摘要
针对气体静压主轴回转误差求解不准确的问题,提出了一种利用气膜阻尼模型预测气体轴承动态特性的计算方法,揭示了气膜阻尼影响气体轴承动态特性的内在机制。首先通过微扰动法和分离变量法对气体轴承的气膜阻尼系数建模并求解分析;然后将气膜阻尼系数引入轴承转子系统进行动力学建模,计算分析阻尼系数对气体轴承动态特性的影响;最后搭建气体轴承回转误差测量试验台,得到主轴实时回转跳动误差信号并与理论结果进行对比。实验结果表明:与未考虑气膜阻尼特性的回转跳动误差相比,考虑气膜阻尼特性计算的主轴回转跳动误差值更加接近实验测量值,考虑气膜阻尼特性使主轴跳动误差率减小了4.93%~8%。研究结果可为气体轴承动态特性的预测和精度控制提供理论参考。
A calculation method for predicting the dynamic characteristics of gas bearings is proposed to solve the problem of inaccurate solution to the aerostatic spindle rotation error and to reveal the internal mechanism of the film damping affecting the dynamic characteristics of gas bearings. The method uses the film damping model, and the gas film damping coefficient of the air bearing is modeled and solved by the micro-perturbation method and the variable separation method. Then, the film damping coefficient is introduced into the dynamic model of bearing-rotor system, and the influence of the damping coefficient on the dynamic characteristics of a gas bearing is calculated and analyzed. Finally, a test bench for measuring the gas bearing rotation error is set up, and the real-time rotary runout error signal of the spindle is obtained and compared with the theoretical result. Experimental results and a comparison with the rotation runout error without considering the damping characteristics of the film show that the value of the spindle runout error calculated by considering the damping characteristics of the film is closer to the experimental value and the spindle runout error rate reduces by 4.93%--8%. Therefore, this research may provide a theoretical reference for the prediction and precision control of the dynamic characteristics of air bearings.
作者
任佟
陈东菊
李彦生
范晋伟
REN Tong;CHEN Dongju;LI Yansheng;FAN Jinwei(Beijing Key Laboratory of Advanced Manufacturing Technology, Beijing University of Technology, 100024, Beijing)
出处
《西安交通大学学报》
EI
CAS
CSCD
北大核心
2019年第8期68-75,共8页
Journal of Xi'an Jiaotong University
基金
国家自然科学基金资助项目(51875005,51475010)
关键词
气体轴承
气膜阻尼系数
轴承转子系统
动态特性
gas bearing
film damping coefficient
bearing-rotor system
dynamic characteristics
