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本文介绍转子系统电磁阻尼器进行主动控制实验研究的基本原理、试验装置、阻尼器结构参数、控制器参数设置以及电流放大器的设计,最后给出实验和理论结果并进行分析。 相似文献
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基于对转子系统振动进行控制的目的,本文研究了电磁阻尼器结构参数的优化设计,建立了一种不完全对称的电磁阻尼器的结构模型。将这种不完全对称的电磁阻尼器应用于滑动轴承支撑的转子系统上,计算机仿真证明这种不完全对称的电磁阻尼器对转子系统的振动控制是有效的。 相似文献
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研究了利用电磁阻尼器在线消除旋转机械运行过程中产生的不平衡振动问题.在分析电磁阻尼器的在线平衡原理基础上,建立了一套电磁阻尼器-转子系统实验台.通过控制两对磁极增益电流的大小及相位,实现了在转子上施加同频的电磁平衡力,达到了消除转子本身不平衡力的目的.研究结果表明,通过对电磁力的相位和大小进行优化控制,可以使2号轴承的水平和垂直方向振动分别降低了69%和55.6%,平衡后两个测量平面的同频振动分量均未超过10μm.实验结果证明,所采用的电磁阻尼器可以在不停机的情况下,对转子进行有效在线平衡,有助于延长转子的稳定运行周期. 相似文献
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电磁阻尼器分段相位控制研究 总被引:1,自引:3,他引:1
对柔性转子轴承系统,用电磁阻尼器实施主动控制时采用分段位控制算法,按转速频率分段设置不同的优化相位超前补偿环节,以便在整个转速范围内有效控制转子过临界振动,获得较好的控制效果,分段相位控制器能提供随转速而变的刚度阻尼特性,实现变刚度及变刚度阻尼控制过程,实验证明,控制算法简单,抑制效果和稳定性好,具有效大实用价值。 相似文献
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提出一种新型可控挤压油膜阻尼器(简称CSFD),并实验研究该CSFD支撑的轴承-转子系统的振动特性。利用数值方法计算得到了转子系统的临界转速和振型图;搭建柔性转子振动试验台,在不同转速和不同的供油压力下,对轴颈处位移信号进行测试和分析研究。实验结果表明:与普通圆瓦轴承相比,CSFD轴承对转子的振动起到良好的抑制作用;无论是在低速还是高速情况下,CSFD轴承的供油压力越大,转子的振幅越小,特别是在临界转速下减振效果显著。通过Hilbert-Huang变换对升速位移信号进行分析,发现随着供油压力的增加,竖直方向上在临界转速时的能量发散现象严重,出现较多高频成分。 相似文献
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扭转振动是旋转机械中普遍存在的问题,特别是汽轮发电机轴系,由于电力系统瞬变过程,引起的汽轮发电机组轴系的扭振,扭振引起的最大的附加应力可以超过驱动力矩所产生的工作应力数倍,可以产生累计疲劳破坏和随之而来的轴的预期寿命的缩短,这将引起发电机严重事故。 相似文献
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将O型环阻尼器与挤压油膜阻尼器组合使用,可以克服SFD设计中固有的缺陷,通过对刚性转子的不平衡响应分析表明,OSFD的设计既可以满足正常设计工况下的小不平衡量,又可以对较大的不平衡量起到良好的减振作用,从而扩大了阻尼器的适用范围,且结构简单,有利于广泛应用。 相似文献
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针对大型旋转机械通过临界转速时振动过大的问题,搭建了转子实验台,在不改变转子轴系原有支撑形式的基础上,将磁流变阻尼器作为辅助机构安装在转子上,通过实验研究了阻尼器对转子振动的影响规律。提出了一种PID控制策略,设计了转子振动主动控制系统,以振动幅值为反馈参数,实时调节阻尼器电流,在线抑制转子振动。研究结果表明,该阻尼器可以有效抑制转子临界转速附近的振动,降幅可达90%;通过采用PID控制策略,可根据转子振动变化在线改变控制电流,使转子振动稳定在目标值附近,实现了转子系统开机加速过程振动的自动调控。 相似文献
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For a rotor bearing system operating at high speed, a solid material flexible damped support called here a solid material damper has been designed and tested. The properties of the damper can be selected and adjusted to provide the necessary damping levels to get the vibration of the rotor under control. This is especially useful for a flexible rotor running in the vicinity of a critical speed or over the threshold speed obtained from calculations on the basis of linearized hydrodynamic forces. The damper was fabricated and installed and its ability to restrain effectively the rotor from vibration was demonstrated by means of an operating test. 相似文献
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自适应阻尼器是在磁场作用下,利用新型智能材料——MR流体(Magnetorheological fluids)为工作介质的智能器件。笔者在自适应阻尼器的结构设计的基础上,对阻尼器进行了性能测试,通过减振试验装置对所设计的自适应阻尼器进行了减振试验研究,取得很好效果。试验结果及分析对自适应阻尼器的结构设计有重要的参考价值。 相似文献
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A modified version of the traditional tuned liquid column damper (TLCD) absorber is proposed as a passive vibration control device for structures vibrating at low frequencies. This new version, denoted as tuned liquid column ball damper (TLCBD), is equipped with a coated steel ball, in place of the orifice in TLCD, immersed inside the horizontal column of the damper. The current study examines the performance of TLCBD for a harmonic excitation which is a simplified model for the vortex shedding forces on structures in the cross wind direction. A parametric study to investigate the effect of the ball size and absorber mass on the suppression capacity is carried out. The absorber damping characteristics is identified experimentally using a single point laser vibrometer system and the measured damping factor is used in the mathematical model. Intensive numerical simulations were conduced and the results are compared with the traditional TLCD with optimum parameters. The results revealed an improvement of the vibration suppression capability of the proposed version that exceeds around 66% reduction. 相似文献
