The Performance of Heavily Loaded Oscillating Roller Bearings from 300 F to 600 F

Over 1000 roller bearings have been evaluated at elevated temperatures as oscillating bearings and load-life characteristics determined through statistical analysis of failure data. Operating temperatures of 300 F, 450 F, and 600 F were investigated. Bearing materials investigated included AISI 52100 steel, M-2 tool steel and 440-C stainless steel. Grease lubrication was used. The bearing load range included 250,000 psi to 500,000 psi maximum Hertz stress. AISI 52100 steel proved satisfactory for temperatures to 450 F. Tool steel (M-2) and 440 C stainless steel proved satisfactory for temperatures to 600 F. Although failure modes were predominantly by plastic deformation, wear and oxidation, failure distribution frequencies fit the Weibull distribution commonly used in bearing fatigue studies. Data scatter was less than that expected for continuously rotating ball bearings.     

推力球轴承接触问题有限元分析

推力球轴承是被广泛应用的支承机械,用于承受转速较低的轴向载荷.它是由上下座圈、保持架和球体组成的可分离结构,分为单向推力球轴承和双向推力球轴承两种.着重分析了不同尺寸、形状的球形滚动体和橄榄球形滚动体对接触情况下的应力和变形量的影响.使用Pro/E建立实体模型,导入ANSYS进行数值模拟和计算.通过对获得的数值模拟结果和赫兹理论解进行对比,结果表明有限元分析是比较准确而且可靠的.最大接触应力和弹性趋近量取决于滚动体与滚道接触处的主曲率和、主曲率差,与滚动体形状、体积没有直接联系.     

滚动轴承动力特性测试方法

轴承的动力特性对转子－轴承系统的动力特性有重要的影响。但至今，滚动轴承的动力特性仍缺乏系统的资料，在许多情况下，将滚动轴承简化为无阻尼的定常弹性元件。本文分析了滚动轴承动力特性的主要影响因素，介绍了滚动轴承动力特性的两种测试方法，并以某航空轴承为例作了具体测试，取得了比较一致的结果。本文提出的方法可作为建立滚动轴承动力特性数据库的基本手段。     

基于混合编程的高速滚动轴承热分析软件的开发

高速滚动轴承的摩擦生热已成为影响其工作寿命和可靠性的重要因素。总结了计算机高级编程语言Visual Basic(简称VB)和FORTRAN以及有限元软件ANSYS的特点,结合3者各自的优点以及高速滚动轴承的热分析理论,采用混合编程的方法,开发了高速滚动轴承热分析软件,使用该软件能够方便地完成高速球轴承和高速圆柱滚子轴承的热分析,有效地预测轴承组件在复杂工况条件下的工作温度场。     

Effect of Silicon Nitride Balls and Rollers on Rolling Bearing Life

Three decades have passed since the introduction of silicon nitride rollers and balls into conventional rolling-element bearings. For a given applied load, the contact (Hertz) stress in a hybrid bearing will be higher than that of an all-steel rolling element bearing. The silicon nitride rolling-element life as well as the lives of the steel races were used to determine the resultant bearing life of both hybrid and all-steel bearings. Life factors were determined and reported for hybrid bearings. Under nominal operating speeds, the resultant calculated lives of the deep-groove, angular-contact, and cylindrical roller hybrid bearings with races made of post-1960 bearing steel increased by factors of 3.7, 3.2, and 5.5, respectively, from those calculated using the Lundberg-Palmgren equations. An all-steel bearing under the same load will have a longer life than the equivalent hybrid bearing under the same conditions. Under these conditions, hybrid bearings are predicted to have a lower fatigue life than all-steel bearings by 58% for deep-groove bearings, 41% for angular contact bearings, and 28% for cylindrical roller bearings.     

