Vibrations control

Install springs between the pump and beam. This will raise the pump above the surface of the beam and the springs will absorb the ocillations. Install with the mounting bolts using longer bolts.

Hey,

Actually this is how the oscillation is happening:

<--(cantilever type beam) -->

so it's swinging it back and forth, not sure why they mounted this pump this way, but that caused this particular grief. So one of the engineer, suggested we put a slab of concrete at the base to increase the dead weight/anchor.

Two co-axial pumps with 180 degree phase shift.

John

A cantilever type mounting may be resonating with the excitation frequency generated by the pump. Three solutions: stiffen up the mount, or add more mass to the pump body, or change the speed of the pump motor

Greg

Install the pump with rubber mounts, you can get different hardness in the rubber to find out which one has the best dampening effect.

We use the same configurations on engine mounts.

Design a spring isolation system.

You will need to determine structural characteristics and natural frequencies of your cantilever beam to provide the vibration cancellation you will need.

Look into spring isolation systems by Barry Controls.

Other options include: pneumatic and piezo controls.

Regards.

The first step is to understand what is happening, then you can figure out why and come up with the right fix.

What is the frequency of the pump oscillation?

Is it mounted rigidly to the beam? If it is both the pump and the beam will move together? If not and there are rubber or spring mountings you may have two resonances to check out.If they are moving together at the frequency of the pump frequency than you are probably close to a beam/pump mass resonance of the cantilever beam support.

Two solutions offered are good ones-- stiffen the beam or add or remove mass.

If you have a good frequency analyzer you can determine whether the cantilever resonance is above or below the pump oscillation frequency. If it is above, adding mass will make it worse, better to stiiffen it and push it further above and away from the pump frequency. If it is below, adding beam stiffness will also make it worse. If you add spring isolators be sure the mounted resonance is well below the pump oscillating frequency so that it will be well isolated. (Factor 8/10)

A bump or displace release test is an easy way to determine the cantilever and/or pump mounted resonance. You bang it, or displace and release it, and check the ring down frequency with a vibration sensor and a scope or analyzer. That is the cantilever ( or system) resonance.

Hi,

Thanks guys, the solutions are all very good.

As of now I guess they will stiffen up the beam, by adding mass to the base of the beam (concrete block, dug deep into the ground) not sure when this will be implemented, but I really want to find out the result. I suggested they reinforce the concrete with metal wire/mesh, since it will most likely crack sooner or later.

Anyways, thanks guys!