钢丝滚道球轴承的点接触问题有限元仿真

以某型飞行器三轴仿真转台主轴轴系中的钢丝滚道球轴承为例,通过ANSYS对该滚珠．滚道间的非协调性接触问题进行有限元建模与仿真,发现最大接触应力发生在钢丝滚道的表面,而滚珠的最大接触应力发生在其接触面正下方短距离内。有限元分析结果有力地阐明了点蚀易在钢丝滚道接触表面形成并逐渐扩展的机理。本文的工作为进一步开展钢丝滚道的点蚀及磨损的实验研究提供了理论依据。     

钢丝滚道球轴承接触问题有限元分析

运用ANSYS有限元仿真软件以及古典Hertz接触理论,对实际工程中的钢丝滚道球轴承的接触问题进行研究,通过对ANSYS有限元分析得到的接触应力结果与Hertz接触理论推导公式计算的结果进行比较,验证了用ANSYS有限元软件分析钢丝滚道球轴承接触问题的可行性.     

基于ABAQUS的单排四点接触回转支承接触分析

以单排四点接触回转支承为研究对象,以其在最大轴向力作用下滚球与滚道接触区应力分布与变形量为研究重点,通过赫兹接触理论求解得到其接触区接触椭圆大小、接触面最大接触应力以及接触中心变形量,利用ABAQUS有限元软件取得了与赫兹接触理论近似的结果,但有限元法得到的接触区应力分布与变形量情况更为全面。此外,有限元法还得到了滚道接触区最大等效应力的位置,该位置距离滚道表面的距离远小于回转支承制造时要求的滚道表面淬硬层深度。     

大型钢丝滚道球轴承的接触特性研究

将大型钢丝滚道球轴承中球-滚道之间的接触问题视为非协调性接触问题,采用Hertz理论分析了其非线性特性。理论分析结果表明,轴承组件的几何尺寸不影响接触特性,但其几何非线性依赖于材料的抗拉强度及硬度。采用螺旋电感测微仪对钢球-钢丝滚道和Si3N4陶瓷球-钢丝滚道两种接触方式进行了实验测试,通过对比发现,理论接触刚度均比实验测试值稍大,且相同条件下混合式的接触刚度比全钢式的接触刚度高,其主要原因是经典Hertz理论的假设忽略了库仑摩擦力的作用以及接触体弹性变形时往往伴随塑性变形的发生。理论和实验结果均表明接触体的材料非线性对接触问题影响显著。研究结果为大型钢丝滚道球轴承的预紧研究和工程应用提供了理论指导。     

歪斜状况下滚子轴承的接触应力求解与分析

根据弹性接触理论,建立了滚子与滚道在歪斜工况下的接触模型,并结合影响系数法,编程求解了歪斜工况下滚子与滚道的接触问题。通过与赫兹理论解及有限元结果的对比,验证了程序结果的准确性。通过分析歪斜角、外载荷及滚道半径对滚子与滚道接触应力分布的影响,得到如下结论：歪斜工况下,滚子与滚道接触时会出现歪斜效应,即滚子与内圈接触时接触应力在接触副中部增大、两端减小,滚子与外圈接触时接触应力在接触副两端增大、中部减小;歪斜效应随着歪斜角的增大、外载荷的减小及滚道半径的减小而逐渐明显。     

薄壁四点接触球轴承接触问题有限元分析

基于Ansys有限元软件,提出薄壁四点接触球轴承的逐级梯度细化接触区域的单元网格划分方法。建立等截面薄壁四点接触球轴承1/2单个滚动体与套圈及整个轴承有限元模型。计算分析了网格单元尺寸对四点接触球轴承接触特性的计算精度影响,求解整个轴承有限元模型在静径向力下的载荷分布规律,获得了薄壁四点接触球轴承较为精确的椭圆接触区域形状和四点接触状态。研究表明:对于接触特性计算,网格划分单元尺寸近似于接触椭圆短半轴的50%时便可以得到较精确计算结果,对于薄壁四点接触球轴承,钢球与内、外圈滚道的接触应力、等效应力和接触变形与径向载荷呈非线性递增关系,接触应力大小和载荷分布的计算结果与赫兹接触理论计算值具有较好的一致性。计算结果较为精确的模拟了薄壁四点接触球轴承的接触特性和载荷分布规律。     