基于热-应力耦合的高速圆柱滚子轴承凸度值分析

考虑到圆柱滚子轴承在运转过程中温升对轴承性能的影响,基于滚动轴承动力学理论、摩擦学原理和热分析理论,利用ANSYS建立了圆柱滚子轴承热-应力耦合有限元分析模型,分析了对数修形滚子的凸度值对轴承温升和接触应力的影响以及径向载荷和转速对最优凸度值的影响。结果表明:滚子最高温度随凸度值增大而增大,最大接触应力随凸度值的增大先减小后增大;考虑耦合时轴承零件的接触应力大于未考虑耦合时的接触应力;考虑耦合时滚子最优凸度值随径向载荷和转速的增大而增大,未考虑耦合时滚子最优凸度值随径向载荷增大而增大,但不随转速增大而变化。     

水泥球磨机调心滚子轴承接触应力和寿命分析

介绍了球磨机小齿轮轴两端调心滚子轴承载荷的计算方法,建立Romax轴系仿真模型,分析了径向力、齿轮推力、温度对轴承接触应力和寿命的影响,结果表明:随径向力增大,轴承最大接触应力增大,寿命减小;随齿轮推力增大,游动端轴承的接触应力和寿命几乎无变化,固定端轴承列1和列2接触应力变化趋势不同,0～225 kN,列1呈减小趋势...     

The effect of hydrogen on the rolling contact fatigue life of AISI 52100 and 440C steel balls

Rolling four ball tests conducted on hydrogen impregnated AISI 52100 and 440C balls lubricated with mineral oil showed that fatigue life is inversely proportional to the hydrogen content in the steel. Longer fatigue lives were found for the treated 440C specimens as compared to the AISI 52100 test balls, and this was consistent with the lower hydrogen permeability that was observed within the 440C steel. Aging of the treated samples was found to have no appreciable effect on their fatigue lives. The same detrimental effect on fatigue life was also observed when tests were conducted using H₂S as a chemical source of hydrogen in the lubricant.In normal bearing operation, hydrogen is considered to come mainly from the reaction of water at the bearing surface and from the decomposition of the lubricant. In the former case, controlled atmosphere experiments showed that both oxygen and water were required to reduce the life of the test bearings. Oxidation studies showed that large quantities of hydrogen were generated during the oxidative decomposition of the lubricant.     

Probabilistic Stress-Life (P-S-N) Study on Bearing Steel Using Alternating Torsion Life Test

Probabilistic stress-life (P-S-N) studies using alternating torsion life test were conducted with the bearing steel JIS SUJ2/AISI 52100 having a hardness range of Rockwell C scale of 58-62 HRC to determine the existence of a fatigue limit for this through-hardened steel. One hundred and fifty (150) alternating torsion tests were performed at six torsion maximum shear stress amplitudes of 0.5, 0.63, 0.76, 0.80, 0.95, and 1.0 GPa. The number of specimens that were run at each stress amplitude varied from 19 to 33. There is no observable fatigue limit for JIS SUJ2/AISI 52100 bearing steel. On log-log plotted data, life is linear and is inversely proportional to shearing stress to a 10.34 exponent. The failure mode of the experiment is due to the conjugate tensile and compressive alternating stresses in accordance with alternating shearing stresses. The three-parameter Weibull life distribution function with a constant value of the Weibull slope m = 3/2 was found to have the best conformity followed by the log-normal distribution and the two-parameter Weibull distribution function. The shear stress-life exponent (A = 10.34) for JIS SUJ2/AISI 52100 bearing steel was independent of the Weibull slope.     

