基于弹流润滑状态下的非圆齿轮啮合效率研究

在分析非圆齿轮啮合特性及齿廓等啮合角分布规律的基础上,综合考虑相对速度、摩擦因数和油膜厚度等关键因子对啮合功率损失的影响规律,建立了弹流润滑状态下非圆齿轮传动啮合效率数学模型.以非圆齿轮节曲线波谷的轮齿齿顶进入啮合到从波峰的轮齿齿根退出啮合为啮合周期,通过计算啮合角变化下的滑动摩擦和滚动摩擦功率损耗,获得非圆齿轮传动的...     

塑料与钢制齿轮啮合的弹流润滑研究

在油润滑条件下，对改性聚醚醚酮塑料齿轮与钢制齿轮啮合时的弹流润滑机理进行了数值模拟研究，并将计算结果与钢制齿轮副的接触点压力、润滑膜厚等进行了对比。结果表明，塑料与钢制齿轮的啮合点处存在弹流润滑油膜，且油膜要比钢制齿轮间的啮合油膜要厚；塑料对钢齿轮啮合点处的最大和中心油膜压力都比钢对钢齿轮的啮合压力明显降低。     

直齿面齿轮啮合效率计算研究

基于直齿面齿轮啮合仿真和弹性流体动力润滑理论,提出了直齿面齿轮啮合效率的计算方法,揭示了输入扭矩、转速等对啮合效率的影响。运用轮齿接触分析和轮齿承载接触分析技术,对直齿面齿轮承载啮合过程进行数值仿真;运用非牛顿热弹流理论,建立滑动摩擦因数的计算模型,从而建立直齿面齿轮啮合效率的计算模型。计算结果表明,滑动摩擦因数是影响齿轮啮合效率的重要因素,齿面不同位置的滑动摩擦因数也不相同,滑动摩擦因数受到输入转速、输入扭矩的影响。     

从弹流润滑到薄膜润滑—润滑理论研究的新领域

本文论述了弹流润滑理论的发展，由此而引出薄膜润滑研究的重要性及其产生的理论和应用背景，并介绍了薄膜润滑研究的特点和主要内容。     

WN齿轮传动弹流润滑及接触摩擦效率研究

应用WN齿轮接触摩擦与弹流润滑机制结合的方法进行效率分析.依据WN齿轮副啮合原理,创建该齿轮动力润滑与混合摩擦分析模型,分析了啮合中载荷与弹性接触对油膜厚度的影响,探讨油膜形成机制和承载特性;通过啮合过程中的接触摩擦分析,推导出WN齿轮啮合时动力传动效率计算新方程;分析齿轮运转速度、负载及润滑等对传动效率的影响.结果表明:在高速下WN齿轮的传动效率高于渐开线齿轮而在低速下却相反;旋转速度对传动效率的影响要比载荷的影响更大.通过实例计算和试验分析验证了本方法的有效性.     

直齿轮啮合弹性流体动力润滑的非稳态效应的研究

分析了渐开线直齿轮啮合弹流润滑的非稳态参数,推导了其弹流润滑方程组,并沿整个啮合线上作了完全的数值解,指出了齿轮啮合弹流润滑应考虑非稳态效应。     

蜗杆传动的弹流润滑研究

平面二次包络环面蜗杆传动属非均匀线接触问题,若采用完全数值解方法求解油膜厚度,则非常困难。本文将采用前人已总结出的膜厚公式,再进行一些必要的数学处理,来近似求解蜗轮副的油膜厚度,并找出其在啮合过程中的变化规律。     

齿轮传动瞬态弹流润滑的计算分析

本文在考虑流体可压缩性的情况下，综合考虑了重合度对轮齿载荷的影响以及变曲率，变速度的瞬态效应，经出了传动瞬态流润滑方程及其求解方法，在经入齿轮传动的实际工况参数后，进行了完全数值解，得到了两齿轮在啮合线任意点处的油膜压力分布和油膜形状以及最小油膜厚度沿啮合线的变化曲线。     

