Tilting Floating Lip Seal for Shaft Misalignment and Radial Deflection
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Solution Overview
Problem
Existing radially floating lip seals are ineffective for cantilever rotating shafts due to significant radial displacements and misalignments, leading to increased cost and wear.
Innovation Solution
A tilting lip seal design with a seal ring assembly and flexible axial arms that accommodate radial deflections and misalignments by tilting relative to the housing bore, using elastic axial lips or U-shaped springs to maintain a seal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a fixed lip seal is used, then the seal maintains coaxial alignment with the housing bore, but it cannot accommodate large radial deflections of the shaft
Solution Approach 1:
The seal ring is made dynamically movable relative to the housing bore through rolling O-ring seals, allowing it to float radially and accommodate shaft deflections while maintaining sealing effectiveness
2Adaptability or versatility
If a radially floating lip seal is used, then the seal can accommodate radial deflections of the shaft, but it cannot handle significant misalignments and tilting of cantilever shafts
Solution Approach 1:
The seal ring is made dynamically movable relative to the housing bore through rolling O-ring seals, allowing it to float radially and accommodate shaft deflections while maintaining sealing effectiveness
Solution Approach 2:
The seal lips are made flexible to change their orientation and angle relative to the shaft, allowing them to adapt to misaligned positions and maintain sealing contact even when the shaft axis deviates from the bore axis
3Adaptability or versatility
If the seal ring is made flexible to accommodate radial deflections, then the seal can follow shaft movement, but the sealing effectiveness is reduced
Solution Approach 1:
The seal ring is made dynamically movable relative to the housing bore through rolling O-ring seals, allowing it to float radially and accommodate shaft deflections while maintaining sealing effectiveness
Solution Approach 2:
The seal lips are made flexible to change their orientation and angle relative to the shaft, allowing them to adapt to misaligned positions and maintain sealing contact even when the shaft axis deviates from the bore axis
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 tilting lip seal effectively reduces friction and wear by allowing radial displacements and misalignments while maintaining a seal, even with cantilever shafts.
Implementation Method 1
a radially 'floating' lip seal can be implemented... the seal ring and lips are deflected radially, thereby accommodating larger radial deflections of the shaft
Implementation Method 2
tension is maintained on the rolling O-ring seals by an axially movable gland that is pushed toward the seal ring by a spring
Implementation Method 3
a buffer fluid is introduced to either press the lips more firmly against the shaft, or to slightly lift the lips away from the shaft, thereby reducing frictional wear
Data Source
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AI summary
A tiltable floating lip seal (200) accommodates both radial displacements and axial misalignments between a shaft (102) and a housing bore hole. Flexible axial arms at opposing ends of a seal ring assembly form seals with the housing to accommodate tipping and radial displacement of the shaft. The axial arms can be axial lips (204) that slide against radial housing walls (120). The axial lips can extend from the seal ring assembly or from separate end rings that form lip seals to both the housing and the seal ring assembly. The axial lips can be energized by springs (400), such as canted coil springs or petalized U-shaped springs. In other embodiments, the distal ends of the flexible axial arms are fixed to the housing, for example compressed between elements of the housing. Buffer fluid can be introduced through ports (116) to press the axial lips against the shaft or lift them slightly to reduce wear.