Research On Miniature High-speed Gerotor Pump

Gerotor pump is a type of positive displacement hydraulic pump with the advantages of simple structure,compact volume,good filling,and light weight.It is widely used in machine tools,vehicle transportation,food machinery and other fields,and its high-end products are also applied in aero engines.With the continuous development of exoskeleton robot technology and China's increased investment in high-end manufacturing,gerotor pumps have a wider range of application scenarios and development prospects and also meet higher performance requirements.This paper takes the miniature high-speed gerotor pump as the research object,and mainly conducts theoretical and simulation research on its working principle,basic parameters,static characteristics,friction pair characteristics and flow characteristics.Experiments are used to verify the correctness of the theory and simulation.Firstly,the generation principle of internal and external rotor tooth profile is studied.The internal rotor tooth profile equation and the rotor meshing equation are established.The basic parameters of the rotor of the gerotor pump and the range of values of the vane coefficient and arc diameter coefficient are determined.Their influence on the tooth profile shape,curvature radius and meshing characteristics are given.The main structural parameters are determined according to the working principle of the cycloid pump,which provides the basis for the following statics and friction pair characteristics,flow characteristics and experimental research.Secondly,the static analysis of the rotor pair of the gerotor pump is carried out,and the stress and deformation cloud diagrams of different meshing positions of the rotor pair under the action of torque and pressure oil are obtained.The static verification and the solution of the auxiliary rotor modes are completed.According to the results of static analysis,the three groups of main friction pairs of the gerotor pumps are studied.An elastohydrodynamic lubrication model of the inter-tooth sliding friction pair,a hydrodynamic lubrication model of the outer rotor circumferential friction pair,and an oil film leakage model of the axial gap were established to complete the analysis and calculation of the friction pair leakage.Thirdly,the flow characteristics of the miniature high-speed gerotor pump were analyzed.AMESim lumped parameter model was established based on the instantaneous displacement curve,and the influence of the starting and end position of the oil suction and drainage window on the flow and pressure pulsation of the gerotor pump was studied.The flow field of the cycloid pump was analyzed by CFD software to study the influence of the gap oil film thickness,rotation speed and pressure on the flow characteristics of the cycloid pump.Finally,an experimental study of the miniature high-speed gerotor pump was carried out.The prototype of the gerotor pump and the test bench of the high-speed hydraulic pump were designed and processed.The prototyping experiment of the the miniature high-speed gerotor pump was completed and the correctness of theoretical analysis and simulation was verified.The experimental results show that the prototype can work normally under high speed,meeting the performance index requirements.