精密滚珠丝杠副精度失效机理及加工工艺特性研究

Aiming at the common problem of precision retaining ability for domestic precision ball screw pair, the fundamental researches on the precision failure mechanism and processing technology characteristics of precision ball screw pair are developed. The relative movement characteristic and the mechanical mechanism between the balls and grooves will be studied and the kinematics and system dynamics of precision ball screw pair considering the influence of lubrication conditions and the grooves' machining error. Combining the experiments with the micro-mesoscopic analytical method, we will explore the precision failure mechanism of precision ball screw pair in use by establishing the mathematical models of elastic contact deformation，friction-wear and surface pitting and studying the precision degradation law under the different operating conditions such as the load, lubrication conditions, preload and feed velocity, and propose a forecast method for the precision retaining ability of precision ball screw pair. Moreover, we will investigate the influence of the processing technology of ball screw pair on the groove surface characteristics and the groove surface characteristics on the precision retaining ability of precision ball screw pair, built the relational model of the processing technology and precision retaining ability of precision ball screw pair, and develop the database on the optimization of processing technology for the promotion of precision retaining ability of precision ball screw pair. The project results can provide a theoretic support to the active design on the precision retaining ability and the optimization of processing technology and material have a important value to solve the problem of precision retaining ability of precision ball screw.

针对国产精密滚珠丝杠副急需解决的精度保持性这一共性技术问题，开展精度失效机理及加工工艺特性的基础研究。研究滚珠丝杠副传动过程中滚珠与滚道的相对运动特性与力学作用机制，考虑润滑状况与滚道加工误差的影响建立系统完整的精密滚珠丝杠副运动学与系统动力学模型；结合实验和微-细观分析方法，探索精密滚珠丝杠副在使用过程中的精度失效机理，建立滚珠与滚道接触变形、摩擦磨损和表面点蚀的数学模型，研究不同工作条件（包括载荷大小、预紧力大小、润滑条件与进给速度）下其精度退化的规律，提出面向精密滚珠丝杠副的精度保持性预测方法；分别研究滚珠丝杠副加工工艺对滚道表面特性、滚道表面特性对精度保持性的影响规律，建立滚珠丝杠副加工工艺与精度保持性的关系模型，开发精密滚珠丝杠副加工工艺优化数据库。项目成果能为精密滚珠丝杠副精度保持性主动设计、材料与加工工艺优化提供理论支撑，对解决国产精密滚珠丝杠副精度保持性问题具有重要价值。

针对国产精密滚珠丝杠副在精度保持性方面与国外同类产品的差距，进行了精度保持性损失机理研究、精度保持性预测方法和精度保持性试验方法设计与对比试验分析，为国产精密滚珠丝杠副精度保持性的提高提供理论依据与检验手段。.首先分析总结精密滚珠丝杠副精度保持性有关的精度指标、概念以及作用机理，制定了精密滚珠丝杠副精度保持性研究的思路。基于已有的有关接触力学和滚珠丝杠副运动特性的研究成果，针对双螺母预紧精密滚珠丝杠副进一步分析其滚珠与滚道之间的接触变形和运动规律。并且，结合粘着磨损的相关理论，分析其精度损失的作用机理，提出精密滚珠丝杠副精度损失模型，建立滚珠丝杠副工作条件、结构参数与精度损失量之间的关系。.分析精密滚珠丝杠副精度保持性的影响因素，根据建立的精密滚珠丝杠副精度损失模型，利用MATLAB软件进行影响因素的单因子仿真试验，研究不同参数下，精密滚珠丝杠副精度保持性的变化规律。在此基础上，提出精密滚珠丝杠副精度保持性的初步预测方法，完善精度保持性的基础理论；并针对其结构参数，利用MATLAB优化工具箱进行了面向精度保持性的优化设计。. 提出精密滚珠丝杠副的精度保持性试验方法与实施步骤，给出精度保持性的评估方法。与合作单位合作开发了配套的试验系统；给出了精密滚珠丝杠副各精度指标的求解方法、精度与摩擦力丧失判断依据。试验结果显示了参与试验的两种型号精密滚珠丝杠副的精度保持性和摩擦力随时间变化的趋势，对比分析出它们的优劣势并推测原因，符合实际生产经验，验证了试验方法与试验装置的有效性，为国产精密滚珠丝杠副精度保持性的提高提供了试验方法与有效试验数据。