An investigation of the effect of counterweight configuration on main bearing load and crankshaft bending stress

In this study, effects of counterweight mass and position on main bearing load and crankshaft bending stress of an in-line six-cylinder diesel engine is investigated using Multibody System Simulation Program, ADAMS. In the analysis, rigid, beam and 3D solid crankshaft models are used. Main bearing load results of rigid, beam and 3D solid models are compared and beam model is used in counterweight configuration analyses. Twelve-counterweight configurations with a zero degree counterweight angle and eight-counterweight configurations with 30° counterweight angle, each for 0%, 50% and 100% counterweight balancing rates, are considered. It is found that maximum main bearing load and web bending stress increase with increasing balancing rate, and average main bearing load decreases with increasing balancing rate. Both configurations show the same trend. The load from gas pressure rather than inertia forces is the parameter with the most important influence on design of the crankshaft. Results of bearing loads and web bending stresses are tabulated.