考虑三维运动和相对滑动的滚动球轴承局部表面损伤动力学建模研究

滚动体通过局部表面损伤时轴承的运动参数及动力学响应是轴承疲劳损伤分析和故障诊断的有效输入和重要依据。基于GUPTA轴承模型构建具有局部表面损伤的滚动球轴承的完整动力学模型。该模型中每个轴承元件(滚球、内圈及外圈)具有6个自由度,并且考虑了元件之间的相对滑动和润滑牵引特性。在对局部表面损伤进行建模时,完整考虑了损伤出现后由于材料缺失而引入的额外间隙,以及损伤对赫兹接触刚度及接触载荷作用方向的影响。研究滚球在通过局部表面损伤时轴承的加速度与滚球/损伤之间冲击力的对应关系,以及轴承转速和损伤宽度对轴承振动响应的影响规律。仿真结果表明,由于考虑了相对滑动和滚球/损伤之间冲击力的影响,本模型能够对具有局部表面损伤的球轴承进行更为合理的动力学特性分析,可为滚动球轴承的疲劳损伤分析和故障定量诊断提供一定的理论依据。     

A New Life Theory for Rolling Bearings—By Linkage between Rolling Contact Fatigue and Structural Fatigue

Based on a linkage between rolling contact fatigue and structural fatigue, a new life theory for rolling bearings has been proposed using the three-parameter Weibull distribution function. A minimum life is introduced as the third parameter, which may be considered independent from the statistical strength of material. The following are the new findings: (1) Reliability functions and life equations were introduced for the rolling bearing races and the life test specimens made of the same material (JIS SUJ2/AISI 52100), and the linkage between them has successfully been established by using linkage factors. (2) The 90% load rating and rating life formulas for the races as well as for the whole bearing were developed. (3) Newly introduced 100% load rating and rating life formulas were postulated by introducing the minimum lives for the life tests and theoretical research. (4) For the ratios of each load rating between the test results on the grease-lubricated deep-groove ball bearings and the new life theory, the linkage factors were determined as β = 2.4 and β′ = 2.16 for 90 and 100% load ratings, respectively. (5) A reduction factor λ for 100% load rating was determined as λ = β′/β = 0.9.     

基于ANSYS／LS—DYNA的陶瓷球轴承仿真与分析

陶瓷球轴承以其自身特点广泛应用于机械、机床、精密仪器、船舶、航空等方面,为了更好的发挥陶瓷球轴承特性．以B7005C滚动轴承为例,运用ANSYS／LS—DYNA软件,建立了陶瓷球轴承的实物模型与有限元模型,实现了陶瓷球轴承的试算与相关参数的显示运动学仿真,分析了陶瓷球轴承运动过程中的转速、载荷、时间与应力、应变、加速度、载荷、振动之间的关系,结果表明,与已有的滚动轴承运动的理论和实际情况基本吻合。     

滚动轴承-双转子系统动态性能分析

在高速圆柱滚子轴承拟动力学分析的基础上,利用整体传递矩阵法对滚动轴承-多转子系统的动态性能进行了分析,并开发了相应的分析软件,在此基础上,对高速圆柱滚子轴承径向游隙与整个系统动态特性的关系进行了研究。结果表明:圆柱滚子轴承的径向游隙直接影响着滚动轴承-双转子系统的稳定性。     

Determination of Static Load Distributions from Elastic Contacts in Rolling Element Bearings

A method has been developed for recording the elastic roll body contacts in the load zone for both radial and thrust rolling element bearings subjected to various static loading conditions. Employed in this investigation were a ball bearing and four types of roller bearings which included cylindrical, needle, tapered and spherical. Inspection of the contact areas, or footprints, yields a qualitative measure of the extent of loading arc, load sharing among rolling elements, contact characteristics such as end loading and effects of misalignment. Quantitative data on individual contacts permits the determination of load and stress distributions. Summation of the vertical components of individual roll body loads agrees with the total load applied to the whole bearing, thereby demonstrating the practicability and accuracy of this technique. Correlation of roll body loads with theoretical values varied, depending on angular position from the radial load plane. Finally, this paper indicates how static stress levels on the most heavily loaded element may be obtained and used as a basis for bearing life prediction.     

