Research On Meshing Characteristics Of Curtate Hypocycloid Of Rotor-stator Pair Of Double-lobe Single Progressing Cavity Pump

Progressing cavity pump is widely used in oil field because of its fewer moving parts, even displacement, and more strong adaptability and so on. The double-lobe PCP has characters such as large displacement, high efficiency, low energy consumption and good mechanics characteristic of rotor compared with single-lobe PCP and has been gradually promoted in the international community. Domestic theoretical and experimental research on double-lobe PCP is less, the single-lobe PCP is used in most oil field at present. Therefore, the in-depth theoretical study on double-lobe PCP has great practical significance.The paper converts complex space meshing problems of the double-lobe PCP into plane meshing problems by introducing the concept of the plane meshing. According to the gearing principle and using the relations of geometry and kinematics of the single PCP, the double-lobe PCP stator and rotor conjugate curve equation is set up. The result shows that the conjugate curve parameters such as spheronization radius R, the circle radius r, coefficient of variation k, isometric radius coefficient ro are main factors that affected the shape of conjugate curve of rotor-stator pair, curvature, flow area and eccentricity, thereby affect mechanical properties such as torque, speed, centrifugal force of the rotor, the largest sliding speed between the rotor and the stator, contact situation, wear situation, and the life of double-lobe PCP, the information for optimization design of the conjugate curve of rotor-stator pair was provided.Taking the largest flow area, minimum of largest integrated curvature and minimum of the largest sliding speed as optimal goal, using complex method to calculate to target function of the double-lobe PCP, the result indicated that when the coefficient of variation k and isometric circle coefficient were 0.8 and 1 respectively, output properties of the progressing cavity pump were the best. Using UG NX software and the optimization results, the 3D solid model of double-lobe PCP was established, using motion simulation module and finite element analysis module in UG NX to simulate and analyze about finite element of double-lobe progressing cavity pump. the result indicated that we can see that the stator wear of the double-lobe PCP which is established when coefficient of variation k was 0.8 is less than the one which was established when k was 0.5, mechanical properties and life index were better. The correctness of the theoretical analysis and the feasibility of the optimization design were verified...