Disk Drive Base Cover Structure for Airtight Welding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In magnetic disk drives, achieving high airtightness while maintaining stable welding quality is challenging due to the need for thinner sidewalls, which reduces the area for welding and can degrade the welding quality, especially when increasing the diameter of the magnetic disk.
Innovation Solution
The design incorporates a fixing rib with alternating regions of different widths and chamfered surfaces on the base, allowing for a consistent welding surface width and maintaining high welding quality by using recessed areas for the outer cover attachment, ensuring reliable sealing and increased storage capacity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the sidewall thickness is reduced to increase magnetic disk diameter, then the storage capacity is improved, but the welding quality deteriorates due to reduced welding area
Solution Approach 1:
The base is designed with a fixing rib that has different width regions: a first width in the radial direction away from the magnetic disk, and a second width closer to the magnetic disk. This local variation in geometry allows the welding surface width to be maintained at critical locations while accommodating the overall thinning of the sidewall for larger disk capacity.
Solution Approach 2:
The fixing rib incorporates chamfered surfaces that extend in the axial direction, adding a dimensional element to the welding surface. This allows the welding area to be sufficient not just in the radial plane but also in the axial dimension, compensating for the reduced sidewall thickness.
2Volume of moving object
If the sidewall thickness is reduced, then the magnetic disk diameter can be increased, but the airtightness may be compromised due to weaker welding
Solution Approach 1:
The fixing rib provides localized structural reinforcement at the welding interface between the base and outer cover. By concentrating material and creating a wider welding surface at specific locations (first width region), the design ensures reliable airtight sealing even when the overall sidewall is thinned to accommodate larger magnetic disks.
Solution Approach 2:
The chamfered surfaces are pre-formed on the fixing rib to prepare an optimal welding surface geometry before the welding process. This preliminary preparation ensures that the welding operation can achieve high-quality, airtight joints despite the thin sidewall conditions.
3Device complexity
If the welding area is reduced due to thinner sidewalls, then the device complexity is reduced, but the manufacturing precision of the welding joint deteriorates
Solution Approach 1:
Rather than uniformly thickening the entire sidewall (which would increase overall complexity), the design applies local geometric features (fixing rib with varying width and chamfered surfaces) only where welding is required. This maintains simplicity in the bulk structure while providing enhanced welding capability at critical interfaces.
Data Source
AI summary
According to one embodiment, a disk device includes a recording medium, a base accommodating the recording medium, the base including a bottom wall, a sidewall on a peripheral portion of the bottom wall, and a rib on a part of an upper surface of the sidewall, a first cover on a part of the upper surface of the sidewall, and a second cover on the rib and above the first cover. The rib includes a first region with a first chamfered surface with a first chamfered width and a second region with a second chamfered surface with a second chamfered width which is less than the first chamfered width. The first region and the second region are located corresponding to a side portion of the recording medium.