Condition Monitoring of Two-Stage Spur Gearbox Using Vibration Signature Spectrum Analysis

To improve the effectiveness of fault monitoring in mechanical systems, particularly rotary machinery, new technologies and methodologies have been developed in recent years. RMS, Kurtosis, and other global vibration indicators are widely used in the industrial sector and are also recommended by international standards. However, these parameters do not allow for a precise diagnosis of the equipment's condition. In this paper, attempt is made to use guidelines of ISO 10816 for fault detection in gearboxes. A test rig is fabricated for a two-stage gearbox, which is connected to a disk break. A speed variation is provided by a one HP three phase induction motor. Speed range of 500, 1200 and 2100 rpm are selected for vibration monitoring. At a 40-h supervision periodicity, the load is increased from zero to 5 Kgf/cm(2). The study considers a total of 5400 hours of gearbox performance. A total of 28 observations of velocity and 4 envelop acceleration is recorded. From the analysis, misalignment is observed on 26/06/18 and reach to gear failure on 20/08/18. After opening the gearbox, the gear near to input and output shaft is found damaged critically prolonged to gear teeth missing, i.e., broken teeth. Replacement of pair of gears and bearing is recommended.