Research On Dynamic Characteristics Of Rub-impact Of Progressive Cavity Pump With Eccentric

The oil extraction single PCP(progressive cavity pump)is widely because of the advantages of simple ground structure,low energy consumption,wide application range.In order to study the phenomenon that the single PCP(progressive cavity pump)operates steadily with the rotating speed is increased when the single PCP is working underground,related issues on dynamic behavior of rub-impact of PCP with eccentric are studied and the characteristic of law of the single PCP rotor eccentrically ratio rub-impact system has been analyzed。The movement of the single PCP rotor in a single cycle is divided into two stages: curve motion and linear motion according to the movement characteristics of the single PCP rotor in the stator.According to the theory of rotor dynamics and combines the Jeffcott rotor system modeling method,the 1/4 lead PCP rotor is equivalent to a single cross section.The two-stage analysis model of motion of rub-impact nonlinear system of single PCP with eccentric is established separately.The transformation equations of the position coordinates of the center of rotation and the center of the circle in the two motion phases are derived.The theoretical amplitudes of the rotor in the two moving phases are analyzed,and the solution method is given.The effect of rotor speed is considered,numerical simulation of two-stage differential equations of motion by variable step size fourth-order Runge-Kutta method,and by combining the rotor system bifurcation diagram,trajectory diagram,phase diagram,Poincarésection diagram,etc.,the dynamic simulation results are analyzed.The results show that during the revolution of the rotor around the center of the stator,the revolution radius changes periodically from high to low to high,and the center of rotation has been keeping moving around the revolution circle,and the movement change process is similar to the change trend of the revolution radius.What’s more,Simulation analysis is performed under different eccentricity,the effect of speed on the dynamic response of the rotor rub-impact system.the relationship between the speed value and the eccentricity that make the rotor system run more and more stable is drawn.