Vibrationproof Device Dual-Liquid Cavitation Control

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing vibrationproof devices face issues with cavitation and noise generation due to sudden changes in liquid volume and pressure, leading to decreased vibrationproof performance and increased complexity in configuration.

Innovation Solution

A liquid sealed vibrationproof device with a first liquid and a second liquid, where the second liquid has a higher vapor pressure and lighter specific gravity, is used to preferentially generate cavitation and suppress noise by dispersing the second liquid in the first liquid, reducing shock waves and maintaining vibrationproof performance without increasing device complexity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a liquid sealed vibrationproof device is used to absorb and damp vibration, then vibrationproof performance is improved, but cavitation occurs in the liquid chamber when internal volume suddenly changes, generating noise and shock waves

Engineering Contradiction:
Improvevibrationproof performanceVSAvoidcavitation and noise
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent changes the physical parameters of the sealing liquid by introducing a second liquid with higher vapor pressure and lighter specific gravity than the first liquid. This parameter change allows the second liquid to preferentially cavitate under pressure decrease, protecting the first liquid from cavitation and reducing harmful shock waves. The specific parameters modified are vapor pressure and specific gravity of the liquids.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The second liquid acts as an intermediary substance between the pressure changes and the first liquid. When pressure decreases occur in the main liquid chamber, the second liquid cavitates first, serving as a buffer that prevents direct cavitation of the first liquid. This intermediary mechanism reduces the generation of harmful shock waves and protects the vibrationproof device from noise and damage.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-generated harmful factors

If a liquid pressure valve is added to suppress cavitation, then cavitation occurrence is reduced, but device complexity and size increase

Engineering Contradiction:
Improvecavitation suppressionVSAvoidconfiguration complexity
Core Design Contradiction:
Object-generated harmful factorsVSDevice complexity

Solution Approach 1:

The patent extracts the cavitation suppression function from the mechanical valve system and transfers it to the chemical/physical properties of the second liquid. Instead of using a complex liquid pressure valve mechanism to control cavitation, the invention utilizes the inherent properties of the second liquid (higher vapor pressure) to automatically suppress cavitation through preferential cavitation and shock wave absorption, thereby eliminating the need for additional valve components.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the physical parameters of the sealing liquid system by adding a second liquid with higher vapor pressure. This parameter change enables the liquid system itself to suppress cavitation naturally through the preferential cavitation of the second liquid, replacing the need for mechanical cavitation suppression devices and simplifying the overall device configuration.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If the internal volume of the main liquid chamber is suddenly increased due to elastic body rebounding, then vibration absorption occurs, but sudden pressure decrease generates cavitation and shock waves

Engineering Contradiction:
Improvevibration absorptionVSAvoidpressure decrease and shock waves
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent converts the harmful effect of pressure decrease into a beneficial effect by utilizing the higher vapor pressure of the second liquid. When the elastic body rebounds and causes sudden pressure decrease, the second liquid preferentially cavitates and absorbs the pressure shock, transforming what would be harmful cavitation of the first liquid into a protective mechanism. The shock waves that would normally damage the device are instead absorbed by the second liquid's cavitation and vaporization.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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 suppresses cavitation and noise in vibrationproof devices, maintaining performance and simplicity by using a second liquid with higher vapor pressure and lighter specific gravity, ensuring stable noise reduction even during large vibrations.

Implementation Method 1

the vapor pressure of the second liquid is higher than the vapor pressure of a main component of the first liquid... cavitation is preferentially generated in the second liquid... shock waves are generated when the bubbles disappear

Methodology Applied
Scientific EffectCavitation: Cavitation

Implementation Method 2

the vapor pressure of the second liquid is higher than the vapor pressure of a main component of the first liquid in the same temperature

Methodology Applied
Scientific EffectVapor pressure: Vapour Pressure

Implementation Method 3

a restricting passage which communicates with the main liquid chamber and the auxiliary liquid chamber and in which a liquid column resonance is generated due to the fact that a liquid in the liquid chamber is circulated

Methodology Applied
Scientific EffectLiquid column resonance: Resonance

Implementation Method 4

an elastic body that elastically connects the first mounting member and the second mounting member to each other

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 5

a specific gravity of the second liquid is lighter than a specific gravity of the first liquid... the second liquid... is dispersed in the first liquid independent of one another

Methodology Applied
Scientific EffectDensity difference: Density Gradient

Data Source

PatentEP2441976B1Vibrationproof device
Publication Date: 2018.04.11 BRIDGESTONE CORP
  • EP2441976B1 patent drawingFigure 1
  • EP2441976B1 patent drawingFigure 2
  • EP2441976B1 patent drawingFigure 3

AI summary

A vibrationproof device which is a liquid sealed vibrationproof device includes a tubular first mounting member (3) that is connected to either one of a vibration generating portion and a vibration receiving portion, a second mounting member (4) that is connected to other one, an elastic body (5) that elastically connects the first mounting member (3) and the second mounting member (4), and a partition member (8) that partitions a liquid chamber (7) of the inside of the first mounting member (3) into a main liquid chamber (7A) of an upper side having the elastic body as a portion of a wall surface and an auxiliary liquid chamber (7B) of a lower side, and a restricting passage (80) which communicates with the main liquid chamber (7A) and the auxiliary liquid chamber (7B). In addition, a first liquid (L1) is contained as a main liquid and a second liquid (L2) which is insoluble in the first liquid (L1) is contained as an added liquid in the sealed liquid (L), and the vapor pressure of the second liquid (L2) is higher than the vapor pressure of a main component of the first liquid (L1) in the same temperature and a specific gravity of the second liquid (L2) is lighter than a specific gravity of the first liquid (L1).