Multi-material Abradable Shroud with Protrusions and Elastomer

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Solution Overview

Problem

Existing abradable shrouds for gas turbine engines do not effectively address the need for improved wear resistance and self-clearance mechanisms, leading to inefficiencies and potential damage from rotor blade interactions.

Innovation Solution

The development of an abradable shroud with a base and an abradable coating system that includes a plurality of protrusions made from abradable material and an elastomeric material filling the gaps between them, providing enhanced wear resistance and self-clearance capabilities.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a traditional abradable shroud is used, then the structure is simple and easy to manufacture, but the wear resistance and self-clearance capability are insufficient

Engineering Contradiction:
Improvewear resistance and self-clearance capabilityVSAvoidcoating system structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies composite materials by combining abradable material protrusions with elastomeric material in a multi-material coating system. The abradable material provides wear resistance and self-clearance capability when rotor blades contact the shroud, while the elastomeric material provides damping and sealing. This composite structure resolves the contradiction by achieving improved reliability through material composition rather than simple structural design.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The coating system is segmented into distinct functional components: abradable material protrusions for wear resistance and self-clearance, elastomeric material for damping and sealing, and a gradient transition zone. This segmentation allows each material to perform its specific function optimally, achieving superior wear resistance and self-clearance capability while maintaining manufacturability through modular coating application processes.

Inventive Principle:
Principle #1Segmentation

2Reliability

If the abradable coating system includes multiple materials and protrusions, then wear resistance and self-clearance are improved, but the manufacturing complexity increases

Engineering Contradiction:
Improveself-clearance mechanism effectivenessVSAvoidcoating application process
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The abradable material protrusions are pre-formed and positioned on the shroud surface before final coating completion. This preliminary action allows the complex multi-material structure to be built systematically, with each layer and component placed in its correct position and orientation, thereby improving self-clearance mechanism effectiveness while making the manufacturing process more manageable and less complex.

Inventive Principle:
Principle #10Preliminary action

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 proposed solution significantly improves wear resistance and self-clearance in gas turbine engines, reducing the risk of damage from rotor blade interactions and enhancing the overall efficiency and reliability of the engine.

Implementation Method 1

an elastomeric material filling a gap between each circumferentially neighboring pair of the protrusions

Methodology Applied
Scientific EffectVibration damping: Damping

Implementation Method 2

Each of the protrusions is configured from or otherwise includes an abradable material

Methodology Applied
Scientific EffectAbrasion: Abrasion

Data Source

PatentEP4556685A1Multi-material abradable shroud for gas turbine engine rotor
Publication Date: 2025.05.21 PRATT & WHITNEY CANADA CORP
  • EP4556685A1 patent drawingFigure 1
  • EP4556685A1 patent drawingFigure 2~3
  • EP4556685A1 patent drawingFigure 4

AI summary

An apparatus is provided for a gas turbine engine. This apparatus includes a shroud (24), and the shroud (24) includes a base (62) and an abradable coating system (64). The base (62) extends axially along and circumferentially about an axis (28). The base (62) extends radially between a base inner side (70) and a base outer side (72). The abradable coating system (64) is bonded to and covers the base (62) at the base inner side (70). The abradable coating system (64) includes a plurality of protrusions (74) and an elastomeric material (76). The protrusions (74) are arranged circumferentially about the axis (28) in a circumferentially extending array (78). Each of the protrusions (74) projects in a radial inward direction away from the base inner side (70) to a distal inner end (86). Each of the protrusions (74) is configured from or otherwise includes an abradable material. The elastomeric material (76) fills a gap (80) between each circumferentially neighboring pair of the protrusions (74).