LONGITUDINAL EFFORT IN CRANKSHAFT

In the last two decades, torsional and axial vibrations of the engine crankshaft have become more severe than before, because of the increase of the engine speed and mean effective gas pressure, and reduction of engine size. Under these new conditions, more severe forces and torques are applied to the crankshaft. That forces and torques can increase the noise radiation, wear and damage of the components connected to crankshaft. This paper presents a multi-degree-of-freedom model of crankshaft under axial and torsional excitations. The motion equation of the system is solved numerically with Newmark beta Method in Matlab environment. The interaction with axial bearing is also considered, the Reynods Equation that govern the generation of hydrodynamic pressure in axial bearing is solved with Finite Difference Method and the boundary condition of Sommerfeld (pressure equal to zero at the boundary). A simulation of 4-cylinder crankshaft is presented. Results are shown in terms of crankshaft's displacement and pressure in axial bearing.