Active Magnetic Bearings for Rolling Element Bearings Outer Race Incipient Defect Diagnosis

The active health monitoring of rotordynamic systems in the presence of bearing outer race defect is considered in this paper. The shaft is assumed to be supported by conventional mechanical bearings and an active magnetic bearing (AMB) is used in the mid of the shaft or outboard location as an actuator to apply constant force to the system. We present a nonlinear bearing-pedestal system model with the outer race defect under the AMB force. The nonlinear differential equations are integrated using the fourth-order Runge—Kutta algorithm in MATLAB and the simulation result is obtained. The simulation results show that the characteristic outer race defect signal is significantly amplified under the AMB force, which is helpful to improve the diagnosis accuracy of outer race defect.