基于ABAQUS的列车轴箱轴承动力学分析

以列车轴箱轴承为研究对象,在给定的使用工况下推导出其所承受的径向载荷,针对不同等级轮轴转速,利用Newton-Rampson法求解出轴承内部的载荷分布规律,并根据Hertz接触理论给出了内、外滚道接触应力的理论解,讨论了转速变化对接触应力的影响,最后利用ABAQUS-explicit对简化轴承模型的动力学特性进行了求解,相关结果与实际工况基本吻合。     

等截面四点接触球轴承承载能力分析

等截面四点接触球轴承是工业设备中核心部件之一，实现两部件之间的载荷传递和相对运转，较高的使用频率、冲击载荷、材料的原始缺陷等极易造成薄壁四点接触球轴承损伤，影响工业设备工作精度和效率。通过赫兹接触理论进行接触应力和接触面积的理论分析，获得滚动体与滚道接触区域接触应力和接触面积的解析解。建立滚动体与滚道接触有限元验证模型，通过与赫兹接触理论进行对比，验证数值模型的有效性。最后，运用验证过的滚动体与滚道接触有限元模型对滚动体与滚道接触区域承载能力进行分析。本文的研究有利于提高工业设备等截面四点接触球轴承承载能力的计算精度，为等截面四点接触球轴承的研发设计和优化设计提供可靠的手段和依据。     

硅微球轴承接触问题的有限元分析

利用有限元分析软件Abaqus建立了硅微球轴承的有限元模型,采用有限单元法(FEM)对微球与硅滚道的接触问题进行数值求解。考察了微球的不同尺寸和材料对硅微球轴承滚道接触应力的影响。结果表明:随着微球尺寸的增大,滚道表面最大接触压力和滚道内最大Mises应力均减小;随着微球公转速度的增大,微球材料密度对滚道侧壁表面接触压力和侧壁内Mises应力有显著的影响。该研究将为MEMS旋转机械中硅微球轴承的设计提供理论依据。     

固体润滑滚子轴承的接触表面应力分析研究

为获得固体润滑滚动轴承滚动体与滚道处的接触应力,通过固体润滑滚子轴承拟动力学分析并考虑涂层的影响,获得了滚子轴承稳定运行过程中滚动体的力载分布。通过建立带涂层接触的平面应变问题的力学模型,将涂层与基底两种材料的特性等效为一种材料来求解滚子与接滚道触应力分布情况,并与轴承的拟动力学分析相结合,获得了滚子轴承中滚动体与固体润滑膜接触表面的接触变形、接触半径与外加载荷之间的关系,讨论了不同涂层的弹性模量以及不同涂层厚度对接触界面应力分布的影响。当涂层弹性模量比基底大时,涂层的存在使得接触半宽减少,最大名义接触应力增加;涂层弹性模量比基底小时,则与之相反。当涂层的厚度<0.01mm时,涂层的存在对固体润滑滚子轴承的接触表面应力分布影响较小;在一定范围内,当涂层的厚度逐渐增大时,涂层对轴承接触表面应力分布的影响增大。     

A new method for determining the preload in a wire race ball bearing

This paper explores a numerical method to calculate the frictionless three-dimensional non-conforming contact problem associated with a wire race ball bearing used in a certain aircraft simulating rotary table, for challenging the conventional method on the determination of the preload magnitude. A computer program based on the Hertz elastic contact theory and a mathematical model of two critical loading conditions was performed in MATLAB^® by using an example of a wire race ball bearing having an approximately 900 mm diameter. The normal contact forces, the contact deformation, the maximum contact pressure, the semi-major axes and the semi-minor axes of contact ellipses of the ball-wire race were computed. The analytic results show that the overturning moment, the pitting corrosion and the shear failure due to combined stresses can be avoided by controlling preload values in the range 11.3–169.9 μm. The experimental results are closely in agreement with the theoretical results, and verify the availability of the numerical method. The research provides theoretical support for the development and further application of wire race ball bearings with large diameters.     

点蚀故障对齿轮传动系统噪声的影响

针对不同数滚机床齿轮齿面点蚀故障严重程度对齿轮传动系统噪声的影响,基于赫兹理论力学模型,运用ABAQUS创建了齿轮副的应力仿真分析模型,求解在未点蚀及不同点蚀故障严重程度下齿面最大接触应力,并对比了传动扭矩对不同点蚀故模型最大接触应力的影响。开展了不同齿面点蚀故障齿轮模拟工况下的噪声测试实验,通过对比齿轮副试样噪声的敏感性分析不同点蚀故障严重程度的影响。有限元结果表明,传动扭矩与齿面最大接触应力呈线性关系,点蚀故障越严重,齿面点蚀区域接触冲击应力越大;齿轮故障噪声测试实验研究结果则表明,基于微点蚀、点蚀失效形式之间存在的竞争机制,点蚀故障越严重,对应的噪声曲线峰值越大;随着齿轮负载、转速的增大,点蚀故障齿轮噪声也逐渐增大。     

