Removable External Labyrinth Path for Helium Servo Writing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current disk drive designs face challenges in efficiently introducing and maintaining alternative gases like helium during manufacturing, particularly for servo track writing, due to issues with gas leakage and pressure changes, which complicates high-volume manufacturing and increases costs.
Innovation Solution
The implementation of a removable external labyrinth path in conjunction with a breather filter and labyrinth seal layer within the disk drive enclosure, allowing for controlled gas flow and diffusion, enables the temporary introduction of alternative gases during specific processes while maintaining air-filled conditions for operational use.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the disk drive is hermetically sealed to contain alternative gas like helium, then gas leakage is prevented and servo track writing precision is improved, but manufacturing complexity increases and hermetic sealing costs increase
Solution Approach 1:
The gas flow path is segmented into multiple components: breather port, breather filter, and labyrinth path. This segmentation allows each component to perform its specific function independently while collectively achieving gas flow control without hermetic sealing.
Solution Approach 2:
The labyrinth path acts as an intermediary structure between the internal disk drive environment and external atmosphere. It mediates gas flow by providing a controlled diffusion path that limits exchange rates without requiring complete sealing.
2Ease of manufacture
If the disk drive is air-filled with a breather filter and breather port, then manufacturing is simplified and pressure equilibration is achieved, but gas diffusion and flow rates are difficult to control during servo track writing
Solution Approach 1:
The labyrinth path introduces localized structural features (narrow passages, turns, and bends) at specific locations in the gas flow path. These local modifications create resistance to gas flow and diffusion without affecting the overall breather filter design or pressure equilibration function.
Solution Approach 2:
The labyrinth path provides dynamic control over gas exchange rates. The complex path geometry creates variable flow resistance that adapts to pressure differences, allowing controlled gas diffusion during servo track writing while maintaining pressure equilibration during normal operation.
3Productivity
If the top cover is removed or left open to change gas quickly, then gas replacement efficiency is improved, but the disk drive becomes unsuitable for use outside clean environment
Solution Approach 1:
The labyrinth path is pre-configured in the breather filter assembly before gas replacement operations. This preliminary structure is ready to control gas flow immediately when the cover is opened, preventing uncontrolled exposure while allowing efficient gas exchange.
Solution Approach 2:
The breather filter assembly with labyrinth path acts as a flexible gas control interface. It allows the cover to be opened for gas replacement while the filter and labyrinth structure maintain protection against contamination during the transition period.
4Manufacturing precision
If alternative gas like helium is introduced during servo track writing, then servo track positioning precision is improved and flying height is reduced, but gas leakage causes pressure drop and cover deflection
Solution Approach 1:
The labyrinth path is designed in advance to counteract potential pressure loss during helium introduction. Its flow-resisting structure prevents excessive helium leakage, maintaining pressure stability throughout the servo track writing process.
Solution Approach 2:
The labyrinth path provides a buffer against pressure fluctuations by creating flow resistance. This cushioning effect absorbs pressure variations that would otherwise cause cover deflection during gas replacement and servo writing operations.
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 solution effectively reduces gas leakage and pressure fluctuations, allowing for precise servo track writing and increased data storage densities without the need for hermetic sealing, thus enhancing manufacturing efficiency and reducing costs.
Implementation Method 1
The fluid communication between the interior of the disk drive and the external environment (through the breather filter and breather port) may also be required to pass through a narrow passage referred to as a 'labyrinth path' in order to limit the rate of flow and/or diffusion.
Implementation Method 2
Helium may also be used, for example, because it has higher thermal conductivity than air, and therefore may improve disk drive cooling.
Implementation Method 3
because the air bearing thickness depends on the gas viscosity and density, the air bearing thickness may be advantageously reduced in helium relative to air... because helium has lower density than air, it may not buffet components within the disk drive as much, which may reduce track misregistration and thereby improve track following capability
Data Source
AI summary
A disk drive includes an enclosure that has a breather port therethrough. A first labyrinth path may be disposed inside the disk drive enclosure, in fluid connection with the breather port. A second labyrinth path may be temporarily disposed outside the disk drive enclosure, in fluid connection with the breather port. An alternative gas such as helium may be allowed to bleed out through the second labyrinth path during a period of servo track writing. The second labyrinth path may be removed after servo track writing.