Evaluation of Stress Cycles of Differential Bevel Pinion 2011-01-0717
Bevel planetary in the differential helps the vehicle in negotiating a turn and splitting the torque between the axles. The bevel gear differential assembly consists of two bevel pinions, two side gears, differential shaft and washers, enclosed in differential housing. Bevel pinions mounted on the differential shaft act as idlers for power transfer from carrier to side gears which are splined to axles.
This paper is aimed at evaluation of stress cycles in fillets of bevel pinion in a differential. Generally analysis of bevel pinion is carried out using specialized codes. These codes ignore the stiffness of differential housing and differential shaft and effect of surface hardness on the gear tooth. Hence, in this work, a method has been proposed to simulate the complex mechanism of differential assembly with simple static analysis using commercial Finite Element Analysis Software ABAQUS/STANDARD.
This analysis is carried out at nine equal time steps for a given base pitch rotation of bevel pinion. In this analysis, torque is applied on differential shaft which gets transferred to the axles through bevel pinions and side bevel gears. Further, the internal splines of the side gears are constrained to simulate torque transfer to axle. Stress cycles are evaluated at fillets of bevel pinion, considering the load sharing by two teeth mesh. Static strength of the bevel pinion tooth is also evaluated considering the heat treatment thickness on the bevel pinion surface. Using this method contact patterns of mating tooth profiles is also studied at various time steps for a given clearance between shaft and bevel pinion.