Ventilator Wheel With Irregular Blade Spacing

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Solution Overview

Problem

Existing fan designs fail to effectively improve cooling capacity while minimizing environmental noise pollution and resonance effects with regular blade arrangements, which lead to inefficient airflow and increased noise levels.

Innovation Solution

The fan wheel features irregularly spaced fan blades with varying angular distances, forming air ducts with a minimum cross-section for directed airflow and reduced noise, along with a base body and air guide ring that facilitate easy manufacturing and efficient air flow, allowing for reduced noise pollution and improved cooling capacity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If fan blades are arranged regularly in the circumferential direction, then the structural simplicity and ease of manufacture are improved, but the noise level and vibration excitations increase due to higher frequency components

Engineering Contradiction:
Improveease of manufactureVSAvoidnoise level
Core Design Contradiction:
Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The patent applies asymmetry by arranging fan blades at irregular angular distances from each other in the circumferential direction. Specifically, the angular distance between adjacent fan blades varies, with some gaps being smaller and others larger, breaking the regular periodic pattern. This asymmetric arrangement reduces the frequency of vibration excitations and noise emissions, as the main frequency component becomes lower compared to regular spacing, thereby addressing the noise issue while maintaining manufacturing feasibility.

Inventive Principle:
Principle #4Asymmetry

2Object-affected harmful factors

If fan blades are spaced irregularly to reduce noise, then the noise pollution and vibration excitations are reduced, but the manufacturing complexity increases

Engineering Contradiction:
Improvenoise pollutionVSAvoiddevice complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent applies local quality by creating specific local variations in the angular spacing between fan blades while maintaining overall structural simplicity. The irregular spacing is implemented as a localized feature in the circumferential arrangement, where specific blades are positioned at non-uniform intervals. This approach reduces noise pollution by lowering vibration frequency without requiring complete redesign of the entire fan structure, thus limiting the increase in manufacturing complexity to only the blade positioning aspect.

Inventive Principle:
Principle #3Local quality

3Productivity

If the cross section of air duct is minimized to create nozzle effect, then the directed airflow and cooling capacity are improved, but the air duct dimensions are reduced

Engineering Contradiction:
Improvecooling capacityVSAvoidair duct cross section
Core Design Contradiction:
ProductivityVSArea of moving object

Solution Approach 1:

The patent applies periodic action through the irregular angular spacing of fan blades, which creates a periodic but non-uniform flow pattern through the air ducts. The varying angular distances between blades generate a sequence of excitations with a period greater than one nth of the revolution time, where n is the number of blades. This periodic variation in blade positioning creates a nozzle-like effect that directs airflow radially outward while maintaining reduced cross-sectional area, thereby improving cooling capacity without requiring large duct dimensions.

Inventive Principle:
Principle #19Periodic action

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

The solution results in a significant reduction of noise pollution by lowering the main frequency component of vibration excitations below the audible limit, enhancing cooling performance, and reducing material usage for the air guide ring, thus minimizing stress on bearings and material imbalance.

Implementation Method 1

the fan blades generate periodic excitations, the main frequency component of which is lower than would be the case if all angular distances were the same size

Methodology Applied
Scientific EffectPeriodic excitation: Vibration

Implementation Method 2

Air channels with a nozzle effect are thus formed. These nozzles advantageously bring about a directed flow of the cooling air

Methodology Applied
Scientific EffectNozzle effect: Venturi Effect

Data Source

PatentEP2122181B1Ventilator wheel, system and transmission line
Publication Date: 2018.06.27 SEW EURODRIVE GMBH & CO KG
  • EP2122181B1 patent drawingFigure 1
  • EP2122181B1 patent drawingFigure 2
  • EP2122181B1 patent drawingFigure 3

AI summary

A ventilator wheel is provided with a convex air guiding ring (12) which forms, together with a base body (10) of the ventilator wheel and ventilator blades (11), nozzle-type air channels. Said air channels extend along the periphery in irregular angular positions.