刚柔球面接触副关节轴承复合摆频下的摩擦诱导成膜机理与寿命评估

The life of a spherical plain bearing is shortened rapidly under supernormal conditions of combined oscillating, high oscillating frequency and heavy load, and it affects badly safety and reliability of a host machine. In order to advance the life of a spherical plain bearing, the spherical plain bearings with typical rigid-flexible surface contact pair are investegated in this project. Thermal-stress effects on the liner stripping induced by combined oscillating, frictional heat induced by swing frequency and deformation induced by loads are discussed. From the curve peeling aspect, spheric evaluation rule and quantitative evaluated parameter for adhesive quality of flexible liners are put forward. The dynamic relevant behaviors of liners and rings deformation are investigated by finite element method, and coordination rules of liners and rings deformation are established. With the micro-analysis, film forming and damage mechanisms induced by friction are clarified for the spherical plain bearing with rigid-flexible contact surface, film-forming conditions and wear failure criterions of spherical plain bearing are put forward. With information fusion and multivariate statistical analysis, the relationships between the life of spherical plain bearing and influencing factors are investigated. The characteristic parameter simple representations of life influencing factors are put forward. Using the intelligence algorithm, the life intelligence prediction models of the spherical plain bearing with rigid-flexible contact are constituted. The design rules of the spherical plain bearing life-prolonging under supernormal conditions are put forward further. The research findings will promote the development and application of long-life spherical plain bearing under supernormal conditions. The new theoretical basis is provided for bearing design.

复合摆动、高摆频、重载荷等超常条件下关节轴承寿命急剧缩短，严重影响主机整体运行的安全可靠性。为了提高关节轴承寿命，本项目以典型的刚柔球面接触副关节轴承为研究对象，探讨复合摆动引起的衬垫剥离、摆动频率引起的摩擦热、外加载荷引起的变形等热力耦合效应；从曲面剥离角度，提出柔性衬垫粘接质量的球面评价方法和定量评价指标；运用有限元法研究关节轴承衬垫与套圈变形的动态关联行为，建立衬垫与套圈的变形协调准则；借助微观表面分析手段，阐明关节轴承刚柔接触界面摩擦诱导的成膜机理和破坏机制，提出关节轴承成膜条件和磨损失效判据；运用信息融合和多元判别分析等手段，研究关节轴承寿命与影响因素的关联性，提出寿命影响因素的特征参数简约表征方法；采用智能算法建立刚柔接触副关节轴承寿命智能预测模型，并进一步提出超常条件下关节轴承延寿的设计准则。研究成果将促进超常条件下长寿命关节轴承的开发与应用，为轴承设计提供新的理论基础。

关节轴承属于球面接触副，内外圈多以刚性轴承钢为制造材料。随着航空航天、高速运输和军工装备等高精尖领域应用发展的需求，由刚性和柔性材料组成接触副的关节轴承服役于复合摆动、高摆频、重载荷等超常工况条件日益增多，其寿命的延长已成为整体装备寿命提高的关键问题。刚柔接触副关节轴承多以自润滑衬垫的磨损为失效方式,摆动方式、摆动频率和外加载荷极大地影响表面膜的形成及组织构成，进而导致关节轴承寿命缩短。本项目拟开展的柔性衬垫粘接质量评价方法、复合摆频下关节轴承的动态承载性能、球面滑动接触副的摩擦诱导成膜机理与磨损失效机理、关节轴承寿命与影响因子的关联方法等方面的研究，期望能为极端苛刻条件下刚柔接触副关节轴承寿命的准确评估提供理论依据。.项目主要研究内容如下：提出了改性处理方案，对PTFE/芳纶织物衬垫进行系列改性处理（包括稀土处理、超声波处理、甘油醚处理等），并将自润滑衬垫材料粘接到向心关节轴承外圈内表面，进行衬垫成膜机理、磨损机理以及粘接性能的研究。结果表明：衬垫的相关改性处理能显著提高轴承的摩擦学性能。应用ABAQUS有限元层合板理论，模拟关节轴承编织衬垫，探讨了不同编织角度下衬垫的接触应力和变形情况，力图找出最佳编织纹路；并对关节轴承进行热力耦合分析, 研究了不同内、外圈间隙对衬垫应力分布和热分布的影响。基于组合磨损理论，进行了自润滑向心关节轴承的解析式磨损寿命模型研究，建立了适合轴承不同摆动方式的寿命评估模型。基于ABAQUS有限元分析, 进行关节轴承在不同摆动方式下衬垫失效机理分析，揭示了纤维蠕变断裂、表面疲劳磨损、冲击效应等对衬垫失效机理的影响。基于PTFE/芳纶织物衬垫的微观结构，根据细观力学和复合材料力学的分析方法，建立了衬垫物理磨损分析模型；结合有限元分析和试验，考察了衬垫粘结剂含量和磨损深度对衬垫力学性能的影响。利用自主研制的向心关节轴承寿命试验机，进行了关节轴承不同摆动方式下的加速寿命试验；利用最好线性无偏估计法, 对加速寿命方程和寿命分布规律进行研究；并对寿命公式加以修正，推导出不同摆动方式下轴承寿命重要评估参数，建立了适用于轴承不同摆动工况的新的寿命估算公式。本项目的研究对揭示关节轴承失效机理，延长和准确评估其服役寿命具有重要意义。