Most Common Causes of Machine Vibration

Posted by eliteinternet on September 5th, 2022

Vibration in industrial machinery can be both a sign or a source of trouble. The two most important numerical descriptors of machine vibration are amplitude and frequency. Excessive vibration of a rotating instrument like a pump, gearbox, turbine, or compressor is a clear sign that the equipment is not working properly.

Equipment that shows excessive vibration will most likely not achieve the expected lifespan and can be a source of unscheduled downtime or become a reason for a dangerous situation. So, it is important to find out the root cause of vibration by measuring and analyzing the vibration signals. The most common fault and causes of abnormal vibration are misalignment, imbalance, bearing wear, or looseness, in pumps, motors, and other rotating equipment. Here in this article, we will discuss the major causes of machine vibration.

Imbalance in assembly

Imbalance can be a reason for vibration and heat build-up. Impellers should be precision balanced, which has a great effect on the lifespan of the pump bearings. Pumps may be seen to be overheated, misaligned, or have bad bearings, but the main cause is often an imbalance in the pump assembly or other components. They can be imbalanced due to bent shafts, improper bearing installation, and others.

Looseness in parts of a machine

When the parts of the equipment like the bearing, and bolts are loose, they are often a cause of excessive vibration in the machine. Loose parts can rapidly cause damage due to the mechanical forces in the machine. Dynamic unbalance is the most common type of unbalance and the result of static and coupled unbalance. Here the principal mass axis is missing and not parallel to the shaft.

Misalignment

Vibration can also occur when machine shafts are out of line. Sometimes angular misalignment occurs when the axes of pumps and motors are not parallel. When the axes are parallel but not exactly aligned, the condition is called parallel misalignment. It can occur at the time of assembly or develop over time due to thermal expansion, improper reassembly after maintenance, or component shifting. 

Wear

When the components of a machine such as a ball or a roller, bearings, drive belts, or gears become worn, they might cause vibration. A drive belt that is breaking down or a gear tooth that is heavily chipped or worn can also produce vibration. When the roller bearings race becomes pitted, the bearing ruler will cause vibration every time they travel over the damaged area. 

The cause of vibration in the machine can be checked with the help of a vibration meter. When measured and analyzed properly, vibration can play an important role in a preventive maintenance program.