轴承座受冲击条件下转子系统碰摩动力学行为研究

The study on rub dynamic behaviors in a rotor system of the bearing pedestal under the impact conditions

针对基础受冲击激励的一转子-轴承系统,在线性和非线性范围内分别建立了其动力学模型和相应的微分方程组,其中考虑了碰摩的因素。运用数值计算的方法进行动力学响应求解,得到了时间历程响应。对响应结果进行分析后表明,碰摩对冲击响应的影响是有益的,表现在转子瞬态振动最大振幅减小,转子振动能量衰减加快;对冲击碰摩动力学模型进行线性化近似处理是不合适的;冲击不会改变稳定碰摩运动形式;冲击激励持续时间对响应的影响十分明显,且当冲击激励频率接近或等于转子固有频率和涡动频率时响应较大。

Dynamic model and corresponding differential equations of a rotor-bearing system under base-transferred shock excitations were established in linear and nonlinear field respectively. Rubs between rotor and stator were taken into consideration. Time-varying responses were obtained by numerical calculation. The results show that rubs decrease transient response amplitude and make oscillation back into equilibrium within less time. Shock disturbance wouldn′t change the form of rub motion. Dynamic behaviors are sensitive to the duration of shock excitation. In particular,in cases where the frequencies of shock excitations are equal or close to the natural frequencies and whirl frequencies of the rotor,resonances may occur,and the transient responses are amplified.