Understanding the Principle of Dampening in Hydrostatic Systems

[Andrea Vironda]

Hi,
In some hydrostatic tables I can see many spring-shaped pipes that are traversed by oil.
Spring is responsible for a kind of dampening that I ignore how to deal with.
Do you have any idea of the physical principle behind it?

 

[Baluncore]

Do you have any idea of the physical principle behind it?

The "spring" = helical pipe, has a great length without sharp corners. The viscosity of the oil flowing in the long thin pipe wastes energy, and so damps movement.

 

[Andrea Vironda]

Thanks Baluncore.
What's the law governing this behavior? Navier-Stokes?

 

[Baluncore]

The Darcy–Weisbach equation.
https://en.wikipedia.org/wiki/Darcy–Weisbach_equation

 

[berkeman]

I was confused by the title, since "Hydrostatics" implies that the fluid is not moving. Is this more about how to damp motion in a flowing fluid? I can change the thread title if that would help to make it more descriptive.

https://en.wikipedia.org/wiki/Hydrostatics

 

[Baluncore]

@berkeman
I am also guessing wildly here, which certainly makes it interesting.

I suspect it is a static fluid support for a large and heavy slab of material, such as a granite precision surface plate. I think it is hydraulic damping of the static position, so maybe only stress reduction?

@Andrea Vironda
What is the table used for. Is it optics, machining or metrology ?

We need a manufacturer and model number, or a link on the web, to a picture of a similar table, with coils of tubing between supporting bladders?

 

[Andrea Vironda]

This table is used for machining. I have this marketing image in with you can see a general layout (column is around 6m tall).

The main advantage in using hydrostatic technology is vibration dampening.
The hydrostatic rotary tables are the 2 scrolling on the blue bases

 

[Lnewqban]

Are the mentioned coils visible in that image?