在转子—轴承系统中，由于制造、安装和运行环境的影响，不对中是不可避免的。不对中状态转子的运动能引起机械的振动、轴承的磨损和轴的挠曲变形等，对系统的平稳运行危害极大。因此研究转子系统的不对中量对轴承的动静特性、系统的临界转速、稳定性和不平衡响应等动力学特性的影响，具有重要的理论意义和实用价值。 本文根据集总参数法建立了滚动轴承和滑动轴承联合作用下的不对中转子—轴承系统的动力学模型。基于线性振动理论分析了系统的临界转速、稳定性和不平衡响应。主要内容和结论如下： 首先计算向心滚动轴承各滚动体的负荷，并对工作状态下单个滚动体单元进行受力分析，建立滚动轴承的动力学模型，得出刚度与滚动轴承动力学特性的关系。对动态油膜力进行线性化，将径向滑动轴承模化成刚度阻尼系统，计算径向滑动轴承的油膜力；采用窄轴承理论和甘贝尔边界条件，得出短轴承的刚度系数和阻尼系数表达式。建立转子—滑动轴承系统的运动微分方程。 然后分析轴段的受力和圆盘的运动，列出了质点单元的运动方程和单元的运动微分方程。并结合系统中典型部件的受力情况，建立不对中的转子—轴承系统的运动微分方程。考虑到实际系统的复杂性，对系统中的参数进行无量纲化处理。讨论不对中因素对转子—轴承系统动力学模型的影响，理论分析的结果表明轴承的静动特性（负荷分配、轴承的刚度和阻尼）与转子系统的不对中量有关。此外，分别计算对称转子—滑动轴承和不对称—转子滑动轴承系统的临界转速，失稳转速和不平衡响应，分析了系统的固有振型，稳定性和不平衡响应。 最后计算了滚动轴承和滑动轴承联合作用下不对中转子系统的临界转速，失稳转速和不平衡响应。重点讨论系统的固有振型，稳定性和不平衡响应，分析不对中量对系统各结点振动的影响。数值分析表明不对中转子系统的低阶临界转速与对中转子系统的相比有较大的提高。系统失稳前，对中系统存在一些高阶临界转速，而不对中系统不存在，说明不对中量对系统的临界转速影响很大；对于同阶临界转速而言，不对中转子系统的临界转速比对中转子系统的临界转速高。联轴器两侧和系统两端轴承处的不对中量对系统支承负荷分配的影响是不同的；联轴器两侧支承的负荷分配随该处不对中量增加而增大，而在系统两端轴承处不对中量的影响下减少。系统的稳定性在不对中量的作用下发生改变，其系统特征值实部的绝对值减小；系统的最小对数衰减率减小，失稳转速明显下降，稳定性降低。系统不平衡响应在临界转速处比较敏感，不平衡响应幅值在临界转速处相对其他转速处较大。在临界转速处，不对中量对系统不平衡响应幅值的影响比较显著；而在其他转速处，不对中量对系统不平衡响应幅值的影响较小。

It is unavoidable that misalignment appears in the rotor-bearing system because of some factors, such as manufacturing, installation and operational environment. The misaligned rotor can cause vibration and fatigue of bearings and twist of axles, etc; it is harm to work smoothly. Therefore dynamic analysis of misaligned rotor-bearing system (the static and dynamic characteristics of bearings, critical speed, stability and unbalance response) is very important in the theory and practical engineering. In this dissertation, the dynamic model of misaligned rotor-bearing system equipped with rolling bearing and journal bearing is developed by the method of lumped parameter. The dynamic behavior, such as the nature characteristics (critical speed, stability), unbalance response of the system, etc. is analyzed based on the theory of linear vibration. The main contributions and conclusions of the work are summarized as follows. Firstly, the load of every rolling unit of rolling bearing is calculated, the static and dynamic characteristics of the rolling bearings are analyzed. For the journal bearing, the film force is calculated based on the theory of linear vibration. On the base of narrow bearing theory and Campbell boundary condition, stiffness and damping coefficient expression is carried out. Then, after discussing the forces on the typical components of the system and their motions, the dynamic model of rotor-bearing system supported on rolling bearing and journal bearing is developed, in which the effects of the misalignment and unbalance of the rotor system are considered, and the dynamic characteristics of rotor-bearing system are simply investigated due to misalignment and unbalance. Additionally,the dynamics of the symmetric and non-symmetric rotor-journal bearing system is discussed. Finally, the critical speed, stability and unbalance response of a rotor system equipped with both rolling bearing and journal bearing is analyzed. The mode, stability and the unbalance response of system are discussed in detail, in which the effects of the misalignment and unbalance of rotor are included. The results show that the lowest critical speeds of the misaligned rotor-bearing system are increased comparing to those of aligned rotor-bearing system and the misalignment of the system can make the stability deteriorate largely. Additionally, the unbalance responses of the rotor-bearing system are also investigated, in which the effects of the misalignment of the rotors are mainly taken into account. When the speed of rotor passes through the critical speed, the influence of the unbalance response of the system due to the misalignment is remarkable, and at the others its influence is not large when the misalignment is small.