X20 system modules • Other functions • X20CM4810
X20 system User's Manual 3.10
2119
Loose parts, parts striking each other
If individual parts in the machine are loose, they can cause unwanted oscillations. When individual parts strike
housings or attachment parts, these appear very similar. As a result, the two causes of damage cannot be analyzed
separately.
In addition, components strike their counterparts on each revolution. This in turn causes the attachment parts to
vibrate at their natural frequency. Envelope analysis can be used to separate the causes of impact.
Failure mode
Frequency in raw
signal spectrum
Frequency in en-
velope spectrum
Comment
Loose parts, parts
striking each other
(1 x fn)
1 x fn
There is usually one strike per revolution. If an envelope oc-
curs for the load, a double frequency can be seen.
Table 736: Frequency of failure indicators for loose or impacting components
fn
... Nominal speed
Breakage of attachment parts
Loosening of connections (screw connections)
PeakHighFrequency
CrestFactorHighFrequency
Vdi3832KtHighFrequency
PeakRaw
CrestFactorRaw
SkewnessRaw
KurtosisRaw
Vdi3832KtRaw
RmsHighFrequency
RmsAccRaw
RmsVelRaw
ISO10816
RmsAccEnvelope
RmsVelEnvelope
FrequencyBandRmsVelEnvelope
FrequencyBandRmsAccEnvelope
FrequencyBandRmsAccRaw
FrequencyBandRmsVelRaw
FrequencyBandNoiseAccEnvelope
FrequencyBandNoiseVelEnvelope
FrequencyBandNoiseAccRaw
FrequencyBandNoiseVelRaw
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Application possibilities
Potential failures
Characteristic values
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
Figure 687: Failure causes and effects of belt damage
Summary of Contents for X20 System
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