The Design And Calculation Of The Pumping Unit Driven By The Permanent Magnet Linear Motor

The beam pumping units in oil field have the advantages of simple structure and high reliability at the present time. But they have the problem of high energy consumption and low efficiency. So in the past half century , in recent years in particular, along with the develop of science and technology, the operator in oil field explore the new oil recovery equipment constantly.Facing the practical problems of the beam pumping unit, this paper put forward a plan of the design of pumping unit driven by a permanent magnet linear motor. This pumping unit driven by a permanent magnet linear motor, the straight reciprocating motion of electric machinery's kinetosome can switch to the upward and downward reciprocating of donkey head's suspension center through a crown block and flexible. The kinetosome can achieve a low and wide ranged motion velocity easily. So we can cancel the link mechanism and reduction box of original beam pumping unit. It can greatly simplify the monolithic construction of pumping unit, it can rise the ground efficiency of pumping unit, the reliability of machine's transmission devices and operating efficiency of pumping unit greatly.This paper introduce the basic structure and operating principle of the permanent magnet linear motor, and analyze its magnetic field pattern detailedly. It also analyze the control policy of electric machinery , and use direct force control for the permanent magnet linear motor on the basis of the results. This paper also study the basic structure and domination principle of the direct force control, design the basic structure of the pumping unit driven by permanent magnet linear motor, analyse the polished rod load and equilibrium principle. Analyse the rod pumping system's prediction model bring forward by S.G. Gibbs and analyze the sucker rod's running status through the computer, and design the concrete parameter of the permanent magnet linear motor as a result. And design the concrete structure of pumping unit system. Figure out the high energy consumption and low efficiency problem of beam pumping unit.it has a big development potential.