速度滑移下液压主轴轴心轨迹动态研究

中文摘要: 基于载荷增量法和扰动压力法，研究液体液压主轴系统的动态性能。通过有限差分法求解计入微尺度速度滑移效应的不定常油膜压力分布的雷诺方程，并得出非线性油膜力。应用载荷增量法和扰动压力法求解反映油膜动态特性的4个动态刚度和阻尼系数，并用于转子轴心轨迹的动力学描述，求解存在偏心质量下的转子轴心轨迹，实现液压主轴系统的流-固耦合分析。研究结果表明：速度滑移对液压主轴的动态刚度和阻尼性能造成了一定的影响。动刚度系数 K xx、 K xy、 K yx和 K yy受滑移影响降低的最大比率分别为4.85%、4.85%、7.20%、7.16%，速度滑移降低了油膜阻尼系数 C yx、 C xy和 C yy，阻尼系数 C xx受滑移影响比较复杂；随着转子偏心质量距的不断增加，主轴轴心运行轨迹在不断扩大，系统的稳定性不断降低。最后，通过液压主轴回转精度实验验证了轴心轨迹模型的正确性和有效性。
Abstract:Based on the load increment method and the pressure perturbation method,the dynamic performance of liquid hydraulic spindle system was researched.Using the finite difference method,the nonlinear oil film force was calculated by solving the Reynolds equation of unsteady oil film pressure distribution which was included in the micro-scale velocity slip effect.Four dynamic stiffness and damping coefficients reflecting the dynamic characteristics of the oil film were calculated by using the load increment method and the pressure perturbation method,and were used to the analysis of hydraulic spindle system.The research results showed that:Velocity slip caused a certain impact on dynamics of hydraulic spindle stiffness and damping performance.The maximum decreasing ratios of dynamic stiffness coefficient K xx, K xy, K yx and K yy which were caused by velocity slip were 4.85%,4.85%,7.20%,7.16% respectively.Velocity slip reduced the oil film damping coefficient C yx, C xy and C yy, the change rule of damping coefficient C xx by slippage effect was more complex.With the increasing eccentric quality of the rotor, running track of the spindle axis was in the expanding,and the stability of the system decreased continuously.The experiment of the measuring path of the shaft verified the correctness and validity of the orbit of shaft centre model.