Hello all -
I'm looking for some help finding some vibration dampers. I have some xray thickness measurement equipment that is located next to (50 yards) some vacuum pumps (oxygen service pumps) that rotate at 512rpm. My first problem is that these pumps shake miserably due to a poor base design and the fact that they are mounted on a precast slab with a basement underneath so propagation is prominent. The location of the pumps nor the poor base design are going to be fixed/altered anytime soon so I'm trying to find a way to isolate the tables (inspctn equip) from the moving floor. Any ideas?

You might want to give the Fabreeka people a call. Years ago I had good luck with isoltaing some diesel structural borne energy from some nearby machinery. I know as well that the Coast Guard and Navy use the products extensively to reduce the water borne signature from shipboard machinery.

Link is http://www.fabreeka.com/

Agoenner,
You should be looking for vibration isolators not vibration dampers. There are specialty vibration isolation tables (Newport), but you may find them to be expensive. There are many types of isolators available including, coil springs, rubber/elastomer elements, pads, and air springs. You need to know the total weight of the table and X-ray equipment and the amount of isolation needed by frequency to specify or select isolators. In general, you want a heavy table supported by soft spring elements.

Walt
w_f_strong {at} msn [dot] com

Agoenner,

I had experience with replacing the vibration isolator on a 3000 RPM Direct Coupled Fan. The vibration reduced from Danger to Okay.

Please find the attachment of a guidance to select Mounting Bases and Vibration Isolations in the second attachment.

Please keep in mind that there may be several grades of isolator installed on the fan to cope with uneven load distribution.

If you have a drawing of the unit please indicate on the drawing where the Centre of Gravity is located.

Also have a close look at each isolator and see if there is a coloured DOT on the rubber. This coloured DOT will help in the selection of a replacement.

I may end up suggesting to replace all the isolators. I do not think it is a good idea to replace just a few.

You may want to find out why the isolators are failing. These isolators are made of natural rubber and they are not tolerant of oil and high temperatures ( use below 82 Deg C. ). A Neoprene or Spring type alternative may need to be selected if the failure is due to these conditions.

Hope this will help you.

Regards,
Helmy

Vibr_Isolation.pdf (415 Kb, 33 downloads) Vibration Isolator

Sorry,

I think I can attach more than one attachment to this forum. So this is the first attachment of photos between bad and good Vibration Isolators on our fan.

Regards,
Helmy

Nicely done Helmy.
Good to see you in the Forum.
Petri