Thermally Protected Seal Assembly for Turbine Engines

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Solution Overview

Problem

Turbine engine seals face challenges in sealing against leakage and accommodating relative movement and high temperatures, while also needing to withstand wear and vibration, due to thermal displacement and temperature differentials.

Innovation Solution

A thermally protected seal assembly featuring a convoluted seal with a porous, compliant shield that extends circumferentially between annular surfaces, including cooling fluid flow and a lip ring for thermal isolation, to minimize wear and enhance durability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a seal is placed in a high-temperature environment to seal gaps between turbine engine parts, then sealing effectiveness is improved, but thermal exposure and wear increase

Engineering Contradiction:

Improvesealing effectivenessVSAvoidthermal exposure

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

A shield member is introduced as an intermediary component between the seal and the hot gas path. The shield blocks direct thermal exposure to the seal while allowing the seal to maintain its sealing function against the rotating and stationary surfaces. This mediator protects the seal from harmful thermal effects without compromising sealing effectiveness.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The seal assembly uses different materials with specific properties for different components: the seal is made of a material suitable for sealing contact, while the shield is made of a heat-resistant material capable of withstanding high temperatures. This local differentiation of material properties allows each component to optimize its function in its specific operational environment.

Inventive Principle:

Principle #3Local quality

2Reliability

If a seal is compressed between surfaces to prevent leakage, then sealing integrity is improved, but wear from relative movement increases

Engineering Contradiction:

Improvesealing integrityVSAvoiddurability

Core Design Contradiction:

ReliabilityVSDuration of action of moving object

Solution Approach 1:

The shield acts as a protective intermediary that absorbs wear and thermal exposure, allowing the seal to maintain its compressed sealing state without direct contact with the harshest environmental factors. This extends the service life of the seal while maintaining sealing integrity.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The shield is positioned in advance to protect the seal from wear and thermal damage before the seal degrades. This preventive protection allows the seal to operate in its optimal sealing state for an extended duration without direct exposure to damaging conditions.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

3Adaptability or versatility

If a seal accommodates relative movement between parts, then adaptability is improved, but wear and vibration increase

Engineering Contradiction:

Improveaccommodation of relative movementVSAvoidwear and vibration

Core Design Contradiction:

Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The shield serves as a mediator that allows the seal to accommodate relative movement between rotating and stationary surfaces while protecting the seal from the full impact of wear and vibration. The shield absorbs some of the mechanical stress and thermal exposure.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The seal uses a flexible, convoluted geometry with bends and members that can deform and adapt to relative movement between surfaces. This flexibility allows the seal to maintain contact and sealing effectiveness while accommodating thermal expansion and mechanical displacement.

Inventive Principle:

Principle #30Flexible shells and thin films

4Adaptability or versatility

If a seal is made resilient to accommodate movement, then adaptability is improved, but seal wear increases

Engineering Contradiction:

ImproveresilienceVSAvoidseal life

Core Design Contradiction:

Adaptability or versatilityVSDuration of action of moving object

Solution Approach 1:

The shield protects the resilient seal material from direct wear and thermal degradation, allowing the seal to maintain its resilient properties and adaptability over an extended service life. The shield acts as a sacrificial or protective element that preserves the seal's functional properties.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 reduces seal wear and thermal exposure, maintaining sealing integrity and durability under high-temperature and vibration conditions, while allowing for relative movement and thermal expansion.

Implementation Method 1

the shield is porous

Methodology Applied

Scientific EffectPorous flow: Porosity

Implementation Method 2

a seal resiliently compressed between the first and second surfaces

Methodology Applied

Scientific EffectElasticity: Elasticity

Implementation Method 3

temperature differentials that cause thermal displacement

Methodology Applied

Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentUS10088049B2Thermally protected seal assembly

Publication Date: 2018.10.02 RTX CORP

AI summary

A seal assembly that may be for turbine engine includes first and second rings with a convoluted seal resiliently compressed there-between. The seal may define a gap for receipt of a thermally resistant shield that may also reduce wear of the seal. The seal may include a hole for the flow of cooling air and the shield may be porous so as not to obstruct the cooling air flow for cooling of the seal.