Simple planetary gears are widely used in automobile industry due to their compact design and high power density. A simple planetary gear set consists of a Sun gear, Ring gear, Planets and Carrier which houses planet gears. Mounting of planet pinions on carrier is through pins which is supported on needle roller bearings. A process called staking is used to assemble the pinion pins on to the carrier. Pinion pins have a staking region which after assembly expands outward into staking groove on the carrier to prevent axial movement of the pins. Design of the groove plays a vital role for the fixation of planet pins and robustness a carrier. Planetary carrier staking grooves are designed to meet pinion pin retention and strength targets.
In this work, an automated work flow is developed using an automation tool Isight to alter the design of staking groove and perform FE analysis to find out the effect of various groove design parameters on the stresses at staking groove location in order to arrive at optimized design. Developed Isight workflow involves parametrically updating the groove geometry, FE model setup, analysis and post-processing of the results. Commonly used staking groove shapes in the industry are considered for this study. Effect of each parameters like, fillet radius of the groove and lateral/longitudinal groove width on stresses are analyzed to optimize staking groove design. Pinion pin retention of the groove is evaluated based on the cross sectional area of the groove.
This paper presents an automated Isight based method to quickly evaluate multiple staking groove designs and identify optimum design. Developed method offers a promising approach to gear designers in order come up with optimum grove design at an early stage of development.