Liquid-Sealed Vibration Isolator Cavitation Prevention
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Solution Overview
Problem
Existing liquid-sealed vibration isolators face issues with abnormal noise generation due to cavitation during large vibrations, and previous solutions either suffer from high costs due to metal components or reduced damping performance.
Innovation Solution
A liquid-sealed vibration isolator design featuring a rubber-like elastic membrane for the second diaphragm that blocks the orifice flow path in normal conditions, allowing liquid flow through both low-frequency and high-frequency orifice paths to maintain damping and anti-vibration performance while preventing cavitation, and eliminating the need for rust-proofing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a metal spring is used as a valve main body to prevent cavitation, then cavitation is prevented, but abnormal noise is generated due to impact between rigid bodies and rust proofing is needed
Solution Approach 1:
The patent applies this principle by using a flexible membrane instead of a rigid metal spring as the valve main body. The flexible membrane can open and close the communication hole between liquid chambers without generating impact noise, while still preventing cavitation by controlling liquid flow. This directly resolves the noise issue caused by rigid body collision.
Solution Approach 2:
The flexible membrane acts as an intermediary between the pressure differential and the liquid flow control. Instead of direct metal-to-metal contact, the membrane mediates the opening and closing action, reducing impact and noise while maintaining the cavitation prevention function.
2Reliability
If a slit-like opening is provided in a movable membrane to prevent cavitation, then cavitation is prevented, but liquid leaks at all times and damping performance is reduced
Solution Approach 1:
The patent applies this principle by making the opening dynamic rather than static. The communication hole is closed during normal operation and opens only when needed to prevent cavitation. This dynamic control allows the system to maintain damping performance during normal use while preventing cavitation when pressure differential becomes excessive.
Solution Approach 2:
The flexible membrane is pre-positioned to block the communication hole before any cavitation occurs. This preliminary blocking action prevents liquid leakage during normal operation, and the hole opens only when the pressure differential reaches a threshold that would cause cavitation.
3Ease of operation
If a rigid valve main body is used to control liquid flow, then liquid flow control is effective, but impact noise is generated during valve operation
Solution Approach 1:
The flexible membrane replaces the rigid valve main body, maintaining effective liquid flow control through its ability to deform and seal the communication hole. The flexibility eliminates impact noise during opening and closing operations, as the membrane gradually deforms rather than colliding rigidly.
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 design effectively alleviates cavitation and maintains damping performance across various frequency ranges, reducing abnormal noise and costs by using a rubber-like elastic membrane for the second diaphragm.
Implementation Method 1
a rubber-like elastic membrane... configured so that an outer peripheral portion is held against the partitioning body in a liquid-tight manner, the rubber-like elastic membrane is provided by coming into contact with an opening periphery portion so as to block the opening
Implementation Method 2
a vibration isolating base interposed between the fixtures and constituted by a rubber-like elastic body
Implementation Method 3
a vibration isolating base interposed between the fixtures and constituted by a rubber-like elastic body
Implementation Method 4
a vibration damping function and a vibration isolation function are fulfilled by a liquid column resonance action due to a fluid flow in the orifice flow path
Implementation Method 5
a vibration damping function and a vibration isolation function are fulfilled by a liquid column resonance action due to a fluid flow in the orifice flow path
Implementation Method 6
Cavitation is a phenomenon caused by the fact that, when a large vibration is input into the vibration isolator, the orifice flow path is clogged, whereby the inner portion of the main liquid chamber enters an excessive negative pressure state and falls below the saturated vapor pressure of the sealed liquid, and a large number of bubbles are generated
Data Source
AI summary
Disclosed is a liquid-sealed vibration isolator (10) provided with a main liquid chamber (42), a portion of the chamber wall of which is formed from a vibration isolating base (16), a subsidiary liquid chamber (44), a portion of the chamber wall of which is formed from a first diaphragm (38), and a first orifice flow path (50) which connects both liquid chambers, wherein a high-frequency second orifice flow path (54) which connects the main liquid chamber (42) and the subsidiary liquid chamber (44) is formed on a partitioning body (40), and a second diaphragm (60) is provided on the opening (59A) of the second orifice flow path (54) on the side of the main liquid chamber. The outer peripheral portion (60A) of the second diaphragm is held by the partitioning body (40) in a liquid-tight manner, and the second diaphragm (60) abuts the peripheral edge portion of the opening (54A) so as to block said opening with a flexible membrane section (60B) which is provided on the inside of the second diaphragm (60). Moreover, a through hole (74) is disposed on the flexible membrane section (60B) at a position which does not overlap the opening (54A).