Additive Manufacturing Impeller Reinforcement for Shape Accuracy

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Solution Overview

Problem

In impellers formed by additive manufacturing, the thin end portions where flow path inlets or outlets are located are prone to deformation during the lamination process, affecting the accuracy of the molding process.

Innovation Solution

Integrating a reinforcement portion with the impeller, which can be removed after molding, to reinforce the end portions and support the flow path, including a communication hole for removing unmelted metal powder, and forming the impeller molding body with inclined inner peripheral surfaces to enhance shape accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the additive manufacturing method is used to form the impeller, then complex shapes can be achieved, but the thin end portions are prone to deformation

Engineering Contradiction:
Improveability to form complex impeller shapesVSAvoidshape accuracy of end portions
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The invention applies preliminary anti-action by forming a reinforcement portion at the thin end portions of the impeller before the additive manufacturing process. This reinforcement structure prevents deformation during lamination by counteracting the weak structural integrity of thin sections, thereby maintaining manufacturing precision while enabling complex shape formation

Inventive Principle:
Principle #9Preliminary anti-action

Solution Approach 2:

The invention segments the impeller formation process into distinct stages: forming the reinforcement portion first, then building the main impeller body through additive manufacturing. This segmentation allows the reinforcement structure to be established independently to support subsequent lamination operations on thin sections

Inventive Principle:
Principle #1Segmentation

2Manufacturing precision

If the end portion is reinforced to prevent deformation, then manufacturing precision is improved, but the device complexity increases

Engineering Contradiction:
Improveshape accuracy of end portionsVSAvoidstructural complexity of impeller
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The reinforcement portion serves as a temporary structural aid during manufacturing that is discarded after serving its purpose. The communication holes are formed to allow removal of the reinforcement portion and unmelted metal powder, thereby reducing device complexity while maintaining manufacturing precision during the critical formation stage

Inventive Principle:
Principle #34Discarding and recovering

Solution Approach 2:

The reinforcement portion acts as an intermediary structure that temporarily supports the thin end portions during additive manufacturing. This mediator enables precise formation of complex shapes without requiring permanent structural modifications to the final impeller design

Inventive Principle:
Principle #24Intermediary (Mediator)

3Manufacturing precision

If communication holes are added to remove unmelted metal powder, then manufacturing precision is improved, but device complexity increases

Engineering Contradiction:
Improvecleanliness of flow pathVSAvoidstructural complexity of impeller
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The invention extracts the problem of unmelted metal powder removal by incorporating communication holes that provide access pathways. This allows extraction of residual powder through the reinforcement portion without adding complex external removal systems, thereby improving manufacturing precision with minimal increase in device complexity

Inventive Principle:
Principle #2Taking out (Extraction)

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 prevents deformation of the impeller end portions, allows for high-accuracy molding, and effectively removes residual metal powder, ensuring the impeller maintains its desired shape and structural integrity.

Implementation Method 1

a metal powder which is disposed to match a shape of a desired impeller is sintered by thermal energy generated by laser

Methodology Applied
Scientific EffectLaser: Laser

Implementation Method 2

the metal powder which is disposed to match a shape of a desired impeller is sintered by thermal energy generated by laser

Methodology Applied
Scientific EffectSintering: Sintering

Data Source

PatentEP3561308B1Production method for impeller
Publication Date: 2021.08.18 MITSUBISHI HEAVY INDUSTIES COMPRESSOR CORP
  • EP3561308B1 patent drawingFigure 1
  • EP3561308B1 patent drawingFigure 2
  • EP3561308B1 patent drawingFigure 3

AI summary

A production method for an impeller (1) includes an impeller molding body forming step of forming an impeller molding body (100) in which a reinforcement portion (110) which reinforces at least one of end portions of the impeller (1) in which an inlet and an outlet of a flow path (12) are formed and the impeller (1) are integrated with each other, by an additive manufacturing method using a metal powder, and a removal step of removing the reinforcement portion (110) from the impeller molding body (100).