共查询到19条相似文献,搜索用时 718 毫秒
1.
弹性流体动力润滑是润滑理论的一个重要分支,也是关系到高副接触机械零件使用耐久性和可靠性的关键技术问题。计算机模拟仿真技术、数值计算方法和弹流测试技术的发展,推动了弹流润滑理论的发展和该理论在高副零件摩擦副设计中的广泛应用。综述齿轮、凸轮、轴承3种高副接触零件基于表面粗糙纹理、轮齿修形、有限长接触、热效应、镀层等因素的弹流润滑研究发展概况。指出现代弹流润滑理论虽然在高副接触零件中的应用已逐渐接近工程实际要求,能够较可靠地解决实际工况下的润滑难题,但在非稳态效应和真实粗糙表面对高副零件弹流润滑的影响方面,高副零件弹流润滑的多重参数耦合、计算机仿真及相关实验验证方面,还须进一步深入研究。 相似文献
2.
3.
用光干涉测试方法研究了点接触条件下润滑脂弹流膜的形状和变化。在充分供油和供脂条件下,润滑脂弹流膜厚大于基础油弹流膜厚。给出了润滑脂弹流膜随载荷、温度和速度变化的实验结果。同时,研究了润滑脂的一些理化性质对弹流膜的影响。 相似文献
4.
5.
6.
7.
8.
为了更好地观测滚子摩擦副在不同卷吸速度下的弹流润滑现象,开展有限长线接触弹流润滑油膜成膜机制的实验研究,对原有的线接触光干涉实验装置进行改进,将原有的曲柄滑块机构设计成丝杠推杆,从而将旋转运动转变成直线运动。实验表明:改进后的实验装置可以有效地实现滚子卷吸运动速度大小和运动规律的变化,可以观测到非常清晰的油膜干涉图像,在滚子接触区域油膜呈现出较为明显的弹流特征,可为线接触弹流的理论研究提供可靠的实验数据。在改进后的实验装置上,对滚子在突然加速的工况下进行了实验研究,由于步进电机的特点,在突然加速的瞬间有极短的停顿,导致挤压效应较为明显,油膜被封在滚子的接触区域内形成凹陷,出现封油现象,当滚子卷吸速度增加时,油膜厚度也会随之增加。 相似文献
9.
由于弹流润滑的接触区域小、润滑膜厚度薄,且由于润滑脂的非线性黏塑性和强烈的非牛顿性,使得弹流脂润滑的润滑膜厚度测量及实验研究十分困难。基于光干涉测量润滑膜厚度的基本原理,研制出一种弹性流体动力脂润滑的光干涉试验台,并设计其机械传动装置、图像采集装置、供脂及加载装置。在该光干涉试验台上进行白光干涉和单色光干涉试验,Hertz干接触及弹流脂润滑试验。结果表明,该光干涉试验台采集的图像清晰稳定;采用单色光干涉试验比白光干涉试验获得的条纹更加清晰,且测量范围更大。理论计算与实验测量结果一致,表明该试验台可用于弹流脂润滑的实验研究。 相似文献
10.
11.
12.
A Review of Elasto-Hydrodynamic Lubrication Theory 总被引:1,自引:0,他引:1
The development and understanding of elastohydrodynamic lubrication (EHL) can be traced back to the beginning of the previous century. However, it was not until 1949 that the first real solution of the problem was published. Since then, the technology has evolved enormously. In the current article a summary of these developments is given. Smooth surface EHL has become well established. Numerical methods, analytical solutions, and experimental techniques have become mature. Focus areas of research today are thermal EHL, starved EHL, friction (non-Newtonian lubricants), roughness, and grease. The scope of EHL is so wide that the authors needed select the topics of focus in this article. Therefore, in addition to the general overview of the areas of friction, analytical methods, starved EHL, and grease EHL are highlighted in this article. 相似文献
13.
采用微机对弹性流体动力润滑点接触问题的数值解进行了研究,得出了不同工况下该问题的数值解。经比较所得数值解与公开发表的研究结果一致,且所用方法简明、直观,结果可靠。 相似文献
14.
The elastohydrodynamic lubrication (EHL) problem of an axi-symmetric, elastomeric, reciprocating seal may be considered as one of a heavily loaded line contact with only small piezo-viscous effects. A method is presented to calculate the overall film thickness for the stationary, isothermal situation with sufficient lubricant supply and negligible surface roughness effects. It applies the inverse theory to the frictionless dry contact pressure distribution, considering the influence of the boosting action in the entry zone of the film. Its validity is shown for the isoviscous EHL of the Hertzian contact. The finite element method (FEM) may be used to calculate the contact situation of mounted and pressurized seals. Important aspects of such calculations are discussed. To calculate film thicknesses using such FEM results, a computer program PROGRES was written. Good correspondence between the predictions of PROGRES and experimental outstroke film thicknesses are obtained for a rectangular rod seal with rounded edges. 相似文献
15.
