有限元法在液压缸Y形密封圈接触应力分析中的应用

应用有限单元方法计算了Y形密封圈在不同工作压力下的变形、应力及其分布情况,获得了该型密封圈与液压缸 筒接触面之间接触应力的分布规律以及接触应力与工作介质压力的关系。此有限元法为各类密封圈接触应力研究提供了 一行之有效的方法,其结果对密封圈密封机理的研究提供了计算依据。     

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.     

角接触球轴承动特性的数值与试验研究

角接触球轴承的动特性对机床主轴的回转精度、可靠性及寿命等有重要影响。以弹性力学理论、滚动轴承动力学和沟道控制理论为基础,研究角接触球轴承的动特性。推导了计及过盈配合量和预紧力影响的高速角接触球轴承动刚度计算方法,并对轴承动刚度的影响因素进行了理论分析和试验验证。结果表明:随着过盈量的增大,轴向刚度逐渐减小,径向刚度则逐渐增大,外圈过盈量影响更显著;预紧力过小时,刚度会出现明显的波动现象,适当的预紧力对角接触球轴承刚度的稳定至关重要。     

Elastohydrodynamics of lip seals

A numerical elastohydrodynamic analysis of a rotary lip seal with microundulations reveals that the undulation pattern plays a central role in the operation of the seal. The undulations hydrodynamically generate elevated pressures within the lubricating film, providing load support, and deform in such a manner as to produce reverse pumping. The reverse pumping counteracts the flow induced by the sealed pressure, and thereby prevents leakage through the seal.

1 See p. 25 for the nomenclature.

     

双排四点接触球转盘轴承的有限元分析

针对转盘轴承在受载时不再遵循刚性套圈假设这一实际情况,利用有限元分析软件ANSYS建立了双排四点接触球转盘轴承的实体有限元模型。根据转盘轴承的实际工况设置了模型的边界条件,通过求解计算得到了转盘轴承内部的受力状况,并将本文的计算结果与基于刚性套圈假设数值计算结果进行了比较。结果表明:采用有限元方法得到的结果中有更多的钢球受载,且钢球与滚道之间的最大接触应力值有所降低。这归因于有限元方法将套圈看作是弹性体,在转盘轴承受到外部载荷作用时套圈将发生径向平面内的结构变形。有限元方法得到的结果更加符合转盘轴承的实际受力状况。     

基于ANSYS的球轴承赫兹接触问题有限元分析

以推力球轴承的赫兹接触问题为例,介绍ANSYS软件的接触分析功能和建模的方法,基于ANSYS软件面-面接触方式中的柔-柔接触类型计算出接触区域的最大接触应力和变形,并对比了赫兹理论解,指出网格局部细化是影响计算精度的主要原因.研究表明,提出的这种方法是正确的,为分析赫兹接触问题探索出一种新途径.     

Analysis of contact force and thermal behaviour of lip seals

Using the Mooney-Rivlin model, the contact force and thermal behaviour of a radial lip seal are studied numerically and experimentally as a function of the interference. The numerical and experimental results on the static contact forces show good correspondence with and without the garter spring. The FEM calculated results indicate that increased interference may increase the eracking of seal material due to the maximum contact stresses close to the contacting area of the seal lip and produce local separation between the seal lip and the shaft. Also a coupled thermal-mechanical analysis method will be a useful tool to predict the contact behaviour of rubber lip seals for small values of the interference.     

基于COBRA的角接触球轴承仿真分析

借助COBRA软件对某角接触球轴承的游隙和结构参数进行了仿真分析,大大减少轴承的接触应力和滚道磨损发热量,缩短了设计周期,提高了生产效率。     

Numerical simulation and experimental study of shaft pumping by laser structured shafts with rotary lip seals

A simulation model to predict pumping by shafts with various surface finishes, in combination with a rotary lip seal, has been developed and validated by experiment. The model consists of a fluid mechanics analysis of the flow in the sealing zone coupled with a deformation analysis of the seal. The experimental validation consists of pumping rate measurements with shafts whose surface structures contain laser generated oblique grooves. Plots of pumping rate vs. various parameters show good agreement between the model and experiment. Plots of torque vs. speed, as well, show good agreement between the model and experiment.     