齿轮传动啮合效率计算方法的研究

研究了齿轮传动中啮合效率的计算方法,推导出渐开线圆柱齿轮内外啮合传动的效率函数,证明了效率函数在啮合区间的连续性。基于连续函数积分中值定理,定义了齿轮传动啮合效率的积分形式,通过积分运算得到了渐开线内外齿轮啮合效率的计算公式,并从理论上证明了效率公式的正确性。结合数据计算结果的图表分析,进一步验证了效率公式的有效性。     

轮齿压力角对弹性流体动力润滑的影响分析

运用弹流润滑理论，分析了轮齿压力角对弹性流体动力润滑的影响，发现轮齿压力角的变化对弹性参数和粘性参数的影响不明显，但压力角的增大，最小油膜厚度和油膜比厚显著增大，对改善齿面润滑极为有利，为重载齿轮的设计提供了理论依据。     

齿轮几何参数的选择对传动效率影响的研究

采用单参数齿轮台架试验的方法，基于对试验的曲线和结果分析，揭示了齿轮各几何参数对其传动效率的影响。针对低速重载工况下选择高传动效率、高啮合质量的齿轮副几何参数，提出了几何参数选择原则。研究结果表明，在产品的设计过程中齿轮几何参数的选择，是影响产品具有良好的啮合和节能低耗效果的重要因素。     

On the effort to discriminate the principal function of tribofilm on friction under the boundary lubrication condition

Friction coefficient under boundary lubrication conditions is affected by many factors. In order to study the friction characteristic of tribofilm, friction coefficient of tribofilm formed on steel disk under the boundary lubrication conditions was separately measured under dry condition using a laboratory-made micro-tribometer to eliminate the hydrodynamic lubrication action of fluid. This paper introduces the approaching method to understand the friction characteristic of tribofilm. In this paper, sliding speed dependency of friction exerted by tribofilm was observed that could not be interpreted by the classical boundary lubrication mechanisms. The additives having long alkyl chain showed strong sliding speed dependency of friction.     

齿面摩擦和啮合刚度对双渐开线齿轮传动动态特性的影响研究

针对双渐开线齿轮传动动态特性问题,通过建立双渐开线齿轮的有限元模型,综合考虑齿面摩擦与齿轮啮合刚度二因素,对双渐开线齿轮传动系统进行了有限元模态分析,运用响应曲面法研究了齿面摩擦与齿轮啮合刚度对双渐开线齿轮振动变形和模态频率的影响;选取不同模态阶数对双渐开线齿轮传动系统进行了动态特性研究,分析了不同模态阶数下双渐开线齿轮的振动变形与模态频率变化状况。研究结果表明,随着齿面摩擦因数与齿轮啮合刚度的增加,不同模态阶数下双渐开线齿轮传动系统各阶振动变形与模态频率均显著增加,齿面摩擦与齿轮啮合刚度对双渐开线齿轮传动动态特性有一定影响,在对齿轮传动系统进行动态特性研究时,必须对齿面摩擦与齿轮啮合刚度进行充分考虑。     

Modelling the effect of lubrication on friction behaviour

Models of typical characteristics of the surfaces of two solids interfacing one another under pressure and sliding with respect to each other are described in Models 1 (Figure 1) and 2 (Figure 2). In Model 1 (Figure 1) the asperities, wedges of the harder surface indent into the softer surface due to the applied pressure, thus producing opposing ridges on the surface of the softer component. The gap between the opposing asperities is filled with liquid, establishing boundary lubrication. As sliding is maintained, the ridges are mobilized and an eddy flow is established in the trapped lubricant. The power required to mobilize the ridges and to establish eddy flow in the lubricant is calculated and thus the friction resistance to sliding is determined. Simultaneously, the pressure generated in the liquid due to shear is also evaluated. It becomes clear that the height of the ridge due to indentation is inversely proportional to the speed of sliding. The higher the sliding speed, the higher is the liquid pressure that is countering the loading pressure and the smaller is the indentation. At a high enough speed (to be replaced in due course by the Sommerfeld Number) the entire load is supported by the pressure generated in the liquid, indentation is eliminated and hydrodynamic lubrication commences. The classic model for hydrodynamic lubrication where two inclined surfaces glide atop each other is described in figure 2. Here the gap between the two surfaces (q.J a t their closest point is a monotonically increasing function of Sommerfeld Number (S). The resistance to sliding as established through the shear in the liquid determines thefriction value. This model leads directly to the characteristic of Coulomb or Emontons where for diminishing values of Sommerfeld Number the resistance to sliding is proportional to the pressure (τ = μp) and the proportionality factor is equal to the tangent of the angle of inclination (μ = tana). In the present work, the increase infnction with increasing values of the Sommerfeld Number is also determined. Combining the two models one notices that, a t low speed and Somrfeld Number values, the liquid pressure is not sufftcient tofloat the two surfaces and indentation prevails together with boundary lubrication. With increasing speed (Sommerfeld Number) the height of the ridge (by Model 1) decreases, and when it diminishes to values lower than those predicted for the gap between the surfaces in the second model for the same speed, the boundary lubrication ceases and hydrodynamic lubrication commences.     

