Design Development and Weight Optimization of Crankshaft for Commercial Vehicle Application

In crank- train system, the prime objective of crankshaft is to facilitate the transformation of reciprocating motion of connecting rod into rotational motion at flywheel end. Moreover, the contribution of mass from crankshaft is in the same order as of flywheel assembly mass which accounts to approximately 40% to 50% of total mass of engine. Therefore, to accomplish the development of an efficient engine it is vital to optimize the crankshaft based on simulation parameters like balance rate, mass, torsional frequency, web shear stress etc. In the given work, crankshaft has been designed and developed for an engine used in light duty commercial vehicle. The defined work demonstrates the application of 1D simulation tool AVL Excite in development phase of the engine. To establish equilibrium between the weight and simulation guidelines, many iterations of models were evaluated and finally we were able to achieve mass reduction of nearly 8% from the base model. Thenceforth, validation of the entire system was executed for bearing, torsional and strength parameters first in AVL Excite and then in engine test bed. The validation phase is under progress and initial trials are showing no issues, in parallel fatigue test is planned for further design validation.Additionally, as an initiative we have considered hollow crankshaft technology concept for better reduction in weight of crankshaft. Soft simulation has been completed and further process of part development is in progress, the work highlights in detail and necessary reference used for developing the concept.