Multi-stage Compressor Case Assembly with Snap-fit Vane Stages

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Solution Overview

Problem

The assembly and disassembly of compressor sections in gas turbine engines are labor-intensive due to the need for heating and snap fitting of vane stages, which requires significant time and effort.

Innovation Solution

A compressor inner case with a unitary construction featuring vane stages connected by flanges and windows, with wear strips and locking members, allowing for vane alignment and secure engagement without fasteners, facilitating efficient assembly and disassembly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If vane stages are connected by heating and snap fitting, then the compressor section can be assembled, but the assembly and disassembly process requires significant time and labor

Engineering Contradiction:
Improveease of assemblyVSAvoidassembly time
Core Design Contradiction:
Ease of manufactureVSLoss of time

Solution Approach 1:

The compressor case is divided into multiple modular vane stages that can be independently assembled and disassembled. Each vane stage includes a vane holder with integrated vanes, allowing the entire stage to be installed as a single unit through the window opening, eliminating the need to assemble individual vanes within the holder

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The vane stages are extracted from the traditional fastened configuration and reconfigured to use a snap-fit mechanism. The vane holder is designed with an outer periphery that engages with the window opening through elastic deformation, allowing the stage to be 'taken out' and removed without fasteners or heating processes

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 3:

The material properties of the vane holder are utilized to enable snap-fit assembly. The holder is made from elastic or plastic material that can be temporarily deformed during installation and then returns to its original shape to secure the vane stage, changing the physical state from rigid to flexible during the assembly process

Inventive Principle:
Principle #35Parameter changes

2Reliability

If fasteners are used to connect vane stages, then the connection is secure, but the assembly process becomes more complex and time-consuming

Engineering Contradiction:
Improveconnection reliabilityVSAvoidassembly complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Fasteners are completely removed from the connection mechanism. The vane holder's outer periphery directly engages with the window opening through a snap-fit mechanism, extracting the fastening function from separate components and integrating it into the structural design of the vane holder itself

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The connection function is merged with the structural components. The vane holder serves both as the mounting structure and as the fastening mechanism, with its outer periphery designed to engage with the window opening, eliminating the need for separate fasteners and reducing assembly complexity

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP2898189B1Multi-stage high pressure compressor case
Publication Date: 2017.04.19 UNITED TECH CORP
  • EP2898189B1 patent drawingFigure 1
  • EP2898189B1 patent drawingFigure 2
  • EP2898189B1 patent drawingFigure 3~5

AI summary

A disclosed compressor case assembly includes a case with a plurality of vane stages that circumscribe an interior of the case. Each of the plurality of vane stages includes a vane guide and at least one window axially aligned with each of the vane guides. The at least one window extends from an outer surface of the case into each of the vane guides.