Study On Axial Load Uniformity Method Of Electrical Submersible Motor Driven Progressing Cavity Pumping System

The axial load fed back by the rotor of the progressing cavity pumping of electrical submersible motor driven progressing cavity pumping system is mainly afforded by the thrust bearing placed in the coupling.Due to the harsh working conditions of the bearing,the service life of the current standard bearing is short and the effect is not good,and the effect of the earlier solution measures is not very ideal.Once the bearing fails,it will inevitably lead to a decline in the overall life of the system,and ultimately restrict the development and application of the system.This paper proposes an optimal design scheme from the perspective of structural design,bases on the design concept of " series configuration,parallel load uniformity " to carry out bearing configuration innovation,in the form of tandem bearings instead of the original single bearing configuration,aims at making the bearing units of the bearings can carry the axial load fed back by the rotor of the progressing cavity pumping in a average way,realizes the uniform effect of axial load,decreases the axial load of the bearing unit in order to improve the reliability of bearing parts,so as to break the restrictions on the size and depth of the well radial,thus improve the overall reliability of electrical submersible motor driven progressing cavity pumping system.The equivalent mechanical model of bearings was established according to the elastic system.The equivalent mechanical network of the equivalent mechanical model was obtained by using mechanical impedance analysis method,and the theoretical conditions of load uniformity of the tandem bearings was analyzed.Numerical simulation method is used to evaluate the load uniformity effect and bearing capacity of tandem bearings,the optimization effect of the innovative configuration is compared and analyzed from two aspects of maximum equivalent stress and ultimate life of multi-stage bearing unit and single bearing.When the axial load is constant,it is concluded that the reduction ratio of the equivalent stress of the second,third,fourth and fifth tandem bearings is respectively 40.75%,60.36%,67.77% and 71.19% than the original configuration,and uniform loading effect is good due to uniform loading rate of multistage bearings over 82%.Compared with the single bearing,the ultimate life of the bearing unit of the second,third,fourth and fifth tandem bearings is respectively increased by 653%,2175%,4589% and 7109%,which effectively solves the problem that the excessive axial load limits the life of the bearing part and the whole system.Under the premise of allowable axial size,the series of tandem bearings is proportional to the optimization effect.The comparative analysis shows that the optimization effect of bearings configuration is very significant,which effectively improves the bearing capacity of bearing,meets the expected goal,and promotes the application and popularization of system.At the same time,the bearing capacity and load uniformity effect of the tandem bearings were further optimized.The bearing capacity and load uniformity effect of the tandem bearings are improved by optimizing the component parameters,improving the manufacturing accuracy and pre-load running-in wear.Tandem bearings configuration realizes the uniform loading effect of axial load,effectively reduces the axial load of the bearing unit,improves the bearing capacity,and successfully solves the problem that the excessive axial load limits the life of the bearing part and the whole system.It is a feasible method to study the axial bearing capacity of electrical submersible motor driven progressing cavity pumping system,which can be used as a reference for other devices that need to improve the bearing capacity and reliability of gauge bearing under extreme working conditions.