配对角接触球轴承静态力学特性

根据角接触球轴承实际的工作状态,建立背靠背配对安装形式的角接触球轴承接触模型,计算配对轴承在径向、轴向和力矩载荷联合作用下的载荷分布以及接触应力,并将理论值与Ansys有限元法得出的结果进行对比,验证计算结果的准确性。详细研究了在联合载荷的作用下,配对轴承静态载荷分布以及接触特性的变化规律。研究结果表明:配对角接触球轴承的内圈在联合载荷作用下发生位移,使载荷分布不均匀,接触应力主要集中在载荷对称线附近的部分钢球上,改变联合载荷会使两列轴承载荷分布规律以及接触特性发生变化。     

新型双向密封件的接触变形及应力分析

利用大型非线性有限元分析软件ABAQUS,建立X型和V型组合式密封件的轴对称有限元模型,分析其在沟槽内受压缩的几何变形与接触应力分布规律,比较了该类型组合式密封件与工程上常用的滑环式组合密封圈的应力分布情况。结果表明:新型组合式密封圈低压时也能很好地密封,而且密封件整体宽度大,可以承受更大的径向载荷。滑环式组合密封圈摩擦阻力小,耐磨性良好,其结构可以承受较高的油压,适合于动、静密封。新型组合密封圈的单位面积上摩擦功耗小,适用于旋转密封或摆动密封。     

钢丝滚道球轴承的点接触问题有限元仿真

以某型飞行器三轴仿真转台主轴轴系中的钢丝滚道球轴承为例,通过ANSYS对该滚珠．滚道间的非协调性接触问题进行有限元建模与仿真,发现最大接触应力发生在钢丝滚道的表面,而滚珠的最大接触应力发生在其接触面正下方短距离内。有限元分析结果有力地阐明了点蚀易在钢丝滚道接触表面形成并逐渐扩展的机理。本文的工作为进一步开展钢丝滚道的点蚀及磨损的实验研究提供了理论依据。     

双浮动密封橡胶O形圈接触应力分析

针对双浮动密封橡胶O形圈接触过程应力的变化,建立双浮动密封二维轴对称非线性接触模型;利用有限元方法对O形圈进行应力计算,分析O形圈在不同压缩率、不同浮封座和浮动环的斜面角度及不同摩擦因数下的应力变化情况。结果表明:橡胶O形圈各应力最大值随压缩率的增加呈线性增大, O形圈内高应力分布区域随压缩率的增加而增大,并由接触部位附近向其中间位置扩散;摩擦因数对O形圈各应力影响很小,而浮封座和浮动环的斜面角度对O形圈等效应力和接触压力影响较大;随着浮封座斜面角的增加,等效应力总体趋于减小,接触压力先减小后缓慢增加,而剪切应力整体变化较小;随着浮动环斜面角的增加,等效应力、接触压力呈递增趋势,剪切应力曲线上下波动,但整体变化不明显。确定双浮动密封浮封座和浮动环斜面角度最优值,为双浮动密封结构设计提供了指导。     

介绍一种角接触球轴承装配工艺方法

角接触球轴承传统的装配工艺方法装球过程所占用的时间相对较长，因此对轴承的产品质量造成很大的不良影响，而这里所介绍的工艺方法对产品质量的提高起到了显著的效果。     

Life tests on elastomeric lip seals for pneumatic cylinders

A test method and a testing machine for evaluating the wear of lip seals for pneumatic cylinders are presented. The method and the machine have been evaluated with tests on different types of seals for cylinders with a 50 mm bore. Three levels of lubrication condition were examined: dry, with a film of grease, and with an optimum amount of grease. Differences were noted both between these conditions of lubrication, and between types of seal. © Leaf Coppin 1997.     

Effect of 3D lip deformations on elastohydrodynamic lip seals behaviour

The numerical simulation of comparative elastohydrodynamic lubrication between axisymmetrical and 3D elastic approaches on the radial lip seals is presented in order to determine the 3D effect of the elastic aspect of the seal lip. Indeed, the consideration of 3D model in other words the circumferential variation of the lip elastic deformation indicated a difference in the deformation distribution of the lip compared to the axisymmetrical approach. Consequently, the results show that the presence of the circumferential variation of the seal lip deformation has a significant effect on the pumping rate values.     

双向推力角接触球轴承接触点沟径尺寸测量方法的改进

随着双向推力轴承不断向大型化发展,传统测量方法无法测量其接触点沟径尺寸。经过改进后,采用以基面为基准,借助于立式、卧式测长仪,可以快速、准确地测量出接触点沟径尺寸。     

The contact problem for a double-layer cylindrical base with account of friction forces

The contact problem of a double-layer cylindrical base is discussed with account of friction forces. The problem is reduced to an integral equation of the first kind in relation to unknown contact stresses. A direct method of collocation is used to solve it, enabling us to obtain sufficiently accurate solutions for virtually any values of the parameters. The contact stresses and the contact-zone area are calculated for various material and geometrical parameters of the base layers.     

A mixed model to predict friction forces in lubricated contact with non-newtonian fluids

A mixed model to predict friction forces in thermohydrodynamic lubricated contacts with non-Newtonian fluids is proposed, with an integral formulation and a finite element method resolution. The mixed model is used here for the first time in lubrication. It takes into account the implicit rheological laws. The shear stress field appears in this formulation as a nodal unknown and eases the use of rheological laws with yield criteria.     

角接触球轴承沟位置标准件测量方法

介绍了角接触球轴承沟位置标准件的两种测量方法,及他们的适用范围,为控制沟位置尺寸偏差、提高装配合套效率奠定了基础。