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发电机组轴系弯扭耦合电磁激发振动数学模型 总被引：1，自引：0，他引：1
依据机电分析动力学理论 ,找到了发电机组定转子间气隙磁场的能量 ,得到了作用在发电机转子上的电磁力 (矩 ) ,建立了一个基于分段连续质量的发电机组轴系弯扭耦合电磁激发振动的数学模型 .该模型考虑了不平衡、陀螺力矩、转动惯量、剪切变形及阻尼的影响 ,是一个比较精确的模型 .对全面探索发电机组的振动规律具有应用价值 相似文献
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建立了电机转子机电耦联的非线性数学模型 ,研究了由电磁力激发的参数振动非线性系统的响应曲线 ,揭示了各种电磁参数及机械参数对共振的影响 .结果表明 ,系统在电磁力作用下存在着 1/2亚谐共振的条件 ,电磁力对稳定区域有明显影响 ,且其线性项和非线性项均能激发参数共振 .同时建立了机电耦联问题的电机系统的稳定性条件 ,并得到了参数域中的稳态共振曲线和运动状态 ,所揭示的动力学现象为定性地控制电机的稳定运行状态提供了理论依据 相似文献
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《浙江大学学报(A卷英文版)》2016,(8)
目的:工业的不断发展对航空发动机、泵、燃气轮机等旋转机械的动力性能提出了更高的要求。转子系统是旋转机械的重要组成部分。复杂的转子系统在高速运转时会产生故障和非线性振动,从而影响系统的可靠性。因此,开展转子系统的非线性动力性研究,研究转子系统在高速运转时的非线性响应及其抑制作用对转子系统的设计和故障诊断具有重要的意义。创新点:1.在建模的时候考虑转子系统的实际结构,在不对中模型中引入齿式联轴器啮合力,在滚动轴承模型中考虑弹流润滑影响;2.探究挤压油膜阻尼器参数对转子系统非线性特性抑制的影响,总结其变化规律。方法:1.基于Hertz接触和弹流润滑理论,建立滚动轴承动力学模型,同时考虑齿式联轴器齿之间的啮合力,建立不对中故障下的齿式联轴器啮合力模型,并在此基础上,根据转子系统的支撑形式,建立0-2-1支撑的转子动力学模型;2.开展转子动力学实验,验证模型的准确性并分析不对中量对系统频谱特性的影响;3.在分析不对中故障非线性特性的基础上,研究挤压油膜阻尼器参数对于非线性特性抑制的作用。结论:1.齿式联轴器啮合作用和滚动轴承的弹流润滑对不对中故障下转子系统的失稳产生一定的影响,润滑会导致系统发生分岔的窗口推迟;2.对于转子系统的弹性支撑,其一阶临界转速和振幅随着刚度的增大而增大,选择合适的刚度有利于转子系统的稳定运行;3.挤压油膜阻尼器的参数对转子系统故障引起的非线性具有较好的抑制作用,其作用的大小取决于不对中量和挤压油膜阻尼器的油膜间隙的耦合,合理地调节油膜间隙有助于增大系统的稳定区间范围。 相似文献
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在弹性梁与磁弹性力学理论的基础上,应用动力学方法建立电磁场和温度场耦合作用下的载流梁的非线性热磁弹性耦合振动方程。应用Galerkin法导出了系统受电磁力和热力共同作用的非线性振动微分方程组。通过数值计算,给出了不同系统参数下的系统振动的时程图和相图。 相似文献
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针对目前振动测试装置振幅固定不能适应多种模拟振动测试的现状,设计了一种新型的振幅可调的振动装置,通过调节加振台的偏心凸轮,控制加振台的振幅。测试结果表明：满足了多种测试的要求,大大减少了生产成本。 相似文献
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对PD控制器作用下的磁力轴承转子的机电耦合振动系统进行了研究．将电压控制改为电流控制，并引入了非线性项，应用平均法研究了转子系统的非线性振动，给出了磁力轴承控制系统参数与转子振动之间的关系． 相似文献
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为研究转子系统耦合故障特性,采用有限元方法建立了含有横向裂纹、转静碰摩的非线性转子动力学模型。首先研究了不同转速下裂纹、碰摩单一故障下转子系统的振动响应,其次研究了两种故障耦合情况下系统的振动响应特征。采用波形图、FFT谱图、瞬时频率和Hilbert-Huang时频谱(HHS)相结合的方法对故障转子振动信号进行了分析。分析结果表明:运用多种时频分析相结合的方法可以较为全面地了解转子的故障特征,裂纹转子在1/5、1/3临界转速时会发生较为明显的5X、3X谐波,且裂纹的产生会导致响应幅值增大,从而引起更为严重的碰摩。 相似文献
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分析了磁悬浮轴承电磁力与其电流和转子位移非线性关系产生的原因,结合国内外文献资料,主要从磁轴承偏置磁场以及本质非线性两方面对磁悬浮轴承力与电流及其位移关系线性化策略进行概述。 相似文献
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In this study a new dynamic model of a rotor system is established based on the Hamilton principle and the finite element method (FEM). We analyze the dynamic behavior of the rotor system with the coupled effects of the nonlinear oil film force, the nonlinear seal force, and the mass eccentricity of the disk. The equations of the motion are solved effectively using the fourth order Runge-Kutta method in MATLAB. The dynamic behavior of the system is illustrated by bifurcation diagrams, largest Lyapunov exponents, phase trajectory diagrams, and Poincaré maps. The numerical results show that the rotational speed of the rotor, the pressure drop in the seal, the seal length, the seal clearance, and the mass eccentricity of the disk are the key parameters that significantly affect the dynamic characteristics of the rotor system. The motion of the rotor system exhibits complex types of periodic, quasi-periodic, double-periodic, multi-periodic, and chaotic vibrations. This analysis can be used to guide the design of seal parameters and to diagnose the vibration of rotor/bearing/seal systems. 相似文献
