中文摘要：

针对航天机构中轴承轴向预紧力精确确定的问题,基于静力学和弹性力学,在考虑配合尺寸、摩擦特性的基础上,研究了轴承预紧力与拧紧力矩的关系.利用锁紧螺母拧紧力矩与轴向力的关系,确定施加于轴承上的轴向力;根据摩擦力与摩擦特性及装配尺寸的关系,分析摩擦力对轴向力的截留作用;通过轴承力平衡方程组,对实际预紧力进行理论分析.文中研究了配合尺寸及摩擦特性对预紧力的影响,揭示了不同装配下预紧力随拧紧力矩的变化规律.研究结果表明：对轴承71807C预紧力结果进行分析,发现相同拧紧力矩下,过盈量增0.5μm,轴向力中约有123 N的力被截留;且摩擦系数增加0.05,轴向力截留率增大约13%.过盈量越大,轴承与主轴间摩擦力对轴向力的截留作用越大,预紧力对应的拧紧力矩越大;相比加热炉加热,油槽加热降低了配合区域的摩擦系数,加载相同的拧紧力矩时使轴承预紧力较大.经试验验证,该理论分析可以确定施加的预紧力,又可以提高装配质量.该研究建立预紧力测量的理论计算模型,并可用此模型较精确地确定预紧力,为轴承预紧力设计和装配提供参考.

英文摘要：

Bearings are a necessary part of mechanism, and have been widely used in various mechanical systems, such as agricultural machinery, engineering machinery, precision machinery, aerospace machinery. The preload of bearings affects bearing stiffness, rotating precision and service life. Meanwhile, precise determination of bearing preload is the guarantee for the high-precision bearing support system. Related determining preloads have already been analyzed, but the literatures don＆#39;t consider the interception of friction at fitting area. Space bearing works in space environment, and it is essential to accurately determine the preload. If the initial preload is not selected appropriately or accurately, the changes of preload induced by alternating temperature may lead to some failures. Therefore, it is necessary to accurately determine the bearing preload to ensure the accuracy and reliability of the shaft system. Focused on applying the accurate axial preload on the bearing of spacecraft mechanism, based on statics and elastic mechanics, and also under the premise of considering the assembly dimension and friction characteristics, the relationship between the bearing preload and the tightening torque is studied. Using the relationship of locknut tightening torque and axial force, the axial force applied on the bearing is got. According to the relationship between friction and friction characteristics as well as assembly dimension, the analysis on the interception of the friction on the axial force is done. Based on the bearing force balance equations, the actual bearing preload is computed. This paper studies the influence of friction characteristics and assembly dimensions on the preload, and reveals the relationship between assembly preload and tightening torque under different assembly conditions. In most researches, the bearing preload equals the force generated by the locknut. Theoretical analysis in this paper shows that the preload is the force required for the ball deformation. It is influenced not only