<正>在计算轴承－ 转子系统的稳定性和轴心轨迹时，为克服特征根法、Ｆｏｕｒｉｅｒ 级数法等计算方法的局限性，提出了用状态方程的时域分析法计算流体润滑轴承在位移扰动、冲击载荷和不平衡激励等典型扰动下的轴心轨迹和判断稳定性的方法，根据当前时刻的状态变量值，只要进行一次矩阵乘法即可得到下一时刻的状态变量值，具有不受步长大小的限制而保持较高的计算精度。同时还讨论了小扰动理论的使用条件。

To avoid the limitations of the eigenvalues of matrix and Fourier series method for calculating stability and whirling trajectories of a rotor bearing system,the state variable equations analysis method in time domain is first proposed in this paper.Multiplying current state variable value by a matrix,the next time state variable value can be obtained by this method,which can select the large step size to satisfy a given accuracy.The typical whirling trajectories under position perturbation,impact excitation and synchronous unbalance excitations are simulated and a method is given to determine the stability threshold of a rotor bearing system.Simultaneously,the applicable condition of small perturbation theory is discussed.