Numerical Modeling of Helical External Gear Pump Through a Lumped Parameter Approach

External gear pumps are a type of positive displacement machines that combine excellent performances with very competitive costs. These characteristics unfold the necessity of tools to accurately simulate their performance. In this article, a numerical methodology based on a lumped parameter approach has been developed for helical External Gear Pumps (EGPs). The methodology is based on the usage of a tool, that, starting from the pump drawing, thanks to different subroutines developed in different interconnected environments, allows to fully analyze EGPs with Helical. The tool is based on a tool called EgeMATor developed by the research group for spur gears and described in a precedent works [1]. The tool has been further expanded in its functionality and optimized becoming EgeMATor MP+. Indeed, the new release has been expanded not only to include helical gears but also to simulate the bearings’ reaction and consequently the gears’ eccentricity variations. Results obtained from the simulations have been compared with data obtained thanks to an experimental campaign carried on a series of reference pumps done to further validate the numerical model and the new implemented functionalities. Then, a new methodology that, for a defined tooth gears profile, is able to automatically obtain an optimized design of the pressure relief grooves of the wear plate has been studied. This methodology, through a flow ripple fluctuation, pressure spikes and crossflow optimization based on geometric assumptions, has the objective to characterize a design that permits to improve the volumetric efficiency as well as to reduce the fluid-borne noise emission of the pump analyzed.