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Application of smart passive damping system using MR damper to highway bridge structure 总被引:1,自引:0,他引:1
Kang-Min Choi Hyung-Jo Jung Sang-Won Cho In-Won Lee 《Journal of Mechanical Science and Technology》2007,21(6):870-874
Magnetorheological (i.e., MR) dampers are one of the most prospective semiactive control devices for civil engineering applications
to earthquake hazard mitigation, because they have many advantages such as small power requirement, reliability, and low price
to manufacture. A smart passive system based on an MR damper system without including a power supply, controller, and sensors
consists of an MR damper and an electromagnetic induction (i.e., EMI) system that uses a permanent magnet and a coil. The
electromotive force induced by movement of a structure can control MR damper effectively without any external power supply
and control algorithm. This smart passive control system is implemented to verify the effectiveness for seismic protection
of benchmark structural control problem for the seismically excited highway bridge, which is based on the newly constructed
91/5 highway over-crossing in Southern California. The results of the numerical simulations show that the presented control
system can be beneficial in reducing seismic responses of benchmark bridge structure. 相似文献
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转子系统振动信号形态滤波器的设计 总被引:2,自引:0,他引:2
针对转子系统振动信号中可能夹杂的各种干扰,通过数值仿真定量分析了结构元素的形状、宽度、高度等因素对形态滤波器性能的影响程度以及振动信号的采样频率对结构元素尺寸的影响.对不同信号干扰的滤波处理,证实了形态滤波器对抑制各类信号干扰、保留信号原有特征方面的作用.在形态滤波器设计时,应优先选取正弦形状的结构元素,而结构元素的尺寸应考虑实际振动信号,即宽度Ls取信号基频一周期内的采样点数Ps的1/12,高度As取信号的最大振幅Amax的0.22~0.26倍.采用按此原则定义的结构元素对实例振动信号进行形态滤波处理验证,取得了令人满意的降噪滤波效果. 相似文献
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Liming Zhai Yongyao Luo Zhengwei Wang Seishiro Kitauchi Kazuyoshi Miyagawa 《机械工程学报(英文版)》2016,29(2):260-270
Many industrial applications and experiments have shown that sliding bearings often experience fluid film whip due to nonlinear fluid film forces which can cause rotor-stator rub-impact failures. The oil-film whips have attracted many studies while the water-film whips in the water lubricated sliding bearing have been little researched with the mechanism still an open problem. The dynamic fluid film forces in a water sliding bearing are investigated numerically with rotational, whirling and squeezing motions of the journal using a nonlinear model to identify the relationships between the three motions. Rotor speed-up and slow-down experiments are then conducted with the rotor system supported by a water lubricated sliding bearing to induce the water-film whirl/whip and verify the relationship. The experimental results show that the vibrations of the journal alternated between increasing and decreasing rather than continuously increasing as the rotational speed increased to twice the first critical speed, which can be explained well by the nonlinear model. The radial growth rate of the whirl motion greatly affects the whirl frequency of the journal and is responsible for the frequency lock in the water-film whip. Further analysis shows that increasing the lubricating water flow rate changes the water-film whirl/whip characteristics, reduces the first critical speed, advances the time when significant water-film whirling motion occurs, and also increases the vibration amplitude at the bearing center which may lead to the rotor-stator rub-impact. The study gives the insight into the water-film whirl and whip in the water lubricated sliding bearing. 相似文献