Unducted Turbomachine Stator Vane Attachment System

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Solution Overview

Problem

Current propeller attachment technologies for unducted turbomachines, such as those with a single unducted propeller and a flow straightener, are bulky and designed to withstand high centrifugal forces, making them unsuitable for attaching stator vanes with variable pitch to pivots in a radially compact manner.

Innovation Solution

The solution involves an unducted turbomachine flow straightener with stator vanes attached to pivots using a compact attachment system. This system includes a clamping mechanism and plates shaped to match the half-platforms of the stator vane roots and the pivots, allowing for secure attachment without increasing radial dimensions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If current propeller attachment technologies are used to attach stator vanes to pivots, then the attachment is secure and can withstand high centrifugal forces, but the radial dimension increases making the system bulky

Engineering Contradiction:

Improveattachment strengthVSAvoidradial dimension

Core Design Contradiction:

StrengthVSLength of moving object

Solution Approach 1:

The attachment system nests the clamping mechanism within the radial space already defined by the pivot structure. The clamps engage with the pivot and vane root in a compact arrangement where components are nested within each other's spatial envelope, achieving secure attachment without increasing overall radial dimension.

Inventive Principle:

Principle #7Nested doll (Nesting)

Solution Approach 2:

The attachment system transitions from a radially-extending configuration to one that utilizes axial and tangential dimensions for clamping forces. The clamps apply forces primarily in the axial direction rather than radially, allowing secure attachment while maintaining compact radial profile.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Strength

If clamping systems directly contact the vane roots, then secure attachment is achieved, but the vane roots are exposed to damage and external aggression

Engineering Contradiction:

Improveattachment securityVSAvoidvane root damage risk

Core Design Contradiction:

StrengthVSObject-affected harmful factors

Solution Approach 1:

The attachment system introduces intermediary clamping elements that contact the vane root through protected interfaces rather than direct exposure. These intermediaries distribute clamping forces and protect the composite vane root material from mechanical damage, chemical exposure, and environmental degradation while maintaining secure attachment.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS12291980B2Unducted rectifier for a turbomachine, turbomachine module and aircraft turbomachine

Publication Date: 2025.05.06 SAFRAN AIRCRAFT ENGINES SAS

AI summary

An unducted rectifier for a turbomachine is provided. The rectifier includes: (1) stator vanes each having a root and a blade radially projecting from the root, the root having two half-platforms; (2) pivots, each associated with a vane mounted so as to pivot about a pitch axis and configured to connect to a system for changing the pitch of the blades, each pivot having an upper platform and a cylindrical lower portion; and (3) attachment systems for attaching the half-platforms of the root of the vane to the associated pivot, each having two plates having a substantially identical shape to each half-platform and a clamping system for clamping the half-platforms between the plates of the attachment system and the upper platform of the pivot.