Gas Turbine Blade Axial Retention via Segmented Elongated Members

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Solution Overview

Problem

Gas turbine engines face challenges in axially retaining blades under both normal and abnormal operating conditions, with existing solutions either requiring additional axial length or being complex in assembly and disassembly.

Innovation Solution

A retention device for gas turbine engines featuring projections forming circumferential slots with elongated members and stops to prevent axial, circumferential, and radial movement of blades, allowing for easy removal and reinstallation of elongated members without disturbing other components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a retention device with multiple components (projections, elongated members, stops, supports) is used to axially retain blades, then blade retention reliability is improved, but device complexity increases

Engineering Contradiction:
Improveblade retention reliabilityVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The retention device is segmented into distinct functional components: projections forming circumferential slots, elongated members for axial retention, stops for circumferential positioning, and supports for radial positioning. This segmentation allows each component to perform its specific function independently, improving overall reliability while enabling modular assembly and disassembly procedures.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The elongated members are nested within the circumferential slots formed by the projections, while the stops and supports are positioned within or alongside these slots. This nested arrangement consolidates multiple retention functions into a compact structure, reducing the overall space required and simplifying the assembly compared to separate distributed components.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Reliability

If a single-piece retention ring is used to retain blades, then blade retention is achieved, but friction and deformation increase during installation

Engineering Contradiction:
Improveblade retentionVSAvoidinstallation ease
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The retention system uses multiple discrete elongated members instead of a single continuous ring. Each elongated member can be independently installed into the circumferential slots, reducing the total friction that would occur with a single large ring. This segmentation also reduces deformation risks during installation as each smaller component requires less force to install.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The elongated members are designed to be removable and reinstallable, providing dynamic adaptability for maintenance and replacement. This allows the retention system to be adjusted or repaired without complete disassembly, improving ease of manufacture and maintenance compared to a permanent single-piece ring.

Inventive Principle:
Principle #15Dynamics

3Ease of repair

If elongated members are made removable for maintenance, then ease of repair is improved, but the risk of component misplacement increases

Engineering Contradiction:
Improveease of repairVSAvoidcomponent management complexity
Core Design Contradiction:
Ease of repairVSDevice complexity

Solution Approach 1:

The stops and supports are integrated with the circumferential slots structure, forming a unified retention framework. When elongated members are removed for maintenance, the stops and supports remain in place to maintain structural integrity and guide reinstallation, reducing the risk of misplacement while still allowing easy removal and reattachment of the elongated members.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The stops act as intermediary elements that remain fixed in the circumferential slots while the elongated members are removed and reinstalled. These stops serve as reference points and guides, ensuring that removed elongated members are reinstalled in the correct positions, thereby reducing misplacement risk while maintaining ease of repair.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Reliability

If additional axial length is provided between stages, then blade retention is improved, but the engine length increases

Engineering Contradiction:
Improveblade retentionVSAvoidengine length
Core Design Contradiction:
ReliabilityVSLength of moving object

Solution Approach 1:

Instead of providing additional axial length between stages for blade retention, the invention uses circumferential slots and radially extending projections to create retention in the radial and circumferential dimensions. The elongated members engage with these slots to provide axial retention, allowing blade retention without increasing the axial distance between stages.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The retention components (projections, slots, elongated members, stops, supports) are nested within the existing stage structure, utilizing the available radial and circumferential space rather than requiring additional axial space. This nested arrangement achieves blade retention while maintaining compact engine dimensions.

Inventive Principle:
Principle #7Nested doll (Nesting)

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 effectively retains blades axially while simplifying the assembly and disassembly process, reducing the risk of component misplacement and damage, and minimizing downtime by allowing for a multi-piece design that reduces friction and deformation.

Implementation Method 1

Each of the plurality of elongated members comprises a resilient elongated member having a first configuration and a second configuration

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP2722484B1Systems and methods to axially retain blades
Publication Date: 2020.08.05 GENERAL ELECTRIC CO
  • EP2722484B1 patent drawingFigure 1
  • EP2722484B1 patent drawingFigure 2
  • EP2722484B1 patent drawingFigure 3

AI summary

Embodiments of the present disclosure include a gas turbine engine system. The system may include a rotor wheel (32) having a number of blades (20) mounted about a periphery of the rotor wheel (32). Further, the system may include a retention device (100). The retention device may include a number of projections (102) extending from a radial surface of the rotor wheel (32) to form a number of circumferential slots (104) about the rotor wheel (32). The retention device (100) may also include a number of elongated members (106) positioned within the circumferential slots (104) to impede axial movement of the blades (20).