Vibration diagnostic of electric motor roller bearings

Abstract

The low quality of the new rolling bearings leads to additional costs for electric motor repair, and additional expenses connected with the technological process, value of which can reach from several thousand to tens of thousand dollars. To increase detection, the reliability of rolling bearing defects of asynchronous motors, complex vibration diagnostics was used at informative frequencies in the vibration frequency and amplitude in the range of 5-5000 Hz. Based on the diagnostic model of rolling bearings the software program “Tayamnitsa” is developed, which allows to calculate the diagnostic frequency corresponding to certain defects, determine the defect level and form a diagnostic table for defects. Vibration diagnostics of new and used rolling bearings have been conducted for various regional enterprises and power plants. It has been determined that 40-50% of used bearings are removed in good technical condition. When new bearings were diagnosed in the 500-5000 Hz range, only 48.4% of the bearings are considered serviceable due to the low accuracy class of metal processing and unacceptably high vibration level.