Patent ID: 7854167
Filing Date: 2010-12-21
Classification: G01N,H02K

Abstract:
1. A diagnosis device for diagnosing loosening of a stator core of a rotary electrical machine, the stator core being configured by laminating, in an axial direction, electromagnetic steel sheets on both or one of the surfaces of which an insulation film is coated and which has, on its inner radial side, a space into which a coil is inserted, clamping the laminated electromagnetic steel sheets in the axial direction, inserting the coil into the coil insertion space formed on the inner radial side, and connecting the coil outside the stator core, the diagnosis device comprising: excitation means for vibrating the stator core in the radial direction thereof; vibration detection means for detecting the vibration of the stator core in the radial direction; means for frequency-analyzing an output signal of the vibration detection means that detects vibration generated in the stator core when the stator core is vibrated by the excitation means so as to extract a measurement natural vibration mode of the stator core in a circular ring natural vibration mode; means for estimating a circular ring natural vibration mode of the stator core from shape data of the stator core; and means for determining a clamping state of the stator core by comparing the measurement natural vibration mode and a determination criterion obtained based on the estimated natural vibration mode.