Rotor Of Progressive Cavity Pump Reconstruction Research Based On Feature Points

Progressing cavity pump(PCP) is a kind of artificial lift method, the advantages of low investment, equipment simple structure, convenient operation and energy saving effect is obvious and the characteristics of strong adaptability, can effectively reduce the production cost, improve the efficiency of production, so have been paid much attention by oil field at home and abroad.Production of screw pump is mainly composed of eccentric screw(rotor) and with spiral cavity pump body(stator) in two parts, under the condition of normal use of the surface of the rotor of the screw pump wear is the main failure forms, types of the wear of abrasive wear and erosion wear and corrosive wear, abrasive wear of the effect is more obvious.Screw pump rotor wear mechanism in the study found that the concave section of the inner rotor sliding speed, maximum, and the maximum contact stress of the stator, so will the rotor surface to form a spiral wear line of chromium plating layer on the surface of the lead to loss.After wear reaches a certain level can no longer use, need to repair in time. Damaged to repair the key point is need to know the rotor surface morphology, the shape may be expressed through the parameter equations of the rotor, but in the process of production, the design parameters of the rotor is classified data. In this case to repair work, determine the specific parameters of the rotor become the research focus.Based on the linear theory, the basis of PCP based on the forming principle of PCP rotor model, establishes the cycloid in general and short of linear single PCP rotor model, and play the buckle problem, this paper expounds the root cause of the play button.In fully study of common and short of the single screw rotor profile curve of the basic theory, combined with the characteristics of the three coordinate measuring machine, sums up the measures of the rotor based on feature points, the key is the choice of feature point method and the calculation method in the process of rotor refactoring. And application of three coordinates measuring machine to measure the single head screw pump rotor and five head rotor of the screw drilling tools, validate the correctness of this method.In the mode of reconstruction, the shaft section modeling method is relatively simple,known shaft cross section under the condition of two curve and the pitch. Method of point collection intercepted three head screw shaft section, the formation of common screw shaft section intercept method, established the general production screw pump rotor shaft section intercept equation. Five head screw drill with test application. Providing theoretical basis forscrew reverse measurement.