Operation 
  8.6 faults 
1MB..5/6 shaft height 71 ... 355 
Operating Instructions, 07/2020, A5E41926185A 
101 
8.6.3  Mechanical faults 
Table 8- 2  Mechanical faults  
 
 
Possible causes of faults 
Establish the cause and realign the parts. 
Rotor or coupling not balanced. 
Disconnect the rotor 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 
Rotor out of round, shaft bent 
Consult the manufacturing plant. 
Align the machine set; check the coupling. 
(1)
Coupled machine not balanced 
Rebalance the coupled machine. 
Shocks from coupled machine 
Investigate the coupled machine. 
Uneven running of gear unit 
Resonance of the overall system com-
prising motor and foundation 
Stabilize the foundation following consultation. 
Establish the cause of the changes and eliminate them if necessary; 
realign the machine. 
(1)
 Take any changes into account when warming up the machine.