Study On The Theory And The Numerical Simulation Of The Characteristics Of Polymer Gear Pump

There is gear pump with not only the basic characteristics of flux and volume efficiency,torque and mechanical efficiency,power and total efficiency,but also the phenomenons of trapping,yawp,air pocket and so on. These characteristics and phenomenons have effect on the quality of gear pump,and it is difficult relatively to research them by theory. At present the research is limited to the phase of examination testing. Theoretic research of the characteristics and the phenomenons of polymer gear pump are blank in China when the gear pump feeds the viscous polymer liquid of chemical flow with high temperature and high pressure. So the characteristics and the phenomenons of ordinary helical gear pump and the polymer gear pump are researched by theory in this paper,and the new profile of the rotor of polymer gear pump is brought forward,which is very important to the academic development and actual application of the gear pump technology. The main works and the creative ideas are summarized as follows:1 . Based on the action and the capability need of polymer gear pump in oil chemical engineering,the idea of whole profile meshing of polymer gear pump is advanced for the first time. The profile equation of whole profile meshing is worked out by the meshing theory,and the numerical calculation program of the new profile is accomplished. The 3D modeling of the gear rotor and the movement simulation of the gear assembly system are realized. The interference and sidegap of gear meshing are analysed by 3D modeling of the gear,so it can be judged that the gear profile is right whether or not before machining.2. The flux characteristics of ordinary helical gear pump are lucubrated by theory for the first time,on this condition the selective qualification of the helical gear pump is gained. The researchful results indicate that the flux pulse ration of ordinary helical gear pump without clearance is less than that of the gear pump with clearence under the condition that the main parameters are same,and the flux pulse ration of ordinary helical gear pump is less than that of whole profile meshing helical gear pump.3. The trapping characteristics of ordinary helical gear pump are lucubrated by theory for the first time,the theoretic relation of the gear rotor between the end overlap coefficient and trapping phenomenon is discussed respectively with clearence or without clearcence,and the relation of trapping volume with the rotational angle turn is also discussed. The selective range of the helical angle that can eliminate completely the trapping of helical gear pump is gained,which never appeared in literature before. On the condition the trapping characteristics of whole profile meshing helical pump are lucubrated by theory for the first time,and the select range of the helical angle that can eliminate completely the trapping of whole profile meshing helical gear pump is also obtained.4. Based on the viscous hydrodynamics,the leakage characteristics of Newton liquid that is transmitted by helical gear pump are researched for the aim of the least power loss,and the leakage model is founded,the mathematic models of the radial and the axial leakage are gained. At the same time the optimal radial leakage and axial leakage are got,and the numerical calculation is achieved. The researchful result indicates that the optimal axial leakage is a little less than the optimal radial leakage,and the friction power which is caused by liquid viscosity decrease with the increasing of the leakage,and the friction power change not too much with the influence of the leakage.5. Based on the Ostwald-de Waele equation,the leakage characteristics of power-law transmitted by helical gear pump are researched,and the leakage model of power-law in the clearence is founded,and-the velocity distributing and the leakage capacity are worked out by the boundary condition. The power loss of leakage is got through the clearence leakage capacity,and the friction power loss is attained by the velocity distributing. The mathematic calculati...