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Targeting the current demands for engines with lower emissions, reduced fuel consumption, downsizing and higher peak combustion pressures, thyssenkrupp has developed a new cranktrain concept comprising an increased radial transition between journal and web that extends itself into the bearing’s load-carrying zone, creating a symmetrical U-shaped profile. The resulting non-straight bearing contour restricts the use of a standard bearing shell and led to the development of an integral bearing solution, where a copper based material was applied directly to the connecting rod big end bore. The so-called U-shape cranktrain was experimentally evaluated on a fired engine through a series of eight test steps with varied loads and speeds, being each step condition defined in a way that increased severity was applied to the connecting rod bearings as the test proceeded. The engine was disassembled after each step for analysis and measurement of the crankshaft and connecting rods.

The crankshaft dynamic behavior of internal combustion engines are deeply influenced by its geometry and modal parameters. The modal density of a 6 cylinder crankshaft is high and, therefore, it is necessary the evaluation of its several modal parameters during the crankshaft development. This paper presents the calculation of modal parameters such as: natural frequencies, modal shapes and damping factors; of a 6 cylinder in line crankshaft from a Diesel engine. Two approaches are conducted, firstly, a numeric calculation based on finite element method to collect the free body shape modes and its natural frequencies, respectively. Successively, an experiment is realized by the use of an electro-dynamic shaker to excite the structure, and accelerometers to measure the acceleration in 21 interest points of crankshaft geometry. The 3 directions FRFs are presented for each point, and also, the estimation of modal parameters obtained by tools like CMIF, Stabilization Diagram and Polymax.

The aim of this work is to develop a computational algorithm for bearing surface shape optimization. The algorithm uses the Elastohydrodynamic lubrication theory that takes into account the elastic bearing deformation due to hydrodynamic pressure distribution. This pressure distribution is calculated by solving the Reynolds equation using the Finite Elements Method (FEM). The FEM is also used to calculate the bearing radial deformation. Then an optimization methodology is applied to obtain a new bearing with better performance characteristics by changing only the geometry of the bearing surface.