Evaluation of Magnetic Property in Teeth Part of Motor Core by Stress-relief Annealing with Induced Current Heating Method

Abstract

　In this paper, a measurement method of the magnetic properties in the teeth part of motor cores is investigated, and the magnetic properties before and after the stress-relief annealing are compared. At first, the effective magnetic path length for measuring the magnetic field strength was determined using a two-dimensional magnetic filed analysis, and its validity was demonstrated. Next, it was confirmed that the developed magnetic sensor can evaluate the effect of rolling magnetic anisotropy by measuring the magnetic properties in the different teeth of the motor core. Finally, the stress-relief annealing using an induction current was carried out, and it was clear that the magnetic properties of each teeth of the motor differ at the upper and middle parts.