External Actuator for Gas Turbine Blade Tip Clearance Control

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Solution Overview

Problem

Accessing and maintaining the blade tip clearance control system in gas turbine engines is challenging due to the need for disassembly of engine components, resulting in high costs and complexity.

Innovation Solution

An active blade tip clearance control system with an externally mounted actuator that can be installed and serviced without disassembling the outer case, utilizing a mechanism where the actuator is secured from outside the case and can be easily moved between installed and uninstalled positions, allowing for adjustment and maintenance without disassembly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If the clearance control system is integrated inside the engine case, then the structural integrity and compactness are improved, but the ease of repair and maintenance deteriorates due to required disassembly

Engineering Contradiction:
Improvestructural integrityVSAvoidmaintenance accessibility
Core Design Contradiction:
Stability of the object's compositionVSEase of repair

Solution Approach 1:

The clearance control system is segmented into modular components, with the actuator housed in a separate accessible location from the air seal mechanism. This allows the actuator to be serviced independently without disassembling the engine case, while the air seal remains integrated within the engine structure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A transmission mechanism serves as an intermediary between the externally mounted actuator and the internally positioned air seal. This intermediary mechanism transmits the actuating force through the engine case structure, enabling external control of internal components without direct physical connection.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If the actuator is mounted externally for easy access, then the ease of operation is improved, but the device complexity increases due to additional mounting structures

Engineering Contradiction:
Improveactuator accessibilityVSAvoidmounting structure complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The external mounting structure is designed to serve multiple functions: it provides structural support for the actuator, creates a sealed environment for pneumatic/hydraulic lines, and integrates with existing engine case features. This multi-functionality reduces the need for additional separate components.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The actuator mounting structure utilizes existing engine case features and spaces, nesting the actuator assembly within or adjacent to current structural elements rather than adding completely separate external components. This reduces overall complexity by leveraging existing infrastructure.

Inventive Principle:
Principle #7Nested doll (Nesting)

Data Source

PatentEP3097274B1Accessible rapid response blade tip clearance control system
Publication Date: 2021.05.19 RTX CORP
  • EP3097274B1 patent drawingFigure 1
  • EP3097274B1 patent drawingFigure 2
  • EP3097274B1 patent drawingFigure 3~4

AI summary

An example active clearance control system for a gas turbine engine includes an actuator, and a case wall portion defining an aperture configured to receive the actuator. The actuator is configured to move an air seal segment, and the actuator is insertable to an installed position within the aperture through a radially outer side of the case wall portion.