Influence of Bearing Clearance on Load Sharing in Planetary Gears Available to Purchase

Load sharing among plural pinions in planetary gears should be equal to reduce gear noise and to secure the strength of the gears and bearings. This study investigates the influence of bearing clearance on load sharing using multibody dynamics analysis. One of the characteristics of this analysis is its capability to calculate dynamic gear meshes and bearing clearance nonlinearity. Contact analysis of the gears defines the tooth surface expressed by numerical formula involving modified surface geometry. Moreover, nonlinear stiffness is used to express the bearing clearance. The numerical method is verified by experiments that measure bearing loads on pinions using strain gauges. Subsequently, the influence of bearing clearance is examined numerically. The results confirm that the clearance of the carrier is dominant. In addition, unequal loads arise from reductions in the bearing loads and inclination of the carrier. Finally, this paper suggests an appropriate clearance for well-balanced load sharing.