Overview
Closeup |
The laminated structure of a core can be sustained using press-fitting
or shrink fitting.
The press-fitting stress needs to be accounted for in the iron loss analysis
because the stress caused by press-fitting is known to increase the iron
losses when a magnetic steel sheet is used for the core of the motor.
This example presents the use of a structural analysis and magnetic field
analysis to obtain the iron loss density of an IPM motor with and without
the stress by simulating the stress caused by the press fit core and frame
with the press fit condition. |
Minimum Principal Stress Distribution
Closeup |
The minimum principal stress distribution is indicated in Fig. 1. Tensile
stress occurs in the frame and teeth, but compressive stress that especially
effects the iron losses is produced largely in the yoke. The compressive
stress is especially large in the area of the model within the square in
Fig. 1, but this is because of the slots' geometry. |
Iron Loss Density Distribution
| The iron loss density distribution is indicated in Fig. 2. The iron loss
density distribution varies depending on whether or not the stress is applied.
The iron losses are increased by 1.5 % due to the stress. An analysis that
accounts for the compressive stress caused by the press-fitting needs to
be performed to evaluate the iron losses more accurately because the iron
losses increase when the compressive stress is applied. |
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