共查询到19条相似文献，搜索用时 218 毫秒
1.
建立了同时考虑非线性油膜力和非线性密封力的转子-轴承-密封耦合系统的动力学方程,并采用数值模拟的方法对这个耦合系统的分岔和混沌行为进行了研究,通过系统响应随转子转速变化的分叉图和最大Lyapunov指数曲线图、一些典型的Poincare截面图、轴心轨迹图和时间响应图来反映系统响应从周期运动通过倍周期分岔,最后到达混沌的运动及其演变过程。 相似文献
2.
《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
3.
发动机涡轮增压器是一种轻型高速旋转机械,其作用是通过增压增加气缸进气量,提高发动机的燃油经济性和动力性．发动机涡轮增压器核心部件是双盘双支撑的转子轴承系统,所以对转子轴承系统运动稳定性的研究显得尤为重要．通过传递矩阵法建立求解涡轮增压器转子系统临界转速的计算模型,将某型国产汽油机涡轮增压器转子系统的参数带入数学计算模型．利用Matlab软件编程计算涡轮增压器转子系统的临界转速,并通过台架试验验证了理论计算的正确性,为涡轮增压器转子系统设计提供理论参考． 相似文献
4.
根据Jeffcott碰摩转子系统的非线性动力学方程,利用时域波形图、轴心轨迹和Poincare映射图以及全局分岔图对系统的混沌行为进行分析,应用线性压缩映射和小波函数构成的非线性映射对碰摩转子中的混沌行为进行数值仿真,使其控制到稳定周期轨道.研究结果为转子系统的故障诊断、振动控制及安全运行提供了理论参考. 相似文献
5.
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
6.
综合考虑齿轮时变啮合刚度、齿面间隙、轴承游隙和啮合综合误差等多种非线性因素影响,建立三自由度直齿轮振动模型,并对模型进行无量纲化处理。采用4阶变步长Runge－Kutta法对齿轮模型微分方程进行求解,得到齿轮在轴承径向游隙变化时运动的分岔图、相图和Poincaré映射图。发现随着轴承游隙的变小,系统响应也经历了从混沌态到稳态再到混沌态的历程,其中发生了倍周期分岔的现象。给出了系统的分岔值,得到了系统混沌形成的过程。 相似文献
7.
《实验室研究与探索》2015,(7):67-71
参考某型航空发动机的结构特点,提出了一种双转子实验台结构,此台架主要由动力电机、内转轴、外转轴(空心)、支承、轮盘、皮带、皮带轮、底座等构成。其主要特点是:内外2个转子通过中介轴承耦合在一起,分别由不同的电机驱动;4个轮盘分别用来模拟低压压气机、高压压气机、高压涡轮、低压涡轮的质量。采用直接传递矩阵法计算了实验台架的前3阶临界转速,分析了支承刚度、转速比、轮盘的极转动惯量、长径比等因素对台架临界转速的影响,并据此对实验台架作了优化。优化临界转速后可以有效地减小运行时的振动,显示优化是有效的。 相似文献
8.
王立明 《廊坊师范学院学报(自然科学版)》2009,9(4):56-59
对“旋转单摆”的运动进行研究,建立系统的动力学方程,用线性稳定性分析方法讨论平衡点附近邻域的稳定性,给出了系统静态分岔图和运动的相图,利用Jacobi椭圆函数得出不同转速下系统作周期运动的解析解,并绘出图形加以说明。 相似文献
9.
王立明 《河北职业技术学院学报》2009,(4)
对"旋转单摆"的运动进行研究,建立系统的动力学方程,用线性稳定性分析方法讨论平衡点附近邻域的稳定性,给出了系统静态分岔图和运动的相图,利用Jacobi椭圆函数得出不同转速下系统作周期运动的解析解,并绘出图形加以说明。 相似文献
10.
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
11.
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
12.
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
13.
Nomenclaturex,y,x ·, y·-displacement and velocity of rotor-x,-y,x-·,-y·-displacement and velocity of rotor , di mension less¨x,¨y-acceleration of rotor¨-x,¨-y-acceleration of rotor ,di mensionlessω-rotating speed of rotor-ω-rotating speed of rotor ,di mensionlessx,y,z-Cartesian coordinates-x,-y,-z-Cartesian coordinates ,di mensionless2m-mass of rotorg-acceleration of gravityG-weight of rotor ,di mensionlesse=e2x e2y-mass eccentricity of rotorex,ey-mass eccentricity of rotor in thexan… 相似文献
14.
