Addressing the thumping noise generated during the operation of diesel engine chain-driven oil pumps, this paper systematically investigates the noise influence mechanism of sprocket tooth chamfer tolerances through theoretical analysis and experimental validation. A meshing impact dynamics model based on Hertzian contact theory reveals how sprocket chamfer dimensions amplify noise energy via the coupled effects of contact stress concentration and system resonance response. Analysis of vehicle NVH test results for oil pumps equipped with sprockets featuring different tooth flank chamfers confirms significant noise characteristics influenced by chamfer dimensions, aligning closely with theoretical predictions. Based on these findings, an optimized sprocket tooth profile tolerance scheme is proposed, resolving abnormal idle noise in the vehicle. This research provides theoretical support and engineering guidance for optimizing NVH performance in engine chain drive mechanisms.
Zhang et al. (Mon,) studied this question.