V-Pack Seal Bi-Directional Cut Design
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Solution Overview
Problem
Existing V-pack seals on shafts face issues with overlapping cut ends during installation, leading to premature failure and air pockets that compromise the seal's integrity, especially under temperature and pressure changes in submarine applications.
Innovation Solution
A novel bi-directional cut design for V-pack rings, where one cut extends from the top to the shoulder at 45 degrees and a longer second cut from the bottom intersects the first at the shoulder, ensuring proper seating and preventing overlapping, thereby creating a secure and liquid-tight seal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a single diagonal cut is used on V-pack rings, then the installation process is simple, but the free ends of the cut material overlap and ride up on each other causing premature seal failure
Solution Approach 1:
The single diagonal cut is segmented into multiple cuts (first cut from top shoulder to bottom, second cut from top shoulder to side) that create separate end portions. This segmentation prevents the overlapping and riding-up problem while maintaining installation simplicity.
Solution Approach 2:
The cut pattern is made asymmetric with the first cut extending further than the second cut, creating offset arrow-shaped ends that mate in a specific direction. This asymmetry prevents overlapping while guiding proper installation orientation.
2Reliability
If multiple rings of V-pack material are stacked with overlapping ends, then the seal can be created, but air pockets are trapped between layers causing seal unseating under temperature and pressure changes
Solution Approach 1:
The cut pattern segments the ring into portions that interlock in a specific sequence, ensuring that when multiple rings are stacked, the end portions mate properly without creating gaps or air pockets between layers.
Solution Approach 2:
The offset arrow-shaped ends of successive rings are designed to nest within each other in a specific orientation, creating a tight interlocked structure that eliminates air pockets while allowing proper seating under compression.
3Productivity
If the free ends of V-pack material do not seat properly about the shaft, then installation is faster, but a liquid tight seal is not achieved allowing seawater migration
Solution Approach 1:
The asymmetric cut pattern creates offset arrow-shaped ends that can only mate in the correct orientation, providing visual and physical guidance for proper installation while ensuring liquid-tight seal formation.
Solution Approach 2:
The cut pattern is designed in advance to create self-aligning end portions that automatically orient correctly during installation, eliminating the need for complex alignment procedures while ensuring proper seating.
Data Source
AI summary
An improved shaft seal includes a plurality of V-pack rings that each includes a bi-directional cut with cuts of unequal lengths. An upper cut extends from the top of the V-pack ring to the shoulder. A lower cut extends from the bottom of the V-pack to the shoulder and is longer in length than the upper cut.