Abstract:Obtaining the meshing force characteristics is the basis of fault diagnosis of a planetary gear system. The virtual prototypes of planetary gear system under the conditions of health and solar gear pitting failure were established by using SolidWorks and ADAMS. The simulation parameters were set reasonably, and the meshing force between solar gear and planetary gear was simulated. The results show that the timedomain waveform of the meshing force between the solar gear and planetary gear has periodic impact and amplitude modulation under the solar gear pitting failure condition. The frequencydomain waveform of the meshing force not only appears the fault characteristic frequencies of the planetary frame rotation and the solar gear pitting, but also the modulation sideband of the solar gear pitting failure characteristic frequencies appears on both sides of the meshing frequency of the planetary gear system and its doubling frequency. More serious the pitting is, more obviously the amplitude ratio of sideband main frequency increases. The results provide a theoretical reference for the early fault diagnosis of planetary gear system