Asymmetric Hinge Mechanism for Pivot Door Thrust Reverser Sealing

Solution Overview

Problem

Pivot door thrust reversers face challenges in achieving an absolute seal between the aft ends of the doors when deployed, leading to potentially undesired thrust vectoring due to difficulties in aligning and sealing the doors effectively.

Innovation Solution

The design incorporates a frame with pivotally mounted reverser doors and offset panels, utilizing linear actuators to control the doors' movement, allowing one door to pivot farther than the other to offset thrust vectoring issues and facilitate a better seal.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If pivot door thrust reversers use symmetric hinge mounting, then structural simplicity is maintained, but sealing effectiveness deteriorates due to misalignment between doors

Engineering Contradiction:

Improvesealing alignmentVSAvoidhinge mounting configuration

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent applies asymmetry by positioning the first hinge mounting on one side of the longitudinal axis and the second hinge mounting on the opposite side, with different vertical spacings from the longitudinal axis. This asymmetric configuration compensates for the offset between the first and second reverser doors, enabling proper alignment and sealing when the doors are in the deployed position.

Inventive Principle:

Principle #4Asymmetry

2Reliability

If both reverser doors pivot the same distance, then mechanical symmetry is maintained, but thrust vectoring control deteriorates due to inability to offset door misalignment

Engineering Contradiction:

Improvethrust vectoring controlVSAvoiddoor movement control

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The patent employs a counterbalancing approach where the asymmetric hinge mounting positions create differential pivot distances for the two doors. The first reverser door pivots a different distance than the second reverser door, with the offset compensating for the initial misalignment between doors to achieve proper sealing and thrust vectoring control.

Inventive Principle:

Principle #8Anti-weight (Counterweight)

3Manufacturing precision

If hinge mountings are positioned symmetrically relative to the longitudinal axis, then manufacturing is simplified, but sealing performance deteriorates due to door misalignment in deployed position

Engineering Contradiction:

Improvedoor sealingVSAvoidhinge mounting installation

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent applies asymmetry by positioning the first hinge mounting on one side of the longitudinal axis and the second hinge mounting on the opposite side, with different vertical spacings from the longitudinal axis. This asymmetric configuration compensates for the offset between the first and second reverser doors, enabling proper alignment and sealing when the doors are in the deployed position.

Inventive Principle:

Principle #4Asymmetry

Data Source

PatentUS11396854B2Hinge mechanism for pivot door thrust reversers

Publication Date: 2022.07.26 ROHR INC

AI summary

A thrust reverser for a gas turbine engine includes a frame, a first reverser door pivotally mounted to the frame, and a second reverser door pivotally mounted to the first reverser door.