Research on sliding accuracy and precision design of externally pressurized gas-lubricated linear guide way

本文研究了外压气体润滑直线导轨的滑动精度特性，重点研究了滑动精度与导轨配合面加工误差的关系。所得结果总结如下：(1)基于发散式公式得到的轴承间隙内压力分布，建立了轴瓦浮动高度变化和俯仰模态角波动等滑动精度特性的理论分析方法。(2)轴瓦的滑动姿态以轨道表面的波浪形间距与轴瓦长度的比值为特征。根据该值的变化，在垫块在导轨上的移动过程中依次出现间隙高度变化最大的状态或垫块角度波动最大的状态。(3)采用表面有阶跃波动的方轴的实验结果与理论结果吻合较好，可以验证理论分析。(4)介绍了一种简单的轴瓦滑动精度分析模型；利用该模型建立了钢轨表面波浪度与垫块姿态之间的特征量。

The sliding accuracy characteristics of externally pressurized gas-lubricated linear guide way are investigated in this research with a special attention paid to the relation between the sliding accuracy and the machning error of the mating surface of the guide-way rail. The obtained results are summarized as follows :(1) Theoretical analysis method of sliding accuracy characteristics, such as the variation of floating height and the pitching-mode angular fluctuation of the bearing pad, is established on the basis of the pressure distribution in the bearing gap obtained by divergent formulation scheme.(2) The sliding attitude of the bearing pad is characterized by the ratio of the pitch of waviness of the rail surface to the length of the bearing pad. According to the change of this value, either a state with maximum variation in gap height during the travel of the pad on the rail or a state with maximum angular fluctuation of the pad appears in turn.(3) The experimental results with using a square shaft with step-type undulation on its surface coincide well with theoretical ones, which may verify the theoretical analysis.(4) A simple model for the analysis of the sliding accuracy of the bearing pad is introduced ; some characteristic quantities, which relates the waviness of the rail surface with the pad attitude, are formulated with the aid of this model.