一、引言在旋转机械中用来支承高速转子的轴承,目前都用滚动轴承和流体膜滑动轴承。由于滚动轴承在高速下产生噪音和振动,故而在高速机械中的应用受到一定限制,后来就出现了流体膜滑动轴承代替部分滚动轴承的趋势。而流体膜轴承本身,从节能和防止污染的观点出发,在轻载高速机械中,气膜轴承更受到普遍重视。在流体膜轴承中,由于流体膜压力的存在,在外部干扰力的影响下,转子出现半速涡动,引起速度波动,当转速达到2倍左右的一阶临界转速时,将发生流体膜的自激振荡。这种现象一旦发生,轻则发生强烈振动或使轴承立即失效,重则造成严重事故。所以 I. INTRODUCTION Bearings used to support high-speed rotors in rotating machinery are currently used with rolling bearings and fluid-film sliding bearings. As the rolling bearings produce noise and vibration at high speed, the application in high-speed machines is limited, and later there is a tendency that the fluid film sliding bearings replace part of the rolling bearings. The fluid film bearing itself, from the energy saving and pollution prevention point of view, in light-load high-speed machinery, the film bearing more widespread attention. In the fluid film bearing, due to the pressure of the fluid film, under the influence of external interference force, the rotor appears half-speed whirl, causing the speed fluctuation. When the rotational speed reaches about twice of the first-order critical speed, the fluid film will occur Self-excited oscillation. This phenomenon occurs, ranging from strong vibration or failure of the bearing immediately, while causing serious accidents. and so