An optimization procedure to reduce the noise emitted by External Gear Pumps

External gear pumps offer very good performance at competitive costs, making them widely spread worldwide. On the other hand, these machines are generally characterized by high levels of vibrations and noise emissions. This article presents a numerical methodology based on lumped parameter approach to study and optimize both spur and helical gears External Gear Pumps (EGPs). The methodology was implemented in a multi-environment tool, called EgeMATor MP+. This tool executes a closed-loop procedure, which starts from the pump drawing. Thanks to several subroutines developed in different interconnected environments, it permits to globally analyze, and to later optimize, EGPs. A reference pump was optimized acting, in particular, on the geometry of the pressure relief grooves of the wear plate, with the objectives of reducing flow ripple fluctuations, pressure spikes and crossflow. Finally, both reference and optimized pumps were tested in the laboratories of the CNR-STEMS research institute in Ferrara using a specific test rig, which physically isolates the pump from the prime mover. Sound pressure levels were measured in several points around each pump and the results showed an effective reduction of the emitted noise for the optimized design.