Non-Contacting Seal Assembly With Internal Wear-Resistant Coating

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Solution Overview

Problem

Gas turbine engine seal assemblies face issues with wear and contact between rotating components, leading to increased friction, leakage, and reduced operational efficiency due to the lack of effective wear resistance and adaptive sealing mechanisms.

Innovation Solution

A seal assembly design featuring a support ring, shoe, beam, spacer, seal ring, and carrier ring with a wear-resistant coating, such as cobalt-based, applied between the seal ring and shoe surfaces, which reduces friction and prevents contact with rotating components by utilizing the pressure gradient to maintain clearance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of moving object

If a seal assembly is used without wear-resistant coating, then the structure is simpler and manufacturing is easier, but wear resistance is insufficient leading to increased friction and reduced operational life

Engineering Contradiction:
Improveoperational lifeVSAvoidstructure complexity
Core Design Contradiction:
Duration of action of moving objectVSDevice complexity

Solution Approach 1:

The seal assembly incorporates a wear-resistant coating (such as cobalt-based alloy or ceramic coating) applied to the seal ring surface, creating a composite structure that combines the base seal material with a highly wear-resistant layer. This composite approach significantly extends operational life while maintaining reasonable structural complexity.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The invention changes the surface properties of the seal ring by applying a wear-resistant coating with different material parameters (hardness, friction coefficient, wear resistance) than the base material. This parameter change enables the seal to withstand higher wear rates and extend operational life without fundamentally redesigning the entire seal structure.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If the seal ring contacts the rotating component directly, then the sealing mechanism is simpler, but friction increases and leakage occurs due to wear

Engineering Contradiction:
Improvesealing effectivenessVSAvoidfriction force
Core Design Contradiction:
ReliabilityVSForce

Solution Approach 1:

The wear-resistant coating on the seal ring creates a low-friction surface that reduces contact resistance with the rotating component. This composite material approach maintains reliable sealing through the hard, wear-resistant coating while minimizing friction and preventing adhesive wear that would lead to leakage.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The wear-resistant coating is applied specifically to the contact surface of the seal ring where friction and wear occur most intensely. This localized application provides enhanced friction reduction and wear protection exactly where needed, maintaining sealing effectiveness without requiring the entire seal assembly to be redesigned.

Inventive Principle:
Principle #3Local quality

3Reliability

If no wear-resistant coating is applied, then manufacturing cost and process are lower, but wear resistance and durability are insufficient

Engineering Contradiction:
Improvewear resistanceVSAvoidmanufacturing process
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The seal assembly uses a composite structure with a wear-resistant coating (cobalt-based alloy, ceramic, or other hard coating) applied to the seal ring. Common manufacturing methods include thermal spray, plasma spray, CVD, or PVD processes. While this adds a manufacturing step, it significantly enhances wear resistance and reliability.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The invention changes the surface material parameters of the seal ring by applying a wear-resistant coating. This modifies the surface hardness, friction coefficient, and wear resistance without changing the bulk material properties. The coating process is a standard industrial technique that adds minimal complexity to the manufacturing workflow.

Inventive Principle:
Principle #35Parameter changes

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 wear-resistant coating enhances the seal assembly's durability and efficiency by minimizing wear, reducing friction, and preventing sticking, thereby maintaining optimal performance and extending the seal's operational life.

Implementation Method 1

The wear-resistant coating enhances the seal assembly's durability and efficiency by minimizing wear, reducing friction, and preventing sticking

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

preventing contact with rotating components by utilizing the pressure gradient to maintain clearance

Methodology Applied
Scientific EffectPressure gradient: Pressure Gradient

Data Source

PatentEP4047189A1Non-contacting seal assembly with internal coating
Publication Date: 2022.08.24 RTX CORP
  • EP4047189A1 patent drawingFigure 1
  • EP4047189A1 patent drawingFigure 2
  • EP4047189A1 patent drawingFigure 3

AI summary

A seal assembly (80), including: a seal (82), the seal (82) having; a support ring (104), a shoe (102), and a beam (106) extending between the shoe (102) and the support ring (104), wherein the shoe (102) moves relative to the support ring (104) via the beam (106); a spacer (84) and a second seal; a seal ring (94); a carrier ring (96), the second seal being located adjacent to one end of the shoe (102) and the seal ring (94) being located adjacent to an opposite end (126) of the shoe (102) and the carrier ring (96) extends from the seal ring (94) to the spacer (84), the carrier ring (96) being adjacent to the support ring (104) of the seal (82); and a wear resistant coating (136) located between a surface (128) of the seal ring (94) and an opposite end (126) of the shoe (102).