Separable Turbine Disk Platforms for CMC Blade Attachment

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Solution Overview

Problem

Existing turbine disk assemblies with ceramic matrix composite (CMC) blades face challenges in attachment due to material dissimilarity and lack of integral flow path platforms, leading to complicated assembly and reduced effectiveness.

Innovation Solution

A turbine disk assembly design featuring a disk with coupling portions and an attachment member that includes a platform and engagement portions, allowing for secure coupling of CMC blades without fixed fasteners, using friction or press fits, and forming a separable platform to direct airflow and reduce stress concentrations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Weight of moving object

If CMC blades are used without integral flow path platforms, then weight is reduced and material performance is improved, but assembly complexity increases and attachment becomes difficult

Engineering Contradiction:
Improveblade weightVSAvoidassembly complexity
Core Design Contradiction:
Weight of moving objectVSDevice complexity

Solution Approach 1:

The platform and blade are merged into a single integral CMC structure, eliminating the need for separate platform components and their associated attachment hardware. This reduces assembly complexity while maintaining the weight benefits of CMC materials.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The integral CMC platform serves multiple functions: it provides flow path guidance, structural support, and attachment functionality all in one component. This multi-functionality reduces the number of parts and simplifies assembly procedures.

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

2Ease of operation

If separate non-integral platforms are added to CMC blades, then flow path guidance is improved, but assembly complexity increases and attachment effectiveness is compromised

Engineering Contradiction:
Improveflow path guidanceVSAvoidassembly complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The flow path platform is merged with the blade structure to form an integral CMC component. This ensures proper flow path guidance while eliminating the complexity of attaching separate platform components.

Inventive Principle:
Principle #5Merging (Combining)

3Strength

If traditional attachment methods are used for CMC blades, then attachment strength may be sufficient, but material dissimilarity causes attachment difficulties and potential failure points

Engineering Contradiction:
Improveattachment strengthVSAvoidattachment reliability
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The blade and platform are constructed from the same CMC material as an integral structure, eliminating material dissimilarity at the attachment interface. This homogeneity removes potential failure points associated with joining dissimilar materials.

Inventive Principle:
Principle #33Homogeneity

Solution Approach 2:

By merging the blade and platform into a single integral CMC structure, the attachment interface between dissimilar materials is eliminated entirely, improving reliability by removing the weak link.

Inventive Principle:
Principle #5Merging (Combining)

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 solution enhances the attachment of CMC blades to the disk, improves airflow management, and reduces material usage and weight, leading to improved turbine performance and reduced centrifugal loading, while accommodating thermal expansion and stress variations.

Implementation Method 1

using friction or press fits

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3020926B1Turbine disk assembly including separable platforms for blade attachment
Publication Date: 2020.03.04 ROLLS ROYCE CORP
  • EP3020926B1 patent drawingFigure 1
  • EP3020926B1 patent drawingFigure 2
  • EP3020926B1 patent drawingFigure 3~4

AI summary

An apparatus includes a disk, an attachment member, and a blade. The disk has an outer surface including a coupling portion. The attachment member has a coupling portion and defines at least a portion of an opening. The coupling portion of the first attachment member is configured to be coupled to the coupling portion of the disk. A portion of the blade is configured to be disposed within the opening when the coupling portion of the attachment member is coupled to the coupling portion of the disk.