Variable Stator Vane Retention for Large-Diameter Propeller Modules

Solution Overview

Problem

Turbine engines with unducted propellers and stator vanes face challenges in mechanical stability due to the large diameter of stator vanes, which makes it difficult to fit pivoting roots into housings and leads to vibratory stress, potentially causing blocking or breakage.

Innovation Solution

A turbine engine module with stator vanes connected by a retaining member and pivot shafts that are radially distant from the vane roots, equipped with anti-vibration means to dampen vibrations, ensuring improved mechanical strength and stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If stator vanes with large diameter are used to increase bypass ratio, then propulsion efficiency is improved, but mechanical stability deteriorates due to difficulty in fitting pivoting roots and increased vibratory stress

Engineering Contradiction:

Improvebypass ratioVSAvoidmechanical stability

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The retaining member is divided into multiple segments corresponding to different stator vanes, with each segment independently retaining a specific vane. This segmentation allows for localized vibration damping and easier assembly while maintaining overall structural integrity of the large-diameter stator vane assembly

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The retaining member acts as an intermediary component between the stator vane roots and the engine structure. It provides a buffered connection that absorbs vibratory stresses and prevents direct transmission to the pivoting roots, thereby improving mechanical stability while maintaining the large bypass ratio

Inventive Principle:

Principle #24Intermediary (Mediator)

2Productivity

If stator vanes with large diameter are installed, then propulsion performance is improved, but manufacturing and assembly difficulty increases due to difficulty in fitting pivoting roots into housings

Engineering Contradiction:

Improvepropulsion performanceVSAvoidassembly difficulty

Core Design Contradiction:

ProductivityVSEase of manufacture

Solution Approach 1:

The retaining member is divided into multiple segments corresponding to different stator vanes, with each segment independently retaining a specific vane. This segmentation allows for localized vibration damping and easier assembly while maintaining overall structural integrity of the large-diameter stator vane assembly

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The retaining member acts as an intermediary component between the stator vane roots and the engine structure. It provides a buffered connection that absorbs vibratory stresses and prevents direct transmission to the pivoting roots, thereby improving mechanical stability while maintaining the large bypass ratio

Inventive Principle:

Principle #24Intermediary (Mediator)

3Device complexity

If conventional retaining methods are used for stator vanes, then structural simplicity is maintained, but vibration damping is insufficient leading to blocking or breakage

Engineering Contradiction:

Improvestructural simplicityVSAvoidvibration resistance

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The retaining member acts as an intermediary component between the stator vane roots and the engine structure. It provides a buffered connection that absorbs vibratory stresses and prevents direct transmission to the pivoting roots, thereby improving mechanical stability while maintaining the large bypass ratio

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The retaining member is positioned at a radial distance from the root of each stator vane, creating a lever arm that reduces the transmission of vibrations from the root to the free ends. This parameter change in positioning transforms the vibration transmission characteristics and improves overall reliability

Inventive Principle:

Principle #35Parameter changes

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 mechanical stability and reduces vibration transmission, making the assembly more rigid and effective in retaining the stator vanes, while maintaining ease of manufacturing and maintenance.

Implementation Method 1

the anti-vibration means comprise an elastic annulus centered on the pivot axis B of the pivot shaft

Methodology Applied

Scientific EffectElasticity: Elasticity

Data Source

PatentUS12466543B2Turbine engine module equipped with a propeller and stator vanes supported by retaining means and corresponding turbine engine

Publication Date: 2025.11.11 SAFRAN AIRCRAFT ENGINES SAS

AI summary

A turbine engine module having longitudinal axis X including an unducted propeller for rotating about the longitudinal axis X; —at least one flow straightener with a plurality of stator vanes extends substantially along a radial axis Z, each stator vane having a root and a blade rising radially from the root; and—a pitch change system for changing the pitch of the stator vanes. At least two adjacent stator vanes are connected to each other by at least one retaining member coupled to the blades of the stator vanes by at least one pivot shaft and mounted radially from the root of the stator vanes. The pivot shaft extends along a pivot axis B coaxial with the pitch adjustment axis A to enable the stator vanes to pivot about the pivot axis B. An antivibration unit dampens vibration of the pivot shaft.