Balancing Techniques an insight to field balancing

Unbalance is one of the most common causes of machinery vibration and is present to some degree in all equipment. Dynamic unbalance forces are directly related to vibration and equipment life. Unbalance forces are detrimental to the rotor, the support structure and reduce bearing life exponentially. The dynamic force generated is determined by the speed of the machine and the amount of unbalance. Some of the main sources of unbalance are as follows:

• Blow holes in castings.
• Eccentric machining of pulleys and rotors.
• Improper key conventions used.
• Stack up of tolerances in assembly of equipment.
• Corrosion and Wear.
• Deposit build-up.
• Hydraulic or aerodynamic forces.