Analysis and Design Optimization for Improved Fatigue Life of One-Way Clutch Drive Used in Starter Motor

Abstract

Durability of a starter motor system coupled with an engine is mostly determined by the durability of its components design strength. The starter drive one-way clutch is a component which transmits the torque from an electrical motor to a ring gear mounted on a cranking shaft in an engine thus cranks the engine. The one-way clutch also prevents the whole starter from damage caused by extremely high load and/or extremely high speed applied to the starter pinion from the engine. The variability in the design and material parameters has vital effect on the durability life. In order to achieve better performances together with improved safety, the new design methodology for one-way clutch drive is to be strictly followed to build good-quality starter motor. The new approach incorporates all the variability and uncertainties in the design phases with the help of computer simulation methods to guarantee design reliability. Present work deals with the analysis and design optimization for improved fatigue life of a one-way clutch drive and the methods to calculate the fatigue life of the one-way clutch drive barrel. Design parameters have been optimized on the basis of the component life requirement. The design involves the calculation of stress limit for the material stress values, and it is related to the fatigue life calculation, thereby improving the life of the one-way clutch with optimal factor of safety. The optimal factor of safety has been achieved by means of the various design features like increased wall thickness, increased fillets. Starter motor experienced high-impact loading loadings with respect to the working environments. These variable loadings affect the component life abnormally, which may cause the damage of starter motor components within the defined life cycle. To enhance the product performance, fatigue life of the starter motor’s one-way clutch has been predicted and design has been optimized for improved durability.