Triple
E. Troubleshooting
1. Eccentric of gear, belt
sheave and bush.
2. Shaft is not in the middle
or curving (if vibration on
the shaft direction is high).
3. Belt fault
4. Syntony
5. Reciprocate force
Vibration
frequency
Most possible
reason
Other possible reason
Note
Imbalance
Synchronous
with
*
1. Shaft is not in the middle
or curing ( if vibration on
the shaft direction is high).
2. Belt fault
3. Syntony
4. Reciprocate force
Double
Mechanical loose
Not in middle
If loose is worse,
there maybe
higher multiple
frequency.
Gear fault, liquid
force, mechanical
loose, reciprocating
force.
f
s
1 x N x ( N is the tooth
number of the fault gear ).
2 x N x ( N is the paddle
number of the fault pump
or fan ).
f
s
f
s
f
s
f
s
N multiple of
f
s
1. Drive belt fault
2. Interferential vibration
3. Beat frequency
Oil film eddy
turbulence
f
s
Synchronous
with power
frequency
Armature fault
Electric fault such as rotor
broken, rotor eccentric,
there phase imbalance and
air clearance not symmetry.
Double the power
frequency
Torsional impulse
Seldom
High frequency
( not multiple of
)
f
s
Shaft is not
lubricate
1. Cavitations and
turbulent flow.
2. Frictional force.
Amplitude and
frequency of
vibration are
always not steady
* Is the frequency according with the rev of main shaft.
