Impeller with Machining Access Panel for Weld-Free Assembly

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Solution Overview

Problem

Existing impeller designs for fluid machinery often suffer from premature failure due to defects or abnormalities at the joints formed by welding or brazing of blades to the disc and cover, which can lead to reliability issues.

Innovation Solution

The impeller assembly features a main body with integrally formed blades that connect to a separate access body, eliminating the need for welding or brazing at the blade edges, and allowing for complete machining of interior surfaces before attachment, reducing the risk of defects and improving assembly simplicity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If blades are joined to the disc and cover by welding or brazing, then the impeller can be assembled from separate components, but joint defects or abnormalities may lead to premature failure

Engineering Contradiction:
Improveassembly of separate componentsVSAvoidpremature failure due to joint defects
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent merges the blade and disc into a single integral structure, eliminating the need for joining operations. The blade is formed as one continuous piece with the disc, removing the joint that was previously a source of defects and premature failure while maintaining manufacturability through integral forming processes

Inventive Principle:
Principle #5Merging (Combining)

2Ease of manufacture

If the impeller is constructed by separately joining components, then manufacturing flexibility is improved, but the complexity of ensuring defect-free joints increases

Engineering Contradiction:
Improvemanufacturing flexibilityVSAvoidcomplexity of ensuring defect-free joints
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent combines multiple components (blade and disc) into a single integral structure, eliminating the joining processes and associated quality control complexities. The integral design removes the need to ensure defect-free joints while maintaining manufacturing flexibility through forming processes

Inventive Principle:
Principle #5Merging (Combining)

3Manufacturing precision

If access openings are provided in the impeller body for machining, then interior surfaces can be precisely machined, but the impeller structure becomes more complex

Engineering Contradiction:
Improvemachining of interior surfacesVSAvoidimpeller structure with access openings
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent segments the impeller manufacturing process into two stages: first machining the interior surfaces with access openings present, then closing the openings. This segmentation allows precise machining of hard-to-reach interior surfaces while the final closed structure maintains impeller integrity and minimal complexity

Inventive Principle:
Principle #1Segmentation

4Reliability

If the impeller is designed as a single integral piece, then joint defects are eliminated, but machining of interior surfaces becomes more difficult

Engineering Contradiction:
Improveelimination of joint defectsVSAvoidmachining of interior surfaces
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent segments the manufacturing process temporally rather than structurally - the impeller is machined with access openings during the manufacturing phase, then the openings are closed to create the final integral structure. This allows precise machining of interior surfaces while maintaining the reliability benefits of an integral design in the finished product

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP1893481B2Impeller with machining access panel
Publication Date: 2018.03.14 DRESSER RAND CO
  • EP1893481B2 patent drawingFigure 1~2
  • EP1893481B2 patent drawingFigure 3~4
  • EP1893481B2 patent drawingFigure 5~6

AI summary

An impeller assembly is for a fluid machine, such as a compressor, and includes a first, main body and a second body. The main body includes a first section providing at least a substantial portion of either an impeller disc or an impeller cover and a second section spaced generally axially from the first section and providing a portion of the other one of the disc or the cover. A plurality of integrally formed blades extend between and connect the main body first and second sections such that the main body is generally of one piece construction. A plurality of flow channels are defined between the blades and a plurality of access openings extend into the flow channels. The second body provides a remainder of the disc or cover and is attachable to the main body to substantially form an impeller and to close all of the access openings.