Design And Dynamic Analysis Of The Segmented Meshing Profiles Cycloidal Pump

To alleviate electric vehicle mileage anxiety,the gerotor efficiency should be improved.The traditional cycloidal pump model as a lube oil pump no longer meets the development needs of the electric vehicle industry.Based on this,this paper designs the segmented meshing profiles cycloidal pump for the electric vehicles axle lubrication system.Compared with the traditional cycloidal pump,it has the characteristics of small contact force and large flow rate,the specific contents are as follows:Firstly,based on a special mathematical model of the gerotor proposed by G Bonandrini and combined with the design parameters of the traditional cycloidal pump,the inner and outer rotor tooth profile are parametrically designed,the contour lines of the inner and outer rotor and meshing model are designed,and the three-dimensional model of the segmented meshing profiles cycloidal pump is established.The simulation analysis of the traditional model and the design model includes the contact force simulation analysis,transient dynamics simulation analysis,and CFD fluid dynamics simulation analysis.The results show that the working performance of the designed segmented meshing profiles cycloidal pump is better than that of the traditional cycloidal pump.In terms of contact force,when the driving speed of the inner rotor is 2000r/min and the torque applied by the outer rotor is 2N·m,the minimum contact force is only 50%of the traditional cycloidal pump.In terms of transient dynamics,the equivalent stress of the designed segmented meshing profiles cycloidal pump is generally less than that of the traditional cycloidal pump,which conforms to the allowable stress intensity and the maximum defoemation is 1.57μm,only 6.28%of the reserved meshing clearance,which does not affect the normal operation and sealing effect of the inner and outer rotors.In terms of fluid dynamics,compared with the traditional cycloidal pump,the designed segmented meshing profiles cycloidal pump has more uniform pressure fluctuation and better cavitation performance.Secondly,the flow characteristics of the segmented meshing profiles cycloidal pump are studied.Based on the contour lines,the theoretical displacement model,instantaneous displacement model and leakage model are established.The simulation analysis and experimental comparison between the traditional cycloidal pump and the design model are carried out.In addition,the friction torque model between the inner and outer rotor is established to study its frictional characteristics and verified by experiments.The acoustic test of the segmented meshing profiles cycloidal pump prototype is carried out to analyze the acoustic frequency characteristics of the inner and outer rotor matched with two materials under different working conditions.Finally,the mechanical-hydraulic coupling dynamic model of the segmented meshing profiles cycloidal pump is established based on the power bond graph theory,and the experimental platform is built according to the hydraulic system to complete the prototype experiments.The experimental results show that the dynamic model can effectively characterize the working characteristics of the segmented meshing profiles cycloidal pump,which is consistent with the experimental data and can effectively predict the working performance under different operating conditions.