Seal Assembly With Partially Filled Gaps For Vibration Damping
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional seal assemblies in turbomachinery face challenges with root gaps between rotor and stator, leading to vibrations and leakage due to the mismatch in diameters, where thicker seal leaves would be more resilient but result in increased leakage, and thinner leaves are prone to damage.
Innovation Solution
A seal assembly with partially filled root gaps between adjacent seal leaves, utilizing shims, formed seal leaves, or protrusions to create contact faces and residual gaps that generate friction to dampen vibrations while allowing compliant motion and reducing leakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If seal leaves are made thinner to reduce root gap, then leakage is reduced, but the seal leaves become more prone to vibration and damage
Solution Approach 1:
The seal leaf thickness is varied locally: the root portion is made thicker to increase solidity and reduce vibration, while the tip portion maintains appropriate thickness for sealing. This non-uniform thickness distribution allows the seal leaf to simultaneously achieve vibration resistance and effective sealing.
Solution Approach 2:
The seal assembly combines seal leaves with different material properties and geometries - including compliant seal leaves and stiffer support structures - to create a composite system that provides both flexibility for sealing and rigidity for vibration resistance.
2Reliability
If seal leaves are made thicker to increase resilience, then vibration resistance improves, but root gap increases allowing more leakage
Solution Approach 1:
The seal leaf thickness is varied locally: the root portion is made thicker to increase solidity and reduce vibration, while the tip portion maintains appropriate thickness for sealing. This non-uniform thickness distribution allows the seal leaf to simultaneously achieve vibration resistance and effective sealing.
Solution Approach 2:
The seal leaf is divided into functional segments - a thicker root section for structural support and a thinner tip section for compliant sealing - allowing each segment to optimize its local function.
3Loss of substance
If root gap is reduced to minimize leakage, then sealing efficiency improves, but compliant motion capability is reduced
Solution Approach 1:
Different regions of the seal assembly provide different functions: the root gap region allows compliant motion while the contact faces and sealing surfaces provide leakage prevention, achieving both goals through spatial differentiation.
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 effectively reduces vibrations and leakage by providing necessary damping and solidity to the seal leaves, allowing for thicker and more resilient leaves with minimal damage, while maintaining compliant motion and sealing efficiency.
Implementation Method 1
the contact faces generate friction to dampen vibrations during operation
Implementation Method 2
under fluid pressure, the leaf tips move compliantly to seal the rotor surface closely
Data Source
AI summary
A seal assembly between a rotor and a stator is disclosed. In one embodiment, the seal assembly includes: a rotor; a stator positioned around the rotor; and a plurality of seal leaves positioned between the rotor and the stator, the plurality of seal leaves circumferentially stacked around the rotor to define a seal ring between the rotor and the stator, wherein gaps between adjacent seal leaves are partially filled, such that contact faces and residual gaps are between adjacent seal leaves, wherein the contact faces generate friction to dampen vibrations during operation. Such damping effects still allow the compliant motion of the seal leaves with minimal leaf vibration. Also, thicker and more resilient leaves may be applied with reduced leakage through the root gaps.