螺旋油楔滑动轴承轴心轨迹的计算与测试

发布时间：2018-06-18 10:01

本文选题：螺旋油楔 + 滑动轴承　；参考：《山东大学》2012年硕士论文

【摘要】：旋转机械的轴心轨迹作为转子-轴承系统振动状态的一类重要图形征兆,是滑动轴承工作状态的综合反映。通过轴心轨迹可以确定轴承在工作时任一瞬时的油膜形状和最小油膜厚度,清楚的反映轴承的润滑状况,判定轴承工作的可靠性,确定实现轴承液体润滑条件下所必须的最小间隙与精度及润滑油粘度,确定轴承合适的进油孔位置,分析与鉴别轴承故障等。因此,在滑动轴承的研究中,轴心轨迹的研究占据着十分重要的位置,是轴承润滑分析的基础。本课题结合一种新型螺旋油楔滑动轴承支撑的转子-轴承系统,建立了非线性轴心轨迹的计算模型、计算了螺旋油楔滑动轴承和普通圆轴承在不同转速下的轴心轨迹,并对轴心轨迹激振实验进行了仿真。首先,基于轴颈惯性力、非线性油膜力和动载荷之间的平衡关系,建立了滑动轴承-转子系统的运动方程,并基于非线性理论,采用轴心位置配置技术,建立了滑动轴承轴心轨迹的非线性计算模型,计算出了轴承的非线性轴心轨迹。同时,为便于比较,根据油膜力线性化方法,建立了轴心在平衡位置附近作小位移涡动的线性分析模型,应用偏导数法计算了轴心在平衡位置时油膜的刚度、阻尼系数,再根据线性油膜刚度、阻尼系数计算了线性轴心轨迹。其次,计算了螺旋角β=0.1～0.9时,螺旋油楔轴承在n=6000r/min的轴心轨迹,得到了轴心在静平衡位置的各项数据。通过比较这些数据,分析了螺旋角对轴心轨迹的影响；计算了转速不同时的轴心轨迹,得到了轴承系统的临界转速,并分析比较了不同转速下滑动轴承轴心轨迹的特征；最后通过频谱分析比较了螺旋油楔轴承和普通圆轴承分别在各自的临界转速下轴心轨迹的特征。再次,针对螺旋油楔和圆轴承两种不同结构的轴承,对比分析了正弦激振力作用下两种轴承的轴心轨迹特征。分别研究了正弦载荷激励下系统的动力学过程和正弦激励条件下系统的共振现象,采用MATLAB仿真计算得到了正弦载荷作用下系统的幅频特性曲线和共振频率。最后,在滑动轴承实验台上获得实际的轴心轨迹。依据实验步骤测试得到实际的轴心位移数据；通过对实测信号进行FFT并分析,提取有用信号,画出实际轴心轨迹的图形；利用实验数据所做出的实际轨迹与本文理论计算得到的轴心轨迹进行了对比分析。结果表明采用本文的研究方法得到的计算结果与实验结果一致。
[Abstract]:As a kind of important graphical sign of rotor bearing system vibration state, the axis track of rotating machinery is a comprehensive reflection of sliding bearing working state. Through the axis track, any instantaneous oil film shape and minimum oil film thickness can be determined, the lubrication condition of the bearing can be clearly reflected, and the reliability of the bearing can be determined. The minimum clearance, precision and viscosity of lubricating oil are determined to realize the liquid lubrication of bearing, the proper position of oil intake hole is determined, and the fault of bearing is analyzed and identified. Therefore, in the research of sliding bearing, the research of axis track occupies a very important position and is the basis of bearing lubrication analysis. In this paper, a new rotor-bearing system supported by spiral oil wedge sliding bearing is combined, and the nonlinear axis trajectory calculation model is established, and the axis track of spiral oil wedge sliding bearing and ordinary circular bearing at different rotational speeds is calculated. The experiment of axis trajectory excitation is simulated. First of all, based on the balance between journal inertia force, nonlinear oil film force and dynamic load, the motion equation of sliding bearing-rotor system is established. The nonlinear calculation model of the journal bearing's axis track is established, and the nonlinear axis track of the bearing is calculated. At the same time, for the sake of comparison, according to the linearization method of oil film force, the linear analysis model of small displacement vortex of axis near equilibrium position is established, and the stiffness and damping coefficient of oil film are calculated by using partial derivative method. Then the linear axis locus is calculated according to the linear oil film stiffness and damping coefficient. Secondly, the axis trajectory of spiral oil wedge bearing in n=6000r/min is calculated when the helical angle 尾 0. 1 0. 9 is 0. 9, and the data of axis center in static equilibrium position are obtained. By comparing these data, the influence of helical angle on the axis trajectory is analyzed, and the critical speed of the bearing system is obtained by calculating the axis trajectory with different rotational speeds, and the characteristics of the axis trajectory of the sliding bearing under different speeds are analyzed and compared. Finally, the characteristics of the axis locus of the spiral oil wedge bearing and the ordinary round bearing under their respective critical speeds are compared by spectrum analysis. Thirdly, for the two kinds of bearings with different structure of spiral oil wedge and circular bearing, the characteristics of the axis locus of the two kinds of bearings under the action of sinusoidal excitation force are compared and analyzed. The dynamic process of the system under sinusoidal load and the resonance phenomenon of the system under sinusoidal excitation are studied respectively. The amplitude-frequency characteristic curve and resonance frequency of the system under sinusoidal load are obtained by MATLAB simulation. Finally, the actual axis track is obtained on the sliding bearing test table. According to the experimental steps, the actual axial displacement data are obtained, the useful signals are extracted by FFT and analyzed, and the actual axis trajectory is drawn. The actual trajectory obtained from the experimental data is compared with the axis trajectory obtained by the theoretical calculation in this paper. The results show that the calculated results are consistent with the experimental results.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH133.31

【参考文献】