Fluid-filled Vibration Damping Device Dissolved Gas Cavitation Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Fluid-filled vibration damping devices experience noise and vibration issues due to cavitation when subjected to impact loads, which complicates the design and increases the number of parts and structural complexity.
Innovation Solution
Incorporating a sealed fluid with at least 0.03 volume % of dissolved gas and a low-adhesion energy surface with a water contact angle of 90 degrees or more on the inner surface of the primary liquid chamber to stabilize air bubbles and prevent cavitation, thereby reducing noise and vibration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a relief valve or shunt flow path is added to eliminate excessive negative pressure and prevent cavitation, then cavitation noise is reduced, but the number of parts increases and structural complexity increases
Solution Approach 1:
The patent applies the self-service principle by utilizing the dissolved gas already present in the sealed fluid to automatically prevent cavitation. When negative pressure occurs in the primary liquid chamber, the dissolved gas naturally comes out of solution and forms bubbles that absorb the pressure fluctuation, eliminating the need for external relief valves or shunt flow paths. The system serves itself using its own inherent properties.
Solution Approach 2:
The patent applies parameter changes by modifying the physical state of the sealed fluid - specifically, ensuring it contains dissolved gas at appropriate concentrations. By changing the parameter of gas dissolution in the fluid, the system gains the ability to naturally respond to pressure fluctuations without additional mechanical components. This transforms the fluid from a passive damping medium to an active pressure-regulating system.
2Object-affected harmful factors
If additional components are added to prevent cavitation, then noise due to cavitation is reduced, but manufacturing complexity and part quantity increase
Solution Approach 1:
The system uses the sealed fluid's inherent dissolved gas content to prevent cavitation, requiring no additional manufactured components. The fluid itself performs the noise-reduction function through its physical properties, simplifying manufacturing by eliminating the need to produce, assemble, and maintain separate noise-control components.
Solution Approach 2:
By focusing on controlling the dissolved gas parameter in the sealed fluid rather than adding mechanical components, the manufacturing process is simplified to primarily involve fluid filling and sealing. This approach transforms a complex mechanical problem into a simpler material property control issue.
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
This solution effectively suppresses cavitation noise and vibration by maintaining air bubbles in a stable, spherical shape, preventing pressure drops in the primary liquid chamber and maintaining vibration damping performance without increasing the device's complexity.
Implementation Method 1
before the occurrence of vaporous cavitation which is so-called cavitation, a phenomenon of aeration which is gaseous cavitation is generated, and the gas that was dissolved in the liquid appears as air bubbles
Implementation Method 2
when there is a great decrease in the pressure of the primary liquid chamber due to input of an impact load, before the occurrence of vaporous cavitation which is so-called cavitation
Implementation Method 3
a low-adhesion energy surface with a water contact angle of at least 90 degrees is provided on an inner surface of the primary liquid chamber
Implementation Method 4
a low-adhesion energy surface with a water contact angle of at least 90 degrees is provided on an inner surface of the primary liquid chamber
Data Source
AI summary
A fluid-filled vibration damping device including: a primary liquid chamber which gives rise to pressure fluctuations based on deformation of a main rubber elastic body at times of vibration input; an auxiliary liquid chamber which gives rise to pressure fluctuations relative to the primary liquid chamber at times of vibration input; and an orifice passage that allows flow action of a scaled fluid between the primary liquid chamber and the auxiliary liquid chamber. The sealed fluid contains at least 0.03 volume % of a dissolved gas under atmospheric pressure at room temperature. A low-adhesion energy surface with a water contact angle of at least 90 degrees is provided on an inner surface of the primary liquid chamber.