X90 mobile modules
X90 mobile system User's manual V 1.20 - Translation of the original manual
261
Misalignment
During operation, a number of different factors can cause machine parts to fail to align or stop aligning with each
other.
Shafts should rotate around a linear axis at the coupling positions, so that the restoring forces at the coupling
position and the loading forces in the bearings are kept as low as possible. Misalignment causes increased vibra-
tions and wear.
Misalignment usually consists of a parallel and an angular misalignment. In the event of a severe parallel misalign-
ment, strongly increased values can be observed in the area of double speed.
Failure mode
Frequency in raw
signal spectrum
Frequency in en-
velope spectrum
Comment
Misalignment in coupling
1 x fn, 2 x fn
(sometimes 3 x fn, 4 x fn)
-
With parallel misalignment, usually only "1 x fn" occurs.
fn
... Nominal speed
Misalignment of shafts
Misalignment of belt
PeakHighFrequency
CrestFactorHighFrequency
Vdi3832KtHighFrequency
PeakRaw
CrestFactorRaw
SkewnessRaw
KurtosisRaw
Vdi3832KtRaw
RmsHighFrequency
RmsAccRaw
RmsVelRaw
Iso10816
RmsAccEnvelope
RmsVelEnvelope
FrequencyBandRmsVelEnvelope
FrequencyBandRmsAccEnvelope
FrequencyBandRmsAccRaw
FrequencyBandRmsVelRaw
FrequencyBandNoiseAccEnvelope
FrequencyBandNoiseVelEnvelope
FrequencyBandNoiseAccRaw
FrequencyBandNoiseVelRaw
Runs noisily
Increased wear
Failure of components
Suitability of the respective
characteristic values to monitor
the potential failures:
Very good
Good
Less good
Not assessed
Frequency of the cause of failure in these
Potential failures:
Frequent
Depends on where used
Rare to never
Not assessed
Failure causes
Possible effects
Characteristic values
Figure 94: Failure causes and effects of an alignment failure
For the meaning of individual characteristic values, see
"Characteristic values" on page 170
and
"Configuration"
on page 193
.
