Hollow Integrally Bladed Rotor Manufacturing via Segmented Layering

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Solution Overview

Problem

Current manufacturing methods cannot produce integrally bladed rotors with hollow blades using additive manufacturing, as they fail to achieve precision formation of hollow spaces and are hindered by thermal stresses and material deformations, leading to imbalanced components.

Innovation Solution

A hybrid manufacturing method combining additive and subtractive processes, where segmented layers are formed outward from a hub, with cavities created by omitting material and using a wind curtain or evacuation tool to remove excess material, and relief holes are formed and filled to achieve balanced, hollow blades.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Weight of moving object

If additive manufacturing is used to form hollow blades, then weight reduction is achieved, but thermal stresses cause deformations that hinder subsequent layer deposition

Engineering Contradiction:
Improveblade weightVSAvoidlayer deposition precision
Core Design Contradiction:
Weight of moving objectVSManufacturing precision

Solution Approach 1:

The blade is constructed as a stack of discrete segmented layers that are formed successively. Each layer can be independently manufactured and then assembled, allowing thermal stress deformations in one layer to be compensated by adjacent layers. This segmentation enables the creation of hollow blades with internal cavities while maintaining overall structural integrity and balance.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Multiple segmented layers are nested together to form the complete blade structure. Each layer contains portions of the previous layer, creating an interlocking assembly that compensates for thermal deformations. The hollow cavity is formed by nesting layers with progressively smaller inner dimensions, creating a stable hollow structure resistant to thermal stress.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Weight of moving object

If material is omitted to form cavities, then weight reduction is achieved, but excess material accumulates in cavities causing imbalance

Engineering Contradiction:
Improveblade weightVSAvoidmanufacturing efficiency
Core Design Contradiction:
Weight of moving objectVSProductivity

Solution Approach 1:

Evacuation channels are pre-formed within the segmented layers during the additive manufacturing process, before the blade is complete. These channels provide predetermined pathways for removing excess material from the hollow cavities. By preparing these evacuation routes in advance, the process efficiently removes trapped material without requiring complex post-processing operations.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent replaces traditional mechanical evacuation methods with pneumatic or vacuum-based systems. Gas or vacuum is used to remove excess material from the cavities through the pre-formed evacuation channels, substituting for time-consuming mechanical machining or manual removal processes.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Weight of moving object

If hollow cavities are formed, then weight reduction is achieved, but precision formation of hollow spaces is difficult

Engineering Contradiction:
Improveblade weightVSAvoidhollow space precision
Core Design Contradiction:
Weight of moving objectVSManufacturing precision

Solution Approach 1:

The hollow cavity is formed by stacking multiple segmented layers, each contributing a portion of the cavity structure. This segmentation allows precise control over the cavity's geometry, as each layer can be manufactured with high precision using additive manufacturing techniques. The cumulative effect of precisely controlled layers creates an accurate hollow space.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent utilizes changes in material parameters and process parameters during additive manufacturing to achieve precise cavity formation. By controlling layer thickness, material deposition rates, and heating/cooling cycles, the process achieves high precision in forming the hollow cavity geometry while accommodating thermal stresses.

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

This method enables the production of hollow-bladed rotors with improved weight reduction (up to 40%) and balanced components, reducing material trapped in cavities and minimizing thermal stresses, thus overcoming the limitations of existing additive manufacturing techniques.

Implementation Method 1

Each of plurality of hollow blades is formed by using an additive manufacturing process to integrally form a plurality of segmented layers successively outward from a radially outward surface of a hub

Methodology Applied
Scientific EffectAdditive manufacturing: 3D Printing

Implementation Method 2

periodically evacuating a quantity of excess material from the one or more cavities

Methodology Applied
Scientific EffectEvacuation: Vacuum

Data Source

PatentEP2957380B1Method for making an integrally bladed rotor with hollow blades
Publication Date: 2018.08.01 HAMILTON SUNDSTRAND CORP
  • EP2957380B1 patent drawingFigure 1A~1B
  • EP2957380B1 patent drawingFigure 2~3
  • EP2957380B1 patent drawingFigure 4~5B

AI summary

A method of making an integrally bladed rotor with hollow blades (4). A plurality of segmented layers (9) are sequentially placed to form each one of a plurality of blades (4) on a radially outward surface (3) of a hub (2). This is done using an additive manufacturing process. The placement of the segmented layers (9) also comprises omitting portions of one or more of the plurality of segmented layers (9) to form one or more cavities (7) and intermittently removing a quantity of particles from the one or more cavities (7) using an evacuation tool.