Investigation into cage slip and vibration behavior of rolling bearing based on weak magnetic detection

Cage slip and vibration are two key indicators for evaluating bearing health status. However, in actual service, due to the limitations of installation space and interference from harsh environments such as high temperatures and oil mist, it is difficult to detect the cage slip and vibration of rolling bearings. To solve this problem, based on the principle of bearing motion under magnetic field disturbance, a weak magnetic detection method is proposed to obtain mixed feature information about cage motion and bearing vibration. To separate the kinematic characteristics of the bearings, a method of local reconstruction based on intrinsic mode functions and a comprehensive evaluation index based on statistical parameters is proposed to identify the relevant mode including cage motion and vibration behavior. The cage slip and vibration characteristics are obtained by the fast Fourier transform and envelope demodulation technique. The different fault levels of rolling bearings are used to evaluate the performance of the proposed method under variable speed. The results show that the proposed method can identify cage slip and vibration behavior effectively.