This study evaluates the size of outer race defects of ball bearings during accelerated life testing by analyzing the signal of an electromagnetic sensor. The electromagnetic sensor consists of a pickup coil wrapped around a permanent magnet. When a conductor passes in the static magnetic field, the generated eddy currents are detected as a change of the magnetic field. The autocorrelation method is applied for sizing defects in the early phase of the damage growth and the RMS method is applied for la...
英字タイトル:
Nondestructive Electromagnetic Monitoring and Diagnosis of Damage Growth in Ball Bearings

This study evaluates the outer race defect size of ball bearings in the accelerated life test by analyzing the signal of electromagnetic sensor. The electromagnetic sensor consists of a permanent magnet and a pickup coil. When a conductor passes in the static magnetic field, the generated eddy current is detected as the change of the magnetic field. The autocorrelatio n method is applied for sizing defects in the early phase of the damage progress and the RMS method is developed for bigger defects. With th...
英字タイトル:
Electromagnetic Nondestructive Detection for Monitoring the Damage Progress of Ball Bearings

In order to investigate a method for efficiently monitoring multiple machines in a building with an acoustic sensor, an experiment was performed to acquire acoustic data of three rotating machines running simultaneously in a state in which all three machines are normal or one of three is abnormal, with two microphones placed at different positions. The abnormality can be detected from the acoustic signal level, and it can also be specified that the bearing abnormality has occurred by frequency analysis. A m...
英字タイトル:
Study of efficient condition monitoring method by acoustic diagnosis