气浮活塞优化设计及其径向承载力试验研究

Optimization design and experimental study on radial bearing capacity of air-floating piston

对于气缸的高精度伺服控制而言,从根本上消除摩擦力具有重要的意义。气浮活塞是气浮无摩擦气缸的重要构成部件。在气缸的运行过程中,气浮活塞的径向承载力不足会引发活塞与缸筒内壁接触,致使气体润滑失效。为了提高无摩擦气缸中气浮活塞的径向承载性能,期望在实现更大承载力的前提下尽量减少耗气量,采用有限元仿真与试验相结合的方法,开展了气浮活塞径向承载力的研究工作。首先,采用Fluent软件仿真分析了供气压力、偏心率和节流孔直径等参数对气浮活塞径向承载力和耗气量的影响;然后,在综合考量后,优选出了气浮活塞的节流孔径,并以此加工出了气浮活塞样机;最后,为了测试实际情况下不同供气压力和偏心状态下的气浮活塞的径向承载能力,设计并搭建了一套以气浮无摩擦气缸作为加载装置的高精度径向承载力检测装置。研究结果表明:从定性的角度上看,仿真和试验结果趋势一致;从定量的角度上看,试验结果与仿真结果的吻合度在90%以上。该研究可为采用Fluent软件仿真研究气浮活塞径向承载力的准确性提供依据,为后续仿真模型的修正提供一定的指导。

For high-precision servo control of cylinders,fundamentally eliminating friction is of great significance.The air-floating piston is an important component of an air-floating frictionless cylinder.During the operation of the cylinder,the insufficient radial bearing capacity of the air-floating piston will contact the inner wall of the cylinder,and there is a problem of gas lubrication failure under radial load.In order to improve the radial load-bearing performance of the air suspension piston in a frictionless cylinder and minimize air consumption while achieving greater load-bearing capacity,a study on the radial load-bearing capacity of the air suspension piston was carried out,using a combination of finite element simulation and experiments.Firstly,Fluent software was used to simulate and analyze the effects of parameters such as supply pressure,eccentricity,and orifice diameter on the radial bearing capacity and air consumption of the air-floating piston.Then,based on comprehensive considerations,the optimal orifice diameter for the air-floating piston was selected,and a prototype of the piston was manufactured accordingly.Finally,in order to test the radial bearing capacity of the air-floating piston under different air supply pressures and eccentric conditions in actual conditions,a high-precision radial bearing capacity testing device using an air-floating frictionless cylinder as the loading device was designed and built.The research results indicatethat from a qualitative point of view,the trend of the simulation and test results is consistent,from a quantitative point of view,the coincidence between the test results and the simulation results is more than 90%.This research can provide a basis for the accuracy of the radial bearing capacity of the air bearing piston using Fluent software,and provide some guidance for the subsequent revision of the simulation model.