Investigation of effects of the selected design parameters on NVH behavior of a diesel engine's oil pump chain drive

Drive systems on internal combustion engines aim to perform transfer of rotational motion. One of the commonly used drive elements is the chain, due to its high strength to wear ratio. Chain drives also present extended service life compared to belt drives that generally require frequent service replacements therefore are widely used on diesel engines which are expected to represent extended durability. Chain as a drive element have various advantages like durability, standardized application and easy to fit tight package designs, but have a particular disadvantage of noise excitation tendency due to chordal action existing on the nature of the dynamics. There are various types of chain elements used for optimization of noise behavior of chain drives, like silent (inverted tooth) chain, gemini chain and in particular cases where applicable roller chains, instead of almost standard bush type of chain design. In most cases, engineers are expected to improve the NVH behavior of the existing systems with minimum design changes and cost effects. This paper explains about the design and optimization of a new oil pump chain drive which aims to meet 5 cylinder diesel engine's lubrication requirements (flow & pressure) that will allow the usage of the oil pump designed to work on a 4 cylinder same family diesel engine. Durability and NVH performance are the main design responses for the system as per customer expectations and homologations. Several investigations performed on different levels with the design available on simulation programs, and results correlated to the rig, engine, and vehicle based measurements.