Seal Assembly Flexure Vibration Damping
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional seal assemblies for machines, such as turbomachines, face issues with dust accumulation in grooves limiting axial movement and inefficient vibration damping due to the use of helical springs, which can lead to quick wear of seal components.
Innovation Solution
A seal assembly utilizing a rotatable and non-rotatable seal component with pairs of flexures disposed in a stressed condition, allowing for axial movement and effective vibration damping by biasing the flexures against each other, eliminating the need for grooves and providing a larger axial span without restricting radial motion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If helical springs are used as biasing members, then the seal assembly can maintain axial movement capability, but the axial movement span is limited and vibration damping efficiency is poor
Solution Approach 1:
The patent replaces traditional helical springs with flexible biasing members that have a leaf-spring-like structure. These flexible members can bend and deform to provide axial movement while maintaining contact between seal faces, enabling a larger axial movement span while effectively damping vibrations through their flexible deformation characteristics.
Solution Approach 2:
The patent changes the physical parameters of the biasing member by using a flexible structure with controlled stiffness characteristics. This allows the biasing member to provide both axial movement capability and vibration damping function simultaneously, resolving the contradiction between movement span and damping efficiency.
2Ease of operation
If grooves are provided in the driving member for tongue movement, then axial movement is enabled, but dust particles clog the grooves and obstruct movement
Solution Approach 1:
The patent eliminates the groove structure and tongue mechanism from the design. By removing these components that are prone to dust accumulation, the invention prevents the clogging problem while still achieving axial movement through the flexible biasing members that directly couple the seal faces without requiring guiding grooves.
3Reliability
If helical springs are used for biasing, then axial movement is maintained, but vibration attenuation is excessive or moderate leading to quick wear
Solution Approach 1:
The flexible biasing members with leaf-spring-like structure provide optimal vibration attenuation by flexing under vibrational loads. This flexible deformation absorbs vibration energy without being excessively stiff (which would cause wear) or overly compliant (which would allow excessive vibration), thereby extending seal component durability.
Solution Approach 2:
The patent employs dynamic biasing members that can adapt their stiffness characteristics during operation. The flexible members dynamically adjust to vibration frequencies and amplitudes, providing optimal damping across different operating conditions while maintaining seal face contact and preventing wear.
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 enhances the axial movement range and effectively dampens vibrations, reducing wear and maintaining clearance between seal components, while avoiding dust accumulation and the limitations of traditional spring-based systems.
Implementation Method 1
damping vibrations of the non-rotatable seal component and the stator housing by biasing the first flexure and the second flexure against each other
Data Source
AI summary
A seal assembly that includes a rotatable seal component, a non-rotatable seal component, and a plurality of pairs of flexures. The non-rotatable seal component is disposed facing the rotatable seal component. The plurality of pairs of flexures is spaced apart from each other along a circumferential direction of the seal assembly. Each pair of the plurality of pairs of flexures has a center line and includes a first flexure and a second flexure disposed in a stressed condition such that a portion of the first flexure and a portion of the second flexure are in contact with each other. Further, the first end of the first flexure is inclined at a first angle relative to the center line and a first end of the second flexure is inclined at a second angle relative to the center line. Also, first end of the first flexure and a first end of the second flexure are coupled to each other and to the non-rotatable seal component.