为分析空气动压箔片轴承启停过程的内在机制,构建箔片轴承试验平台,采用连续启停和阶梯转速启停2种实验模式对箔片轴承的启停特性进行深入研究,获得箔片轴承启停过程中摩擦力矩的真实变化规律；结合气体润滑理论,预测箔片轴承摩擦力矩在全转速范围内的变化规律,从工程角度给出了箔片轴承起飞转速的合理定义.结果表明:体接触摩擦力矩和气膜剪切摩擦力矩组成,在全转速范围内,箔片轴承的合成力矩随着转速的升高先降低后升高；工程角度看,当箔片轴承在设定转速下工作时,只要测量合成力矩相对于启动时最大力矩下降了很大的幅度,可以认为此时的箔片轴承已经起飞,即当前状态的箔片轴承具备承受相应负载的承载能力.%In order to analyze the intrinsic characteristics of foil air bearing during the start and stop process,a test rig was built and experiments with two kinds of experiment mode, continuous rotary speed start-stop and stepped rotary speed start-stop were implemented. From the experiment results the real law of friction moment of foil air bearing during the start and stop process was concluded, the law of friction moment in the full speed range was predicted integrating with the theory of gas lubrication, and a reasonable definition of lift-off speed of foil air bearing was given from the sight of engineering. The experiments reveal that the tested moment of foil air bearing is composed of contact friction moment between solids and shear friction moment of gas film, and the tested composed moment of foil air bearing increases with the rotary speed in the beginning but decreases later. From the point of engineering, when foil air bearing is stably running at working speed, as long as the tested composed moment decreases with high percent comparing with the maximum moment when started, a liftoff can be considered to happen, which means that the foil air bearing in this condition is capable to afford the corresponding load.
展开▼
