Influences of Leakage Gap Variations on the Dynamics of Hydraulic Chain Tensioners – Experiment and Simulation

In this work several hydraulic chain tensioners with and without check valves are analysed. Using experiment and simulation the influence of the variation of the leakage gap on the performance of the tensioners is shown. Firstly, an experimental test setup to analyse the dynamical behavior of the tensioners is introduced. The tensioners can be excited kinematically with sinusoidal signals having amplitudes between 0.02mm and 1mm and frequencies up to 250 Hz. The temperature range of the measurements matches real engine operation points. Secondly, a modular simulation approach for the hydraulic tensioning systems is presented. These models are suitable for the integration in timing chain simulations. Hence, influences of parameter variations such as leakage gap variations are directly seen. Thirdly, a comparison between simulation and measured data is shown for the analysed hydraulic chain tensioners. The simulation shows a very good match of the experimental data and the significant influence of the leakage gap on the dynamics is seen.