Dynamics Simulation And Experimental Research Of Micro Screw Pump

In order to meet the requirements of micro-flow application of various liquid materials in precise dispensing process.To realize the application of fluid from high viscosity to low viscosity in dispensing process.It should have the characteristics of small volume,simple ’structure,strong practicability and high stability,so as to achieve stable flow,even drop and good consistency.And it can be better used in precision dispensing industry.Therefore,the influence of main parameters on the working characteristics of micro screw pump is the goal of research.The related application theory of screw pump,the kinematics and dynamics simulation of the rotor and stator of the key structure of screw pump,and the internal flow field of screw pump are studied.And the micro screw pump experiment was used for verification.Based on the application theory of screw pump.The mathematical model is deduced and the 3d model is created.And the relative motion of rotor and stator of screw pump is simulated by NX 10.0 software.The kinematics of the rotor is verified by the data graph.It is obtained that the motion trajectory of any point on the rotor line is ellipse,and these ellipse parameters are different.The velocity of these points is harmonic variable motion.Based on the theory of fluid mechanics,the laminar flow pattern and flow equation of the internal flow field are obtained.The structural dynamics simulation of stator model of screw pump is carried out by means of analysis software.The influence of different parameters on the working characteristics of micro screw pump is studied.It is concluded that the interference between rotor and stator is an important factor of stator deformation.In the rotor motion,the stator deformation presents a waveform relationship,in which the largest shape variable is located at the central meshing point of the rotor in the straight segment of the stator contour.It is concluded that the hardness of stator material is the key factor affecting the stress coefficient.The flow field of micro screw pump is simulated by UDF dynamic grid technique Pressure field,velocity field and wall stress of flow field under different rotating speed,medium viscosity was analyzed.It is concluded that the increase of medium viscosity has a great influence on the distribution of flow field.As the rotor speed increases,the stator wall stress increases,which leads to the decrease of the sealing property and the increase of leakage.When the rotor moves to the stator center,the stator is subjected to the maximum wall stress,which is the most prone to wear,leading to loss of sealing performance of screw pump.Therefore,choosing appropriate speed and viscosity can effectively improve the performance of micro screw pump.Finally,it is found that the increase of interstator interference makes the error of working flow of micro-screw pump increase obviously,which leads to the decrease of flow characteristic stability.And the increase of fluid viscosity reduces the flow rate error of screw pump and effectively improves the flow rate characteristic of micro screw pump.With the increase of rotating speed,the flow volume increases linearly,but the relative error decreases,and the flow characteristic of micro screw pump tends to be stable.The consistency effect of micro screw pump at different rotating speed is obtained by the point experiment.