Damper Vane and Housing Geometry for Low Air Leakage
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Solution Overview
Problem
Dampers in closed positions allow airflow around the edges due to gaps between the vane and the housing, leading to inefficiencies in air flow stoppage and potential wear and noise from misaligned tolerances.
Innovation Solution
The damper design incorporates recessed areas and raised ridges in the housing to accommodate a larger vane, reducing airflow in the closed position while allowing for greater tolerances during rotation, with longitudinal channels and ridges on the sidewalls to minimize air leakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the vane is made larger to minimize air passage around the edges in closed position, then air flow stoppage capability is improved, but manufacturing precision requirements become more critical and the vane may contact the frame during rotation
Solution Approach 1:
The housing is segmented into different regions: a first region with a first width that receives the vane, and a second region with a second width that is greater than the first width. This segmentation allows the vane to be larger for better air sealing while providing additional space in the second region to accommodate manufacturing tolerances and prevent contact during rotation.
Solution Approach 2:
The patent introduces a dimensional variation in the housing width along the airflow direction. By creating a housing that is wider in the second region compared to the first region, the design adds a dimensional solution that resolves the conflict between vane size and tolerance requirements.
2Reliability
If a gap is left around the edge of the vane to prevent contact with the frame during rotation, then reliability is improved, but air passage around the vane increases reducing air flow stoppage capability
Solution Approach 1:
The housing cross-section is segmented into a first region with smaller width for tight vane clearance and a second region with larger width for tolerance accommodation. This spatial segmentation allows different functional requirements to be met in different regions simultaneously.
3Loss of energy
If the housing width is reduced to minimize gap around the vane, then air flow stoppage is improved, but the housing cannot accommodate manufacturing tolerances and the vane may rub on the housing walls
Solution Approach 1:
The patent varies the housing width dimension along the airflow direction, creating a tapered or stepped profile. The housing is narrower at the inlet end and wider at the outlet end, providing both tight clearance for air sealing and sufficient space for tolerance accommodation.
Data Source
AI summary
A damper having a housing includes a rotatable damper vane therein constructed to minimize the passage of air between the vane and the housing when the vane is in a closed position. The housing includes a pair of opposed walls having a channel or flute therein adjacent outer edges of the vane when the vane is in the closed position. The outer edges of the vane terminate in domed or arcuate shaped surfaces that generally correspond with the channel. The arcuate shaped surfaces are a distance apart that is greater than a distance between the opposed walls such that the arcuate shaped surfaces are received in the channels when the vane is in the closed position. The housing also includes a pair of opposed sidewalls having a ridge therein at a location that aligns with an edge of the vane when the vane is in the closed position.