滚珠丝杠副可靠性增长关键技术研究

【作者】 张杰；

【导师】 祖莉；

【作者基本信息】 南京理工大学 ， 机械电子工程， 2020， 硕士

【摘要】 滚珠丝杠副作为数控机床的核心传动部件,其性能直接影响数控机床的定位与传动精度。经过多年可靠性工程的研究,国内滚珠丝杠副的综合性能已经获得了极大的提升。而作为可靠性工程的重要组成部分,滚珠丝杠副的可靠性增长承担着设计加工优化改良,现场使用规范操作的任务,而目前对这方面还鲜有研究。本文依托国家科技重大专项,旨在建立与验证一个适用于不同型号丝杠的可靠性增长体系与评估方法。本文首先建立了滚珠丝杠副可靠性增长体系,从加工、使用、试验三个方面进行规范,用可靠性增长管理进行监测,最后用可靠性增长指标来评估。构建了一个完整的可靠性增长过程。在建立体系的基础上,选取了中心孔、滚道表面质量、预紧力以及安装要求这几个关键核心参数,进行定量的分析,给出加工时的具体参数需求。并选取了支撑方式、安装工艺以及预拉伸量三种关键安装方法,设计试验研究它们对于丝杠付综合性能的影响。当滚珠丝杠副严格遵守可靠性增长体系加工后,利用可靠性增长试验评估出当前的精度可靠性为5220h,完成了可靠性增长定下的4500h的目标。在此基础上进行主机安装下的可靠性试验与相应的台架对比试验,分析体系中使用保障措施的有效性,以及当前的滚珠丝杠副改进的方向。对数控机床进行可靠性分配,得到滚珠丝杠副的MTBF要求为16633h。针对可靠性增长试验提出相应的评估方法,分为小样本的MTBF算法与大样本情况下的AMSAA-BISE可靠性增长模型,并通过评估得出试验的滚珠丝杠副MTBF为17800h,满足可靠性分配的要求。更多还原

【Abstract】 As the core transmission component of CNC machine tools,the performance of ball screw pair directly affects the positioning and transmission accuracy of CNC machine tools.After years of reliability engineering research,the comprehensive performance of domestic ball screw has been greatly improved.As an important part of reliability engineering,the reliability growth of ball screw pair undertakes the task of optimization and improvement of design and processing,standardized operation of field use,but there is little research on this aspect at present.Based on the National Science and Technology major project,this paper aims to establish and verify a reliability growth system and evaluation method for different types of ball screws.This paper firstly establishes the reliability growth system of ball screw pair,which is standardized from three aspects of processing,use and test,monitored by reliability growth management,and evaluated by reliability growth index.A complete reliability growth process is constructed.On the basis of the establishment of the system,several key core parameters,such as center hole,surface quality of raceway,preload and installation requirements,were selected to carry out quantitative analysis,and the specific parameter requirements during processing were given.Three key installation methods,including support mode,installation process and pre-drawing amount,were selected to design and test their effects on the integrated performance of lead screw.When the ball screw pair is processed in strict accordance with the reliability growth system,the reliability growth test is used to evaluate that the current accuracy reliability is 5220 h,and the 4500 h target of reliability growth is achieved.Based on this,the reliability test under the installation of CNC machine tools and the corresponding bench comparison test are performed to analyze the effectiveness of the using safeguard measures in the system and the current direction of improvement of the ball screw pair.According to the reliability distribution of the CNC machine tools,the MTBF requirement of the ball screw pair is 16633 h.A corresponding evaluation method is proposed for the reliability growth test,which is divided into a small sample MTBF algorithm and a large sample AMSAA-BISE reliability growth model.The evaluation results show that the test ball screw pair MTBF is 17800 h,which meets the reliability Allocation requirements.更多还原