Spring-Loaded Compression Rod Engagement for Thrust Reverser Fit

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Solution Overview

Problem

In gas turbine propulsion systems, the existing compression rods used to react forces between thrust reverser halves during varying air pressure conditions often require time-consuming and skill-intensive rigging to ensure proper engagement, leading to potential vibration, wear, and damage due to loose fits and large tolerances in the thrust reverser structure.

Innovation Solution

A compression rod engagement apparatus is introduced, featuring engagement features with spring mechanisms and mounting members to ensure precise contact and preload between the compression rod and thrust reverser halves, preventing rattling and vibration by using engagement cones and spring biases to maintain contact.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If traditional compression rods are used without engagement apparatus, then the structure is simpler, but the engagement precision and reliability deteriorate due to large tolerances and loose fits

Engineering Contradiction:
Improveengagement precisionVSAvoidstructure complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent introduces an engagement apparatus with engagement features (such as engagement cones or protrusions) as an intermediary component between the compression rod and the thrust reverser halves. This intermediary mechanism ensures precise alignment and contact, resolving the tolerance and loose fit issues without requiring the compression rod itself to be manufactured with extremely high precision.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The engagement apparatus performs preliminary alignment and positioning actions before the compression rod fully engages with the thrust reverser halves. The engagement features guide the compression rod into proper position, ensuring correct engagement before load is applied, thereby improving manufacturing precision requirements.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If rigid compression rods are used, then the structure is simpler, but vibration and wear increase due to loose fits and large tolerances

Engineering Contradiction:
Improveengagement reliabilityVSAvoidvibration and wear
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The engagement apparatus incorporates cushioning or damping features that absorb vibrations and shocks before they can cause harmful effects. The engagement mechanism is designed to accommodate minor misalignments and reduce impact forces during engagement, preventing vibration and wear before they occur.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The engagement apparatus acts as a mediator that isolates the compression rod from direct contact with the thrust reverser halves, reducing wear and vibration. The engagement features provide a controlled interface that minimizes harmful interactions while maintaining reliable load transfer.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If engagement features with spring mechanisms are added, then contact consistency improves, but device complexity increases

Engineering Contradiction:
Improvecontact consistencyVSAvoidengagement mechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The engagement apparatus incorporates spring mechanisms that provide dynamic adjustment capabilities. The springs allow the engagement features to self-adjust to variations in tolerance and maintain consistent contact pressure under different operating conditions, improving reliability while the modular design keeps complexity manageable.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The spring-loaded engagement features are designed to self-adjust and self-regulate contact pressure without external control systems. The mechanism automatically compensates for wear, tolerance variations, and load changes, maintaining consistent engagement through self-service functionality.

Inventive Principle:
Principle #25Self-service

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 apparatus ensures consistent and secure engagement of the compression rod with thrust reverser halves, reducing wear and the risk of damage by maintaining contact and preloading, thus enhancing the reliability and durability of the thrust reverser system.

Implementation Method 1

an engagement feature biased by a spring toward the compression rod

Methodology Applied
Scientific EffectSpring: Spring

Data Source

PatentEP3633172B1Thrust reverser compression rod engagement apparatus
Publication Date: 2022.12.07 ROHR INC
  • EP3633172B1 patent drawingFigure 1~2
  • EP3633172B1 patent drawingFigure 3~4
  • EP3633172B1 patent drawingFigure 5~6

AI summary

A compression rod engagement apparatus (70) is provided that includes an engagement feature (60), an engagement feature pin (72), and a mounting member (66). The engagement feature (60) is attached to the engagement feature pin (72). The engagement feature pin (72) is engaged with the mounting member (66) in a home position and axial travel of the engagement feature pin (72) along a lengthwise axis away from the home position in either axial direction is resisted by at least one spring force.