【作者】 刘宝庆；

【导师】 王德伦；

【作者基本信息】 大连理工大学 ， 机械设计及理论， 2008， 博士

【摘要】 本文开展的“过盈联接摩擦系数的理论及试验研究”,是在国家高技术研究发展计划项目(863项目)(No.2006AA04Z101)和国家科技支撑计划项(No 2007BAF21B01)的支持的资助下,从大连重工·起重集团减速机厂风机设备的工程实际背景出发,从理论和试验的角度对过盈联接的摩擦系数进行分析研究,为风机等大型工程设备的性能特征信息获取和产品创新设计奠定基础。过盈联接摩擦系数作为一个表面接触摩擦特性的表征参数,在理论和试验研究方面均需要开展大量的研究工作,本文采用数值分析方法首先从理论上对过盈联接摩擦系数进行研究分析,利用过盈联接的有限元接触模型分析计算各影响因素的影响程度,然后采用试验的方法测量过盈联接试件的承载扭矩,间接计算并验证摩擦系数,最后通过正交表分析摩擦系数的影响因素。基于这些研究目的,本文研究内容包括:1.建立过盈联接的接触分析模型,分析过盈量、长短轴比值与最大承载扭矩、摩擦系数之间的关系,基于有限元方法计算分析对摩擦系数有影响的过盈量、锥度、表面粗糙度等因素的影响程度。数值分析部分具体包括:(1)基于曲面模型建立了摩擦系数求解模型,得到摩擦系数的解析表达式;(2)基于软件分析,研究过盈联接的过盈量、锥度、表面粗糙度等因素对接触应力的影响程度,并获得一组比较完整的计算结果;(3)建立了过盈联接的接触应力分析模型,对过盈联接摩擦特性的影响因素进行深入研究,基于面—面接触进行接触应力分析,进而获得摩擦力和摩擦力矩的情况;(4)建立了采用过盈联接中两个零件的体积变形量(称之为“过盈体积”)来描述实际过盈效果的理论方法,基于重构接触曲面的数学理论,分析、计算过盈体积,从而研究过盈体积与过盈联接摩擦系数之间的关系。2.设计正交试验方案,通过数据分析、计算获得摩擦系数,具体内容包括:(1)进行过盈联接摩擦系数测试系统方案设计以及其正交试验方案设计。在分析确定试验所需要的测量参数的基础上,由于摩擦系数的影响因素较多,提出设计正交试验的测试设计思路,以此来确定各因素对摩擦系数的影响。按照设计的正交表,设计每个试件的详细尺寸;(2)完成对具体试件的测量、计算与装配。对加工的试件进行表面粗糙度测量和锥面轮廓测量,拟合得到过盈联接的配合尺寸。为保证测量数据能真实反映零件表面状况,进行了粗大误差的剔除。利用软件的优化工具箱,采用自适应圆锥的方法进行圆锥拟合,为使优化结果达到最优,通过多步拟合得到了较优的初始点并采用序列二次规划的算法进行求解。根据计算结果,采用缩胀法进行试件装配;(3)通过扭转试验得到每个试件的失效扭矩。为保证试验结果真实有效,试验前对试验台进行标定,试验时记录每个试件的扭矩和时间,绘制曲线确定失效扭矩。为了解决某些试件超出试验台扭距量程的问题,专门设计并制造了大量程扭距试验台;(4)基于零件表面的测量数据进行接触曲面重构,将重构的接触曲面转换成为结点形式,使用有限元分析软件进行静力分析,获得每个接触结点的外力,然后通过外力和力臂的累加计算获得接触面平均摩擦系数。(5)实际装配对原有因素的各个水平产生了影响,为了满足试验的正交性,必须重构正交表。通过分析重构的正交表得到了各因素对摩擦系数的影响程度。经过计算极差和剔除误差等操作,得到摩擦系数的经验公式。3.对理论和试验研究的过盈联接摩擦系数进行对比分析和联合求证,一方面完善过盈联接摩擦系数的计算方法和过程,另一方面从试验和理论角度给出了可以用于风机等大型设备的过盈联接摩擦系数具体推荐值。本文开展对过盈联接摩擦系数的研究,在理论上将完善目前国内大型设备过盈联接的摩擦系数确定过程,从试验角度对摩擦系数进行验证分析,最后形成可以用于风机等大型工程设备过盈联接摩擦系数的经验公式,这对于提高设备的运行效率和运行可靠性都具有重要意义。更多还原

