Adjustable Tip Clearance Cooling Fan Design
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Solution Overview
Problem
Existing axial flow fans face challenges in increasing airflow volume without increasing operating speed, which can lead to increased noise, vibration, and reduced component life due to large tip clearances and manufacturing tolerances.
Innovation Solution
A cooling fan design with a tip clearance reduction system that allows adjustable tip clearance during assembly, using mechanisms such as adjustable blade assemblies, inserts, and alignment rings to minimize tip clearance and optimize blade diameter, thereby enhancing airflow efficiency and reducing noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If fan speed is increased to increase airflow volume, then airflow volume is improved, but noise and vibration increase and component life decreases
Solution Approach 1:
The patent changes the geometric parameters of the blade tips by adding curved tip extensions that increase the effective blade diameter and surface area without increasing rotational speed. This allows the fan to move more air (increased CFM) while maintaining lower operating speeds, thereby reducing noise and vibration. The tip extensions modify the airflow characteristics and increase the volumetric displacement of each rotation.
2Volume of moving object
If fan size is reduced to meet space constraints, then device compactness is improved, but airflow volume decreases
Solution Approach 1:
The patent extends the blade tips in a radial direction outward from the hub, utilizing the available radial space within the housing. This dimensional extension increases the effective blade diameter and swept area without increasing the axial height or overall fan housing dimensions. The curved tip extensions optimize the use of radial space to maximize airflow volume within compact constraints.
3Ease of manufacture
If manufacturing tolerances are loose to reduce cost, then ease of manufacture is improved, but tip clearance increases and airflow efficiency decreases
Solution Approach 1:
The patent introduces an adjustable tip clearance mechanism that allows the blade assembly to be positioned at different radial distances from the housing wall. This dynamic adjustment capability compensates for variations in manufacturing tolerances of individual components, enabling the achievement of optimal tight tip clearances even when using standard, cost-effective manufacturing processes. The adjustability ensures consistent airflow efficiency across production batches.
Data Source
AI summary
A cooling fan comprising a fan housing and a plurality of blades rotatably disposed within a conduit through the fan housing. Each of the plurality of blades extends radially outward from a hub to a tip. The radial gap between the tips of the blades and the conduit defines a tip clearance. The cooling fan further comprises an tip clearance reduction system operable to control the tip clearance.