Ceramic Matrix Composite Blade Outer Air Seal Assembly

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Solution Overview

Problem

Gas turbine engines face efficiency losses due to air leakage around turbine blades, which existing seal technologies fail to adequately address, particularly in maintaining optimal tip clearance and reducing assembly complexity.

Innovation Solution

A seal assembly for gas turbine engines featuring a ceramic matrix composite blade outer air seal with a unique geometry and attachment system, including a wear liner and attachment bodies with tabs, that allows for efficient assembly and reduced leakage by optimizing the radial spacing and contact points between components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If a traditional blade outer air seal is used to prevent air leakage, then sealing effectiveness is improved, but device complexity increases due to multiple components and attachment mechanisms

Engineering Contradiction:

Improveair leakageVSAvoidassembly complexity

Core Design Contradiction:

Loss of energyVSDevice complexity

Solution Approach 1:

The patent combines the blade outer air seal with the wear liner into a single integrated component. The wear liner is formed with a blade outer air seal portion that includes a radially inner portion and a radially outer portion, eliminating the need for separate attachment bodies and reducing assembly complexity while maintaining sealing effectiveness.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The wear liner serves multiple functions: it provides wear protection for the turbine blade tip region and simultaneously functions as the blade outer air seal. This multi-functionality reduces the number of components needed while achieving both protection and sealing objectives.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Reliability

If multiple attachment bodies are used to secure the blade outer air seal, then reliability of attachment is improved, but ease of manufacture deteriorates

Engineering Contradiction:

Improveattachment reliabilityVSAvoidassembly ease

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The attachment function is integrated into the wear liner structure itself through the radially outer portion that extends toward the blade tip. This eliminates the need for separate attachment bodies while maintaining secure attachment through the unified structure.

Inventive Principle:

Principle #5Merging (Combining)

3Loss of energy

If a complex multi-component seal assembly is used, then sealing performance is improved, but loss of time in assembly increases

Engineering Contradiction:

Improveair leakage reductionVSAvoidassembly time

Core Design Contradiction:

Loss of energyVSLoss of time

Solution Approach 1:

The wear liner and blade outer air seal are manufactured as a single integrated component, eliminating the need for multiple assembly steps. This reduces assembly time while maintaining the sealing performance achieved through the optimized radially outer portion geometry.

Inventive Principle:

Principle #5Merging (Combining)

Data Source

PatentEP3587740B1Seal assembly for a gas turbine engine and method of assembling

Publication Date: 2022.04.06 RTX CORP

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AI summary

A blade outer air seal (82) includes a base portion (108) that extends between a leading edge (98) and a trailing edge (100). A forward wall (102) and an aft wall (104) extend radially outward from the base portion (108) to a radially outer portion (106). The radially outer portion (106) is spaced from the base portion (108).