Crankshaft Design Optimization to Improve Dynamic Balancing and Fatigue Strength

Abstract

This study demonstrates crankshaft counterweight profile optimization to achieve better dynamic balancing. Balancing simulation was carried to predict initial unbalance. During balancing of actual crankshaft, the position of unbalance is sometimes shifted due to machining stock distribution towards non-favorable direction resulting into more number of balancing holes, thus productivity loss. To reduce this, counterweight profile optimized. After balancing, bending fatigue test carried out. Crankshaft exhibited pre-mature failure at unusual location. To determine the reason of failure, stress analysis was performed using FEA. Design enhancement solution proposed to reduce the stresses & subsequently enhance bending fatigue strength.