Analysis of hydrodynamic bearings in lightweight crankshaft

Guilherme Gall Silva¹; Marco Lúcio Bittencourt¹

¹ Unicamp

doi:10.20906/CPS/CILAMCE2015-0861

Resumo

The crankshaft and connecting rods are some of the most important components of an internal combustion engine, making them responsible for transforming the linear motion of the pistons into rotational motion. To allow such a rotary movement and prevent wear, the crankshaft is seated on hydrodynamic bearings, which sustain the weight of the crankshaft and the acting loads. To sustain those loads, a film of oil is generated in the connection surface of the crankshaft and rod due to relative movement between them. Lately , with the current need for reducing emissions and fuel consumption, weight relief and compression ratio increase are sought to meet such requirements. However , these changes have great influence in the hydrodynamic bearings that support the crankshaft, and may lead to premature wear This work aims to study the influence of weight relief of crankshafts on the load carrying capacity by hydrodynamic bearings. Therefore, commercial software ALV Excite was used to perform dynamic simulations and assess the tribological performance of the same through the curve of pressure generated, thus verifying if the weight reduction can be enough to compensate for an increase in the compression ratio.

Palavras-chave: hydrodynamic bearings; crankshaft; Internal Combustion Engines