Tribological behaviour of steel‐alumina sliding pairs under boundary lubrication conditions

The tribological behaviour of oil‐lubricated steel‐alumina sliding pairs was investigated using a ball‐on‐disc tribometer at room temperature. Commercial bearing balls of 10 mm diameter were mated to 99.7% Al₂O₃ discs, and additive‐free mineral oil was fed into the contact area. The sliding speed and the applied normal load were varied, and the initial surface roughness of the Al₂O₃ disc was altered using different polishing and grinding procedures. The results showed that the surface roughness of the ceramic discs dominated the tribological behaviour under the given experimental conditions. The sliding speed as well as the normal load showed less effect on the friction behaviour, but the amount of wear depended strongly on the normal load. From the results it was concluded that improvement of the surface roughness and optimised surface machining of the ceramic material can be essential for improving the tribological performance for boundary‐lubricated steel‐ceramic sliding pairs.     

弹流润滑高速角接触球轴承旋滚比分析

为了提高主轴轴承的高速性能,提出弹流润滑高速角接触球轴承的数学计算与分析模型.针对实际生产工况建立弹流润滑高速角接触球轴承分析计算模型.并将弹流润滑高速角接触球轴承的旋转打滑分析转化为旋滚比的分析.通过计算与分析,得出弹流润滑高速角接触球轴承在不同工作条件下或选用不同轴承参数时,轴承旋滚比的变化规律及旋滚比与各参数之间的关系.为实际生产中高速角接触轴承的选择使用和轴承的参数优化设计提供了理论依据,并为机床高速主轴用支撑轴承的设计与优化提供分析计算模型.     

大模数大直径内啮合齿轮精确成形方法的研究

大模数大直径内啮合齿轮的加工，目前在国内是一个急待解决的难题。为了解决这个难题，本文对大模数大直径内啮合齿轮精确成形方法进行研究。首先对内齿轮的一种齿形进行啮合理论分析，同时根据共轭原理求出与其相啮合的外齿轮齿形，并且将求出的外齿轮齿形与渐开线齿形进行比较，然后对该内啮合传动进行啮合性能分析及干涉校核。通过分析计算及实验，结果表明，大模数大直径内啮合齿轮的这种精确成形方法比其它方法要好。     

滚动与滑动耦合作用下GCr15钢的磨损行为研究

选用GCr15钢在M2000磨损试验机上进行了干摩擦和油润滑的摩擦磨损试验，用表面粗糙度仪测量试件在不同磨损阶段的表面形貌，用称重法测量其磨损量，分析了滚动与滑动耦合作用下GCr15钢的磨损机理。研究表明，在滚动与滑动耦合作用下GCr15钢的磨损以滑动摩擦磨损为主，温度和润滑条件直接决定着GCr15钢的磨损情况。     

弹流润滑条件下齿轮传动润滑油膜厚度影响参数研究

基于弹性流体动力润滑理论,利用Dowson-Higginson公式推导出渐开线直齿轮基本参数与最小油膜厚度计算关系式,并通过MATLAB软件编程绘制出相应的关系曲线图,分析了传动比、模数、重合度、齿宽系数等齿轮传动参数对齿轮副润滑油膜厚度的影响,从而揭示了齿轮传动参数与齿轮副润滑性能之间的关系,为弹流润滑条件下齿轮传动的设计提供了理论依据.