Research On The Line Style Of Shaft-Housing Pairs Of Progressing Cavity Pump

It's not a long time since the progressing cavity pump(PCP) has been developed. Now there is some development in the lifting theory and match technology, but the characters and potentials of this new hydraulic mechanism aren't been discovered sufficiently, so quite a few academic questions need to be solved, these questions restrict the further application of PCP. Simultaneously, the developments of the oil fields require that the PCP has more excellent lifting capability. To solve these questions, we need to go deep into application research and theoretic study of PCP.In this paper, by means of researching the forming principle of the hypocycloid PCP's horizontal cross section, the analysis of motion of the isometric profiles was developed. At the same time, the changing rules of the contact angle of the turning point and the midpoint, how the contact angle of turning point influencing the PCP's performance were also discussed especially. Here, the contact angle is a value, obtained by subtracting between the angle when the rotor leaves a point and the angle when the rotor begins to contact this point.Furthermore, the engagement process of the hypocycloid PCP was researched, and the relationship between the engagement motion and the molding motion of the primary line style were discovered. Accordingly, the rule of motion and comparatively slide velocity formula of fixation contact point and the floating contact point were obtained. The research findings of how the radius variation ratio influences the line-stye of shaft-housing pairs shows that: when the radius variation ratio is a comparatively bigger value, the isometric profiles isn't very good, so the turning zone is frayed rapidly. On the other hand, when the radius variation ratio is very small, such as 0.2, the floating contact area centralizes to the midpoint, the midpoint zone will be frayed rapidly. So the conclusion is that the finer radius variation ratio should be close to 1 under the circumstances that the isometric profiles has no drape on it.According to nitrile-butadiene rubber(NBR) tribological rules, of which the minimum value of the comparatively slide velocity of the floating contact point will influence the stator abrasion mostly, we can conclude that the minimum value of the comparatively slide velocity of the floating contact point should be increased in order to prolong PCP's working lifetime. A set of excellent performance indexes is very important for the design of PCP. This paper confirms the flow area, the minimum value of the comparative slide velocity of the floating contact point, the maximum integration curvature, and the radius variation ratio as the performance indexes, discussed how the single parameter such as the number of the lobe influences the performance indexes, deducted the formulas of these performance indexes of the hypocycloid PCP. Subsequently, optimal design program of the hypocycloid PCP was set up, by resolving mathematical model, PCP's conjugate curve with excellent performance was obtained.Finally, secondary development technology of CAD system based on UG was researched, a new way to build a CAD system for the hypocycloid PCP, which combined UG/Open GRIP with VB.net, was selected. Using this CAD system, parameterized and three-dimensional model, kinematics simulation, and the finite element analysis of hypocycloid PCP were established orderly. The results show that the performance indexes are appropriate and the hypocycloid PCP optimization design is unsatisfactory, the model of shaft-housing pairs, which comes from optimized parameters, has distinct advantages accordingly.