圆柱径向轴承性能的可视化研究

利用Elrod空穴计算法对考虑气穴因素的雷诺方程进行Fortran程序编制,并且利用VB与Fortran的混合编程,编制一个圆柱径向轴承性能分析的可视化软件。该程序采用相对路径法调用动态链接库,更方便可视化软件的快速应用。以圆柱径向轴承为例,采用该软件分析轴承压力、温度场的三维分布以及主要特性参数,并与文献结果进行比较。分析结果表明,该程序既可以方便、准确地得到轴承相关特性,又能实现可视化来帮助使用者了解圆柱径向轴承的工作状况。     

GMA止推油膜轴承瓦块均载调整试验研究

介绍了一种基于超磁致伸缩驱动器(GMA)的止推油膜轴承的结构和工作原理,搭建了GMA止推油膜轴承试验台,进行了止推油膜轴承的跑合试验、单瓦载荷调节试验以及手动和自动均载调节试验。该轴承以瓦块的温度作为反馈信号,改变GMA的伸长量可控制止推瓦块的油膜间隙,使同一止推轴承的不同瓦块承受载荷尽量均匀,能够防止止推轴承偏载现象发生,避免止推油膜轴承由于偏载引起的局部高温。试验结果表明,利用GMA调节止推轴承的油膜间隙、实现止推瓦块的均载方案是可行的。     

微位移驱动器在止推油膜轴承中的应用

针对止推油膜轴承的偏载问题,研究了微位移驱动器在止推油膜轴承中的应用。通过理论计算得到油膜厚度、压力和温度分布,分析了止推轴承油膜厚度的变化对载荷与温度的影响。设计了一种超磁致伸缩微位移驱动器微位移驱动器,并建立了杠杆试验机测试其静态位移输出特性,证实超磁致伸缩微位移驱动器具有与润滑膜厚同一数量级的位移输出,可应用于止推轴承油膜间隙的主动调节,均衡瓦块间载荷并降低温升。利用超磁致伸缩微位移驱动器微位移驱动器设计了一种新型结构的可自动调节间隙的止推油膜轴承,并建立了用于测试该新型轴承的止推轴承实验台。     

滑动径向轴承轴心轨迹的可视化及其应用

讨论了轴承 转子系统的非线性动力分析 ,由此计算轴心轨迹 ,并研制开发了滑动径向轴承轴颈轨迹数值实验软件系统。能指导设计人员预先了解轴承的运行状态 ,从而提高了滑动轴承和机械产品的设计质量和效率 ,在应用中具有很强的实用性。     

基于MATLAB和Visual C++的风机流场分析的可视化研究

为提高风机可视化仿真系统的可维护性和可移植性,采用了MATLAB编写流场数据图形显示程序,并将其转换为动态链接库,作为其他程序调用图形显示程序的接口,使系统能独立运行。     

圆柱浮环液体动静压轴承止推环性能的有限元分析

本文对圆柱浮环液体动静压轴承的止推环静动态特性进行了有限元分析。提出了保证浮环正常工作的平衡条件,并据此给出了浮环轴承的设计准则;在有限元分析中求解了该轴承内、外膜压力场;用小扰动法分析了动态雷诺方程,得到内外膜的刚度系数和阻尼系数;在求得浮环静压、动压平衡的基础上,得到了该轴承的静、动态特性及稳定性参数。     

基于OpenGL技术的滑动轴承油膜特性可视化研究

为解决滑动轴承油膜厚度场、温度场和压力场的可视化问题,将OpenGL图形技术应用到滑动轴承油膜特性三维模型的显示中,研究开发了流体动压径向滑动轴承油膜特性的三维可视化仿真系统.模型中将轴瓦简化为略去厚度的圆柱面来处理;为便于观察,厚度场、温度场和压力场建立在轴瓦曲面的外表面,并以“高度+颜色”的组合方法表现了油膜特性参数的大小,给出了各模型的具体建立方法;通过人机交互的方式控制模型的缩放、旋转,并给出了模型旋转、缩放的具体方案.研究结果表明,该仿真系统实现了对流体动压径向滑动轴承的油膜特性可视化模型的观察分析及交互操作,可方便、直观地研究轴承油膜的工作性能,有助于对滑动轴承进行故障分析从而提高其设计质量.     

滑动轴承三维油膜压力动态分布可视化研究

研究开发了基于OpenGL交互控制的滑动轴承油膜压力动态分布三维可视化仿真系统.将油膜压力的实时计算、压力分布三维图形的绘制与立体显示相结合,通过人机交互,实时显示任意转速、润滑油粘度、宽径比等参数下的油膜压力动态分布三维模型,在沉浸感环境下直观、逼真地进行滑动轴承三维油膜压力分布的分析研究,有助于提高滑动轴承设计质量.     

基于OpenGL技术的滑动轴承油膜特性的可视化研究

以VC 6.0为开发平台,以OpenGL为开发工具,研究开发了流体动压径向滑动轴承油膜静特性的三维可视化仿真系统,绘制了油膜动力学特性(刚度、阻尼)随转速和载荷的变化趋势曲线,并且可以通过对可视化模型的观察分析及交互操作,更方便、直观、高效地研究轴承油膜工作性能.     

