Transient Thermo ElastoHydrodynamic Lubrication of Connecting Rod Big-End Bearings

The bearing load in today's engines has increased significantly due to the improvement of the combustion method and the increasingly demanded output power.

Numerous studies including thermo-elastic deformation have already been done for steady state loading. However, engine bearings cannot be considered as working under such steady state. Recently, few transient THD analyses took place to get close to the engine actual working conditions.

In this work, a numerical method is developed for the analysis of transient thermo-elasto-hydrodynamic behavior of connecting rod big-end bearings. The energy equation of the oil film and the heat transfer equation of the bearing solids together with the Reynolds' equations are solved. The bearing mechanical and thermal deformations are calculated using Finite element method.

Results showed that the mechanical and thermal distortion of the bearing solids couldn't be ignored because of their significant effects on the film thickness as well as other bearing characteristics