The Design And Evaluation Of Double-drum Long Stroke Pumping Unit

This paper introduces and analyzes the following topics,conventional beam pumping unit and its improved version has several problems such as poor balance effect,high energy consumption and low oil extraction efficiency;long stroke pumping unit has a longer stroke,higher transmission efficiency,easier to adjust balance,lighter in weight,lower energy consumption and many other advantages;introduced the classification of domestic and foreign long-stroke pumping unit and described several products in use,also predict its development trend.The main subjects of this research paper include the following:Consider the pumping unit actual working conditions and needs to determine its performance parameters,then draft the long stroke pumping unit motion design solution;perform movement analysis for the pumping unit in the upper and lower stroke and give mathematical forms to its suspension point displacement,suspension point speed and suspension point velocity;based on the analysis of the static and dynamic load of the suspension point,to draw pumping unit indicating diagram;analyze the pumping unit workload to determine the power parameters for the pumping unit power transmission system.Using the frequency converter as the pumping unit direction switch device to control motor rotation direction,to implement the upper and lower stroke;and use gravity potential energy balance method to achieve the overall power balance of the pumping unit,then to reach the motor up and down stroke power balance;based on pumping unit upper stroke maximum power consumption and weight to calculate motor power required,and select motor and frequency converter's model accordingly,then confirm V belt speed,number and model,determine the size of the belt wheel.The driving device is designed with a double-row gear speed reducer,which is a purely mechanical drive and enhance the strength of the main unit.In the following part of paper,it used the above calculation and results to re-design the reducer shaft,roller shaft and counterweight roller shaft;it also verified shaft key and speed reducer output shaft.At the end of this paper,it confirmed evaluation index set of the pumping unit;obtained different evaluation indexes by using the analytic hierarchy process;and used fuzzy evaluation method to give an overall review to the pumping units.