【Abstract】 This paper studies on the "Theoretical and Experimental Research on Interference Fit Friction Coefficient", which seek proceed from the practical engineering background from DHI-DCW Group. Based on the theoretical and experimental point, the friction coefficient of the interference fit is analyzed. The result will help to obtain the performance characteristics of wind generator and lay the foundation for innovative design. This research is supported by the National High Technology Research and Development Program of China (863 program) under Grant No. 2006AA04Z101 and National Technology Suporting Program of China under Grant No. 2007BAF21B01.Interference fit friction coefficient is a friction characterization parameter expressing the surface contact condition. It needs to launch a lot of research work on its theoretical and experimental research. So this paper will firstly study the numerical analysis methods of the interference fit friction coefficient, then by the use of indirect methods, verify the fiction coefficient calculated by orthogonal experiment. Meantime, the factors which influence the friction coefficient will be discussed with the finite element analysis method. The impact size of different factors will be obtained. For the objects, this paper includes:1. Establish the two contact analysis model for interference fit and analysis the fit capacity and the maximum torque load. Based on the finite element method, the influencing factor of the friction coefficient, such as the fit capacity, taper, the surface Roughness, has been studied, and the incidence of different factors has been obtained. The specific parts of the numerical analysis include:(1) Based on the model of solving friction coefficient which is based on surface model, the analytical expression of friction coefficient is obtained;(2) Based on analysis, study the influencing factosr of the interference fit, such as fit capacity, taper, surface roughness. The incidence of different factors has been discussed; a group of the optimal results have been received;(3) Establish interference fit contact stress analysis model, with in-depth researching on the influencing factor for the interference fit friction characteristics. Based on its face - contact stress analysis method, get the interference fit contact stress, and further access to the friction and friction torque; (4) Establish theory method which can be use to describe a fit in the two parts of the size of deformation (referred to as "the volume of fit"). Based on the reconstruction contact surface mathematical theory, the volume of fit have been analyzed and calculated, which will be help to study and contact stress and the friction coefficient of interference fit.2. Design orthogonal experimental to determine the friction coefficient of interference fit, the specific contents are:(1) Design the interference fit friction coefficient test system and its orthogonal test programme table. the measured parameters have been determined. Because more factors influence on friction coefficient, the orthogonal experimental table is designed. In accordance with the orthogonal design, the details of each sample size are designed.(2) Complete the measurement, calculation and assembly of the specific samples. Surface roughness and cone profile have been measured, and the fit size has been received by tight fitting. To ensure that measurement data can reflect the true state of the surface, the error has been eliminated by using intuitive methods. Using software optimization toolbox and adaptive approach to taper cone fitting, optimal results of taper cone fitting have been achieved. The solving algorithm of sequential quadratic programming (SQP) and an adaptive initial point based on fitting step by step are provided for the optimal results. According to the results, a reduction expansion assembly way has been proposed.(3) Failure torque is determined by torsion test. The test-bed is calibrated with proving ring. Each couple of specimen is tested with time, torque and corner being recorded. The failure torque is obtained from the curve of torque and time. In order to solve issues of some samples exceeded the test-bed torque range, the large torque test-bed is designed and made specially.(4) Reconstruction surface which is based on measurements of parts has been converted into contact model with the form of nodes. By using of finite element analysis software the result of static analysis is achieved and the average friction coefficient can be implemented through accumulating the external force and force-arm.(5) Orthogonal reconstruction table is used to analyse the influence factors of the friction coefficient.After actually assembling, the levels of factor are affected.In order to satisfy the orthogonality, the orthogonal table is strongly demanded to reconstruct.The empirical formula of friction coefficient is obtained after range calculating and error rejecting. 3. Theoretical and experimental research process on the interference fit coefficient friction were analyzed and verified. On the one hand, it will improve the interference fit friction coefficient method and calculating process, on the other hand, the friction coefficient from theoretical point with the test point can be used for the wind generator and other large equipments.This paper researches on the interference fit coefficient friction. In theory, it will improve determined process of interference fit coefficient friction for the current domestic large equipments. From the test results, the paper verifies and obtains the empirical formula of interference fit friction coefficient which can be used in wind generator and other large equipments. The research results are of great value to improve the efficiency of the devices operation and operating reliability.更多还原