Research on Dynamic Characteristics of Rub-Impact of Progressive Cavity Pump with Rotation Speed

Abstract

The dynamic characteristics of Progressive Cavity Pump (PCP) have an important influence on the stability of oil wells string system. A nonlinear dynamics model of rotor system was presented. The equations of unbalance rotor were established by the Lagrange approach and the vibration characteristics of the rotor system under rub-impact was analyzed by used the modern nonlinear dynamics and bifurcation theories, through numerical calculation. The bifurcation diagrams, time domain charts and Poincaré maps were obtained to analyze dynamic characteristics of the system and the results reveal the multiform complex nonlinear dynamic behavior of the rotor-bearing system under rub-impact. Moreover, the influence of the speed on the relatively stable speed of the rotor system was analyzed. These analysis results provide theoretical bases for the rotor system's status recognition, diagnosis as well as safe and economic operation.