Suction Unit Impeller Coupling and Noise Reduction Design

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Solution Overview

Problem

Existing suction units face issues where the impeller can separate from the rotating shaft, run idle, and generate flow noise due to incomplete coupling or reduced adhesion, and the impeller can contact the fan cover, causing friction noise.

Innovation Solution

A suction unit design featuring a noise reduction part with multiple flow paths, a shaft coupling part with screw threads for secure impeller attachment, and a guide mechanism with a bearing to prevent impeller separation and contact with the cover, reducing noise and ensuring proper airflow.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the rotating shaft is coupled to the impeller using adhesive, then the assembly is simple, but the impeller may separate or run idle when adhesion is reduced

Engineering Contradiction:
Improveassembly simplicityVSAvoidimpeller coupling reliability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent replaces the adhesive coupling method with a mechanical coupling system consisting of a coupling member with external threads that engages with internal threads in the impeller hub. This mechanical thread engagement provides reliable coupling without relying on adhesive bonds, preventing impeller separation and idle rotation while maintaining assembly simplicity.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Device complexity

If air is introduced through a single suction hole, then the structure is simple, but flow noise is generated due to uneven air distribution

Engineering Contradiction:
Improveair inlet structure complexityVSAvoidflow noise
Core Design Contradiction:
Device complexityVSObject-generated harmful factors

Solution Approach 1:

The patent divides the single suction hole into multiple suction holes (first suction hole and second suction hole) positioned at different locations. This segmentation allows air to be drawn from multiple positions simultaneously, creating more uniform airflow distribution and reducing turbulent flow noise while maintaining relatively simple structure.

Inventive Principle:
Principle #1Segmentation

3Ease of operation

If the rotating shaft is inserted into the guide member with a gap, then the rotating shaft can move freely, but the impeller contacts the fan cover causing friction noise

Engineering Contradiction:
Improverotating shaft movement freedomVSAvoidfriction noise
Core Design Contradiction:
Ease of operationVSObject-generated harmful factors

Solution Approach 1:

The patent introduces a bearing as an intermediary component between the rotating shaft and the guide member. The bearing allows the rotating shaft to rotate freely while constraining radial movement, preventing the impeller from contacting the fan cover and eliminating friction noise while maintaining rotational freedom.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Reliability

If the impeller hub diameter is large, then the shaft coupling part is securely held, but the impeller cannot pass through the guide mechanism

Engineering Contradiction:
Improveshaft coupling retentionVSAvoidimpeller passage capability
Core Design Contradiction:
ReliabilityVSLength of moving object

Solution Approach 1:

The patent segments the impeller structure by creating a through-hole in the impeller hub that allows the rotating shaft to pass through. The shaft coupling member is positioned within this through-hole and secured using threaded engagement, providing reliable coupling while maintaining a compact profile that allows the impeller assembly to pass through the guide mechanism.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP3345522B1Suction unit
Publication Date: 2020.03.18 LG ELECTRONICS INC
  • EP3345522B1 patent drawingFigure 1
  • EP3345522B1 patent drawingFigure 2
  • EP3345522B1 patent drawingFigure 3

AI summary

The suction unit comprises: a cover having an air inlet; a noise reduction part provided in the cover, arranged outside the air inlet and spaced therefrom; an impeller for flowing the air which has passed through the noise reduction part and then the air inlet; a motor having a rotating shaft connected to the impeller; a guide apparatus for guiding the flow of the air which has flown from the exit of the impeller; and a shaft coupling part coupled to the rotating shaft connected to the impeller.