On The Nonlinear Dynamics of Two Types of Backup Bearings — Theoretical and Experimental Aspects
On The Nonlinear Dynamics of Two Types of Backup Bearings — Theoretical and Experimental Aspects
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两种支撑轴承的非线性动力学——理论和实验方面
DOI：
10.1115/1.4007166
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发表时间：
2012
影响因子：
1.5
通讯作者：
H. Hartmann
中科院分区：
文献类型：
--
作者：
Said Lahriri;I. Santos;H. Weber;H. Hartmann
方面DTU Orbit（2018年12月29日）关于两种备用轴承的非线性动力学理论和实验方面转子和定子之间可能的接触在某些情况下可以被认为是一种严重的故障，可能导致灾难性的故障。转子摩擦被认为是由导致正常操作条件中断的主要来源引起的次要现象。它是由突然的质量不平衡、密封件和轴承中的空气动力和流体动力产生的不稳定性引起的。接触事件引起在冲击事件时施加在转子上的法向力和摩擦力。摩擦力通过将转子的一些旋转能量转换为横向运动，冲击定子而起重要作用。这种情况导致转子和定子的持续耦合横向振动。本文提出了一种新的非传统的支持轴承的设计，以减少摩擦相关的严重程度。这个想法是利用销连接的中心转子在影响。以这种方式，转子被强制到中心并且横向运动被减轻。四个销是被动可调的，这使得间隙可以定制。已经开发了一个数学模型来捕捉传统的备用轴承（环形导轨）和新的盘销备用轴承的冲击所产生的现象。对于传统的环形引导装置，将冲击条件叠加到摩擦是合理的，其中转子自旋能量可以完全转化为转子横向运动。使用非理想驱动器，即，没有任何速度反馈控制的电动机，甚至可以在摩擦条件下几乎停止转子旋转。所有的旋转能量将转化为一种自激转子的横向振动与反复冲击的住房。壳体的振动通过相互作用力耦合。实验和数值分析表明，对于常规的环形导向装置，旋转能量完全转化为横向运动，转子自旋停止。然而，通过采用新的盘销设计，分析表明，转子在冲击时被迫到备用轴承的中心，横向运动得到缓解。因此，转子旋转保持恒定。© 2012美国机械工程师协会。
aspects DTU Orbit (29/12/2018) On the nonlinear dynamics of two types of backup bearings Theoretical and experimental aspects The possible contact between rotor and stator can for some cases be considered a serious malfunction that may lead to catastrophic failure. Rotor rub is considered a secondary phenomenon caused by a primary source that leads to a disruption of the normal operational condition. It arises from sudden mass unbalance, instabilities generated by aerodynamic and hydrodynamic forces in seals and bearings among others. The contact event gives rise to normal and friction forces exerted on the rotor at impact events. The friction force plays a significant role by transferring some rotational energy of the rotor to lateral motion, impacting the stator. This event results in persistent coupled lateral vibration of the rotor and stator. This paper proposes a new unconventional backup bearing design in order to reduce the rub related severity in friction. The idea is to utilize pin connections that center the rotor during impacts. In this way, the rotor is forced to the center and the lateral motion is mitigated. The four pins are passively adjustable, which allows the clearance to be customized. A mathematical model has been developed to capture phenomena arising from impact for the conventional backup bearing (annular guide) and for the new disk-pin backup bearing. For the conventional annular guide setup, it is reasonable to superpose an impact condition to the rub, where the rotor spin energy can be fully transformed into rotor lateral movements. Using a nonideal drive, i.e., an electric motor without any kind of velocity feedback control, it is even possible to almost stop the rotor spin under rubbing conditions. All the rotational energy will be transformed in a kind of self-excited rotor lateral vibration with repeated impacts against the housing. The vibration of the housing is coupled through the interaction force. The experimental and numerical analysis shows that for the conventional annular guide setup, the rotational energy is fully transformed into lateral motion and the rotor spin is stopped. However, by employing the new disk-pin design the analysis shows that the rotor at impact is forced to the center of the backup bearing and the lateral motion is mitigated. As a result of this, the rotor spin is kept constant. © 2012 American Society of Mechanical Engineers.