Optimal Design Of Reversing Mechanism Of Drum Pumping Unit Based On Non-circular Gears

With the rapid development of industrial technology,the demand for energy from human society is more urgent.Oil is known as the "blood of industry" and holds an absolute dominant position in human energy consumption.However,the exploitation of most oil fields in China has entered the middle and late stages,and the difficulty of oil extraction is becoming increasingly difficult.Traditional pumping units have low efficiency,poor adaptability to the environmental,and low utilization rates of energy,and it is difficult to meet the needs of modern oil fields.The new beamless pumping unit is small in size,low in energy consumption,and strong in adaptability to the environment.It is precisely the equipment that is urgently needed in modern oil fields.However,due to its lack of economic use and high reliability of the commutation mechanism,it is currently not widely used.Therefore,in this subject,the non-circular gear planetary gear train reversing mechanism used in a new type of drum pumping unit is analyzed for the non-circular gear bearing capacity and the overall dynamics of the planetary gear train.Corresponding to the factors affecting the stroke of the pumping unit,the mechanism has optimized the design of the transmission scheme and key components of the commutation mechanism,and verified the correctness of the optimized design through motion simulation.First of all,in view of the problem of difficult to check the tooth surface contact strength due to the special geometry of non-circular gears,combined with the meshing principle of non-circular gears,a calculation model of tooth surface contact stress for non-circular gears was proposed based on Hertz contact theory.The influence of different design parameters on the contact stress of tooth surface was studied.It is found that during the rotation of non-circular gears,the contact stress of the tooth surface changes periodically,and the eccentricity of non-circular gears is the main reason affecting the stress fluctuations,which provides a theoretical basis and a verification method for subsequent non-circular gear designs.Secondly,the excitation forms of non-circular gears during slewing are analyzed and calculation methods are given.Considering the time-varying meshing stiffness and damping of the gear teeth,a torsional vibration model of a non-circular gear pair was established using concentrated parameter generation.The non-circular gearvibration model is generalized,and other forms of vibration of non-circular planetary gear trains are considered.The translation-torsional coupled dynamic model of non-circular planetary gear trains is established,and the differential equations of motion are obtained.By solving the equation,the dynamic response of the planetary gear train under different conditions and different excitations is quantitatively studied,which provides a reference for the vibration reduction of the pumping unit reversing mechanism.Finally,the transmission scheme and key components of the commutation mechanism were optimized and a three-dimensional model of the commutation mechanism was established.The motion simulation software was used to simulate the optimized reversing mechanism.The transmission characteristics of the reversing mechanism before and after optimization were compared,and the rationality and correctness of the optimized design were verified.Through the above research,the reversing mechanism of the new drum-type pumping unit is optimized to improve the carrying capacity,reduced the vibration,and obtain a longer stroke,which meets the current oil field demend for oil production equipment,and provides a new theoretical basis for the promotion and use of the new type drum pumping unit.