基于接触和结构弹性的高速薄壁轻量化滚动轴承分析基础研究

High-speed thin-walled rolling element bearings with light-weight structure is not only one of the core technology for high-speed small inertia power unit of equipments such as precision manufacturing, industrial robots and so on, but also the development trend of core technology of high-speed rolling bearings with longer life and higher reliability used on equipments of clear energy, rail transportation and aerospace. Structural elasticity and flexible support elasticity of thin-walled rolling bearings have significant influence on the local effect of internal contact loads, tribological and thermal property of rolling bearings. So the current L-P theory system for rolling bearing analyses, which is based on the assumption of rigid rings, need developing and improving. Focused on the flexible support, structural and contact elasticity of high-speed thin-walled light-weight rolling bearings, this proposed project will investigate the local effect of internal contact load distribution, thermal, dynamic and tribological properties of rolling bearings, while with the complex load conditions, centrifugal, thermal environment and assembling effects. Furthermore, theoretical analysis model will be developed based on the internal tribo-pair failure probability of rolling bearing, and then the failure transition rule and prediction method of failure modes will be studied ,consequently the analysis method of more accurate and limits design for high-quality rolling bearings with thin-walled light-weight structure will be improved. Finally the experiments of thin-walled rolling bearings with flexible supporting will be carried out to validate the accuracy of the models and methods. All these fundamental research results will provide, based on the failure modes transformation, a solid basis for developing the theoretical system of rolling bearings life and promoting the design level and innovation ability on key basic component technology.

高速薄壁轻量化结构的滚动轴承既是精密制造、工业机器人等装备高速小惯量动力单元的核心技术之一，也是长寿命和高可靠洁净能源、轨道交通、航空、航天装备高速轴承的核心技术发展趋势，此时薄壁轴承结构弹性和柔性支承弹性对轴承内部载荷局部效应、摩擦学特性、热特性的影响非常显著，目前基于刚性套圈假设的轴承L-P理论体系需要发展和完善。本课题针对高速轻量化轴承的支承弹性和结构弹性、以及接触弹性，考虑复杂载荷工况、离心效应、热效应、配合效应等，研究轴承内部载荷再分布的局部效应、摩擦学特性、动态特性和热特性，发展基于轴承内部摩擦副独立失效概率的理论分析模型，研究失效模式的转变规律和预测方法，突破未来高速薄壁轻量化高端滚动轴承精确设计和极限设计的分析方法，通过柔性支承薄壁轴承实验以验证模型和方法正确性，为发展基于多失效模式转化的滚动轴承寿命理论体系、提升关键基础件的设计水平和创新能力提供坚实的基础。

高速薄壁轻量化结构的滚动轴承是高速轴承的核心技术发展趋势。薄壁轴承结构弹性和柔性支承弹性对轴承内部载荷局部效应、摩擦学特性、热特性的影响非常显著。.本研究建立了考虑接触弹性和结构弹性协调变形的薄壁轴承动态特性分析模型，能够综合考虑轴承系统结构力学特性，摩擦学特性，润滑状态及瞬态热特性等影响因素。基于次表层疲劳起源的 L-P 寿命理论，分析了轴承薄壁结构及柔性支撑结构变形的影响，形成了能够精确计算工况影响的基于轴承内部载荷分布的薄壁轴承寿命修正计算方法。考虑瞬态效应，对加速过程中航空发动机主轴承进行了轴承动态特性和热弹流润滑瞬态耦合分析。对三维仿真软件进行二次开发，对8类薄壁弹性支承结构轴承进行参数化建模分析。完成了对薄壁弹性支承轴承的非线性接触力学仿真，开发了参数化薄壁弹性支承轴承分析软件，大大提高了计算速度和分析效率。.研究结果表明轴承套圈结构弹性对轴承动态特性影响显著。套圈的弹性变形会导致轴承内部载荷重新分配，最大滚子载荷减少11.5%，最大接触应力由1.55GPa减少7.1%，最大滑动速度减少35.6%，较小的装配间隙能够有效减少轴承内部最大接触应力，延长疲劳寿命。但是当间隙过大时，会对轴承动态特性产生不良影响。柔性支撑结构弹性变形会显著减小轴承刚度，改变轴承内部载荷，随着壁厚的增大波动变大，载荷分布均匀性变差，同时滚动体的承受的循环应力峰值也减小，轴承寿命提高10%以上。对轴承寿命的分析表明，初始游隙的大小、温度、过盈配合及弯矩均会改变轴承内的载荷分布，从而影响轴承疲劳寿命，过盈配合、残余应力及温度会改变轴承套圈上的周向应力，降低轴承疲劳寿命。.本研究探索了柔性支撑薄壁轴承结构弹性与接触弹性的协调变形机制，系统分析了结构变形对轴承内部动态特性的影响规律，建立了薄壁轻量化滚动轴承分析基础理论，为发展薄壁轻量化滚动轴承理论体系，提升高端滚动轴承设计水平，突破高速滚动轴承寿命极限提供了坚实的基础。