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Torsional Oscillation Characteristics of Rotary Shafts Based on Torsion and Bending Coupled Vibration 总被引：1，自引：0，他引：1
THE TORSIONAL OSCILLATION CHARACTERISTICS ON THE BENDING AND TORSION COUPLED VIBRATION OF ROTARY SHAFT SYSTEM WERE INVESTIGATED USING THE ELASTO-DYNAMIC THEORY AND OTHER MATHEMATIC METHODS, SUCH AS DIFFERENCE APPROACH, FOURIER TRANSFORM, AND WAVELET TRANSFORM. IT IS CONCLUDED THAT MASS ECCENTRICITY AND OTHER EXCITING MODALITIES AFFECT THE BENDING AND TORSION COUPLED VIBRATION OF ROTARY SHAFTS. TORSIONAL VIBRATION CAUSED BY BENDING VIBRATION FEATURES LINEARITY ALONG WITH THE CHANGE OF AMPLITUDE OF BENDING VIBRATION. MEANWHILE, ENERGY SPECTRUM CONCENTRATES ON HIGH FREQUENCY ARE-A WITH THE WAVELET ANALYSIS. 相似文献
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The passive electromagnetic damper has the same configuration as that of the electromagnetic bearing, but no sensors and no closed loop control are needed. Its robustness and no-contact structure are its great advantages. When the rotor vibrates, the electromagnetic field intensity in the air gap is altered, then fluctuating currents in the damper coils and eddy currents inside the surface layer of rotor are created. Damping force is caused by the fluctuating currents, while retardation torque is generated by eddy currents. The characteristics of a damper may be improved by adding an additional electrical circuit. Numerical studies showed that damping coefficient increases with increasing static current, but decreases with increasing frequency. And the damping coefficient of the improved damper at higher frequency is more evident than that of the original damper. Experimental results showed that the resonant vibration around the first critical speed was obviously suppressed by both types of passive electromagnetic damper. 相似文献
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研究目的：求斛双圆盘转了-密封系统的非线性振动特性和运动响应 创新要点：采用有限元法（FEM）和拉格朗目方程求解双圆盘转子-密封系统,进而为研究多级转了系统的非线性振动问题提供有效方法。研究方法：基于有限元法（FEM）和拉格朗目方程。同时利用四阶龙格-库塔法求解系统动特性运动响应情况,利用风岔图、时间历程图、轴心轨迹图、庞加莱映射和幅值谱等分析图研究双圆盘转子-密封系统的非线性振动特性。重要结论：随着转速的增大,双圆盘转子-密封系统呈现丰富的非线性运动形式,包括周期性运动、多周期运动,准周期运动以及混沌运动。在右端圆盘不平衡质量小于34kg、密封间隙范围为0.376mm-0.54mm、密封长度大于0.13m或者密封压差高于0.104MPa的情况下均有利于提高双圆盘转子-密封系统的稳定性。 相似文献
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针对振动摩擦焊接机在焊接过程中的外激振力幅值确定较为困难的问题,对振动摩擦焊接机中的电磁振动原理、电磁力计算、电磁力仿真分析等方面进行研究,对静态进程模式下正余弦信号与电磁力之间关系进行归纳,提出一种基于MATLAB的电磁振动仿真分析方法。结合电磁振动学和牛顿运动学方法综合建立简化的电磁力理论推导,借用MATLAB分析正弦和余弦对电磁力的影响规律,利用振动摩擦焊接试验台对所建立的电磁力理论推导方法进行实验验证。研究结果表明,当输入正弦信号,时间为0.002 5s时,电磁力最大值为400N;当输入余弦信号,时间为0.002 6s时,电磁力最大值为556.080 0N,从而为振动摩擦焊接机的外激振力及其频率确定提供了依据。 相似文献
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REN Wan-bin CUI Li LUO Fu-biao ZHAI Guo-fu 《浙江大学学报(A卷英文版)》2007,8(3):434-438
