Simulation and analysis of long-stroke reciprocating pump with rack-and-pinion combined crank connecting rod mechanism
Although the reciprocating pump with the crank connecting rod is widely used in various fields,especially in the oil-drilling industry,such defects as short stroke,high speed and short life of wearing parts restrict its further development.In this article,in order to address these defects,a composite mechanism based on the rack-and-pinion and crank connecting rod is proposed.The traditional reciprocating pump's crosshead structure is replaced by the straight-tooth cylindrical gear,and the pis-ton's long-stroke reciprocating motion is realized by combining the fixed upper rack and the movable lower rack.Efforts are made to set up the piston's motion equation as well as the dynamics simulation model of the three-cylinder drilling pump equipped with this composite mechanism.Both the piston's motion characteristics and the rack and pinion's dynamics characteristics with a certain amount of load areexplored;and the fatigue analysis is carried out on the gear.The results show that the piston stroke of the new reciprocating pump is doubled than that of the traditional reciprocating pump with the same crank radius,and the flow pulsation rate does not increase but the pulsation frequency reduces by twice.The number of pump-and-valve switching is effec-tively reduced,which will greatly prolong the wearing parts'life.The gear's fatigue life lasts for more than 13 000 hours.These results show the composite mechanism is feasible and provide theoretical support for further development of subsequent products.
reciprocating pumprack and pinioncrank connecting rodcombined structuredynamicsfatigue life
万方数据
维普
