Analyses of engineered surfaces for performance improvements of external gear pumps

In the field of fluid power systems the research is constantly aimed at the development of more efficient components. Electro-hydraulic solutions present an interaction between hydraulic and electrical machine, often with the aim of controlling the delivered flow rate by changing the pump shaft speed over a possibly wide range; these solutions pose new challenges for the design of hydraulic machines. This work focuses on the possibility of extending the working range of external gear pumps by increasing the hydrodynamic bearing capacity in the meatus between gear wheels and lateral plates. The goal is to accomplish this result through the introduction of a textured surface on the lateral plates. Starting from the results of CFD simulations, some physical prototypes have been realized to carry out an experimental verification activity. Bench tests have been then conducted to measure the efficiency of pumps with textured lateral plates, to be compared with the efficiency of standard pumps. The results obtained, showing different behaviours between the samples compared, create the basis for future developments.