Searching for the best passive isolator

[Ezlifer]

Hello All,

Currently i am working on one highly vibration sensitive equipment development, my task is to determine the isolator configuration to imrpove vibration isolation performance to create a low level vibration environment for this machine platform. So i need to isolate the low frequency micro-disturbances due to floor motion.

As the cost control, we considered to use passive isolator for this task, the playload on isolators are about 70Kg, footprints distance bewteen isolators are 300mm*300mm. CG of playload is at the geometric center of 4 isolators in horizontal, 80mm above isolators in vertical.
Machine is settled on ground floor, floor vibration disturbances are usually consisted of 16Hz,25Hz and 27Hz, the max. vibration mag. is about 150ug rms in vertical.

I already tried Newport SLM series but it did not wrok,also used Bilz Biair 0.15ED but need load more 88Kg extra mass onto machine to make it works. Because we do not want to increase the weight of machine too much. Can anyone kindly advise which kind of isolator is the most efficient damper for our application?

Any suggestion will be appreciated.

Regards,

 

[drawoh]

Ezlifer,

Have you looked at Barry Controls yet?

JHG

 

[IRstuff]

A concrete slab, isolated from the rest of the floor. Beyond that, you need to go back to Newport.

Nor have you said what level of vibration you can tolerate. In such cases, you may also need to shield everything from the air conditioner outlets, as the air flow will also induce vibrations.

TTFN

FAQ731-376

 

[GregLocock]

of the isolators, steel springs have the best high frequency attenuation, but you haven't specified enough details to allow a ballpark estimate of the required suspension frequency.

If we want good isolation we use a 30 tonne block of concrete resting on rubber blocks, then mount the instrument on that.

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

http://eng-tips.com/market.cfm?

 

[hydtools]

See also lord.com

Ted

 

[FeX32]

Using a passive isolator means likely you have to design the fundamental frequency to be 10Hz or lower in you case. You can reduce compliance to a certain extent.

But, with passive isolation how do we prevent the unwanted vibration if the system is subjected to random noise disturbances or impulses? Say someone drops something heavy near the system. ( this is not unreasonable )



Fe