During the simulation average number of particles

The analysis results in both Sections 6.3 and 6.4 show that the proposed time–frequency analysis method can effectively pinpoint the time-varying frequency components of planetary gearbox signals under nonstationary running conditions, and the findings are all consistent with the actual experimental settings of the sun fault, showing that the proposed method is effective in detecting both local (chipping) and distributed (wear) fault. Besides, after speed PCI-34051 via the fixed-shaft gearbox and stage 1 of the planetary gearbox, the rotating speed of the planetary gearbox stage 2 is very low. It is difficult for the sun gear fault to excite relevant vibration under low speed condition. Even though, the stage 2 sun gear chipping symptoms has been successfully extracted using the proposed time–frequency method. This further demonstrates its effectiveness in detecting and diagnosing faults with a weak signature.
7. Conclusions
AcknowledgementThis work is asexual reproduction supported by the National Natural Science Foundation of China (11272047, 51475038), the Program for New Century Excellent Talents in University (NCET-12-0775), the Natural Sciences and Engineering Research Council of Canada (I2IPJ 387179 and RGPIN 121433-2011) and Ontario Centers of Excellence (OT-SE-E50622). The authors would like to thank the reviewers for their valuable comments and suggestions.