Design And Analysis Of Double Helix Cam Pumping Unit

With the increasing number of high water-containing oil wells,low-pressure wells and heavy oil wells,the demand for long-stroke,low-shock,high-efficiency and energy-saving pumping units has increased,meeting the requirements of oilfield conservation and sustainable development.At present,the most widely used pumping unit in our country is the beam pumping units,which has poor balance ability,low transmission efficiency and large inertia load.When exploiting heavy oil and high water-bearing oil fields,it can no longer meet the requirements of more economical and efficient mining.And the existing beam-free pumping unit has some problems such as complicated commutation structure and high failure rate.therefore,developing a new type of long stroke energy-saving pumping unit with high efficiency and energy saving,which is suitable for the actual working conditions of modern oilfields,is the main research topic in the future development of pumping units.Aiming at the shortcomings of existing pumping units with mechanical commutation device,a new type of double helical cam pumping unit is proposed in this paper.This type of pumping unit realizes automatic commutation through the reciprocating screw,eliminating intermediate transmission link,has simple structure,high efficiency and easy maintenance.The double camshaft structure can improve the balancing ability of the pumping unit,has high reliability and small floor space.The suspension point makes uniform motion for most of the time,so its inertia loss is small and the energy saving effect is remarkable.This paper mainly carried out the following aspects of work:Firstly,the overall scheme of the new double helix cam pumping unit was designed.According to its basic working parameters,the suspension point load is calculated to determine the load required by the pumping unit.According to the load,the key components of the pumping unit are designed and selected in detail,and modeled by SolidWorks 3D software to prepare for the next analysis.Secondly,the kinematics and dynamics analysis of the double helical cam pumping unit are carried out.In the ADAMS,the simulation model of double helix cam pumping unit is established,and then analyzes the motion law of suspension point,the suspension point load,the load on crowned pulley axle under different strokes;the contact load of cam pair is also analyzed.Through the force analysis of the sucker rod string,the vibration wave equation of the sucker rod string is established,and the finite difference method is used to program and solve in the MATLAB to analyze its dynamic characteristics.Finally,the thesis use ANSYS Workbench software to carry out static analysis of key components of double helix cam pumping unit,mainly including finite element analysis of pumping unit frame,spiral camshaft,reversing device and gear structure,check whether the strength and stiffness are fulfil requirements.