Gas bearings are widely used in micro- and small turbomachinery. Because of the pursuit of high efficiency, turbomachinery adopts small clearance of rotor and stator. The gas bearing rotor system easily suffers from rub impact due to the inherently low damping and load capacity of gas film. Axial rub impact may lead to catastrophic failure of gas bearing rotor system. Previous work put emphasis on radial rub, and only a few papers researched on the axial rub impact by simulation method. In this paper, dynamic responses of full annular axial rub are investigated numerically and experimentally. A single span flexible rotor test rig is established to support this research. Dynamic characteristics of full annular axial rub of this gas bearing rotor system are obtained with finite element language-APDL. Dynamic characteristics within full speed range are experimentally researched based on the test rig. The dynamic behaviors are analyzed by means of waterfall diagrams, frequency spectrums, orbit trails, and vibration amplitude waveforms. During speed up, half speed whirl and gas film oscillation occur in radial direction. During speed down, the full annular axial rub between rotor thrust disk and gas bearing occurs. When lightly axial rub impact happens, the vibration patterns in the radial direction change barely, and 0 Hz component appears in the axial direction. When serious full annular axial rub impact happens, 0 Hz component occurs in both radial and axial directions and rotor orbit shows transverse motion in radial direction. These forms of dynamic characteristics can be effectively used to diagnose the full annular axial rub impact.

气体轴承广泛用于微型和小型涡轮机械。由于追求高效率，涡轮机械采用了较小的转子和定子间隙。由于气体膜固有的低阻尼和负载能力，气体轴承转子系统很容易受到摩擦的影响。轴向摩擦冲击可能导致气体轴承转子系统发生灾难性故障。以前的工作重点是径向摩擦，而通过模拟方法研究轴向摩擦影响的文献很少。本文通过数值和实验研究了全环形轴向摩擦的动力响应。建立了单跨度柔性转子试验台以支持这项研究。利用有限元语言-APDL获得了该气体轴承转子系统全环形轴向摩擦的动力学特性。基于试验台，对全速范围内的动态特性进行了实验研究。通过瀑布图，频谱，轨道轨迹和振动幅度波形来分析动态行为。在加速过程中，在径向方向发生半速旋转和气膜振荡。在减速期间，转子止推盘和气体轴承之间会发生整个环形轴向摩擦。当发生轻微的轴向摩擦冲击时，径向方向的振动模式几乎不变，并且轴向方向上出现0 Hz分量。当发生严重的完全环形轴向摩擦冲击时，在径向和轴向两个方向上都会出现0 Hz分量，并且转子轨道会在径向上显示出横向运动。这些形式的动态特性可以有效地用于诊断整个环形轴向摩擦的影响。