Injection-Molded Hard Drive Cover With Metal-Reinforced Seal Flange
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Solution Overview
Problem
Existing hard drive top covers made from injection molded polymers face issues with viscoelastic creep, leading to relaxation of sealing pressure and potential leakage due to lack of reinforcement at screw locations, which compromises the seal's effectiveness over time.
Innovation Solution
Incorporating an injection molded metallic strip within the polymeric flange portion of the top cover, specifically between screw locations, to maintain consistent and non-relaxing pressure on the seal element, which can be convexly curved to enhance pressure distribution and feature apertures for improved bonding with the polymer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If an injection molded polymeric cover is used, then manufacturing cost is reduced and ease of manufacture is improved, but sealing pressure relaxes over time due to viscoelastic creep
Solution Approach 1:
The patent combines polymeric material with metallic reinforcement elements to create a composite structure. The metallic strips or rings are embedded within the polymeric flange portion, providing structural support and preventing viscoelastic creep while maintaining the cost advantages of injection molded polymer construction.
Solution Approach 2:
The patent applies reinforcement selectively at critical locations where sealing pressure must be maintained, such as the flange portion and areas surrounding screw holes. This localized reinforcement prevents creep at stress concentration points without requiring reinforcement throughout the entire cover structure.
2Reliability
If the polymeric cover is reinforced with metallic strips, then sealing pressure is maintained and reliability is improved, but device complexity increases
Solution Approach 1:
The patent merges the polymeric cover and metallic reinforcement elements into a single integrated component through insertion injection molding. This process combines multiple manufacturing steps into one, reducing assembly complexity while maintaining the structural benefits of the composite construction.
Solution Approach 2:
The metallic reinforcement elements are designed to work passively within the polymeric structure, providing creep resistance and sealing pressure maintenance without requiring active control mechanisms or additional components. The structure serves its own reinforcement needs through the embedded metallic elements.
3Manufacturing precision
If metallic reinforcement is added to the flange, then contact pressure uniformity is improved and sealing is enhanced, but manufacturing complexity increases
Solution Approach 1:
The metallic reinforcement elements act as intermediaries between the screw fastening points and the seal interface, distributing the clamping force uniformly across the flange portion. This mediation ensures consistent contact pressure on the seal element without requiring complex pressure control mechanisms.
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 ensures a reliable, long-lasting seal by maintaining uniform contact pressure on the seal element, preventing moisture, gas, and dust ingress into the hard drive, while minimizing vibrational coupling and providing electromagnetic interference shielding.
Implementation Method 1
Since polymers are generally viscoelastic bodies, the force applied by screws in clamping the hard disk top cover against a seal on bottom base member thereby applying sealing pressure. However, the seal pressure relaxes between the screws locations due to viscoelastic creep thereby relieving the sealing pressure.
Data Source
AI summary
Provided herein is a low cost high performance light weight hard drive cover that is injection molded. The hard drive top cover has a flange portion that applies pressure to an elastomeric seal preventing ingress of moisture dust and other contaminants into the sensitive components. The flange portion is reinforced with a plurality of metallic strips that are placed between pressure application locations embedded within the polymer flange. The viscoelastic creep response of the polymer flange does not contribute to relaxation of pressure on the elastomeric seal due to the presence of the metallic reinforcement strips. The metallic reinforcement strips may have a convex curvature between pressure application locations. The metallic reinforcement strip may have apertures for passage of injection molded polymer creating delamination free intimate bond between the polymer in the flange and the metallic reinforcement strip.