Angled-Channel Turbine Shroud Seals for Thermal Expansion

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Solution Overview

Problem

Sealing between turbine shroud components with different thermal expansion coefficients is challenging due to differential expansion, leading to potential gas leakage and reduced effectiveness of existing seal members.

Innovation Solution

A turbine shroud assembly with a carrier segment, blade track segment, and a buffer air seal assembly, where buffer air is used to pressurize discrete seal members in angled channels, urging them into engagement with the blade track segment to enhance sealing efficacy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If seal members are used to seal between carrier segment and blade track segment, then gas leakage is prevented, but sealing effectiveness deteriorates due to differential thermal expansion

Engineering Contradiction:

Improvesealing effectivenessVSAvoiddifferential thermal expansion

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

A buffer air seal assembly is introduced as an intermediary component between the carrier segment and blade track segment. This seal assembly includes multiple seal members arranged in discrete channels with buffer air passageways that supply pressurized buffer air to the channels, causing the seal members to expand and engage firmly with the blade track segment, thereby maintaining effective sealing despite differential thermal expansion of the underlying components

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The seal members are made elastically deformable and are positioned in channels that allow them to change their radial position in response to pressure changes. Buffer air is supplied through passageways to increase the pressure within the channels, which causes the elastically deformable seal members to expand radially and engage more firmly with the blade track segment, maintaining sealing effectiveness under thermal expansion conditions

Inventive Principle:

Principle #35Parameter changes

2Reliability

If existing seal members are used without buffer air activation, then structure is simpler, but sealing performance is reduced due to inconsistent engagement

Engineering Contradiction:

Improvesealing performanceVSAvoidseal system structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The seal system incorporates buffer air passageways that deliver pressurized buffer air to discrete channels containing seal members. The pneumatic pressure from the buffer air causes the elastically deformable seal members to expand and engage consistently with the blade track segment, achieving reliable sealing performance. The complexity is localized to the seal assembly rather than the entire shroud structure

Inventive Principle:

Principle #29Pneumatics and hydraulics

3Manufacturing precision

If seal members are positioned in discrete channels, then engagement consistency is improved, but manufacturing complexity increases

Engineering Contradiction:

Improveseal member engagement consistencyVSAvoidchannel formation precision

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The seal system divides the sealing function into multiple discrete seal members positioned in separate channels within the carrier segment. Each seal member can be independently positioned and engaged with the blade track segment, allowing for consistent sealing engagement. The segmentation enables precise control over each seal member's position while maintaining overall manufacturing feasibility through modular assembly

Inventive Principle:

Principle #1Segmentation

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 buffer air seal assembly effectively blocks gas leakage by ensuring consistent engagement of seal members with the blade track segment, enhancing the sealing performance and reducing wear on the seal members.

Implementation Method 1

The at least one buffer air passageway discharges buffer air radially inward axially between the first and second seal members into the first channel and the second channel to urge the first seal member radially inward and axially forward and the second seal member radially inward and axially aft into engagement with the carrier segment and the blade track segment

Methodology Applied

Scientific EffectPressure: Pressure Increase

Implementation Method 2

The first and second channel cooperate to define a partition wall formed in the first support wall axially therebetween. The partition wall may extend circumferentially relative to the axis

Methodology Applied

Scientific EffectGeometry: Geometry

Data Source

PatentUS20260036066A1Turbine shroud assemblies with angled channels and air activated buffer cavity seals

Publication Date: 2026.02.05 ROLLS ROYCE CORP

AI summary

A turbine shroud assembly adapted for use with a gas turbine engine includes a carrier segment, a blade track segment, and a seal system. The carrier segment arranged circumferentially at least partway around an axis. The blade track segment is coupled to the carrier segment and defines a portion of a gas path of the gas turbine engine. The seal system includes seals arranged radially between the carrier segment and the blade track segment to block gases from flowing between the carrier segment and the blade track segment.