Investigation of cavitation erosion using X-ray residual stress analysis

In this paper it will be shown that by X-ray residual stress analysis it is possible to obtain information on the cavitation process after only short cavitation times. To clarify the correlation between cavitation erosion and changes in residual stress, samples of various steels were tested in a flow cavitation device. The residual stress measurements showed that cavitation leads to the development of compressive residual stresses in the surface of the samples. The rate at which these residual stresses develop depends on the intensity of cavitation. Cavitation-induced changes in residual stress may also be observed in samples with pre-existing residual stresses due to handling, e. g. mechanical working, heat treatment etc. After very short cavitation times the local variation in cavitation intensity may be very clearly seen in the residual stress distribution in the surface. After a longer period of cavitation, compressive residual stresses reach a limiting value which is not exceeded even at points of highest cavitation intensity.     

An effective residual life prediction method of rolling element bearings based on degradation trajectory analysis

Journal of Mechanical Science and Technology - Rolling element bearings are widely employed in rotating machines. The health monitoring and the residual life prediction of bearings are significant...     

Reliability analysis of rolling bearings considering internal clearance

Journal of Mechanical Science and Technology - The internal clearance is a decisive parameter for life prediction and reliability analysis of rolling bearings. In this paper, a comprehensive...     

振动分析用于滚动轴承故障诊断

对运行中设备滚动轴承的振动及噪声频谱进行分析,确定其运行状态及损坏程度,进而制定处理方案.     

辊轮的失效分析

本文介绍了轧管机上辊轮的失效分析过程。分析了辊轮开裂和磨损的原因，并提出了提高辊轮寿命的措施。     

FEM analysis of plasticity-induced error on measurement of welding residual stress by the contour method

The contour method relies on deformations that occur when a residually stressed component is cut along a plane. The method is based on the elastic superposition principle. When plasticity is involved in the relaxation process, stress error in the resulting measurement of residual stress would be caused. During the cutting the specimen is constrained at a location along the cut so that deformations are restrained as much as possible during cutting. With proper selection of the constraining location the plasticity effect can also be minimized. Typical patterns of longitudinal welding residual stress state were taken to assess the plasticity effect along with constraining locations.     

Abrasive wear of rolling bearings

Various mechanisms of microslip are discussed; abrasive wear is considered the most important. An equation to predict the wear rate of rolling bearings is presented, based on previous work, and illustrated by an example     

基于Pro/MECHANICA的滚动轴承应力分析

对于一些承载较大的滚动轴承,应力分析的意义突出。目前滚动轴承的应力分析一般采用通用有限元分析软件（如ANSYS、MARC等）来进行。针对通用有限元分析软件在轴承应力兮析中的缺陷,本文讨论直接利用Pro／MECHANICA分析Pro／ENGINEER建立的滚动轴承模型。并将该分析值与ANSYS值进行分析对比,以讨论Pro／MECHANICA分析方法在轴承应力分析中的壹用。     

基于无失效数据的滚动轴承剩余寿命非等间隔灰色预测方法

传统的滚动轴承寿命预测都需要进行全寿命实验,并且需要数学或物理模型处理大量的实验数据,针对这一问题,提出了一种基于无失效数据的滚动轴承剩余寿命非等间隔灰色预测方法.首先,采用滚动轴承的无失效数据模型和E-Bayes理论,计算出了每一个截尾时间滚动轴承可靠度估计值;然后,将滚动轴承每个截尾时间计算出的可靠度估计值进行了等...     

