Bidirectional Hydrodynamic Rotary Seal With Offset Lip Waves
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Solution Overview
Problem
Existing hydrodynamic rotary seals face challenges in minimizing width while maintaining effective sealing capabilities for high pressure and high speed applications, particularly in bidirectional rotation scenarios.
Innovation Solution
The development of a specially configured mold and manufacturing process that produces a compact rotary seal with hydrodynamic waves on both sides of the dynamic lip, offsetting these waves to minimize axial width and ensure efficient lubrication and sealing, using a plastic liner to prevent elastomer migration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If the seal width is minimized to reduce size, then the axial width decreases, but the sealing capability under high pressure and high speed conditions deteriorates
Solution Approach 1:
The seal is segmented into multiple functional zones along its axial width, with hydrodynamic waves positioned at specific locations to create distinct lubrication and sealing zones. This segmentation allows each portion of the seal to perform optimized functions, maintaining high-pressure sealing capability while reducing overall axial width.
Solution Approach 2:
The invention transitions from a single-plane sealing approach to a three-dimensional hydrodynamic wave structure that utilizes axial, radial, and circumferential dimensions simultaneously. The offset hydrodynamic waves create a volumetric sealing zone that provides effective sealing with reduced axial width.
2Reliability
If hydrodynamic waves are added to both sides of the dynamic lip to improve bidirectional sealing, then the sealing performance improves, but the axial width increases
Solution Approach 1:
The hydrodynamic waves on both sides of the dynamic lip are merged into a coordinated offset pattern, where the wave troughs and peaks are strategically positioned relative to each other. This merging creates an interlocking hydrodynamic system that provides bidirectional sealing while minimizing the axial space required through constructive interference of the wave patterns.
Solution Approach 2:
The hydrodynamic waves are positioned asymmetrically with offsets between the two sides, creating different wave patterns on each side of the dynamic lip. This asymmetric configuration optimizes lubrication and sealing for bidirectional rotation while maintaining compact axial dimensions through non-uniform wave distribution.
3Adaptability or versatility
If elastomer is used for sealing flexibility, then the sealing adaptability improves, but elastomer migration onto critical surfaces occurs
Solution Approach 1:
The elastomer material is extracted from the critical radial inward-facing portions of the dynamic lip where migration would occur. By removing elastomer from these specific locations and retaining it only where flexibility is needed, the invention maintains sealing adaptability while eliminating the harmful migration effect onto critical surfaces.
Solution Approach 2:
The seal structure implements local quality by providing elastomer material only in specific zones where flexibility is required, while using plastic or other migration-resistant materials in zones where elastomer migration would be harmful. This localized material distribution maintains sealing flexibility in critical areas while preventing migration onto radially inward-facing surfaces.
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 solution achieves a narrow rotary seal design that effectively seals and lubricates under varying pressures, reducing friction and wear, even in high-pressure and high-speed conditions.
Implementation Method 1
when the pressure of the first fluid exceeds the pressure of the second fluid, the geometry of the seal interacts with the first fluid during relative rotation to wedge a lubricating film of the first fluid into the dynamic sealing interface
Implementation Method 2
when the pressure of the second fluid exceeds the pressure of the first fluid the geometry of the seal interacts with the second fluid during relative rotation to wedge a lubricating film of the second fluid into the dynamic sealing interface
Data Source
AI summary
A seal configuration, mold and manufacturing process that inhibits undesirable elastomer migration onto critical radially inwardly facing portions of a plastic-lined dynamic sealing lip, for improved high-pressure seal operation. The seal configuration is a hydrodynamically lubricating rotary seal for differential pressure acting in either axial direction that establishes compressed sealing engagement with a relatively rotatable surface and wedges a film of lubricating fluid into the interface between the rotary seal and the relatively rotatable surface in response to relative rotation that may occur in the clockwise or counter-clockwise direction. The rotary seal having a dynamic lip with hydrodynamic waves on both sides of the dynamic lip with the axial width of the seal minimized while maximizing the axial width of the dynamic sealing surface.