One-Piece Outer Shell for Adjustable Stator Vanes

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Solution Overview

Problem

Existing axial turbomachines with adjustable stator vanes face limitations in efficiency and complexity due to cumbersome architectures and limited performance, particularly in achieving precise angular positioning and variable geometry configurations.

Innovation Solution

The proposed solution involves a compact, one-piece outer shroud supporting multiple annular rows of stator vanes with adjustable orientation, including a rotor with integral blades, allowing for precise positioning and adjustable vanes that can pivot up to 30°, enhancing operational range and efficiency while maintaining a simple assembly process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple rows of adjustable stator blades are supported by dedicated external ferrules attached by radial annular flanges, then the stator can support variable geometry configurations, but the architecture becomes bulky and assembly complexity increases

Engineering Contradiction:
Improvevariable geometry configurationVSAvoidassembly complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent merges multiple separate ferrules into a single integrated outer shell structure that supports multiple rows of stator blades simultaneously. This single-piece outer shell eliminates the need for multiple separate ferrule components and their associated radial annular flange attachments, thereby reducing assembly complexity while maintaining the capability to support variable geometry configurations of multiple blade rows.

Inventive Principle:
Principle #5Merging (Combining)

2Ease of operation

If multiple separate ferrules with radial annular flanges are used to support stator blade rows, then each row can be independently mounted, but the overall structure becomes particularly bulky

Engineering Contradiction:
Improveindependent mounting capabilityVSAvoidstructural volume
Core Design Contradiction:
Ease of operationVSVolume of moving object

Solution Approach 1:

The patent combines multiple separate ferrule structures into a single integrated outer shell that accommodates multiple rows of stator blades. This consolidation reduces the overall structural volume by eliminating redundant ferrule components and their radial annular flanges, while the inner ferrules remain attached to individual blade rows, preserving independent mounting and adjustment capabilities for each blade row.

Inventive Principle:
Principle #5Merging (Combining)

3Device complexity

If the outer shell is designed to support only two rows of blades, then the structure remains simple, but the adaptability and performance range are limited

Engineering Contradiction:
Improvestructural simplicityVSAvoidoperating range
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent designs the outer shell as a multi-functional structure that can support more than two rows of stator blades (specifically four rows as shown in the claims). This enhanced outer shell incorporates multiple annular rows of orifices for mounting different blade rows and includes an extended axial portion to accommodate the additional rows, thereby increasing adaptability and performance range while maintaining structural integrity.

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

4Manufacturing precision

If precise angular positioning of blades is achieved through complex mounting architectures, then efficiency improves, but the device becomes less economical and more complex

Engineering Contradiction:
Improveblade positioning accuracyVSAvoidmounting architecture complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent integrates precise positioning functionality directly into the simplified single-piece outer shell structure through precisely engineered annular rows of orifices. These orifices are designed to receive and position the roots of stator blades at accurate angular positions, eliminating the need for complex separate positioning mechanisms. The inner ferrules attached to blade rows further ensure precise angular positioning relative to the outer shell, achieving high manufacturing precision without increasing overall structural complexity.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP3290657B1Stator with adjustable vanes for the compressor of an axial turbine engine
Publication Date: 2021.02.24 SAFRAN AERO BOOSTERS SA
  • EP3290657B1 patent drawingFigure 1
  • EP3290657B1 patent drawingFigure 2

AI summary

The invention relates to a stator assembly (22) for an axial-flow turbomachine compressor, for example, a low-pressure turbojet compressor, also known as a booster. The assembly comprises: a first annular row of first stator (22) blades (26) extending radially in the axial flow; and a second annular row of second stator (22) blades (28) with controlled orientation, also known as variable-pitch or VSV blades. Additionally, the assembly includes a one-piece outer shell on which the first (26) and second (28) blades are pivotally mounted.