基于小波分析多尺度分解的轴承故障检测

归纳和总结了小波分析多尺度分解的滚动轴承故障检测方法的实施步骤,阐述了故障轴承振动与信号的关系以及离散小波算法的原理和实现过程,并以滚动轴承故障诊断为例,运用MATLAB小波分析工具箱将滚动轴承振动信号进行小波离散多尺度分解,然后在分解的结果中寻找滚动轴承的故障特征频率。结果表明,如果在故障检测过程中合理选择小波函数和各种参数,则小波分析多尺度分解具有很强的故障识别能力。     

腐蚀应力加速寿命试验条件下滚动轴承的可靠性评估

为了缩短轴承可靠性评估试验时间,用逆幂律Weibull加速寿命试验方法分析了腐蚀条件下滚动轴承的可靠性。用加权最小二乘法和极大似然法给出了评估模型参数的点估计,结合信息矩阵法给出了评估模型参数及轴承平均寿命、可靠度、可靠寿命等可靠性指标的区间估计。解决了常见轴承可靠性评估中只有可靠性指标点估计而缺少区间估计的问题,使评估结果更加全面。分析了具体实例,基于Akaike信息准则(AIC)、贝叶斯信息准则(BIC)原理,用最佳模型给出了腐蚀条件下轴承的可靠性评估结果。计算结果表明所提方法具有较高的评估精度,且当腐蚀应力提高1倍时,轴承的平均寿命缩短8.75%,可靠度减小16.83%。     

基于ANSYS/LS-DYNA的滚动轴承仿真与分析

基于ANSY/LS-DYNA建立了滚动轴承的有限元模型,有效处理了考虑摩擦条件的接触问题,实现了滚动轴承显式动力学的运动过程仿真.并以6003深沟球轴承为例,进行了试算和相关参数的仿真与分析,结果表明,与滚动轴承运动的实际情况基本吻合.不同工况下的参数仿真分析是进一步研究故障轴承运动仿真与分析的基础.     

An analysis of the mechanisms of grease lubrication in rolling element bearings

There are over eighteen billion bearings in use in the world, and most are grease lubricated. Grease is chosen for a variety of reasons: it gives low friction, is easily confined, and has a long lubricating life at low cost. In many applications, the grease is expected to lubricate effectively over a wide range of conditions and for extended periods. For such applications, lubricant failure leads to instantaneous and rapidly increasing damage of the components and eventually breakdown. Thus, an improved understanding of the fundamental aspects of grease lubrication has far-ranging technical and economic implications. Despite the overwhelming importance of this subject, very little is known about the mechanisms of grease lubrication and the relationship between composition, lubrication performance, and life. This paper attempts to summarise current understanding of grease lubrication mechanisms in rolling element bearings and to consolidate the different aspects of this complex topic.     

基于小波分析和Hilbert变换的滚动轴承故障诊断

针对滚动轴承故障信号的非平稳和调制特点,使用小波分析对包含故障信息的信号进行分解、重构.应用Hilbert变换进行解调和细化频谱分析,提取了故障特征频率,判断轴承故障模式.小波分析和希尔伯特(Hilbert)变换结合对滚动轴承局部损伤故障的检测是有效的.     

Thermal characteristics of spindles on rolling bearings

The influence of factors such as the following on the frictional and thermal characteristics of a spindle is assessed: the spindle speed, its load, the preliminary tension in the bearings, the lubrication method, the lubricant viscosity, and the heat transfer     

Thermal model of spindles on rolling bearings

By means of the proposed thermal model and corresponding software, the thermal characteristics of high-precision spindles may be quickly assessed in the initial stages of design.     

Influence of inclined holes in measurement of residual stress by the hole drilling method

The hole drilling method is widely used in measuring residual stress in surfaces. In this method, the inclination of holes is one of the sources of error. This paper presents a finite element analysis of the influence of inclined holes on the uniaxial residual stress field. The error in stress has been found to increase proportionally to the correct inclined angle of the hole. The correction equations by which one may easily obtain the residual stress, taking account of the inclined angle and direction, have been derived. The error of stress due to the inclined hole has been reduced to around 1% using the correction equations.     

利用弹性支承改善滚动轴承的振动特性

本文研究了弹性支承滚动轴承系统的非线性振动问题，着重分析了利用弹性支承改善滚动轴承振动特性的原理和方法。首先建立了弹性支承滚动轴承的力学模型；然后，根据这一模型对系统进行了振动计算；通过对所得到的最大振幅及轴承动压力的分析，得出了弹性支承可以减小滚动轴承非线性振动的结论；最后，对弹性支承的一个应用实例作了简要说明。