LOOSESS INSPECTING METHOD FOR PHASE-RING SUPPORTING PART

PROBLEM TO BE SOLVED: To provide the looseness inspecting method for a phase-ring supporting part, which can inspect the looseness quantitatively. SOLUTION: In the phase-ring supporting part, one side surface of a phase ring 12 is brought into contact with the supporting surface of a supporting frame 14, and the phase ring 12 is bound to the supporting frame 14 with a band 16. A first vibration sensor 18 is fixed to the side of the phase ring 12 of the phase-ring supporting part, and a second vibration sensor 19 is fixed to the side of the supporting frame 14, respectively. The vicinity of the first vibration sensor 18 is struck, and the vibration caused by the striking is sensed with both vibration sensors 18 and 19. When the difference value of the respective response times of both vibration sensors 18 and 19 exceeds the present reference value, the presence of the looseness is judged.