Hydraulic Thrust Reverser Blocker Door Actuation

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Solution Overview

Problem

Conventional blocker door actuation systems in jet engine thrust reversers employ drag links that interfere with fan airflow, generating drag and limiting thrust reversal efficiency.

Innovation Solution

A hydraulic blocker door deployment system utilizing primary and secondary hydraulic actuators, where primary hydraulic fluid flows through a channel and into secondary actuators to deploy the blocker door without interfering with airflow, and a pressurized reservoir ensures efficient stowage and deployment, eliminating the need for drag links.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If drag links are used to actuate blocker doors, then the blocker doors can be deployed, but the drag links interfere with fan airflow and generate drag

Engineering Contradiction:
Improveblocker door deploymentVSAvoiddrag on fan airflow
Core Design Contradiction:
Ease of operationVSObject-generated harmful factors

Solution Approach 1:

The patent removes the drag links from the system entirely and replaces them with a hydraulic actuation system. The hydraulic actuators are mounted on the engine core or nacelle structure, and they directly actuate the blocker doors through hydraulic cylinders, eliminating the intermediate drag link mechanism that was causing airflow interference and drag.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent employs hydraulic actuators to deploy and stow the blocker doors. Hydraulic fluid is directed to actuators mounted on the engine core, which then move the blocker doors into their deployed or stowed positions. This hydraulic system replaces the mechanical drag link system and eliminates the airflow interference problem while providing reliable actuation.

Inventive Principle:
Principle #29Pneumatics and hydraulics

2Productivity

If drag links are used for blocker door actuation, then deployment is achieved, but thrust reversal efficiency is limited due to drag generation

Engineering Contradiction:
Improvethrust reversal efficiencyVSAvoidenergy lost to drag
Core Design Contradiction:
ProductivityVSLoss of energy

Solution Approach 1:

By removing the drag links from the system, the patent eliminates the source of drag that was reducing thrust reversal efficiency. The hydraulic actuation system operates without interfering with the fan airflow, allowing the blocker doors to be deployed effectively without energy loss to drag.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The hydraulic actuation system provides efficient deployment of blocker doors without the mechanical interference and drag generation associated with drag links. This results in improved thrust reversal efficiency and reduced energy loss, as the hydraulic system operates independently of the airflow path.

Inventive Principle:
Principle #29Pneumatics and hydraulics

3Ease of operation

If conventional actuation systems are used, then blocker doors can be deployed, but uniform deployment is not ensured

Engineering Contradiction:
Improveblocker door deploymentVSAvoiduniformity of deployment
Core Design Contradiction:
Ease of operationVSStability of the object's composition

Solution Approach 1:

The patent divides the actuation system into multiple independent hydraulic actuators, each controlling a specific blocker door or group of blocker doors. This segmentation allows for independent control and adjustment of each actuator, ensuring that all blocker doors deploy uniformly and simultaneously. The hydraulic system can be controlled to provide equal pressure and force to each actuator, achieving uniform deployment.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The hydraulic actuation system provides precise and uniform deployment of blocker doors through controlled hydraulic pressure distribution. Each hydraulic actuator receives hydraulic fluid through controlled valves and passages, ensuring simultaneous and uniform movement of all blocker doors. This hydraulic control mechanism ensures stable and consistent deployment composition.

Inventive Principle:
Principle #29Pneumatics and hydraulics

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 hydraulic system enhances thrust reversal efficiency by reducing drag and ensuring uniform deployment of blocker doors, increasing overall thrust generation compared to conventional systems.

Implementation Method 1

primary hydraulic fluid may flow through a channel extending through the piston and piston rod

Methodology Applied
Scientific EffectHydraulic fluid flow: Hydraulic Press

Implementation Method 2

a pressurized reservoir ensures efficient stowage and deployment

Methodology Applied
Scientific EffectPressurized storage: Hydraulic Accumulator

Data Source

PatentEP2865875B1Jet engine thrust reverser with hydraulic blocker door deployment systems
Publication Date: 2018.09.12 ROHR INC
  • EP2865875B1 patent drawingFigure 1A
  • EP2865875B1 patent drawingFigure 1B
  • EP2865875B1 patent drawingFigure 2

AI summary

A hydraulic circuit for a jet engine thrust reverser (100;500) is disclosed. The hydraulic circuit may comprise a primary hydraulic actuator cylinder assembly (108;204a,204b;302a,302b;402a-402d;508;602,606;702;802a,802b) and a secondary hydraulic actuator cylinder assembly (110;304a-304c,306a-306c;404a-4041;510;604;704a-704i;804a-804c,806a-806c). The primary hydraulic actuator cylinder assembly (108;204a,204b;302a,302b;402a-402d;508;602,606;702;802a,802b) may be hydraulically coupled to the secondary hydraulic actuator cylinder assembly (110;304a-304c,306a-306c;404a-4041;510;604;704a-704i;804a-804c,806a-806c), in a master-slave relationship, and the secondary hydraulic actuator cylinder assembly (110;304a-304c,306a-306c;404a-4041;510;604;704a-704i;804a-804c,806a-806c) may drive a thrust reverser blocker door (106;406a-4061;506). The primary hydraulic actuator cylinder assembly (108;204a,204b;302a,302b;402a-402d;508;602,606;702;802a,802b) may comprise a rod, and the rod may comprise a channel through which hydraulic fluid is capable of flowing. The hydraulic circuit may further comprise a group of secondary hydraulic actuator cylinder assemblies (110;304a-304c,306a-306c;404a-404l;510;604;704a-704i;804a-804c,806a-806c), wherein the group of secondary hydraulic actuator cylinder assemblies (110;304a-304c,306a-306c;404a-4041;510;604;704a-704i;804a-804c,806a-806c) may be coupled to the primary hydraulic actuator cylinder assembly (108;204a,204b;302a,302b;402a-402d;508;602,606;702;802a,802b).