Relative-Rotation Liquid Damper for Resonance-Range Vibration Control
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Solution Overview
Problem
Existing vibration damping devices, such as automatic balancers, are ineffective in low-speed ranges as they amplify vibration and prevent acceleration beyond the resonance range, due to the centrifugal force causing the mass body to move further away from the center, leading to increased vibration.
Innovation Solution
A vibration damping device combining an automatic balancer with a liquid damper that includes a collision member and a relative rotation unit, where the liquid damper's kinetic energy is converted to heat, effectively damping vibrations in both high-speed and resonance ranges by ensuring relative rotation with the rotating body, preventing liquid adhesion and enhancing collision efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an automatic balancer is used to damp vibration in the high-speed range, then vibration damping is achieved, but vibration is amplified in the low-speed range and resonance range
Solution Approach 1:
The patent combines an automatic balancer (effective in high-speed range) with a liquid damper (effective in low-speed and resonance ranges) into a single vibration damping device. The automatic balancer uses movable masses to counterbalance centrifugal forces, while the liquid damper uses viscous liquid flow through gaps to dissipate vibration energy, achieving comprehensive vibration damping across all speed ranges.
Solution Approach 2:
The patent changes the operating parameters of the liquid damper by controlling the relative rotation between the liquid damper and the rotating body. By making the liquid damper rotate at a different speed than the rotating body (creating relative rotation), the liquid continuously flows through the gaps, optimizing the damping effect across different speed ranges including resonance conditions.
2Device complexity
If the liquid damper rotates at the same speed as the rotating body, then the structure is simple, but the liquid adheres to the inner wall and collision with the collision member is insufficient
Solution Approach 1:
The patent makes the liquid damper rotate dynamically at a different speed than the rotating body, creating relative rotation between them. This is achieved by providing the liquid damper with a separate rotation mechanism (such as a bearing supporting it to rotate independently, or driving it via a belt or gear). The relative rotation ensures continuous liquid flow and collision with the collision member, significantly improving vibration damping effectiveness.
3Reliability
If a large amount of liquid is used in the liquid damper, then vibration damping is improved, but the device size and weight increase
Solution Approach 1:
The patent concentrates the liquid in a specific localized chamber within the liquid damper, rather than distributing it throughout a large volume. The liquid is contained in a compact reservoir with controlled flow paths through narrow gaps. This localized arrangement maintains effective damping while minimizing the overall size and weight of the liquid damper component.
Solution Approach 2:
The patent uses the hydraulic properties of the liquid, specifically its viscosity, to create damping forces through controlled flow through narrow gaps. The liquid is pressurized and circulated through these gaps where viscous friction converts vibration energy to heat. This hydraulic damping mechanism achieves high damping effectiveness with minimal liquid volume, reducing weight while maintaining performance.
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 device effectively dampens vibrations across a wide range, allowing the rotating body to be accelerated beyond the resonance range, with significant damping achieved even with a small amount of liquid, improving the vibration damping effect and preventing divergence during resonance.
Implementation Method 1
as the liquid collides with the collision member, part of kinetic energy is converted to heat energy, with the result that the vibration of the rotating body is suppressed
Implementation Method 2
because the liquid damper rotates relative to the rotating body thanks to the relative rotation unit, the orbital revolution of the rotating body due to whirling of the rotating body does not coincide with the axial rotation of the liquid damper. It is therefore possible to prevent the liquid from immovably adhering to the inner wall surface of the liquid damper due to the centrifugal force
Data Source
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AI summary
A vibration damping device which is able to damp vibration of a rotating body in a high-speed range and to certainly accelerate the rotating body to the high-speed range is provided. A vibration damping device 1 damping vibration of a rotating body 100 includes an automatic balancer 2 which is configured to cancel out imbalance of the rotating body 100 when the rotating body rotates 100; a liquid damper 4 which is coaxially rotatable with the rotating body 100 and includes a collision member 23 provided in a casing 20 in which liquid 22 is sealed, the liquid colliding with the collision member 23 when the liquid 22 moves in a circumferential direction; and a relative rotation unit 5 which is configured to cause the liquid damper 4 to rotate relative to the rotating body 100.