摘要
为了分析可变截面节流器对空气静压轴承性能的影响,提出了变截面节流器的空气静压轴承模型,通过轴承承载表面弹性薄板的挠度变形实现节流器截面形状的动态变化。建立固体薄板变形和气体润滑的耦合偏微分方程,采用有限差分法和超松弛迭代法对耦合方程进行离散和数值求解。计算结果表明:节流器的截面形状直接决定了数值计算过程中喷嘴系数的大小,与刚性节流器的空气静压轴承相比,变截面节流器的空气静压轴承刚度提高了15%,在较高承载力的情况下能够获得更大的刚度。实验测试结果和理论分析基本一致,变截面节流器的设计方法能够有效提高空气静压轴承的静特性。
To analyze the effect of a variable section throttle on the performance of aerostatic bearings, an aerostatic bearing model with a variable section throttle was proposed. Furthermore, the dynamic change in the shape of the throttle cavity cross section was realized by deformation of the elastic plate of the bearing surface. First, the coupled partial differential equations of solid plate deformation and gas lubrication were established. Then, they were discretized and solved by the high-precision finite difference and over relaxation iteration methods. The results reveal that the shape of the throttle determines the value of the nozzle coefficient in the numerical calculation. Furthermore, the stiffness of aerostatic bearings with a variable section throttle is 15% higher than that of aerostatic bearings with a rigid throttle, indicating that a variable section throttle allows aerostatic bearings to achieve a greater stiffness under high bearing capacity. The results of the theoretical analysis are in good agreement with experimental results. Moreover, they indicate that a variable section throttle can effectively improve the static characteristics of aerostatic bearings.
引文
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