Hybrid Rotor with Inserts for Weight Distribution

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Solution Overview

Problem

Current compressor rotor designs for turbomachines, such as those described in EP 2 818 635 A1 and EP 2 287 445 A1, face challenges with weight distribution and overall weight, leading to increased energy consumption and manufacturing costs due to heterogeneous weight distribution and complex machining requirements.

Innovation Solution

A rotor design featuring two axisymmetric composite material segments with a metal crown supporting a row of blades, where the crown forms a unitary assembly with the segments through surface adhesion during molding, utilizing serrated inserts and radial holes to enhance adhesion and reduce weight variability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a metal drum design is used for the rotor, then structural strength is ensured, but the rotor weight increases and manufacturing time extends

Engineering Contradiction:
Improvestructural strengthVSAvoidrotor weight
Core Design Contradiction:
StrengthVSWeight of moving object

Solution Approach 1:

The rotor is divided into multiple composite segments (first segment, second segment, etc.) that are molded separately and then assembled around a metal crown. This segmentation allows each segment to be optimized for weight while maintaining overall structural strength through the crown support.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The rotor combines metal (crown) with composite materials (segments made of resin and reinforcing fibers). This composite construction reduces weight compared to a full metal drum while maintaining strength through the synergistic properties of metal and composite materials.

Inventive Principle:
Principle #40Composite materials

2Weight of moving object

If composite material segments are used for the rotor, then rotor weight is reduced, but manufacturing complexity increases due to assembly requirements

Engineering Contradiction:
Improverotor weightVSAvoidmanufacturing complexity
Core Design Contradiction:
Weight of moving objectVSDevice complexity

Solution Approach 1:

The metal crown and multiple composite segments are combined into a unified assembly where the segments are mounted on the crown and secured with retaining means. This merging creates a integrated structure that simplifies manufacturing compared to assembling multiple separate components.

Inventive Principle:
Principle #5Merging (Combining)

3Ease of operation

If dovetail grooves are machined for blade accommodation, then blade mounting is achieved, but manufacturing time and cost increase

Engineering Contradiction:
Improveblade mountingVSAvoidmanufacturing time
Core Design Contradiction:
Ease of operationVSLoss of time

Solution Approach 1:

The blade mounting features (such as recesses or attachment structures) are incorporated into the composite segments during the molding process itself, rather than requiring subsequent machining operations. This preliminary action during molding eliminates time-consuming post-processing steps.

Inventive Principle:
Principle #10Preliminary action

4Strength

If metal rings are used to accommodate rotor blades in composite segments, then blade support is provided, but axial weight distribution becomes inconsistent

Engineering Contradiction:
Improveblade supportVSAvoidaxial weight distribution
Core Design Contradiction:
StrengthVSStability of the object's composition

Solution Approach 1:

Instead of using uniform metal rings throughout, the design employs localized metal elements (such as discrete retaining means or reinforced zones) only where blade support is required. This local quality approach provides necessary blade support while maintaining consistent weight distribution in other areas.

Inventive Principle:
Principle #3Local quality

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

This design achieves a more homogeneous weight distribution, reduces manufacturing time and costs, and results in a significantly lighter rotor compared to traditional metal drum designs, while maintaining aerodynamic continuity and reducing mechanical stress.

Implementation Method 1

a surface bond is created between the irregularities of the metal tab's surface and the resin, which is still liquid, used to manufacture the composite segments

Methodology Applied
Scientific EffectAdhesion: Adhesive

Data Source

PatentEP3726006B1Hybrid rotor with inserts
Publication Date: 2023.05.03 SAFRAN AERO BOOSTERS SA
  • EP3726006B1 patent drawingFigure 1~2
  • EP3726006B1 patent drawingFigure 3
  • EP3726006B1 patent drawingFigure 4~6

AI summary

The invention relates to a turbomachine (2) rotor (12), and in particular to its design and manufacture. The rotor (12) comprises at least two segments (40) of substantially axisymmetric shape and made of composite material, and is notable in that it includes a metal ring (50) supporting a row of blades (24) and interposed axially between the two segments (40), the ring (50) having an upstream tab (55) and a downstream tab (56), each of the tabs (55, 56) comprising a molded insert (59, 60) embedded in one of the two segments (40). The invention also relates to a method for manufacturing such a rotor (12).