Elastomer Damper for Thrust Reverser Actuator Vibration

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Solution Overview

Problem

Thrust reverser actuation systems face challenges in balancing actuator clearance and structural strength within the aft cascade ring, with existing solutions either allowing large gaps for vibration damping but no preload or small pass-throughs with preload issues, and space constraints complicating the design.

Innovation Solution

A thrust reverser assembly with a flexible damper and bumper configuration, where the damper is coupled to the aft cascade ring and actuator, providing increased reaction force with deflection amplitude, preventing contact and applying vibration damping without preload, utilizing an elastomer and bulb seal for effective vibration management.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a large pass-through is provided in the aft cascade ring, then the TRAS actuator avoids contact with the aft cascade ring and side loads are reduced, but the structural strength of the aft cascade ring is compromised

Engineering Contradiction:

Improveactuator reliabilityVSAvoidaft cascade ring structural strength

Core Design Contradiction:

ReliabilityVSStrength

Solution Approach 1:

A damper is introduced as an intermediary component between the TRAS actuator and the aft cascade ring. The damper absorbs vibrations and prevents direct metal-to-metal contact, allowing a smaller pass-through opening while protecting the actuator from side loads and the cascade ring from damage.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The damper is positioned in advance to cushion potential impacts between the actuator and cascade ring. It provides vibration damping and impact absorption before contact occurs, enabling the use of a smaller aperture without compromising structural integrity or actuator reliability.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

2Reliability

If tolerance stack-ups are accounted for by providing additional clearance, then the actuator and cascade ring can accommodate manufacturing variations, but the space available for the damper and other components is reduced

Engineering Contradiction:

Improveassembly reliabilityVSAvoidavailable space

Core Design Contradiction:

ReliabilityVSVolume of moving object

Solution Approach 1:

The damper is designed with specific material properties (elastomer) and geometric parameters that allow it to provide the necessary clearance and vibration damping within a compact space. The elastomer material allows for elastic deformation that accommodates tolerance stack-ups while maintaining a small overall volume.

Inventive Principle:

Principle #35Parameter changes

3Reliability

If a damper is closely positioned relative to the actuator to provide vibration damping, then vibration damping is improved, but the damper may exert preload on the actuator causing premature wear

Engineering Contradiction:

Improvevibration dampingVSAvoidactuator operation

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

Inventive Principle:

Principle #35Parameter changes

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 solution effectively dampens vibrations and prevents actuator damage by increasing reaction force with deflection, maintaining structural integrity and avoiding preload issues, while allowing compact design and easy maintenance.

Implementation Method 1

The damper may comprise an elastomer. The flexible damper may be configured to exert a small reaction force on the TRAS actuator in response to a small deflection of the TRAS actuator. The flexible damper may be configured to exert a large reaction force on the TRAS actuator in response to the damper bottoming out.

Methodology Applied

Scientific EffectElasticity: Elasticity

Implementation Method 2

The damper may be configured to damp vibrations of the TRAS actuator. The flexible damper may be configured to damp vibrations in the TRAS actuator.

Methodology Applied

Scientific EffectVibration damping: Damping

Data Source

PatentUS9494108B2Thrust reverser actuator damper system

Publication Date: 2016.11.15 ROHR INC

AI summary

A nacelle may comprise a thrust reverser. The thrust reverser may comprise a translating sleeve, a cascade array, and a TRAS actuator. The TRAS actuator may pass through an aperture in an aft cascade ring of the cascade array. A retainer may be coupled to the aft cascade ring. A damper may be coupled to the retainer. The damper may circumscribe the TRAS actuator. The damper may be configured to damp vibrations in the TRAS actuator. As an amplitude of vibration or deflection of the TRAS actuator increases, a reaction force applied by the damper on the TRAS actuator increases, which prevents the TRAS actuator from contacting the aft cascade ring.