轴承装配误差及预紧量对导引头伺服机构谐振频率影响与分析

为了在精密装调过程中对导引头伺服机构的动态特性进行准确预测，采用理论建模的方法确定了轴承微量装配参数与伺服机构谐振频率的定量关系。基于Hertz接触理论，建立5自由度轴承刚度模型，并将微量装配误差对轴承刚度矩阵的影响进行建模和分析；采用Timoshenko梁理论推导弹性阶梯轴单元矩阵，并确定系统特征值和特征向量的求解方法；采用MATLAB/GUI建立伺服机构谐振频率分析系统，并搭建实验系统对理论模型进行验证。分析和实验结果表明，所建立的分析方法可以对轴承的微量装配误差引起的谐振频率变化进行比较准确的计算，解决了目前伺服机构精密装调过程中动态特性预测的难题。
To predict the dynamic characteristics of seeker servo mechanism in the process of precision assembly, the quantitative relationship between the micro assembly parameters and the resonance frequency of servo mechanism was built by using the theoretical modeling method. Based on the Hertz contact theory, a five-degree-of-freedom bearing stiffness model was established and the influence of the micro assembly errors on the bearing stiffness matrix was modeled and analyzed. Using the theory of Timoshenko beam, the cell matrix of elastic multi-diameter shaft was derived. The method of solving the eigenvalue and eigenvector of the whole system was determined. An analysis system for resonant frequency of servo mechanism was established through using MATLAB/GUI and the experimental system was established to verify the theoretical model. The analysis and experimental results show that the established analytical method and system can accurately calculate the resonant frequency variation caused by the micro assembly errors of bearing. This method solves the problem of dynamic characteristic prediction in the process of precision assembly of servo mechanism.