Canted Torus Spring Seal Support Against Elastomer Extrusion
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Solution Overview
Problem
Existing extrusion preventing devices in well tool sealing elements, such as coiled springs, fail to maintain structural integrity under high pressures and temperatures, allowing elastomeric material to extrude through increasing gaps between turns when the device expands.
Innovation Solution
A torus-shaped coiled spring with canted turns is integrated into the sealing element, ensuring all turns are canted in the same direction in both the run and set states, preventing material extrusion by maintaining consistent spacing and structural stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a coiled spring is used as an extrusion preventing device, then the sealing element can be made flexible and expandable, but gaps between turns increase when expanded allowing material extrusion
Solution Approach 1:
The patent applies asymmetry by canting the turns of the coiled spring in a specific direction rather than having them symmetrically aligned. This canting creates an asymmetric structure where the spacing between adjacent turns is reduced and maintained consistently during expansion, preventing elastomeric material from extruding through the gaps while preserving the expandability of the sealing element.
2Duration of action of moving object
If the coiled spring expands when the sealing element is set, then it can accommodate the radial expansion, but the gaps between turns increase allowing extrusion
Solution Approach 1:
The asymmetric canting of spring turns is designed to maintain consistent spacing between adjacent turns during the expansion process. The canting angle is specifically chosen so that as the spring expands radially, the turns remain closely spaced in the axial direction, preventing harmful material extrusion while allowing the necessary radial expansion for sealing functionality.
3Ease of manufacture
If straight turns are used in the coiled spring, then manufacturing is simpler, but gaps between turns allow material to extrude under high pressure
Solution Approach 1:
While the canted turns require slightly more complex manufacturing than straight turns, the patent maintains ease of manufacture by using a systematic canting approach that can be achieved through standard spring winding equipment with adjusted parameters. The asymmetric canting significantly improves resistance to material extrusion by eliminating large gaps between turns, achieving a favorable balance between manufacturability and extrusion resistance.
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 canted torus-shaped coiled spring effectively enhances the pressure and temperature ratings of well tool devices by preventing material extrusion and ensuring reliable sealing, even under high differential pressures.
Implementation Method 1
The extrusion preventing device comprises a wire wound with a plurality of turns to form a torus-shaped coiled spring
Implementation Method 2
preventing material extrusion by maintaining consistent spacing and structural stability under high differential pressures
Data Source
Figure 1a~1b
Figure 1c~1d
Figure 2a~2f
AI summary
The present invention relates to an extrusion preventing device (10) for incorporation into a sealing element (7) of a well tool device (1). The extrusion preventing device (10) comprises a wire (11) wound with a plurality of turns (T1, T2, T3,..., Tn) to form a torus-shaped coiled spring (12). Each turn of the torus-shaped coiled spring (12) is canted.