The rattling model of a one stage gear system was established

in which mass unbalance

speed fluctuation of driving shaft and backlash of the gear pair were considered.Its governing equations represent a mapping system.By means of numerical simulation

three rattling conditions were researched:(1) speed fluctuation exists only;(2) mass unbalance exists only;(3) both coexist.According to the calculation results

at different inspiring factors and amplitudes

there are different rattling dynamic characteristics

for example

one period

multiple period and quasi period.The rattling resulting from speed fluctuation is different from that resulting from mass unbalance.The rattling characteristics resulting from both simultaneously are different fro-m overlapped characteristics resulting from both individually.It is more reasonable that the factors of speed and mass unbalance are taken together to investigate the rattling dynamics of a gear system.