Rotor systems supported by angular contact ball bearings are complicated due to nonlinear Hertzian contact force. In this paper, nonlinear bearing forces of ball bearing under five-dimensional loads are given, and 5-DOF dynamic equations of a rigid rotor ball bearing system are established. Continuation-shooting algorithm for periodic solutions of the nonlinear non-autonomous dynamic system and Floquet multipliers of the system are used. Furthermore, the bifurcation and stability of the periodic motion of the system in different parametric domains are also studied. Results show that the bifurcation and stability of period-1 motion vary with structural parameters and operating parameters of the rigid rotor ball bearing system. Avoidance of unbalanced force and bending moment, appropriate initial contact angle, axial load and damping factor help enhance the unstable rotating speed of period-1 motion. 相似文献
15.
ZHANG Zhi ming ZHU Li jin YU Jun 《上海大学学报(英文版)》1999,3(3):227-233
Ｎｏｍａｎｃｌａｔｕｒｅ ｂｉｊ,Ｂｉｊ（ｉ,ｊ＝ｘ,ｙ） ｂｅａｒｉｎｇｄａｍｐｉｎｇａｎｄｎｏｎｄｉｍｅｎｓｉｏｎａｌｄａｍｐｉｎｇｃｏｅｆｆｉｃｉｅｎｔｓ,Ｂｉｊ＝ｂｉｊΨ３ｍｉｎ／（２ｌμ） ｃｍｉｎｍｉｎｉｍｕｍｒａｄｉａｌｃｌｅａｒａｎｃｅｏｆｂｅａｒｉｎｇｄｄｉａｍｅｔｅｒｏｆｂｅａｒｉｎｇｅｕ,Ｅｕｅｃｃｅｎｔｒｉｃｉｔｙａｎｄｒｅｌａｔｉｖｅｅｃｃｅｎｔｒｉｃｉｔｙｏｆｍａｓｓｃｅｎｔｅｒｏｆｒｏｔｏｒ,ｒｅｓｐｅｃｔｉｖｅｌｙ,Ｅｕ＝ｅｕ／ｃｍｉｎＦｓｔａｔｉｃｌｏａｄｏｎｂ… 相似文献
16.
In this paper,a dynamic model on a rigid rotor-sliding bearing system with a SFD is established.The stability and bifurcation behaviors of the system are studied,on The basis of the differential equations of fluid momentum and mass continuity,the distribution pressure function is derived by taking oil film inertia force into consideration.Damping force, clearance excitation force,interference force of different frequencies and static load are also considered in the model,Finally,the governing equations of the stability and bifurcation behaviors of the system are solved by Floquet theory,Simulation of dynamic model shows that the rigid rotor-sliding bearing system can maintain stability and exhibit a Hopt bifurcation phenomenon in a certain range. 相似文献
17.
In this paper, a nonlinear dynamic MIMO model of a 6-DOF underactuated quad rotor rotorcraft is derived based on Newton-Euler formalism. The derivation comprises determining equations of motion of the quad rotor in three dimensions and seeking to approximate the actuation forces through modeling of the aerodynamic coefficients and electric motor dynamics. The derived model is dynamically unstable, so a sequential nonlinear control strategy is implemented for the quad rotor. The control strategy includes exact feedback linearization technique, using the geometric methods of nonlinear control. The performance of the nonlinear control algorithm is evaluated using simulation and the results show the effectiveness of the proposed control strategy for the quad rotor rotorcraft near quasi-stationary flight. 相似文献
18.
The technique of non-stationary oll film force database for hydrodynamic bearing is introduced and its potential applications in nonlinear rotor-dynamics are demonstrated.Through simulations of the locus of the shaft center aided by the database technique,nonlinear stability analysis can be performed and the natural frequency can be obtained as well.The easiness of “assembling” the individual bush forces from the database to form the bearing force.makes it very convenient to evaluate the stability of various types of journal bearings,Examples are demonstrated to show how the database technique makes it possible to get technically abundant simulation results at the expense of very short calculation time. 相似文献
19.
吕曙东 《南通职业大学学报》2010,24(4):90-93
根据异步电机的非线性多变量动态数学模型,利用LabVIEW基于数学模型对异步电机进行了仿真研究。通过分析转子断条后电机的等效电路图,得到了故障模型,并将故障诊断方法中的信号处理方法应用于电机故障诊断实例中,对正常电机模型和故障电机模型中的定子电流信号进行处理,且给出了两种信号处理方法的分析结果。仿真表明,此方法对电机故障诊断有一定实效。 相似文献