Dynamic Modeling And Analysis Of Local Gradual Fault In Rolling Bearing

Rolling bearing is a key component of rotating machinery,the inner and outer ring raceways are susceptible to local failure due to periodic impact of the balls,which affects the normal work of mechanical equipment.Bearing dynamics analysis is one of the important ways to deeply understand the characteristics of bearing failure.The study of bearing dynamics under the condition of local failure of inner and outer rings is especially important to predict the early failure of rolling bearings,reduce the economic loss caused by failure,and deeply study the bearing failure mechanism and its vibration response characteristics.In this paper,a local gradual failure dynamics model of bearing inner and outer rings considering radial load,impact excitation and sliding rate is established based on Hertz contact theory and experimentally verified.The main contents of this paper are as follows.(1)This paper takes rolling bearing inner and outer ring local fault as the research object,for the traditional rectangular fault simplification model is difficult to reflect the actual contact between balls and fault area,introduces displacement excitation function to quantitatively analyze the spherical center position gradient law when balls enter and leave the fault area,adopts random number list to characterize the non-regular bottom shape when balls passe the fault area,the dynamic model of rolling bearing gradual failure under the condition of local fault is constructed,and the local fault characteristics are accurately restored.(2)Considering the radial load,the impact excitation generated,the sliding rate of balls in the fault area,the four-degree-of-freedom dynamics model of rolling bearing inner and outer ring under local gradual fault conditions is constructed.(3)The Runge-Kutta method is used to solve the dynamic model under four degrees of freedom to obtain the time domain diagram and envelope spectrum of the simulated signals,and then the measured signals under different speed conditions are compared with the simulated signals to verify the accuracy of the model.The local gradual fault dynamics model is used to study the influence of the width and depth of the fault on the vibration of the bearing system.