new electromagnetic method for the nondestructive evaluation of electric pumps with ball bearings is roposed. A permanent magnet generates a static magnetic field and a coil of several hundred turns wrapped round it is used to pick up eddy currents induced inside rotating ball bearings and impellers. First, a method hat make use of the autocorrelation is applied to the signals of the ball bearings. A relation between therocessed signals and the size of the defects in the bearings is obtained. In a second...
英字タイトル:
Electromagnetic Nondestructive Detection for Wounded Bearings and Impellers andCorrelation of Size of Defect and Signal