润滑油含水量对轴承性能影响的试验研究

为研究润滑油含水量超标时轴承的运行性能,搭建了滑动轴承试验台,通过试验研究了在不同含水量的润滑油对滑动轴承温度、摩擦力矩及轴心运动轨迹的影响。试验发现,润滑油含水量较低(质量分数0. 5%以下)时对滑动轴承的温度、摩擦力矩和轴心轨迹影响不大,但含水量达到一定程度时(如超过质量分数0. 5%)会使轴心轨迹重复性变差,导致转子运转有不稳定的趋势出现。这表明润滑油含水会对滑动轴承运行性能造成一定的影响,更为准确的结果还需长期的实验验证。     

Optimizing hydrodynamic thrust bearings of Mitchell type

An optimal-design algorithm for hydrodynamic thrust (axial) slip bearings is outlined.     

Experimental investigation into the performance of an aerostatic industrial thrust bearing

Load and flow versus air-gap curves and stability maps have been obtained for an industrial externally-pressurized air-lubricated thrust bearing with a central restrictor. Supply pressure and pocket depth were treated as parameters. Bearing stiffness was estimated by using a computer to fit a polynomial type curve to the test data. The results show that whereas the effect of inserting a pocket into the bearing improves its load capacity, there is no significant improvement in film stiffness at design conditions. The suggestion is made that the diameter of the orifice in the restrictor should be increased. As pocket depth is increased beyond the design value the bearing becomes prone to pneumatic hammer.     

Rotordynamic modelling of a hydrodynamic pivoted-pad thrust bearing

The rotordynamic characteristics of a hydrodynamic pivoted-pad thrust bearing are investigated in this paper. Firstly, the rotordynamic coefficients of a single pad are defined in the case of small perturbation. The Reynolds equation and its perturbed forms are solved by using the boundary element method (BEM). An iterative procedure is proposed to determine the static positions of the thrust pads when the static tilt of the runner is considered by using the Newton–Raphson method. The characteristics of the thrust bearing are obtained by using an approach based on a coordinate transformation principle.     

Experiments on thermal effects in a hydrodynamic thrust bearing

The objective of this work is to analyse the characteristics of a fixed-geometry thrust bearing in typical operating conditions and to give experimental results in order to validate future thermohydrodynamic models. The influence of the applied load, the rotational speed and the feeding temperature on the thrust bearing performance is presented and discussed.     

Analysis of hydrodynamic slider thrust bearings lubricated with non-newtonian fluids

A procedure for solving the Navier-Stokes equations for the steady three-dimensional flow of a non-newtonian fluid within a finite width slider thrust bearing is described. The method uses a finite difference approach together with a technique known as SIMPLE (semi-implicit method for pressure-linked equations) which has now become well established in the field of computational fluid dynamics. The concept of “effective viscosity”, used to describe the non-linear dependence of shear stress on shear rate, is also employed.To illustrate the capabilities of the procedure, results are presented for a wide range of non-linearity factors and these are compared with results from another source.     

万向铰节点推力关节轴承的力学性能分析

针对推力关节轴承复合受载情况下的安全性能问题,根据某场馆所采用的万向铰节点结构特点与承载特点,利用有限元法对结构中的推力关节轴承进行了两种不同载荷工况下的力学性能分析。利用大型有限元前处理软件ANSA对三维模型进行了网格划分,再通过ANSA与ANSYS软件的接口,准确建立了万向铰节点结构有限元计算模型,并计算出两种工况下推力关节轴承内、外圈的应力分布规律。研究结果表明,压剪工况下,除盖板外,各部件最大应力均比拉剪工况大;且两种工况下,万向铰节点的最大VonMises应力值发生的位置一样,均发生在下部轴承外圈内上边缘,因此该部位有可能会是轴承外圈开裂的起始源处。分析结果为万向铰节点推力关节轴承的设计与改进提供了有益的参考。     

新型可逆式动压推力轴承的承载能力计算

根据流体力学有限元理论,对新型可逆式动压推力轴承承载能力作用计算。同时考虑了轴瓦的热变形的影响。建立了最小油膜厚度、油楔角与承载力的关系曲线。并与未考虑热变开遥曲线作了比较。建议在实际调整最小油膜厚度时需增加该值的１３％左右,用来补偿热变形。     

Comparison of an optimum‐profile hydrodynamic thrust bearing with a typical tilting‐pad thrust bearing

The oil gap profile in a hydrodynamic thrust bearing exerts a great influence on the bearing properties, and hence the optimisation of the oil gap profile is one method for improving the bearing properties. In the present work, the properties of two hydrodynamic thrust bearings have been experimentally compared under realistic load/ speed conditions. One was a typical tilting‐pad bearing and the other was an unconventional bearing with an elastic thrust plate. The latter was designed using oil gap profile optimisation and design parameter selection. Owing to the design method used, the oil gap profile was close to optimum for the assumed load/speed conditions. The results show a substantial increase in the minimum oil film thickness and lower temperature in the bearing with the elastic thrust plate. This improvement of properties is thought to be because of the optimised oil gap profile in the bearing.     

Experimental assessment of hydrostatic thrust bearing performance

This work presents an experimental study to assess the performance characteristics of hydrostatic thrust bearings. A test rig is designed for testing two configurations of hydrostatic bearings compensated by a capillary tube, one with a mid-circular recess and the other with multi-sectors (four recesses of different recess radii ratios). The performance characteristics have been measured, namely, oil film thickness, recess pressure, pressure distribution and oil flow rate. A specially devised computer program using an iterative technique has been adopted to compute numerically the pressure distribution and predict other performance characteristics. Good agreement has been obtained between predicted theoretical performance and that experimentally measured. The results demonstrate that the bearing recess size and location have a great influence on the performance of the hydrostatic thrust bearing.