Analytical Predictions for the Chain Drive System Resonance 2007-01-0112

The chain link and sprocket tooth impact during a meshing has been identified as the most significant noise source in a chain drive system. This paper first presents the theoretical derivation of the chain drive natural frequencies and mode shapes using the equations of motion from a stationary undamped chain drive system. The theoretical derivation shows the existence of three types of chain resonances, namely the transverse strand resonance, the longitudinal chain sprocket coupled resonance and the longitudinal chain stress wave type resonance. The chain-sprocket meshing noise is amplified when the chain sprocket meshing frequency corresponds to any one of the above mentioned chain drive system resonances. These theoretical results are then validated by a chain drive system CAE model using ABAQUS to identify the chain drive system resonances. Furthermore, the hemi-anechoic test cell data based on a chain driven transmission also confirmed that a 10dB or higher deviation in the measured chain noise sound pressure levels was observed when the meshing frequencies excited the chain drive system resonance.