基于接触应力的圆柱滚子轴承疲劳寿命分析

首先介绍了圆柱滚子轴承疲劳寿命的经典理论计算方法.然后运用Hertz接触应力理论计算出圆柱滚子轴承的最大接触应力,结合三参数幂函数公式确立疲劳寿命曲线方程计算出轴承的疲劳寿命值.通过改变轴承滚子数目、径向力大小以及径向游隙等参数,将基于接触应力得到的疲劳寿命结果与经典理论结果进行比较,证明了该方法的合理性.并分析了在考虑离心力作用下高速圆柱滚子轴承疲劳寿命与转速之间的关系.     

起重机用滚动轴承有限元分析及故障检测

针对起重机用滚动轴承故障率高且难以检测的问题,首先采用Ansys软件对起重机用滚动轴承进行基于实际接触状态的有限元分析,然后采用基于小波包能量法和Hilbert变换方法对滚动轴承进行信号处理、分析以及故障检测。结果表明:滚动轴承的滚动体与内外圈接触部位存在较大应力集中,最易在此处首先发生破坏;根据轴承故障特征频率与内圈、外圈、滚动体三种故障类型所对应的频谱特征和能量谱相比较,可有效判断轴承故障类型。研究所采用的检测方法可为起重机用滚动轴承的故障预防和检测提供一定理论依据和指导作用。     

游隙对单排四点接触球转盘轴承载荷分布的影响

游隙是影响滚动轴承性能的一个重要参数。研究了游隙对单排四点接触球转盘轴承载荷分布的影响规律。首先,建立轴承的静力模型并得到一组平衡方程;然后,以两套具有不同几何参数及外部载荷的轴承为例,利用静力模型计算了轴承的载荷分布。结果表明:随着游隙的增大,承担载荷的滚动体数目逐渐减少,受载最大的滚动体载荷也逐渐增大。当游隙往小处取值时,有利于提高轴承的承载能力。     

基于ANSYS的四列圆柱滚子轴承接触应力和刚度分析

对四列圆柱滚子轴承的接触应力、变形以及径向刚度进行了研究.建立了四列圆柱滚子轴承的有限元三维模型,基于ANSYS和Hertz接触理论,阐述了建模过程中的关键步骤,结合短应力线轧机的应用实例,计算了轴承滚子、内圈的接触应力与变形分布,直观表达了交错排列滚子之间的应力分布情况,计算结果和Hertz理论值相比较,具有较好的一致性.通过计算不同载荷下的轴承变形（轴承内孔轴线的相对位移）,获得了轴承刚度随径向载荷变化的规律.     

四列圆锥滚子轴承偏斜角与其寿命的关系研究

以重型四列圆锥滚子轴承为研究对象,通过计算轴承在不同偏斜角状况下的疲劳寿命,分析了在偏斜角状况下,轴承疲劳寿命的变化趋势,总结出重型四列圆锥滚子轴承偏斜角对其疲劳寿命的影响,为长寿命重型轴承的设计提供了技术依据。     

角接触球轴承流固耦合仿真分析

角接触球轴承在运行过程中的润滑状况至关重要,润滑油直接影响滚动轴承的接触状态。为分析角接触球轴承的润滑状况以及考虑润滑时轴承的机械特性,基于有限元和晶格玻尔兹曼方法,建立了双向流固耦合轴承仿真模型,对角接触球轴承进行动力学有限元仿真和润滑流体仿真,并与轴承拟静力学理论计算结果进行对比,验证模型的准确性。分析结果表明,保持架与滚珠接触并撞击,在轴承腔内油膜压力最大,滚珠与内圈、外圈滚道接触区分别为第二、第三大油膜压力区。润滑油受滚珠公转影响,沿着滚珠转动方向流动,实现对滚珠与内圈、外圈和保持架之间的润滑。滚珠运动和最大接触应力仿真结果与轴承拟静力学理论求解结果一致,即流固耦合仿真模型计算轴承机械特性具有较高的准确性。