Vibration Analysis-Based Fault Diagnosis of a Dynamically Loaded Bearing with Distributed Defect

This research paper presents the analysis of vibration generated due to the race waviness of rolling element bearing which is under external dynamic load. The waviness on races is modeled either by sinusoidal function or superposition of sinusoidal functions of different orders. The mathematical model developed to analyze elastic deformations at race-rollers contacts and nonlinear contact forces for a defect free bearing under static external loading is modified and extended to take dynamic load into account. The radial waviness on races at these contacts is introduced in order to determine un-balanced excitations causing the bearing to vibrate. The set of equations that represent the dynamics of system have been obtained by inputting the excitations to linear vibratory model of bearing system. The vibration response of bearing has been obtained by numerical simulation of state space model representing dynamics of bearing system. The spectra of vibration response are analyzed for different amplitude contribution of dynamic component of external load. The numerical results have been obtained for NJ204 bearing with known values of order and amplitude of waviness. For harmonic loading, the additional spectral components have been observed for each order of waviness on both outer and inner race. The additional spectral components have also been observed for outer race waviness modeled as superposition of different order waviness models, whereas for inner race, there is some amplitude variation in spectral components. The vibration frequencies resulting from various orders of waviness on races have been validated with those of prior researchers.

Automated summary

This research paper presents the analysis of vibration generated due to the race waviness of rolling element bearing under external dynamic load. The model considers sinusoidal function or superposition of sinusoidal functions of different orders for the waviness on races. Numerical simulations have been used to analyze the vibration response and spectral components resulting from different orders of waviness on races, validating the vibration frequencies.