Vent Filter Structure for Clean Airflow and Low Pressure Loss
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Solution Overview
Problem
Existing vent filters for hard disk drives suffer from contamination issues due to weld flash and dust generated during attachment, and have limited diffusion efficiency and high pressure loss, making them unsuitable for maintaining high air cleanliness.
Innovation Solution
A vent filter design featuring an adhesive layer with through-holes, a flow path member with a path flow, and an air-permeable membrane where the flow path member is held within a hollow portion between the adhesive layer and the membrane, allowing for high diffusion efficiency and low pressure loss, with optional features like gas adsorbents and a fluororesin membrane.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If thermal fusion bonding or ultrasonic welding is used to attach the air-permeable membrane and plastic housing, then the components are securely attached, but weld flash and dust are generated during the attachment process, decreasing air cleanliness within the HDD
Solution Approach 1:
The patent extracts the harmful attachment processes (thermal fusion bonding and ultrasonic welding) from the vent filter assembly. Instead of using these contamination-generating methods, the invention employs adhesive bonding that does not produce weld flash or dust, thereby maintaining high air cleanliness while still achieving secure attachment of the air-permeable membrane and plastic housing components
Solution Approach 2:
The patent introduces an adhesive as an intermediary substance to bond the air-permeable membrane and plastic housing components. This adhesive mediator replaces the direct thermal or ultrasonic contact methods, enabling secure attachment without generating contaminating byproducts like weld flash or dust particles that would compromise HDD air cleanliness
2Device complexity
If the diffusion flow path is formed by punching openings in a thin double-sided pressure-sensitive adhesive tape, then the structure is simple, but it is difficult to lengthen or complicate the diffusion flow path and the cross-sectional area is limited by the tape thickness, resulting in low diffusion efficiency and high pressure loss
Solution Approach 1:
The patent segments the vent filter into multiple functional layers including a base layer with through-holes, an adhesive layer, and an air-permeable membrane layer. This segmentation allows each layer to contribute to the overall diffusion function while enabling a more complex and efficient three-dimensional flow path structure that overcomes the limitations of flat adhesive tape
Solution Approach 2:
The patent transitions from the two-dimensional flat structure of punched adhesive tape to a three-dimensional multi-layer construction. By stacking layers and creating vertical flow paths through the thickness of the assembly, the invention significantly increases the diffusion flow path length and cross-sectional area available for gas distribution, thereby improving diffusion efficiency and reducing pressure loss
3Productivity
If a long and complicated diffusion flow path is needed to improve diffusion efficiency, then the flow path length must be increased, but this increases the pressure loss in the vent filter
Solution Approach 1:
The patent utilizes the third dimension (vertical thickness) to create flow paths that are long in terms of diffusion distance but compact in horizontal footprint. By distributing flow paths across multiple layers and utilizing vertical flow components, the system achieves extended diffusion paths without proportionally increasing pressure loss, as the flow moves through a more efficient three-dimensional geometry rather than a long linear path
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 design effectively reduces contaminants entering the housing, maintains high air cleanliness, and prevents gas leakage by allowing flexible adhesion to the housing, even under deformation, while enhancing diffusion efficiency and reducing pressure loss.
Implementation Method 1
an adhesive layer (1) having a through-hole (1a) at least in one area; a flow path member (2) provided with a flow path (2a) in communication with the through-hole (1a); and an air-permeable membrane (3) covering the flow path member (2) and part of the adhesive layer (1), wherein a peripheral portion of the air-permeable membrane (3) is fixed to the adhesive layer (1) and the flow path member (2) is held within a hollow portion formed between the adhesive layer (1) and the air-permeable membrane (3)
Implementation Method 2
an air-permeable membrane (3) covering the flow path member (2) and part of the adhesive layer (1)
Data Source
AI summary
It is an object to provide a vent filer that can reduce contaminants diffusing through the vent filter into the inside of a housing, and has high diffusion efficiency and low pressure loss. The vent filter has an adhesive layer 1 having a through-hole 1a at least in one area; a flow path member 2 provided with a flow path 2a in communication with the through-hole 1a; and an air-permeable membrane 3 covering the flow path member 2 and part of the adhesive layer 1, wherein the peripheral portion 3a of the air-permeable membrane 3 is fixed to the adhesive layer 1 and the flow path member 2 is held within a hollow portion formed between the adhesive layer 1 and the air-permeable membrane 3.