Counter-rotating Fan Housing Coupling Strength

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Solution Overview

Problem

Conventional counter-rotating axial-flow fans face issues with the coupling of divided housing units, where undue force can lead to breakage and decoupling, necessitating reinforcement with screws or adhesives to prevent disconnection.

Innovation Solution

The design incorporates a coupling structure with engaging members and stopper portions that distribute force evenly, preventing concentration at the fitting structure and ensuring secure engagement between the first and second divided housing units, thereby enhancing mechanical strength and preventing breakage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the fitting portion of the first cylindrical air-channel half-portion and the fitted portion of the second cylindrical air-channel half-portion are strongly pressed against each other to couple the first and second divided housing units, then the coupling strength is improved, but the fitting portions may be broken due to undue force

Engineering Contradiction:
Improvecoupling strengthVSAvoidintegrity of fitting portions
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent introduces a coupling member as an intermediary component between the first and second cylindrical air-channel half-portions. This coupling member distributes the pressing force across multiple engagement points (multiple fitting portions and fitted portions) rather than concentrating it at a single point, thereby achieving strong coupling without breaking the housing units.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The coupling structure is segmented into multiple discrete fitting portions and fitted portions arranged circumferentially around the air-channel halves. This segmentation allows the total coupling force to be distributed across multiple locations, reducing the stress on any single fitting portion while maintaining overall coupling strength.

Inventive Principle:
Principle #1Segmentation

2Ease of manufacture

If the coupling structure is simplified to avoid complex reinforcement, then the ease of manufacture is improved, but the first and second divided housing units may be decoupled when external force is applied

Engineering Contradiction:
Improvesimplicity of coupling structureVSAvoidresistance to decoupling
Core Design Contradiction:
Ease of manufactureVSStability of the object's composition

Solution Approach 1:

The patent transitions from a single-point coupling approach to a multi-dimensional coupling arrangement by distributing multiple fitting portions and fitted portions circumferentially around the air-channel halves. This circumferential distribution creates a stable, multi-point connection that resists decoupling forces while maintaining manufacturing simplicity.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Data Source

PatentEP1983198B1Counter-rotating axial-flow fan
Publication Date: 2018.08.08 SANYO DENKI CO LTD
  • EP1983198B1 patent drawingFigure 1
  • EP1983198B1 patent drawingFigure 2
  • EP1983198B1 patent drawingFigure 3

AI summary

A counter-rotating axial-flow fan includes a housing that is constituted from a first divided housing unit and a second divided housing unit. Engaging members and first stopper portions are integrally formed with a first flange portion of the first divided housing unit. The first stopper portions are arranged adjacent to the engaging members. Engaged members and second stopper portions are integrally formed with a second flange portion of the second divided housing unit. The second stopper portions are arranged adjacent to the engaged members. The second stopper portions have leading ends that are abutted onto leading ends of the first stopper portions when the engaging members are completely engaged with the engaged members. Thus, damage of the first and second divided housing units is prevented when the first and second divided housing units are coupled.