam position controlVSAvoidlanding gear weight
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

The heavy hydraulic actuator and control system are extracted from the landing gear assembly. The passive mechanical linkage uses the existing structural components and forces already present in the landing gear system, eliminating the need for additional heavy actuators while maintaining position control functionality.

Inventive Principle:
Principle #2Taking out (Extraction)

3Reliability

If passive positioners with spring-loaded telescopic links are used, then the truck beam position is maintained, but the device complexity and maintenance requirements increase

Engineering Contradiction:
Improvetruck beam position maintenanceVSAvoidpositioner mechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent removes the spring-loaded telescopic link and limiter mechanism from the positioner system. Instead, the truck beam position is maintained through the inherent mechanical geometry of the simplified linkage connecting the shock strut to the truck beam, eliminating complex positioning mechanisms.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The positioner system now relies on the self-aligning mechanical properties of the linkage rather than active spring-loaded mechanisms. The geometry of the connection automatically maintains the correct truck beam position through the shock strut's movement, without requiring additional positioning components.

Inventive Principle:
Principle #25Self-service

4Reliability

If passive positioners with spring-loaded telescopic links are used, then the truck beam position is maintained, but the weight and maintenance requirements increase

Engineering Contradiction:
Improvetruck beam position maintenanceVSAvoidlanding gear weight
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

The spring-loaded telescopic link and associated limiting mechanisms are extracted from the system. The position maintenance function is achieved through the simplified mechanical linkage that uses the existing structural components of the landing gear, eliminating the need for additional heavy positioning mechanisms.

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentEP4003833B1Aircraft multi-wheel truck beam positioner
Publication Date: 2025.06.04 SAFRAN LANDING SYST CANADA INC
  • EP4003833B1 patent drawingFigure 1
  • EP4003833B1 patent drawingFigure 2
  • EP4003833B1 patent drawingFigure 3~4

AI summary

An aircraft landing gear includes a shock strut with a rod slidably received within a cylinder. A beam is rotatably mounted to the rod, and wheels are mounted to the beam. The landing gear further includes a link assembly with an upper link and a lower link. The upper link has a first end rotatably connected to the cylinder, and the lower link has a first end rotatably connected to the beam. The second ends of the upper and lower links are rotatably coupled to each other by a limiter joint. The limiter joint includes a first stop associated the upper link and a second stop associated with the lower link. The stops are configured such that the first stop engages the second stop to limit rotation of the upper link relative to the lower link.