轴承摩擦力作用下弹性支承轴系自激振动特性研究

发布时间：2018-12-31 18:35

【摘要】：以重力式水洞中的弹性支承轴系为研究对象,研究其在水润滑橡胶轴承摩擦力作用下的自激振动特性及其机理。实验结果表明,系统于某一确定转速产生自激振动,并随转速下降维持不变直到一个较低转速由于驱动力不足而消失,各个转速下的自激振动均表现为转速调制下的单阶模态失稳。为了研究自激振动机理,建立了弹性支承轴系动力学模型。在建模时,将轴系分为弹性支承和转轴两个子结构,分别获取固有振动频率和模态振型,建立在轴承界面摩擦力作用下的支承-转轴耦合动力学模型,并采用模态叠加法对模型进行降阶处理。采用四阶Runge-Kutta方法求解动力学方程,分析主要物理参数对系统的影响。分析结果表明,失稳模态为支承的小阻尼扭转振动模态,支承振动与轴承摩擦耦合作用是系统失稳的主要原因。
[Abstract]:The self-excited vibration characteristics and its mechanism of elastic bearing shafting in gravity water tunnel under the action of water lubricated rubber bearing friction are studied. The experimental results show that the system produces self-excited vibration at a given rotational speed and remains unchanged with the decrease of the rotational speed until a lower rotational speed disappears due to insufficient driving force. The self-excited vibration at each rotational speed is presented as single-order mode instability under rotational speed modulation. In order to study the mechanism of self-excited vibration, a dynamic model of elastic bearing shafting is established. In modeling, the shaft system is divided into two substructures: elastic support and rotary shaft. The natural vibration frequency and modal mode are obtained, respectively, and the coupling dynamic model of supporting and rotating shaft is established under the friction force at the interface of bearing. The mode superposition method is used to reduce the order of the model. The fourth order Runge-Kutta method is used to solve the dynamic equation and the influence of main physical parameters on the system is analyzed. The analysis results show that the instability mode is the small damping torsional vibration mode of the support, and the coupling action between the bearing vibration and the bearing friction is the main cause of the system instability.
【作者单位】：上海交通大学机械系统与振动国家重点实验室;高新船舶与深海开发装备协同创新中心;
【基金】：国家自然科学基金(51505281;11172166)
【分类号】：O327;U661.44

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