Causes Of Machine Vibrations

The machine vibrations are mainly caused design tolerance. When there is a change base vibrations, this indicates that there is a defect starting to change the mechanical condition of the machine.


These defects that change the mechanical condition of the machines are the ones that bring about the vibrations of theses machines.


I will highlight these defects and explain to you how they bring about these vibrations.


But, before I go far there is something you need to know about machine vibrations.


These vibrations are necessary for the machine to work. If the machine won’t vibrate then this will indicate that it has a problem and it will need inspection and maintenance.


If you want to know on the benefits of the vibrations of the machines and their disadvantages, don’t forget to check the article below.


You might like this: Advantages & Disadvantages Of Vibration In Machines


There are vibrations that are usually caused by some defects of the machine while there are those that are just originally from the machines.


The vibrations that are caused by the defects of the machine are a little bit different from the ones that are originally from the machine.


And that is why one of the advantage of machines vibrations is that they are used to check for any defects in the machine when it’s started.


The vibrations that are caused by the defects from the machine usually have a different frequency compared to the original ones.


With that much said let me share with you some of the cause of machine vibrations that are caused by the mechanical condition of the machine.


Causes of machines vibrations;

1. Loosened foundations bolts.

Machines in a plant layout are usually placed in a certain foundation to help layout the plant and also to control the vibrations of these machines.


Different machines require different foundations depending on the uses of that machine and the forces its transmit to the immediate surroundings of the plant.


So, the machines that are bolted on their foundation will at point experience this problem of bolts being loose since it’s constantly on use.


The moment the foundations bolts are loose the machine won’t be stable when it’s started.


When the machine is started, it will transmit forces to the ground of the foundation and this will keep the machine unstable thus resulting into vibrations that are very different from the original one.


You will find the machine moving up and down as it’s working, and this is due to the fact that the foundations bolts are loosened.


So, loosened foundation bolts can cause vibrations in machine when they are working since they won’t be bolted tightly on their foundation.


You have to know that the foundation is usually fixed with vibrations control materials.


But those materials won’t help at all when the bolts holding the machine on those vibration damping materials are loose.


2. Worn out bearings.

In mechanical engineering machines, where there is a rotation, just know that there is a bearing.


Bearing are important in these machines are they facilitate the smooth rotation of them.


The moment there are not bearing then there is no way that rotation will happen the way you expect it to.


When bearing in the machine are worn out, the rotation of the machine won’t be smooth.


This means that the shaft won’t rotate in the manner that it’s expected to.


If the bearing are worn out then you will perceive vibrations of that machine.


This is because there will be a disturbance as the machine is rotating.


So, keep in mind that worn out bearings are also one of the major cause of vibrations in machines.


3. Misalignment or bent shaft (distortion).

If the machine has any part that is involved in the rotation that is broken or distorted in any way then you will receive the vibrations of this machines.


That is why vibrations of the machines are very significant in identifying the any defects in machines.


The moment there is a misalignment or bent shaft then the machine will experience some difficulties as it’s running.


This will be resulted by the shaft knocking or scrubbing against another component in the machine, since it’s not occupying the space it’s suppose to.


As a result it will cause vibrations as it runs because it’s not rotating freely.


This is a problem that if it’s not fixed it will reduce the efficiency of the machine and damage it completely.


4. Unbalanced rotation masses.

In the design of a rotating machine, care is taken to eliminate any outer balance that will cause problems in the machine.


Though, there will always be some residual unbalance left in the finished part of the machine due to slight variation of density in material, improper casing and poor machining of the parts.


It’s hard to completely eliminate the balance issues in a rotating machine.


Now, imagine that there is a unbalanced rotation of masses in the machine, this will be a huge problem because it will intensify the residual unbalance.


And this will cause vibrations of the machine.


So, if there are unbalanced rotation masses this will cause the vibration of the machine especially if it’s moving at a very high speed.


Out of balance rotating machines tend to vibrate and it it’s not immediately fixed it can cause failure of the machine.


5. Unrigidly fixed bearings.

The way bearing are fixed in the machine largely influence how the machine will rotate.


If the bearings are not tightly fixed then the rotation of the machine won’t be smooth.


The bearings will be moving in a direction that are not supposed to due to the speed that the shaft will be rotating on.


This will cause vibrations of the machine as it’s rotating since it’s will not be moving smoothly.


So, if the bearings are not tightly fixed then there will be unpleasant vibrations of the machine.


6. Transmission from other equipment from the same plant.

This is something you should expect if your machine is surrounded by other machines.


The other machines will be transmitting their vibrations to the machine you will be using.


If you are in a plant that has different machines turned on at the same time then this is something you should expect.


Some of the vibrations that you will be getting from that machine will be from other machines.


Transmission of vibrations to the ground and the environment is possible since the machine foundation are mostly on the ground.


The vibration control devices that are usually placed on the ground will enable the other machines to transmit their vibrations to the machine you are using.


This is another cause of vibrations in machines.


But if there are no other machines turned on and you are experiencing some vibrations then know that it’s mainly within the machine.


It can be one of the above causes we talked about.


With the causes of vibrations that I have shared with you, you can come up with a way to control these vibrations.


This is because there is no way you will eliminate them completely. The only thing you can do is to reduce them.


If you have any question leave your comment, see you in my next article.


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