Axial Turbine Stator with Interlocking Shroud Segments

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Solution Overview

Problem

The existing axial turbomachine stator architectures lack sufficient rigidity and effective axial retention of internal shrouds, leading to limited structural integrity and potential aerodynamic disturbances.

Innovation Solution

The introduction of an axial turbomachine stator design featuring one-piece support vanes with internal platforms and connecting vanes, where facets oriented upstream and downstream provide axial blocking, and contact surfaces perpendicular to the rotation axis mechanically interlock internal shroud segments for enhanced retention and stiffness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If traditional stator architectures with internal shrouds are used, then the stator can channel primary flow and ensure seal with rotor, but the rigidity of the assembly remains limited and axial retention of internal shrouds is insufficient

Engineering Contradiction:
ImproverigidityVSAvoidstator architecture complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The internal shroud is divided into multiple segments that can be independently positioned and retained by contact surfaces on support vanes. This segmentation allows for improved rigidity through precise axial retention while maintaining assembly flexibility and managing structural complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Contact surfaces are introduced at the interface between support vanes and shroud segments, creating axial blocking in the axial dimension. This dimensional approach to retention enhances rigidity without requiring complex three-dimensional structural modifications throughout the entire stator assembly.

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

2Strength

If rigid architecture with pins is used to attach composite inner shrouds to metal structuring vanes, then aerodynamic disturbances are avoided, but the rigidity of the assembly remains limited

Engineering Contradiction:
Improveassembly rigidityVSAvoidaerodynamic disturbances
Core Design Contradiction:
StrengthVSObject-generated harmful factors

Solution Approach 1:

The pin connection system is extracted and replaced with direct contact surface interfaces between support vanes and shroud segments. This eliminates the need for intermediate fasteners that could create aerodynamic disturbances while achieving superior rigidity through direct structural contact.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

Contact surfaces act as intermediaries between support vanes and shroud segments, providing rigid mechanical connection and axial retention without requiring pins or other fastening elements that would disrupt airflow.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If internal shrouds are subjected to significant axial forces and pumping phenomena, then they can perform sealing function, but axial retention and structural integrity are compromised

Engineering Contradiction:
Improvesealing functionVSAvoidaxial retention
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

Contact surfaces are pre-configured on support vanes to provide axial blocking before axial forces and pumping phenomena act on the shroud segments. This preliminary structural arrangement ensures reliable sealing function while maintaining structural integrity under operational loads.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3018295B1Mixed stator of axial turbine-engine compressor
Publication Date: 2019.07.03 SAFRAN AERO BOOSTERS SA
  • EP3018295B1 patent drawingFigure 1~2
  • EP3018295B1 patent drawingFigure 3
  • EP3018295B1 patent drawingFigure 4~5

AI summary

The invention relates to a low-pressure compressor stator for an axial turbomachine. The stator comprises an annular row of stator blades with connecting blades (38) and support blades (36) grouped into bladed housings (40). The housings (40) include internal platforms (42) and external platforms (44); they are entirely manufactured by additive manufacturing using titanium powder. The stator exhibits a circular internal shell (32) formed by the internal platforms (42) of the housing blades and internal shell segments (46) attached to the connecting blades (38). The internal platforms (42) include pairs of contact surfaces for fitting the shell segments by butting and sliding against the contact surfaces. The contact surfaces are perpendicular to the axis of rotation and form axial stops.