液力推力器花键联接结构优化设计

Optimal Design of Spline Connection Structure of Hydraulic Thruster

摘要: 液力推力器具有水力柔性加压的特点，广泛应用于钻压不易施加的水平井、大位移延伸井等。液力推力器在工作时，关键部件花键联接结构的磨损较为严重，失效率高。针对该问题，笔者充分考虑芯轴所受轴向压力、径向压力、扭矩和位移载荷等多种因素作用，建立了花键联接结构瞬态接触的有限元模型。借助正交试验法设计实验方案，开展了花键联接结构的齿数、齿根圆角和内圆直径3个关键结构参数对其性能的敏感性分析。最后建立花键联接结构参数优化的数学模型，并采用SQR算法对数学模型进行优化。结果表明，优化模型相比初始模型有效降低了响应量数值，其综合指标值降低约24.9%。该研究为液力推力器的设计提供了理论依据。

Abstract: Hydraulic thruster was characterized by flexible hydraulic compression, which has been widely used in horizontal wells and extension wells, in which drilling pressure was not easy to be exerted. However, in the working process of hydraulic thrusters, its spline connection structure of the key component was serious worn and had high failure rate. Aiming at this problem, a finite element model of transient sliding contact was established in consideration of the axial compressive force, the radial pressure on the inner and outer surface, the torque and the displacement load of the mandrel. Through the test program using the orthogonal experiment, the sensitivity analysis of the key structure parameters of number of tooth, its root fillet and inner circle diameter on its performance was carried out. Finally, the mathematical model is established for the optimal design of connection structure, and then it is optimized for obtaining the optimal combination of parameters using SQR programming. The results show that compared with the initial model, the optimized model effectively reduces the response value by about 24.9%. The research result provides a theoretical basis for the design of hydraulic thrusters.