Fan Wheel Balancing Ring Outside Airflow Path

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Solution Overview

Problem

Existing fan wheels with balancing elements in axial or diagonal fans face challenges such as noise disturbances and deformation due to balancing elements being placed in the air flow path, which affects acoustics and strength, and the complexity of arranging balancing elements in fan blades.

Innovation Solution

A fan wheel design featuring a balancing ring around the centrifugal ring with a free axial edge for mounting balancing weights, positioned outside the air flow path, which enhances the strength and rigidity of the centrifugal ring, allowing for easy one-sided mounting of balancing weights without compromising acoustics or mechanical integrity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If balancing elements are arranged in the nozzle gap between inlet nozzle and centrifugal ring, then imbalance can be compensated, but flow path is disturbed causing noise and affecting acoustics

Engineering Contradiction:
Improvebalancing capabilityVSAvoidnoise and flow disturbance
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The balancing elements are extracted from the nozzle gap area and relocated to the outer lateral surface of the centrifugal ring. This separation removes the disturbing factor (balancing elements) from the sensitive area (flow path) while preserving the useful function (balancing capability). The balancing weights remain effective at compensating imbalance but no longer interfere with air flow or generate noise.

Inventive Principle:
Principle #2Taking out (Extraction)

2Shape

If balancing pockets are arranged in fan blades, then outer geometry is preserved, but implementation becomes very complex

Engineering Contradiction:
Improveouter geometryVSAvoidimplementation complexity
Core Design Contradiction:
ShapeVSEase of manufacture

Solution Approach 1:

The balancing elements are moved from the radial dimension (within fan blades) to the axial dimension (outer surface of centrifugal ring). This dimensional shift allows balancing weights to be mounted on the external surface of the centrifugal ring rather than embedding them within blade structures, significantly simplifying manufacturing and assembly while maintaining geometric integrity.

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

3Reliability

If balancing elements are placed in radial wheels, then balancing can be achieved, but elements cannot be plugged in exclusively from one side

Engineering Contradiction:
Improvebalancing functionVSAvoidmounting accessibility
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The outer lateral surface of the centrifugal ring serves as an intermediary mounting surface that provides accessible engagement for balancing elements. This intermediate structure allows balancing weights to be attached from the external side without requiring disassembly or access to the internal structure of the fan wheel, enabling one-sided mounting while maintaining effective balancing function.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Weight of moving object

If centrifugal ring is made thinner to reduce weight, then material usage decreases, but strength and ability to withstand mechanical loads decreases

Engineering Contradiction:
Improvecentrifugal ring weightVSAvoidmechanical load capacity
Core Design Contradiction:
Weight of moving objectVSStrength

Solution Approach 1:

The centrifugal ring is constructed using composite material technology that combines different materials or material structures to achieve high strength-to-weight ratio. This allows the ring to maintain reduced weight while compensating for the strength loss that would normally accompany thinning, thereby satisfying both weight reduction and mechanical strength requirements simultaneously.

Inventive Principle:
Principle #40Composite materials

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 design effectively compensates for imbalance without affecting the fan's acoustics or strength, improving the fan's mechanical load-bearing capacity and reducing the risk of component failure, while allowing for easy assembly and reduced manufacturing costs.

Implementation Method 1

a deformation of the centrifugal ring is favored by centrifugal forces

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Data Source

PatentEP3872351A1Fan wheel of an axial or diagonal fan with a balancing ring
Publication Date: 2021.09.01 EBM PAPST MULFINGEN GMBH & CO KG
  • EP3872351A1 patent drawingFigure 1
  • EP3872351A1 patent drawingFigure 2
  • EP3872351A1 patent drawingFigure 3

AI summary

The invention relates to a fan wheel of an axial or diagonal fan with a hub and a plurality of impeller blades arranged around a rotational axis of the fan wheel, which extend radially outwards from the hub and whose radially outer end is enclosed by a circumferential centrifugal ring, wherein at least one balancing ring circumferentially surrounding the centrifugal ring is provided on the centrifugal ring, which is designed with a free axial edge for the fastening arrangement of at least one balancing weight.