Latvian Maritime academy

Figure1. The model of the induction machine under investigation.
1 - bearing unit; 2 - shaft; 3 - rotor winding; 4 –stator core; 5 – pressure rings of stator core; 6 - stator winding;
7 – enclosure; 8- rotor core.
The investigations resulted in the pictures of magnetic force lines of the packages edge zone (in X-Y
coordinates) of the investigated model (Figure 1) with a defect (level of rotor shift according to the stator
max / sim = 1,75 ) (Figure 2b) as well as without a defect (rotor symmetrical to stator sim ) (Figure 2a). The
results of the magnetic field allow a qualitative extraction of the zone of significant weakening of
magnetic induction in the area of maximum shift of the rotor axis according to that of stator.
Figure 2. The calculation of magnetic field of induction machine (force lines of the magnetic field in the pole pitch)
without defects - 2a and with defects (in the right bearing unit, rotor shift max / sim = 1,75) - 2b.
Figure 3 demonstrates the results of the calculations of magnetic induction in the air gap of
induction AC machine in axial direction (along Z axis) without defects as well as with that in the right
bearing unit (shift of the rotor max / sim = 1,5 и 1,75). Table 1 represents the results of percentage
changing (reducing) of the amplitude of the air gap induction (B) of basic and tooth harmonics with
different levels of the rotor shift according to the symmetry axis of the stator.
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