Interferometry has been widely utilized in elastohydrodynamic lubrication (EHL) film measurement since the 1960s. In-depth
optical analyses are required to get more fundamentals of optical EHL film tests. In this paper, a stratified-layer model
of optical EHL contact is numerically analyzed by the multi-beam interference approach. It is revealed that the high reflectance
of the beam-splitter and the steel interface generate a deviation of the intensity profile from the two-beam interference.
Previous experimental results about fringe contrast are reproduced, and the determination of the beam-splitter layer is theoretically
clarified. Furthermore, some characteristics of spectrometry for ultra-thin film measurement are studied, and the dependence
of the interference spectrum on the spacer layer thickness is displayed. The measurement simulation has theoretically confirmed
the constant initial phase change assumed in practical measurement. It is theoretically demonstrated that in the spectrometry
approach, TiO2 layer can generate spectrum with high finesse and may be used in the future application. The theoretical results in this
paper are correlated with previous experimental practices, and the optical EHL technique can therefore be much better theoretically
understood. 相似文献
16.
橡胶滑块与镀镍钢环的水润滑机理分析 总被引:3,自引:2,他引:1
对水润滑橡胶轴承在完全水润滑条件下的标准实验模型进行了弹流理论建模,应用多重网格技术对理论模型进行了数值计算和结果分析。结果表明:完全水润滑条件下,在高速轻载时形成了弹流润滑,而在低速重载时,即使在完全水润滑条件下橡胶滑块与镀镍钢环之间也较难形成稳定的弹流润滑。计算结果与实验结果基本一致。 相似文献
17.
H. A. Spikes 《Lubrication Science》2006,18(4):265-291
It is now 60 years since Ertel produced the first solution to the elastohydrodynamic lubrication (EHL) problem. There has been enormous progress since then, both in numerical modelling and in experimental research on EHL. The moving, rough surface EHL problem can now be solved on laptop‐level computers, while maps of film thickness, pressure and temperature can be obtained experimentally from within rolling/sliding contacts. However, there remain some important questions that have not been fully resolved. One of the most contentious is how to describe the rheological properties of lubricants under the very severe conditions present in thin film EHL contacts. A second is how to model mixed lubricated contact, where the fluid film can break down at asperity conjunctions. But perhaps the greatest challenge to researchers in EHL is to produce useful design equations for predicting the performance of machine components operating in EHL and thereby ensure that EHL theory becomes an integral part of the design process. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
18.
The limiting traction provided by typical elastohydrodynamically lubricated (EHL) contacts leads to the postulation that liquid lubricants are subject to limiting shear stress, which is generally accepted as an intrinsic property of the lubricants. The results of recent optical EHL research show that lubricant at EHL contacts may slip on the Cr-coated glass surface under certain circumstances. This paper presents further evidence that high pressure EHL film can slip on a steel surface. Because the steel/steel contacts are common in typical traction drives and the interfaces are therefore oil/steel, the deduction of the limiting shear stress of lubricants from the measured limiting traction may simply reflect a property of the system should boundary slippage occur. 相似文献
19.
The free-volume viscosity model can accurately predict the temperature–pressure–viscosity relationship of lubricants. However,
it is seldom used in elastohydrodynamic lubrication (EHL) simulation. This paper presents the application of the free-volume
viscosity model in a Newtonian EHL simulation of a squalane-lubricated circular contact. Good agreement is observed between
available experimental data and simulation results. The pressure–viscosity coefficients fit from viscometer data are also
discussed. A recently developed definition of the coefficient is used to compare the coefficient value extracted from EHL
film thickness interference measurements. Results indicate that the coefficient values from the curve fitting and EHL film
thickness extraction agree well which has not been previously observed. Two factors help achieve this agreement: the new coefficient
definition and smaller prediction error when using the Hamrock–Dowson formula in the cases studied. The effects of different
pressure–viscosity relationships, including the exponential model, the Roelands model and the free-volume model, are investigated
through an example with bright stock mineral oil. It is found that the real pressure–viscosity behavior predicted by the free-volume
model yields a higher viscosity at the low-pressure area which results in a larger central film thickness. Therefore, due
to use of the free-volume model, the present results are more consistent with experimental observations than previously reported
numerical results. 相似文献