Friction Resistances in a Prototype Internal Gear Pump with Sickle Insert Made of Plastic

Abstract

This paper presents the results on the modification in the areas of design and material of the internal gear pump sickle insert. The modification relies on making a cut in the sickle insert. As a result, the insert raceways are pressed against the tooth tips of the gear wheels. Due to the introduced radial compensation, the discharge flow rate falls less as the discharge pressure increases. The test stand and the measurement results are respectively presented. Friction resistances between the gear wheel material and the insert materials were measured for selected pump operating parameters. The tested materials were found to differ in their friction resistance. The differences were confirmed by shaft torque measurements taken while the pump was running. The results of the investigations indicate the direction for further research with an aim of creating an optimal insert which meets the requirements for a prototype pump with enhanced capacity at higher discharge pressures.