利用轴瓦可调轴承控制柔性转子系统的振动响应

Vibration Response Control of Flexible Rotor SystemUsing Bearing Pad Adjustable Bearings

关键词:  可调滑动轴承  椭圆度  转子-轴承系统  转子动力学  振动抑制

摘要:

提出了一种轴承下瓦可移动轴承，该轴承可以通过改变轴瓦的位置调整转子系统的工作状态。介绍了这种可调椭圆轴承的结构和工作原理，该轴承结构可以实现在连续工作状态下调节轴承椭圆度，而且与传统固定瓦轴承相比更加适合变工况下运行。通过FEM数值方法建立了转子-可调轴承模型，利用该模型研究了可调椭圆轴承对转子加速过程中动力学特性的影响。通过研究发现，转子未达到临界转速前增大椭圆度可以有效减小转子的振动幅值，抑振作用可达到65%；当接近临界转速时，减小椭圆度可以使转子的共振振幅明显降低，抑振作用达到37%左右；越过临界转速后再增大椭圆度有效减小转子振动，抑振作用可达到60%。然后搭建与理论模型完全一致的转子-可调轴承试验台，经过试验验证，证实了在升速过程中，合理调节椭圆度可以明显减小转子的振动，让转子系统更加平稳地升速到工作转速。

Abstract:

A lower pad movable journal bearing is proposed. This bearing can adjust the working status of the rotor system by changing the position of the bearing pad and improve the stability of the rotor system. The structure and working principle of the adjustable elliptical bearing are introduced. The bearing structure can adjust the ellipticity of the bearing under continuous working conditions. This kind of adjustable bearing is more suitable for changing working conditions than traditional fixed-bearing bearings. A simple rotor-adjustable bearing model is established by finite element method. The effects of adjustable elliptical bearing on the dynamic characteristics of the rotor during acceleration are studied by using the model. Through research, it is found that increasing the ellipticity before the rotor reaching the critical speed can effectively reduce the vibration amplitude of the rotor, and the vibration suppression effect can reach 65%. When approaching the critical speed, reducing the ellipticity can significantly reduce the resonance amplitude of the rotor, and the vibration suppression effect reaches about 37%. After crossing the critical speed, increasing the ellipticity can effectively reduce the vibration of the rotor,and the vibration suppression effect can reach 60%. Then, a rotor adjustable bearing test rig which is completely consistent with the theoretical model is built. It has been verified by experiments that during the speed increase process, the reasonable adjustment of the ellipticity can significantly reduce the vibration of the vibrating rotor, allowing the rotor system to rise more smoothly to the working speed.