The Pressure and Efficiency Characteristic of Hydraulic Gerotor Motor with the Floating Outer Ring

A gerotor with the floating outer ring is a low speed high torque hydraulic motor. It is a special type of hydraulic motor, which is very rarely described in literature. In this study, the pressure and efficiency characteristics of hydraulic gerotor motor were investigated. The main purpose of this scientific paper was to analyse the influence of the size of the holes in the valve plate on total efficiency of the gerotor. The total efficiency is the most important and prominent information about energy conversion of hydraulic components such as hydraulic motors and pumps. The operation of gerotor is briefly described as well as some equations for the determination of efficiency. In a section of the methodology, a measurement procedure is presented in detail. A test rig with hydraulic components and sensors was introduced. The analysis was carried out to respect the international standards. With the help of measurement, we determined the pressure distribution in some specific chambers in the hydraulic gerotor motor. The results show that there is correlation between the size of holes in the valve plate and the total efficiency of the gerotor. Furthermore, a very high total efficiency was obtained with the hole size of Φ6,3 mm. In that case, the total efficiency was on average 5% higher in comparison to the initial hole size of Φ5,5 mm