Welded Turbine Casing Assembly Without Large Casting Molds

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Solution Overview

Problem

The existing manufacturing methods for casings in rotating machines, such as steam turbines, require extensive time due to the need for molds, even when using divided block materials and welding techniques, as they often rely on casting which is labor-intensive and costly.

Innovation Solution

A manufacturing method that utilizes a combination of forging, steel plate processing, and fused metal deposition to form multiple metal components, allowing for the assembly of casings without the need for a single large mold, thereby reducing production time and cost by using different materials for various parts based on their specific requirements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If a single large mold is used for casting the entire casing, then the casing can be formed as an integral structure, but it takes a lot of time to make the large mold and the manufacturing period is extended

Engineering Contradiction:
Improveintegral structure of casingVSAvoidmold making time
Core Design Contradiction:
Stability of the object's compositionVSLoss of time

Solution Approach 1:

The casing is divided into multiple separate mold parts (first mold part and second mold part) that can be manufactured independently and then assembled to form the complete casing structure. This segmentation allows each mold part to be made more quickly while still producing an integral casing through subsequent assembly operations.

Inventive Principle:
Principle #1Segmentation

2Volume of stationary object

If the casing is divided into multiple block materials and welded together, then the mold size is reduced, but it still requires mold preparation and takes time

Engineering Contradiction:
Improvemold sizeVSAvoidmanufacturing time
Core Design Contradiction:
Volume of stationary objectVSLoss of time

Solution Approach 1:

The mold is segmented into multiple parts that can be manufactured separately and assembled, reducing the volume and complexity of each individual mold component while maintaining the capability to produce the complete casing structure efficiently.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The mold parts are prepared in advance as separate components that can be quickly assembled when needed, eliminating the time-consuming process of creating and storing a single large mold while still enabling efficient production.

Inventive Principle:
Principle #10Preliminary action

3Ease of manufacture

If traditional casting methods are used with molds, then the casing can be formed, but the process is labor-intensive and costly

Engineering Contradiction:
Improvecasing formationVSAvoidmanufacturing efficiency
Core Design Contradiction:
Ease of manufactureVSProductivity

Solution Approach 1:

By dividing the mold into multiple parts, the manufacturing process becomes more flexible and less labor-intensive. Each mold part can be manufactured using standard processes and assembled relatively easily, reducing overall manufacturing complexity and improving productivity compared to creating and managing a single large mold.

Inventive Principle:
Principle #1Segmentation

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 approach significantly shortens the manufacturing time for casings by eliminating the need for a single mold and enabling the use of diverse materials, enhancing efficiency and reducing production costs while maintaining high strength and functionality.

Implementation Method 1

a three-dimensional model of each of the plurality of metal components is formed by using fused metal deposition

Methodology Applied
Scientific EffectFused metal deposition: 3D Printing

Implementation Method 2

the plurality of metal components are welded to each other in a state where the plurality of metal components abut each other

Methodology Applied
Scientific EffectWelding: Welding

Data Source

PatentEP3871818B1Manufacturing method of casing
Publication Date: 2024.01.17 MITSUBISHI HEAVY INDUSTIES COMPRESSOR CORP
  • EP3871818B1 patent drawingFigure 1
  • EP3871818B1 patent drawingFigure 2
  • EP3871818B1 patent drawingFigure 3

AI summary

A manufacturing method of a casing, the manufacturing method includes a step of manufacturing a plurality of metal members which are components constituting the casing including a casing body having a tubular shape that extends with an axis as a center; a step of arranging the plurality of metal members according to the casing to be formed; and a step of forming the casing by welding the plurality of metal members to each other, in which in the step of manufacturing the metal members, the plurality of metal members are manufactured by at least two kinds of manufacturing methods among forging, steel plate processing, casting, and a fused metal deposition method.