Floating Ring Seal Structure for Shaft Whirl Damping
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Solution Overview
Problem
Existing sealing devices for high-speed rotating shafts, such as those in cryogenic liquid fuel turbopumps, fail to effectively reduce shaft vibration and prevent leakage, as they lack mechanisms to impart tangential damping forces and radial restoring forces to counteract whirling and eccentricity.
Innovation Solution
A sealing device featuring a multi-layered cylindrical body with elastically deformable thin plates, positioned between the floating ring and the housing, which imparts tangential damping and radial restoring forces through a corrugated shape and viscous drag pressure, restoring the shaft to its center position and reducing vibration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional sealing devices with floating rings are used, then leakage prevention is achieved, but shaft vibration and whirling are not effectively reduced
Solution Approach 1:
A multi-layered cylindrical body is introduced as an intermediary element between the floating ring and the housing. This cylindrical body includes multiple elastic cylindrical thin plates layered on top of each other, creating an intermediate structure that generates both radial restoring force and tangential damping force to counteract shaft vibration and whirling while maintaining the sealing function
Solution Approach 2:
The multi-layered cylindrical body combines multiple elastic cylindrical thin plates into a composite structure. This composite design allows the system to simultaneously provide radial support and tangential damping, addressing both the sealing requirement and the vibration reduction requirement
2Object-affected harmful factors
If the floating ring is supported by leaf springs at the outer circumference, then vibration damping in the perpendicular direction is achieved, but radial restoring force against eccentricity is insufficient
Solution Approach 1:
The solution transitions from a two-dimensional support system (leaf springs at the outer circumference providing only tangential damping) to a three-dimensional multi-layered cylindrical body structure. This cylindrical structure extends radially inward and can simultaneously provide both radial restoring force and tangential damping force through its layered elastic plates
3Stability of the object's composition
If support means including an annular holder and cylindrical sleeve are provided, then alignment action is maintained even with increased frictional resistance, but shaft vibration reduction is not achieved
Solution Approach 1:
The multi-layered cylindrical body acts as an intermediary between the support means and the floating ring, adding a vibration-damping function to the existing alignment-stable support structure. The elastic cylindrical thin plates in this intermediary structure generate tangential damping force to reduce shaft vibration while the support means maintains alignment stability
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 whirling and vibration of the rotating shaft by generating tangential damping and radial restoring forces, preventing leakage and maintaining the shaft's center position, while being easy to produce and durable.
Implementation Method 1
a multi-layered cylindrical body including a plurality of elastically deformable cylindrical thin plates layered on top of each other provided between an outer peripheral surface of the floating ring and an inner peripheral surface of the housing
Implementation Method 2
a multi-layered cylindrical body including a plurality of elastically deformable cylindrical thin plates layered on top of each other
Data Source
AI summary
A sealing device includes a floating ring in a space between the outer circumference of a rotating shaft and the inner circumference of a housing, and a multi-layered cylindrical body including a plurality of elastically deformable cylindrical thin plates layered on top of each other provided between an outer peripheral surface of the floating ring and an inner peripheral surface of the housing, so as to impart a radial restoring force against the eccentricity of the rotating shaft to restore it to its center position, and a tangential damping force to reduce the whirling of the rotating shaft.