Development of Vibration Test and Analysis Methods for Diesel Engine Belt System

The engine belt is the critical part of the engine which transfers crankshaft rotational movement to the pulleys. There are several types of belt failures. One of the root causes of the belt failure is the vibration. In this study, the belt vibration of a heavy duty diesel engine has been investigated. Firstly, belt vibration has been quantified with the help of displacement measurements on the belt in lateral direction. Additionally, belt noise measurements have been performed to make further investigations. Pulley torsional vibrations of two different engines were measured and results were compared. Furthermore, system finite element model has been created to do modal and random frequency response analysis by using FEA (Finite Element Analysis) methods. Crank-pulley angular speed power spectral density (PSD) test values were used as an input at the finite element model (FEM) and lateral displacement was calculated on the belt with the help of PSD analysis. Then, FEM model was correlated with test data by tuning belt elasticity module so that a good starting point has been achieved to make further iterations on the model. This study comprises both test and analysis methods and comparison between measured test results and analyses.