Evaluation of Local Residual Stress Distribution of Stator Core in a Rotating Machine

It is well known that magnetic properties deteriorate in constructed cores due to conditions of stress such as riveting and welding during the manufacturing process, or punching and shearing during the cutting of the electrical steel sheets. Therefore, it is important to know the relationship between the stress and magnetic properties of electrical steel in order to design electrical machinery. In this paper, the local residual stress distribution on the cross section of the stator core in a rotating machine is measured with an X-ray stress measurement device. As a result, the difference in the residual stress distribution of each component is obtained in the teeth and core back of the stator core. In addition, we estimated the deterioration of the magnetic properties in the teeth region. We demonstrate that the magnetic properties of the electrical steel sheet deteriorated due to the residual stress. (C) 2012 Wiley Periodicals, Inc. Electr Eng Jpn, 181(3): 1-8, 2012; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.21271