CMC Rotor Module Eliminates Fasteners

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Solution Overview

Problem

The existing gas turbine engine designs with high temperature superalloys and fasteners increase weight and complexity due to the additional material required for supporting fasteners, which is not efficiently addressed by conventional technologies.

Innovation Solution

A rotor module made of Ceramic Matrix Composites (CMC) integrates multiple rows of airfoils and a common CMC drum, eliminating the need for inter-stage fasteners and reducing hardware complexity and weight by forming a unitary CMC structure with knife edge seals and other features bonded or mounted within it.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Weight of moving object

If traditional fasteners and supporting material are used to assemble rotor disks, then structural integrity is maintained, but weight and device complexity increase

Engineering Contradiction:
Improverotor assembly weightVSAvoidfastener and support structure complexity
Core Design Contradiction:
Weight of moving objectVSDevice complexity

Solution Approach 1:

The patent merges multiple rotor disks and fasteners into a single integrated CMC rotor module. The CMC drum integrates the function of multiple rotor disks, while airfoils are directly bonded to the drum, eliminating the need for separate fasteners and supporting structures. This consolidation reduces both weight and complexity while maintaining structural integrity through the monolithic CMC construction.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The invention extracts and eliminates the fastener system entirely from the rotor assembly. By using CMC materials with direct bonding capabilities, the patent removes the need for metal fasteners and their supporting structures, achieving weight reduction and complexity simplification without compromising the assembly's structural integrity.

Inventive Principle:
Principle #2Taking out (Extraction)

2Quantity of substance

If metal fasteners and supporting structures are used, then assembly is straightforward, but weight and material usage increase

Engineering Contradiction:
Improvematerial massVSAvoidassembly simplicity
Core Design Contradiction:
Quantity of substanceVSEase of manufacture

Solution Approach 1:

The CMC rotor module combines multiple components into a single integrated structure where airfoils are directly bonded to the CMC drum. This merging eliminates the need for separate fasteners and supporting materials, significantly reducing total material mass while the bonding process maintains manufacturing feasibility.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent utilizes CMC (ceramic matrix composite) materials that enable direct bonding between components without requiring metal fasteners. This composite material approach reduces the quantity of substance needed while maintaining ease of manufacture through the bonding process, achieving both weight reduction and manufacturing simplicity.

Inventive Principle:
Principle #40Composite materials

3Strength

If inter-stage fasteners are used to connect rotor disks, then structural strength is ensured, but weight and stress concentration increase

Engineering Contradiction:
Improvefastener region strengthVSAvoidfastener and support material weight
Core Design Contradiction:
StrengthVSWeight of moving object

Solution Approach 1:

The invention merges the fastening function into the CMC drum structure itself, where airfoils are directly bonded to the drum surface. This eliminates separate fasteners and their supporting structures, reducing weight while distributing stresses uniformly across the bonded interface rather than concentrating them at fastener points.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The CMC material enables direct bonding between airfoils and the drum, providing structural strength without requiring metal fasteners. This composite material approach eliminates the weight penalty of fasteners and supporting structures while maintaining or improving strength through the bonded connection and uniform stress distribution.

Inventive Principle:
Principle #40Composite materials

Data Source

PatentEP2570608B1Ceramic matrix composite rotor module for a gas turbine engine, corresponding turbine assembly and method of assembling
Publication Date: 2018.07.04 UNITED TECH CORP
  • EP2570608B1 patent drawingFigure 1
  • EP2570608B1 patent drawingFigure 2

AI summary

A rotor (62) module for a gas turbine engine (20) including a multiple of ceramic matrix composite (CMC) airfoil rows (74A,74B,74C) which extend from a common CMC drum (66). A corresponding turbine assembly and a method of assembling are also provided.