Segmented Annular Seal Radial Adjustment

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Solution Overview

Problem

Conventional annular seals in gas turbine engines are difficult and costly to manufacture, with high material and time investment, and are prone to dislodgment during machining, leading to scrapped parts.

Innovation Solution

The annular seal is segmented with cylindrical trunnions that slide within radially extending mount holes, independent spring components that bias and control radial movement, and a knife-edge ridge to inhibit fluid leakage, allowing for self-adjustment and reduced manufacturing complexity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a single conventional annular seal is used, then fluid sealing is achieved, but manufacturing time and cost increase significantly

Engineering Contradiction:
Improvefluid sealingVSAvoidmanufacturing time
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The annular seal is divided into multiple segments that can be manufactured separately and assembled together. Each segment is machined independently, reducing the cumulative machining time and allowing parallel manufacturing processes. The segments are held together by spring components that provide radial biasing force, maintaining the seal's integrity while enabling modular assembly.

Inventive Principle:
Principle #1Segmentation

2Reliability

If a single conventional annular seal is used, then fluid sealing is achieved, but material waste increases due to dislodgment during machining

Engineering Contradiction:
Improvefluid sealingVSAvoidmaterial waste
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

By dividing the seal into smaller segments, the risk of catastrophic failure during machining is reduced. If one segment experiences issues during EDM or other machining processes, only that segment is affected rather than the entire seal. This allows for better quality control and reduces material waste from scrapped parts.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The spring components are pre-installed on the segments before final assembly, providing a cushioning effect that absorbs machining stresses and prevents dislodgment during the manufacturing process. This prior preparation helps protect the segments from damage during subsequent machining operations.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

3Reliability

If a single conventional annular seal is used, then fluid sealing is achieved, but assembly complexity increases

Engineering Contradiction:
Improvefluid sealingVSAvoidassembly complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The segmented design with spring components actually simplifies assembly compared to a single large seal. Each segment can be independently positioned and assembled into the annular configuration, allowing for more flexible installation and easier adjustment. The spring components automatically provide the necessary radial force to maintain sealing contact.

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

This design reduces manufacturing time and costs, maintains seal orientation, and prevents fluid leakage, while allowing for easier assembly and reduced material waste, enhancing the reliability and efficiency of the seal.

Implementation Method 1

A plurality of spring components are coupled between the annular outer casing and the plurality of seal segments and are configured to bias the plurality of seal segments

Methodology Applied
Scientific EffectSpring: Spring

Implementation Method 2

the annular sealing surface includes a knife-edge ridge to inhibit fluid leakage between the rotating structure and the annular sealing surface

Methodology Applied
Scientific EffectMechanical barrier:

Implementation Method 3

The trunnion of each seal segment of the plurality of seal segments may be configured to slide within a respective one of the plurality of radially extending mount holes

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3318785B1Segmented annular seal
Publication Date: 2020.10.28 RTX CORP
  • EP3318785B1 patent drawingFigure 1
  • EP3318785B1 patent drawingFigure 2A~2B
  • EP3318785B1 patent drawingFigure 3

AI summary

An annular seal (100) includes an annular outer casing (110), a plurality of seal segments (120), and a plurality of spring components (130). The plurality of seal segments (120) is coupled to the annular outer casing (110) to cumulatively form an annular sealing surface (124), the annular sealing surface (124) is configured to face a rotating structure (104) to inhibit fluid leakage between the rotating structure (104) and the annular sealing surface (124), and each seal segment of the plurality of seal segments (120) is configured for independent radial movement relative to other seal segments of the plurality of seal segments (120). In various embodiments, the plurality of spring components (130) are configured to bias the plurality of seal segments (120) relative to the radial movement.