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Nowadays, due to high demand for more efficient engines, new technologies are coming in order to reduce engine size and pollutants emissions, but on the other hand pushing for additional performance by peak cylinder pressure (PCP) increasing. In this scenario, solutions as engine bearing downsizing, number of cylinder reduction and variable compression rate (VCR) has been provided. One of these new technologies is the bushingless connecting rod pin joint system in which the small end bushing is no longer used and the powercell system is composed by the piston pin assembled directly in the connecting rod small end. To enable this downsize with loads increasing, a technology with special micro-profile and coated for mid-range diesel vehicle application was developed, since there is a technical & cost restrictions of current bushings for upcoming PCP.

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.