Francis Runner Segments With Blade-Spaced External Welds

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Solution Overview

Problem

Francis-type hydraulic machine runners are expensive, time-consuming to manufacture, difficult to transport, and pose health and safety risks due to large dimensions and the need for skilled labor and confined welding operations, especially when assembled from segments with joints at high-stress areas.

Innovation Solution

A Francis-type runner is formed from multiple segments with integrally formed band, crown, and blade portions, where the joining edges are positioned away from the blade, allowing for welding outside the runner and using narrow gap welding techniques to avoid high-stress areas, enabling efficient and safe assembly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the runner is made as a large single-piece cast or welded structure, then structural integrity is improved, but manufacturing cost and time increase, and transport becomes difficult

Engineering Contradiction:

Improvestructural integrityVSAvoidmanufacturing time and cost

Core Design Contradiction:

StrengthVSProductivity

Solution Approach 1:

The runner is divided into multiple segments that can be manufactured separately and assembled together. Each segment is cast or welded independently, reducing the complexity and time of manufacturing while maintaining structural integrity through proper joining at crown and band locations.

Inventive Principle:

Principle #1Segmentation

2Strength

If the runner is made as a large single-piece structure, then structural integrity is improved, but transport difficulty increases

Engineering Contradiction:

Improvestructural integrityVSAvoidtransport ease

Core Design Contradiction:

StrengthVSEase of operation

Solution Approach 1:

Inventive Principle:

Principle #1Segmentation

3Ease of manufacture

If welding operations are performed in confined sections of the runner, then assembly is achieved, but health and safety risks increase

Engineering Contradiction:

Improveassembly capabilityVSAvoidhealth and safety risks

Core Design Contradiction:

Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Instead of performing welding operations from the inside of confined hydraulic passages, the segments are assembled by making welding joints at the external crown and band locations, allowing welders to work from the outside where access is safer and easier.

Inventive Principle:

Principle #13The other way round (Inversion)

4Ease of manufacture

If the runner is assembled with welding joints at the crown, band, and split blades, then assembly is achieved, but manufacturing complexity and skill requirements increase

Engineering Contradiction:

Improveassembly capabilityVSAvoidmanufacturing complexity

Core Design Contradiction:

Ease of manufactureVSDevice complexity

Solution Approach 1:

Inventive Principle:

Principle #1Segmentation

Data Source

PatentUS11808245B2Hydroturbine manufacture

Publication Date: 2023.11.07 GE RENEWABLE TECH

AI summary

A runner for a hydraulic machine comprising a band, a crown, a plurality of blades extending between the crown and the band, wherein the runner comprises a plurality of runner segments which together define the runner, each runner segment comprising a band portion, a crown portion and a blade, which portions are integrally formed with one another, each runner segment being attachable to another segment at a band joining edge and a crown joining edge, wherein the band joining edge and the crown joining edge are each spaced apart from the blade of the segment.