Theoretical Discussion on Backlash in Planetary Gear Trains

Based on the theory of the backlash for fixed axis gear trains and the motion characteristics of the planetary gear trains,the floating displacement of the sun gear/annulus was calculated by using the theory of load sharing.The limit deviation of the center distance was substituted by the sum of the floating displacement of the sun gear/annulus and the position errors of the planet gear,an analytical theory of the backlash which was available for the planetary gear trains was presented with the help of aforementioned improvement of the theory of the backlash for fixed axis gear trains.