RESEARCH ON MODELING AND CHARACTERISTICS OF THE SPINDLE DYNAMIC COUPLING ABSORBERING SYSTEM OF A SUPER-PRECISION SURFACE GRINDING MACHINE

The bearing is described by constrain matrix, and the spindle system of a NCsurface grinding machine is simplified as elastic-coupling beam, then modal synthesis method is usedto establish the dynamic model of beam. Moreover, the response of the end of rotor is analyzed, andthe natural frequency, principle mode and other dynamic characteristics of the coupling system arestudied, the law of bearing stiffness to coupling frequency and amplitude of rotor is also found.Finally, according to the actual condition, a dynamic absorber is designed. The simulation andexperimental results show that the amplitude of spindle can be declined effectively when the dynamicabsorber is attached.

20万千瓦汽轮发电机组转子轴承系统稳定性研究

在已知滑动轴承动力特性的8个系数的基础上,通过计算来预报转子轴承系统失稳转速及稳定裕度.从理论上比较了用不同沟槽结构参数的椭圆轴承支承的转子轴承系统的阻尼变化趋势,定量地判断了系统的失稳转速,并研制了计算程序,对20万千瓦汽轮发电机组转子轴承系统稳定性进行了理论分析和计算.

具有不对中故障的转子-滑动轴承系统动力学特性研究

在深入分析多跨度双转子模型建立方法及联轴器模型的基础上,综合考虑离心、碰摩等故障,建立双跨度转子-联轴器平行偏角综合不对中模型。采用变步长四阶-五阶Runge-Kutta法求解不对中故障双跨转子-滑动轴承系统的非线性动力学模型,通过Poincare截面图、轴心轨迹图、波形图和频谱图,直观地显示了系统在某些参数域中的运动状态,通过分岔图和三维谱图分析,揭示了转子系统周期、倍周期、拟周期等分岔行为以及同频振动、幅值跳动、拟周期运动、混沌等非线性动力学现象。研究结果表明,该类系统在运行过程中转子的运动范围增大且运动更加混乱,甚至严重的综合不对中故障导致转子系统进入混沌运动的状态;不对中故障对转子系统的整体振动影响较明显,不对中故障较严重时,整个系统振动形式更加复杂,并且仿真分析结果与实验结果能够较好的吻合。研究结果为转子-滑动轴承系统故障诊断、动态设计和安全运行提供了理论参考。