Best way to reduce vibration on 2 Pumps mounted on a baseplate, 3 point vs 4 point mount
Best way to reduce vibration on 2 Pumps mounted on a baseplate, 3 point vs 4 point mount
(OP)
I'v been told that a 3 point mount is better to reduce vibration but wanted to expand on how and why it's better. The mount is for a couple of 1/2HP pumps on a single baseplate with isolation mount points to reduce vibration.
The 2 pumps are similar are not the same model (1 for compressed air and 1 for vacuum). Here is mock up of the 3 point mount, but would love to hear if there is a better option to reduce vibration. When both pumps are running where it'll oscillate where they may cancel each other out, combine to have a higher vibration, and most likely somewhere in between.

Thanks!
The 2 pumps are similar are not the same model (1 for compressed air and 1 for vacuum). Here is mock up of the 3 point mount, but would love to hear if there is a better option to reduce vibration. When both pumps are running where it'll oscillate where they may cancel each other out, combine to have a higher vibration, and most likely somewhere in between.

Thanks!
RE: Best way to reduce vibration on 2 Pumps mounted on a baseplate, 3 point vs 4 point mount
I do wonder why the mounts are not as widely spaced as possible. There can be advantages in keeping them close together in some axes, but it is not, done like that as a general principle.
I realise it is probably just a sketch, but the baseplate design you show is going to cause more problems than it solves. You also haven't included the pipework, that can be another source of angst and may govern your choice of mount location.
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?
RE: Best way to reduce vibration on 2 Pumps mounted on a baseplate, 3 point vs 4 point mount
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(2B)+(2B)' ?
RE: Best way to reduce vibration on 2 Pumps mounted on a baseplate, 3 point vs 4 point mount
I was thinking false brinneling was not going to be a big issue as there is no long periods of time (<3 min) when only 1 pump is running, the rest of the time both pumps are running.
RE: Best way to reduce vibration on 2 Pumps mounted on a baseplate, 3 point vs 4 point mount
1) Common support plate must be stiff to transfer dynamic forces from each machine base to the vibration mounts.
2) Vibration mount stiffness must provide adequate isolation based on machine speed and the fact that foundation (mobile cart) is probably not infinitely rigid. The mount stiffness will probably be much softer than from a simple calculation or chart on last page of catalog.
3) The foundation (cart frame) should not have natural frequencies near 1xSS and pulsation frequencies.
Walt
RE: Best way to reduce vibration on 2 Pumps mounted on a baseplate, 3 point vs 4 point mount
Is it possible that your mounts are too stiff for proper vibration isolation?
In that case, three is better than four. Otherwise, I agree with the comments above.
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JHG
RE: Best way to reduce vibration on 2 Pumps mounted on a baseplate, 3 point vs 4 point mount
RE: Best way to reduce vibration on 2 Pumps mounted on a baseplate, 3 point vs 4 point mount
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?
RE: Best way to reduce vibration on 2 Pumps mounted on a baseplate, 3 point vs 4 point mount
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?
RE: Best way to reduce vibration on 2 Pumps mounted on a baseplate, 3 point vs 4 point mount
RE: Best way to reduce vibration on 2 Pumps mounted on a baseplate, 3 point vs 4 point mount
Are you concerned about resonant frequency, or the pumps tearing loose under some sort of impact?
You should be using anti-vibration mounts rated for your suspended mass, regardless.
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JHG
RE: Best way to reduce vibration on 2 Pumps mounted on a baseplate, 3 point vs 4 point mount
RE: Best way to reduce vibration on 2 Pumps mounted on a baseplate, 3 point vs 4 point mount
You want anti-vibration mounts with a low spring rate. Mounts rated for higher masses will have higher spring rates, and will resonate at higher frequencies.
Anti-vibration mounts isolate your pump from the floor. How are your pumps attached to your fluid system? If they are attached through rigid pipes or tubes, your mounts will not work.
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JHG
RE: Best way to reduce vibration on 2 Pumps mounted on a baseplate, 3 point vs 4 point mount
Are the pumps to be mounted on the bottom shelf of the cart, or 32" off the floor?
I picture the sheet metal cart shelves and the casters uniting to create a wimpy, light weight 2 or 3 mass system under the compressors.
I'd Pay special attention to "static deflection" and ignore the weight rating of the mounts you are contemplating.
https://mason-ind.com/ashrae-lecture/
RE: Best way to reduce vibration on 2 Pumps mounted on a baseplate, 3 point vs 4 point mount
Pumps are rocking piston twin, mounted on the bottom shelf of cart about 8" off the floor. The plan is to make cart is made of 3/16" thick aluminum so shouldn't have issues with static deflection.
Could use 4 Sorbothane stud mounts rated at 11-16lbs each 0510330-50-10 to mount the baseplate: https://www.sorbothane.com/Data/Sites/31/pdfs/prod...
I may be able to separating the pumps and mount them individually if this is the best way to reduce the vibration, but have limited space and may become a cost issue.
RE: Best way to reduce vibration on 2 Pumps mounted on a baseplate, 3 point vs 4 point mount
Over 2 score years ago it was not uncommon to hang the turn table ( record pLayer ) in the party house from the ceiling with bungie cords etc to keep the floor vibration from causing skipping.
I think you might have better results trying this with very flexible springs ( > 2" static deflection with your pump assembly on board) with their upper ends attached to the 2nd shelf's corners.
RE: Best way to reduce vibration on 2 Pumps mounted on a baseplate, 3 point vs 4 point mount
The old Cadillacs had extremely soft suspensions (springs) such that you felt you were riding on a comfy cloud; high frequency bumps, etc., was only road noise. Of course, the fact that it was a tank also helped.
TTFN (ta ta for now)
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RE: Best way to reduce vibration on 2 Pumps mounted on a baseplate, 3 point vs 4 point mount
There are two ways to reduce your resonant frequency. You can reduce the spring rate, and you can increase the mass. There is more than one reason that Tmoose's suggesting above is correct.
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JHG