Theoretical Analysis And Digital Prototype Design Of The Non-circular Gear Transmission Pumping Unit

Pumping unit is one of the most important machines in petroleum exploitation.In the current method of mechanical oil production,beam pumping unit accounted for most of the proportion.It has the following disadvantages: The excessive acceleration of hanging point is caused by the uneven movement of Horsehead;Dimensions and weight of the unit are increased significantly as we increasing the length of the stroke;This kind of pumping unit is low working efficiency,high manufacturing costs and energy consumption.This paper puts forward a oval gear transmission gear rack type pumping unit to solve above problems.It mainly has carried on several aspects about the plan design,three dimensional modeling,structural analysis,motion simulation and parameter analysis.First of all,three different types of gear transmission pumping unit are designed.The first plan of gear-rack type pumping unit is to use clutch commutator to transform direction.The second plan of gear-rack type pumping unit is to use gear commutator to transform direction.The last plan of gear-rack type pumping unit is to use Switched reluctance motor to transform direction,and the unit has a pair of elliptical gear.Through comprehensive comparison,it is concluded that the third plan is more conform to the requirements than the first and second plan on the structure performance,the smooth movement and energy consumption.Secondly,calculate the basic parameters of non-circular gear pumping unit which are Static load of hanging point,dynamic load of hanging point,and the balance of the pumping unit.Designed and calculated the main components that are power plant,steel wire rope,V belt transmission parts,gear reducer,elliptical gear,gear-rack,shaft and rack.The precise sizes of each part are determined by the calculation.By using three dimensional software to respectively build the three dimensional modeling.Finally put every part together and finish the digital prototype design of the pumping unit.Thirdly,by using the finite element software to static analysis of the main components of the gear-rack.The results show that the contact stress and displacement deformation are in accordance with the requirements,and the safety is verified.In this paper,the strength of elliptical gears with special components is analyzed,and its dynamic characteristics are estimated by modal analysis method.It is concluded that the minimum natural frequency is 2056.1 Hz,which is far less than the natural frequency of the pumping unit,and the resonance phenomenon will not occur.Finally,the changeable curve of hanging point speed and hanging point acceleration,which are using elliptical gear drive and conventional gear transmission pumping unit,can be calculated respectively by using the Matlab simulation system.Use SolidWorks software to draw the speed trajectory curve of hanging rod of point Sucker.It is concluded that the performance of the elliptical gear pumping unit is relatively good by comparing and analyzing the two curves of before.Analyze the influence of the main parameters eccentricity of elliptical gear to the velocity and acceleration of the hanging point.It is concluded that we should choose the larger eccentricity to ensure achieve the best performance of the pumping unit in a reasonable range.