Aiming at the complexity of the vibration mechanism of rolling bearing induced by compound fault under radial load

based on Hertz contact theory

a 4-DOF dynamic model of deep groove ball bearing with compound fault is proposed by considering compound fault

coupled excitation between the shaft and the bearing housing and the bearing

time-varying displacement excitation and rolling element sliding. The model describes the contact and movement of rolling element on the raceway surface

explores the compound fault excitation mechanism of the bearing

and analyzes the influence of rolling bearing compound fault on the system dynamic vibration response under three kinds of working conditions

which provides a theoretical basis for bearing condition monitoring and diagnose. The experimental and simulation results show that the vibration response of the compound fault is the result of the coupling of vibration response of single fault on the inner and outer ring. The fault characteristic frequency and multiple frequency components of the inner and outer ring can be clearly distinguished in the spectrum. Compared with a single fault

the vibration amplitude of the compound fault is higher than that of the single fault. The increasing of size

speed and load will increase the vibration amplitude of the bearing with compound fault and affect its operating state

which will accelerate the failure and reduce the service life of bearing.