Gearbox Fault Diagnosis Based on the Ratio of Characteristic Energy

The kurtosis index in resonance demodulation technology is vulnerable to random and unexpected period impulsiveness. To overcome this drawback, a novel criterion named the ratio of characteristic energy (RCE) is proposed in this paper to detect the gearbox fault with the help of the fast kurtogram method. Firstly, signal is decomposed into a series of sub-signals with different bandwidths. Then each sub-signal is analyzed by square envelope spectrum (SES) technology. And the SES is transformed into energy by square operation. Then, each amplitude of the fault characteristic and its harmonics are summed. Therefore, RCE is calculated by the ratio of the sum of characteristic energy and the total energy. Finally, the optimal resonance demodulation bandwidth is determined by maxing RCE. Signal from gearbox with sun gear wear fault is applied to verify the effectiveness of the proposed method. Furthermore, the superiority of it is shown by comparing with the existing work.