Modeling And Optimization Of Non-circular Gear Reverse Mechanism Of Vertical Pumping Unit

The reversing mechanism is one of the important components of the pumping unit.At present,the main reversing ways of vertical pumping unit include mechanical commutation and electrical machinery commutation.The mechanical commutation focus on chain commutation mechanism which hid some disadvantages,such as a large degree of difficulty on the site maintenance,the short life of chain frame and the large impact load and so on.The cost of electrical machinery commutation is high and need to improve the life and reliability of the commutation system.The former researchers of the subject designed a new type of incomplete non-circular gear commutation mechanism based on the characteristics of incomplete gear intermittent transmission and non-circular gear variable transmission which realizes continuous constant rotation by driving input shaft and the output shaft forward and backward cyclical rotation with uniform acceleration-uniform-uniform deceleration.This paper completed studies for non-circular gear commutation mechanism of vertical pumping unit based on the preliminary research work.(1)Designed 3 kinds of models by changing the position of the output shaft and whether adds supported bearing on the intermediate drive shaft.Compared and analyzed the advantages and disadvantages of different programs to select the best solution suitable for practical application.Based on the sucker rod stroke,the curve integral method is used to determine the input shaft speed of the non-circular gear mechanism,which can meet the output stroke requirement accurately.(2)Analyzed the total work process of non-circular commutation mechanism and according to the structural characteristics of incomplete non-circular gear tooth profile,analyzed the commutation process of the first and the end of the tooth of incomplete non-circular gear.According to the theoretical angle relationship,the position of the tooth interference is obtained,put forward 2 kinds of tooth modification methods under the premise of ensuring the non-circular gear commutation mechanism can work normally.(3)Using Solidworks build 3D model for 2 kinds of tooth modification methods of non-circular gear commutation mechanism,and then imported into the kinetic analysis software ADAMS to make kinematics analysis and obtained the displacement,velocity,acceleration and contact force curve of each gear and shaft.Obtained the best contrast method by comparing the curves of different modification methods.And the maximum impact force of the gear teeth provides the basis for the maximum bending stress analysis and tooth optimization.(4)The finite static element analysis of the output shaft,the first and last teeth of active non-circular gear was carried out by ANSYS.The stress and strain distribution cloud images were obtained and optimized the parameters of the non-circular gear according to the analysis results.Then check the strength of the optimized gear to check whether it meets the bending fatigue strength conditions.The optimized commutation mechanism not only satisfies the fatigue strength requirement but also reduces the overall size of the mechanism,which is of great significance to the engineering practice.