Modelling and simulation of the load in the epicyclic rotary pump with trochoidal gear profiles

This paper presents an analysis of the load distribution in the trochoid pump with the planetary movement of the impeller. There are a lot of theoretical and numerical analyses conducted for the gerotor of the pump with fixed positions of the gear axis. Design of planetary gerotor pump has a different load distribution than gerotor with fixed axes. A planetary gerotor consists of a fixed outer gerotor gear with internal gearing and inner gear with an external gearing. The centre axis of the inner gear has a circular motion around the central axis of the fixed gear, because of the eccentricity on drive shaft. The special shape of the gerotor teeth forms chambers with varying volume that allows the flow and pressure of the fluid. During the pump working process the forces of different direction and intensity are present in each of the working chambers. It is necessary to determine the pressure in each of the chambers in order to obtain the load model of the gerotor. Load model will enable the calculation of load distribution in the zone of the maximum contact stresses. This calculation should help in dimensioning of the pump and the achievement of better performance characteristics. (paper)