Uneven vane spacing design for reducing noise emission in a variable displacement vane oil pump

The variable displacement vane pump is part of the engine lubrication system, and is subjected to strict oil flow requirements, wide range of temperatures and different aerations levels. In this context, the target of the designer consists in the development and implementation of energy efficient devices able to ensure the necessary NVH targets. In this work it has been developed a strategy to improve the pump's tonal noise. This has been achieved introducing a specific vane spacing in the pump core. That was a great challenge due to high oil pressure pulsations, created by this device design, which are the main excitation energy within the lubricating system. First was developed a numerical model of the system, accounting for aeration, engine permeability and oil dynamics. Then different rotor designs have been studied with the focus of NVH performance and tonal prominences. For validation purposes, numerical and experimental results will be compared, in order to evaluate the best vane spacing logic among the prototypes.