Causes of Vibration
There are basically three fundamental causes of vibration, which are the following:
- Inertia Effects
- Acceleration and Deceleration
- Looseness and Impacts
Some examples of these causes are as follows:
a) Forces generated by rotating impellers and their shafts and couplings like in the case of fans, blowers, pumps, compressors.
b) Reciprocating effects like in the case of a reciprocating compressor or hydraulic piston, or movement of pistons as in Internal Combustion engines.
c) Torques related to gear mesh frequencies, turbine blades passing frequencies, vane pass frequencies and torques of electrical machines.
d) Effects due to fluid flows and their interactions with other elements of the system.
e) Electromagnetic interference
f) Natural frequency
g) Torsional frequency
h) Temperature effects and gradients
a) Movement of rolling elements in anti-friction bearings
b) Cavitation as in pumps
c) Eddy currents and their flows
d) Shock loads applied to electrical machinery such as in the case of a generator fault followed by fault removal and automatic closure.
e) Rate of heat flow
g) Environmental effects
h) Lubrication effects
Looseness and Impacts
a) Impulsive forces as experienced in punch press
b) Foundation bolts
d) Fits and interfaces
e) Wear Out of machinery elements
h) Flow interference