Critical stress and load conditions for pitting calculations of involute spur and helical gear teeth

Calculation methods of spur and helical gear drives for preliminary designs or standardization purposes available in technical literature, use the Hertz equation to evaluate the contact stress, assuming the load to be uniformly distributed along the line of contact. However, this model presents some discrepancies with experimental results because the changing rigidity of the pair of teeth along the path of contact produces a non-uniform load distribution, which implies that some load distribution factors are required to compute the contact stress. In this paper, a non-uniform model of load distribution along the line of contact, recently developed, obtained from the minimum elastic potential criterion, has been used. This model combined with the Hertz equation yields more accurate values of the contact stress. As the load per unit of length at any point of the line of contact and any position of the meshing cycle has been described by a very simple analytic equation, a complete study of the location and value of the critical contact stress has been carried out. From this study, a recommendation for the calculation of the pitting load capacity of spur and helical gears is proposed.     

Contact stress calculation of undercut spur and helical gear teeth

The presence of undercut at the pinion root may affect the load sharing among couples of spur gear teeth in simultaneous contact, as well as the load distribution along the line of contact of helical gears. This occurs if the outside points of the wheel profile do not find, due to undercut, mating profile to mesh with, which is called vacuum gearing. Under these conditions, the effective contact ratio is reduced, and the critical contact points may be shifted from their locations at non-undercut profiles. In this paper, a non-uniform model of load distribution along the line of contact, obtained from the minimum elastic potential criterion, has been used combined with the Hertz equation for the calculation of the contact stress. A complete study on the critical load conditions and the value of the critical contact stress has been carried out, considering a wide range of the values of the geometrical parameters. As a result, a recommendation for pitting load capacity calculations of vacuum-gearing spur and helical gears is proposed.     

基于ANSYS的球轴承赫兹接触问题有限元分析

以推力球轴承的赫兹接触问题为例,介绍ANSYS软件的接触分析功能和建模的方法,基于ANSYS软件面-面接触方式中的柔-柔接触类型计算出接触区域的最大接触应力和变形,并对比了赫兹理论解,指出网格局部细化是影响计算精度的主要原因.研究表明,提出的这种方法是正确的,为分析赫兹接触问题探索出一种新途径.     

少齿数渐开线齿轮副点蚀失效的理论研究

分析了摩擦力和润滑油对少齿数渐开线齿轮副齿面赫兹应力的影响，并利用断裂力学的观点解释了少齿数渐开线齿轮副齿面疲劳点蚀的最终形成。得出了与齿面实际失效事实相符的慢速齿面首先出现疲劳点蚀的结论。     

基于ANSYS的混合陶瓷球轴承接触问题仿真与分析

运用ANSYS软件,以B7005C混合陶瓷球轴承为样本,进行实体建模、网格划分、接触对设置,然后进行后处理分析,根据轴承实际工况仿真得出了内外圈的接触应力与接触变形。仿真分析结果和经典的赫兹解进行对比后,表明运用ANSYS仿真轴承的接触问题是比较理想的。     

FEM Comparison of Ball and Roller Bullgears

A structural finite element model has been developed for calculating the forces transmitted through the rolling elements (load distribution) in a bullgear assembly. The elastic structural model consists of 3-D beam elements used to approximate the global race deflection and non-linear springs that approximate the combined rolling element/raceway contact deflections. For rollers, an upperbound on the contact stress (assuming linear variation of force along the length of the roller) is estimated by modeling the rollers as pairs of nonlinear springs. The finite element approach iteratively solves the contact forces at each, rolling element. Contact stresses are then calculated from the contact, forces using Hertz contact theory. This approach is applied to analyze two proposed designs of ball and crossed roller bearing, bullgear assemblies used for rotating the radar antenna on top of a ship's mast. The loads analyzed include those arising from wind loading and from out-of-flatness of the inner race of the bearings due to deflection of the mast. The distribution of the load and the maximum contact stresses for the proposed bullgear assemblies are estimated and compared. It is found that the maximum contact stress in the crossed roller bearing is less than that in the ball bearing for both types of loads. Furthermore, the analysis shows that the out-of-flatness loading produces significantly higher stresses than wind loading.