Siemens 1MB115 Installation And Maintenance Manual page 125

6.6.3 Mechanical faults
Table 6-2 Mechanical faults
↓ Grinding noise
X
(1)
6.6.4 Rolling bearing faults
Damage to rolling bearings can be difficult to detect in some cases. If in doubt,
replace the rolling bearing. Use other bearing designs only after consulting
the manufacturer.
↓ Radial vibrations
↓ Axial vibrations
Possible causes of faults
Rotating parts grind
Stator or coupling not
X
balanced.
X Rotor out of true, shaft bent
X X Poor alignment
X Coupled machine not balanced
X Shocks from coupled machine
X X Uneven running of gear unit
X X Resonance of the overall
system comprising motor and
foundation
X X Changes in foundation
Take any changes into account when warming up the machine.
Remedial measures
Establish the cause and realign
the parts.
Disconnect the stator or coupling
and rebalance.
If the machine has two shaft
ends, and a transmission element
is only fitted to one end, secure
the fitted key at the other end
to prevent it from being thrown
out. If the rotor has balance type
"H" (standard type), the fitted key
must be cut back to roughly half
of its length.
Consult the manufacturing plant.
Align the machine set; check the
(1)
coupling.
Rebalance the coupled machine.
Investigate the coupled machine.
Fix the gearing.
Stabilize the foundation following
consultation.
Establish the cause of the changes
and eliminate them if necessary;
realign the machine.
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