Improving the efficiency on gerotor type pumps by optimization between rotor-stator set and pump body

Gerotor pumps, which are a kind of internal gear pumps, are consisting of 2 sub-parts which are rotor (external gear) and stator (internal gear). Gerotor pumps are simple, small and work with low noise. In this study, the effect of the clearance between rotor-stator group and pump body on pump efficiency was investigated in gerotor type pumps. The clearance between the rotor-stator group and the pump body was defined as 30-40μm, 40-50μm, 50-60μm and 60-70 μm and were matched for same sized 10 pumps for each clearence and a total of 40 pumps were produced and subjected to flow and torque tests. The tests were carried out at a constant pressure of 20 bar and for speeds of 600-1000-1500 and 2000 rpm. Pumps volumetric, mechanical and total efficiencies were calculated with the obtained data. The results were compared for each package gap and the appropriate package gap was determined for optimum performance.