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Automotive internal combustion engines use connecting rods to compose its mechanical set-up based on a piston-rod-crank mechanism. Typically, a connecting rod has an i-shaped beam along its length in order to have better moment of inertia distribution on two axes, one aligned to the engine rotating axis and other, orthogonal to the same. An alternative design was developed by the use of an oval shaped beam in order concentrate the moment of inertia just along the engine rotating axis. The structural simulations based on Finite Element Analysis showed that the fatigue and buckling strength were maintained and finally, experimental fatigue testing had proven that oval beam design kept the fatigue and also buckling strength

Due to the huge demand for more efficient engines, as consequence of reduced pollutant emission, not only has the automotive industry been trying to achieve deeper understanding of the physical mechanisms present in the engines, but also to improve its mathematical modeling. Concerning the journal bearings, this task has extreme relevance, when either downsizing or repowering approaches are aimed to be performed. Regarding the mathematical models, identification of a model which is able to guarantee both reliable results and non-prohibitive computational costs should be achieved. This work aims to present the comparison between hydrodynamic and elastohydrodynamic simulation, showing the particularities of each approach and its advantages and disadvantages.

In order to achieve new emission regulations and customer requirements, the peak cylinder pressure (PCP) is steadily being increased and as a consequence, the loads applied on the cranktrain have increased significantly over the last decade. The higher loads have forced a complete revision of the cranktrain design affecting the design of pistons, connecting rods, and crankshafts. Consequently, the concept and performance of the related bearings have to be improved, since they are the key elements that link the cranktrain components. The purpose of this work is to evaluate the lubrication parameters of a non-straight bearing, so called U-Shape bearing. This development presents two main challenges: one is the simulation of the lubrication parameters and the other is the achievement of an ensemble of bearing dimensions that makes the prototypes construction feasible. Due to this particular bearing design, the commercial simulation tools do not apply.

Nowadays, there is a demand for ICE (Internal Combustion Engines) with higher PCP (Peak Cylinder Pressure) in order to improve the engine performance and decrease the level of emissions. Due to this PCP increasing, the engine components must have higher structural strength. This work aims to perform a structural investigation of an innovative and revolutionary non-straight bearing applied to the pin journal of a crankshaft for a mid-range application (called U-Shape bearing). By using of structural optimization tools applied to this non-conventional bearing it was achieved substantial reduction of the stress concentration in the pin fillet and also substantial improvement in the crankshaft torsion stiffness, which results in a better dynamic performance regarding torsional vibration and potential for better NVH behavior.