Published research is minimal on vibration characteristics of hermetically sealed electromagnetic relay (EMR) ex- posed to mechanical environment. The vibration characteristics of armature system, link contact system with electromagnetic system will cause EMR malfunction. The nonlinear dynamics model of armature systems was studied by considering electro- magnetic attraction force and opposite mechanical force in this paper. Angular displacements of armature under different sinu- soidal vibration conditions are solved in order to obtain the failure mode result from armature system. Vibration tests showed the presented analyzing method is suitable for EMR. The conclusions are instructive for increasing vibration resistance of armature systems of EMR, and are significant for reliability design of switch apparatus. 相似文献
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对交流电机转子横振时电磁阻尼及考虑电磁阻尼时转子横振进行了研究.首先应用磁场理论求得了电机三相不对称运行时电磁阻尼力,并对三相对称时的电磁阻尼进行了计算.接着用拉格朗日-麦克斯韦方程求得了转子横向振动的方程,画出了三相对称时转子强迫振动的幅频曲线,并与实验进行了对照,实验结果与理论结果吻合的很好. 相似文献
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ＩＮＴＲＯＤＵＣＴＩＯＮＣａｂｌｅ ｓｔａｙｅｄｂｒｉｄｇｅｓａｒｅｗｉｄｅｌｙａｐｐｌｉｅｄｉｎｍｏｄｅｒｎｂｒｉｄｇｅｓｔｒｕｃｔｕｒａｌｓｙｓｔｅｍ .Ｔｈｅｌａｒｇｅｓｔｓｐａｎｏｆｃａｂｌｅ ｓｔａｙｅｄｂｒｉｄｇｅｉｓｃｌｏｓｅｔｏ 1 0 0 0ｍｗｈｅｎｍａｎｙｎｅｗｍａｔｅｒｉａｌｓａｎｄｔｅｃｈｎｏｌｏｇｉｅｓａｒｅａｐｐｌｉｅｄ.Ｔｈｅｓｔａｙｃａｂｌｅｓａｒｅｉｍｐｏｒｔａｎｔｂｒｉｄｇｅｓｔｒｕｃｔｕｒｅｃｏｍｐｏｎｅｎｔｓｍｏｓｔｐｒｏｎｅｔｏｅｘｈｉｂｉｔｈｉｇｈａｍｐｌｉｔｕ… 相似文献
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Dynamic characteristics analysis of a misaligned rotor-bearing system with squeeze film dampers 总被引：1，自引：0，他引：1
In this paper, a dynamic model is established for a two-stage rotor system connected by a gear coupling and supported on ball bearings with squeeze film dampers (SFDs). The nonlinear dynamic behavior of the rotor system is studied under misalignment fault condition. The meshing force of the gear coupling is calculated considering the deformation of the tooth caused by torque transmission and dynamic vibration. The contact force between the ball and race is computed based on the Hertzian elastic contact deformation theory and the elastohydrodynamic lubrication theory. The supported force of SFD is simulated by integrating the pressure distribution derived from Reynolds’s equation. The equations of motion are rewritten in non-dimensional differential form, and the fourth-order Runge-Kutta method is employed to solve the nonlinear dynamic equilibrium equations iteratively. To verify the validity of the dynamic model and the correctness of the numerical solution method, the experimental power spectra of the rotor system under various misalignment degrees are compared with the analytical results. The effects of several important parameters, such as the lubrication of the ball bearing, the centralizing spring stiffness, the radial clearance of SFD, and the misalignment of gear coupling, on the dynamic characteristics of the rotor system are investigated and discussed mainly focusing on the system stability. The response spectra, bifurcation diagrams, and Pointcaré maps are analyzed accordingly. These parametric analyses are very helpful in the development of a high-speed rotor system and provide a theoretical reference for the vibration control and optimal design of rotating machinery. 相似文献