【作者】 华同曙；

【导师】 陈晓阳；

【作者基本信息】 上海大学 ， 机械设计及理论， 2010， 博士

【摘要】 线接触副能够承受比点接触更大的载荷,因此在工程中得到广泛地应用。这些线接触副通常工作在润滑条件下,其压力分布、膜厚及膜形对机器零部件的性能和寿命有很大影响。目前综合考虑各种效应的现代弹流润滑理论已经基本形成,并在进一步完善的基础上向更接近实际工况的方向发展。但是有限长线接触副光弹流的实验研究还是很少,而相关的非稳态实验研究至今尚未见报导。为了如实地考察工程中机械零件的润滑状况,本文对非稳态(摆动工况)有限长线接触副的弹流特性进行了实验研究。一、根据光干涉原理,综合分析了影响线接触光弹流实验的各种因素,采用新的设计方法,将试验机由经典的旋转方式改变成沿直线运动的方式,基本上消除了透明材料所受到的弯矩作用,克服了试验机难以承受重载的缺点,实验最大载荷量为2450 N、最大接触压力为0.92 GPa。研制出一套非稳态(摆动)线接触纯滚动光弹流实验装置。实验滚子由两浮动陪试滚子支承,实现了纯滚动且有利于加载;驱动部分为曲柄滑块机构,实验滚子卷吸速度呈近似正弦规律变化;往复摆动频率由电机控制。实验装置的光源采用氙气冷光源,前端加一个中心波长为600 nm的窄带滤光片,成为准单色光;两纯滚动接触体之间的干涉条纹通过显微镜由CCD拍摄,再由磁带录像系统采集。二、在新研制出的光弹流实验装置上对对数凸度滚子开展了实验对比研究。包括:①相同润滑剂、相同载荷、不同摆动频率;②相同润滑剂、相同摆动频率、不同载荷;③相同摆动频率、相同载荷、不同润滑剂。实验表明:滚子的出口区有颈缩;润滑剂粘度、载荷、摆动频率等因素都对有限长线接触滚子的弹流特性有一定的影响,其中影响最大的为摆动频率,主要还是因为卷吸速度的影响。三、对重载工况下的成膜性能进行了实验研究。所使用的透明材料为K9玻璃,实验时发现当最大接触压力为1.0 GPa时玻璃表面有压溃现象,因此重载实验的最大接触压力是在小于1.0 GPa下进行。实验表明:重载工况下滚子的端部有″边缘效应″和″闭合效应″,载荷越重越明显,滚子端部的油膜厚度比中部出口区油膜厚度还要小很多。四、运用课题组已有的多重网格数值分析技术进行理论分析,结果表明:理论计算值要大于实验测量值,理论计算未能反映滚子中部出口区的颈缩;但两者在膜厚随速度的变化、闭合效应以及膜厚建立的滞后方面都是一致的。五、基于静弹性理论,应用数值计算方法,研究开发了一套可视化的对数滚子凸度设计的应用软件,并成功用于十字万向节产品的设计中。经产品的疲劳寿命实验,结果表明该软件在工程上有一定的实用价值。研究工作有助于线接触光弹流实验的进一步开展与完善,有助于认识有限长线接触弹流润滑机理和特性的各种影响因素,可为线接触副的工程优化设计及其性能分析提供良好的基础。更多还原

【Abstract】 As the line contacts can understand greater load than the point contacts, it has been widely used in engineering. The line contacts, usually working under lubrication, whose pressure distribution, film thickness and shape are very important for performance and life of the machine parts. The current account of various effects of the modern theory of EHL has been formed, and further improved on the basis of conditions to a more realistic direction. However, the experimental study of EHL finite line contact, especially under non-steady state has not been reported. In order to faithfully study the lubrication of mechanical parts under the engineering situation, whose condition is limited to the oscillation of the line contact EHL lubrication, characteristics are studied.1. According to the optical interference principle, taken into account and analysis of the influence line contact factors EHL experiments, it has been founded test rig newly design method based on optical interference, basically from the classic way of rotation to linear mode, eliminating the transparent material, overcoming the shortcoming of testing machine unbearable overload. It is showed that the total load capacity 2450N, the maximum contact pressure 0.92GPa in experiment.A newly set of experimental setup has been designed and manufactured for non-steady state (oscillation) of pure rolling line contact based on optical interference. Experimental rig to accompany two floating rollers bearing test method, moving parts are crank, the entrainment speed of test roller was similar to the sine law of change, reciprocating frequency variable speed by motor control. Experimental device with adjustable intensity light source with xenon gas-cooled light source, plus a narrow-band front-end filter, a quasi-monochromatic light, the center wavelength of 600 nm, between two bodies of pure rolling contact the interference fringes were taken by CCD through the microscope, and then collected by tape recording system.2. The newly developed EHL experiments carried out on a logarithmic profile rollers device on several crown roller. It is included that:①same lubricant viscosity, same load, different oscillation frequencies;②same lubricant viscosity, same oscillating frequency, different loads;③oscillating in the same frequency, the same load, different lubricant viscosity. It is showed that have been the necking in roller’s export zone and lubricant viscosity, load, oscillating frequency and other factors to EHL of finite line contact has some effect, the largest of the oscillating frequency, mainly entrainment velocity.3. Overload experiment was studied. K9 used as a transparent glass, when it is 1.0GPa crushing phenomenon exists, this study the maximum contact pressure is less 1.0 GPa, It is indicated that a roller end condition of "edge effects" and " closure effect" under overload, the more obvious roller film thickness than the end of the exit zone in central film thickness much smaller. and closure effect is more apparent under heavy load.4. Numerical analysis applied by multi-grid technique, theory discussion group has research and experimental results were compared, the result is basically the same. Application research group have numerical analysis of multigrid technique theory, theory of computation results indicate that the value is greater than the experimental measurements, theoretical calculations do not reflect the roller in the middle of the zone of the neck; but in the film thickness varies, depending on the speed of change, as well as the closure of film thickness of lag are consistent.5. It has been researched and developed of a visual software of logarithmic profile rollers crown designed based on static elasticity theory, numerical calculation methods, and it has showed that this software works on a certain value by the fatigue life of roller results.The research is useful for help line contact EHL experiments to further develop and perfect understanding of the finite line contact mechanism of lubrication and its characteristics of a variety of factors, deputy for engineering optimization line contact design and performance analysis to provide good foundation.更多还原