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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.

Connecting rod joint optimization is a well-known design procedure used for new cranktrains, not only for truck applications, but also for passenger cars. Big end bolted joint is one of the most critical connecting rods regions under engine operation, especially due to joint opening phenomenon and consequent engine failure. Thus, in order to have a robust design, it is usually applied safety factors to absorb this design margin. However, due to the continuous increase of engine loads to attend different emission regulations, this design condition became a vital parameter for connecting rods. thyssenkrupp developed a joint evaluation methodology to be applied during conrod design, presenting better accuracy when compared to the standard development procedure, the VDI 2230 part 1, thus leading to better performance for real engine application. This approach combines the VDI design algorithm with a simple and fast finite element model for force and moment extraction.

In recent years, the concern about pollutants emissions has increased along with as customer requirements for more efficient internal combustion engine (ICE). To satisfy these demands, new technologies have been introduced in ICE, such as smaller engine bearings, a reduction in the number of cylinders, variable displacements, peak cylinder pressure (PCP) increases, among other things. Sliding bearings are responsible for vital function under engine operation and also friction losses, impacting on fuel consumption as well as pollutants emissions. To maximize the bearing’s performance, it is important to guarantee a hydrodynamic regime, in order to reduce wear and avoid power loss due to metal-to-metal friction, and consequently, premature failure of engine components. Material roughness indicates, with oil film, the lubrication regime as boundary, mixed or hydrodynamic.

Nowadays, due to the emissions regulations and customer requirements for more economic vehicles there is a demand of more efficient Internal Combustion Engine (ICE). The hydrodynamic bearings play an important rule converting the piston reciprocating displacement into a rotational motion. Thus, considering the sliding bearings vital to define the engine life and also responsible for part of friction loss inside the engine, it is important to optimize its profile and consequently tribological performance parameters which impact on fuel consumption. All in all, this work shows the analysis between lemon shape big end bearing and cylindrical one, in order to evaluate the advantages and disadvantages related to this micro profile.

Nowadays, the new emission regulations and customer requirements such as low level of fuel consumption, mass reduction, NVH (noise, vibration and harshness) are pushing the product development to the limit. Thus, engine balancing become a vital aspect during the ICE (internal combustion engine) development cycle. The crankshaft balancing plays an important role in the engine vibration. As a consequence, the balancing criterion may be correctly applied in order to improve the engine performance. This work shows an inline-four cylinder crankshaft static balanced and its performance under virtual engine operation. Not only is the crankshaft balancing discussed, but also dynamic performance. Moreover, in order to have a lightweight crankshaft, a sensitivity study was performed to understand the influence of counterweights reduction. Thus, it was showed that if an alternative design is desired, there are some alternatives to minimize the unbalancing impact when saving counterweight mass.

In order to guarantee the new emission regulations and customer requirements, crank train components must be developed for engine operation boundary conditions. In the last years, analytical formulation is being replaced by flexible dynamic analysis. This paper shows how important it is to develop crankshafts considering engine actual cyclic loads. Moreover, stresses and fatigue safety factors are evaluated as vital outputs. The consideration of the elastic matrix in the movement equation enabled the achievement of more precise results according to the actual crankshaft behavior. The procedure described in this paper is strongly recommended for new crankshafts design regarding their actual structural behavior under engine operation condition.

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.

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.