滚齿机分度挂轮引起齿向误差的实验研究

通过对滚切直齿、斜齿圆柱齿轮时，分度挂轮传动比不精确调整造成的齿向误差的理论分析和实验研究，推导出了齿向误差的计算公式，找出了影响齿向误差大小的因素。研究结果对提高齿轮加工精度有一定的指导作用。     

考虑啮合错位的斜齿轮复合修形优化研究

为了减少斜齿轮传动因啮合错位导致的齿面偏载、传递误差增大、啮合冲击增大,研究考虑啮合错位的斜齿轮复合修形方法,讨论修形前后不同错位量下齿面啮合性能的变化规律。该方法考虑了啮合错位对齿轮啮合性能的影响,基于斜齿轮啮合接触计算模型,以齿面载荷分布、传递误差、啮合冲击等性能指标为评价依据,进行了“螺旋角修形+齿廓鼓形修形”的复合修形。结果表明：基于多目标的“螺旋角修形+齿廓鼓形修形”复合修形能有效改善因啮合错位造成的齿向偏载,且在降低传动误差峰峰值和改善啮合冲击方面显著优于单一的螺旋角修形,能较全面地改善斜齿轮的啮合质量。     

滚齿机床振动对齿轮几何精度的影响

滚齿机床切削加工过程中,刀刃成排轮流从切入到切出,切削力由小逐渐变大,再逐渐变小,在工件和刀具之间产生周期性的激振力,使刀刃和工件加工表面产生相对位移,对加工齿轮的几何精度产生影响。研究机床结构振动与被加工齿轮精度的关系,建立滚刀和工件加工表面产生的相对位移对齿轮几何精度影响的理论模型,定量推导出了由此相对位移产生的齿廓误差;通过大量实验,对滚刀和工件加工表面产生相对位移对应的齿轮齿廓误差进行在线精密测量;使用此齿廓误差减法运算新方法,对两组实验数据进行对比分析。结果表明:提出的运算新方法能够准确地处理数据,实验数据很好地验证了建立的理论模型的正确性,误差小于2%。     

大齿轮齿向误差在机测量技术

从大齿轮及其齿向测量的特殊性入手,分析了大齿轮齿向在机测量的关键问题;创新提出了利用高精度水平仪调整仪器测量基准的方法和对测量数据进行系统误差补偿的思想;研究了大齿轮齿向在机测量技术和方法。     

基于平面砂轮的面齿轮数控切、磨齿技术

传统上面齿轮的加工都是基于小齿轮与其啮合的模拟,导致刀具没有通用性,加工过程复杂,针对这一问题,借助数控技术,提出了采用平面刀具加工面齿轮的方法。首先论述了平面刀具的设计、平面刀具展成加工面齿轮的原理,并结合格林森的技术,提出了平面刀具加工面齿轮所需运动配置。其次通过数学推导,建立了平面刀具加工面齿轮的数学模型,并进行了数控转换。最后对平面刀具加工面齿轮的理论方法及其数控方法进行了仿真模拟,模拟表明:采用平面刀具加工面齿轮可获得理论齿面,其数控加工方法的齿面误差可小达2.56μm。     

高接触比螺旋锥齿面修形方法及动态特性研究

为抑制高接触比螺旋锥齿轮传动的振动,提出一种新的高阶齿面修形方法。根据高接触比螺旋锥齿轮的啮合特点,提出一种新的修形曲线,采用辅助齿面修形方法生成高阶修形螺旋锥齿轮。在考虑齿变形的情况下,计算了高阶修正弧齿锥齿轮传动的载荷传递误差和啮合冲击,在此基础上建立了降低高接触比螺旋锥齿轮传动的载荷传递误差和啮合冲击的优化模型。仿真结果表明：与二阶修形弧齿锥齿轮相比,高阶齿面修形方法不仅可以有效降低高接触比螺旋锥齿的载荷传递误差、啮合冲击和动态负载系数,而且可以提高其在全速范围内的动态性能。     

机床误差正交光栅检测及补偿的研究

文章提出了多轴机床空间误差的平面正交光栅检测和补偿方法.建立了包含21项几何误差的数控机床误差模型,给出了应用神经网络进行空间误差识别和补偿的技术.通过试验对比,验证了该方法的可行性.     

再制造双圆弧齿轮单齿切削机床设计

目前抽油机减速器双圆弧齿轮使用一段时间后会出现单个齿破损或多个齿间隔破损的情况,现有的修复方法效率低。针对这种情况,提出设计一种对修复后的再制造双圆弧齿轮进行再加工的切削机床,验证再制造双圆弧齿轮单齿加工的可行性。结合再制造双圆弧齿轮单齿展成加工理论,对单齿加工机床的刀具运动部件、齿向螺旋进给部件、齿形展成进给部件以及工件运动部件进行设计,最终得到满足加工要求的再制造双圆弧齿轮单齿切削机床。分析再制造双圆弧齿轮单齿加工的误差后,提出一种减小再制造双圆弧齿轮轴向齿距误差的方法。     

基于逆向工程的双圆弧齿轮测量与偏差分析北大核心

为降低抽油机运行维护成本,对抽油机减速器进行再制造,针对减速器中磨损的双圆弧齿轮进行修复。在已有研究的基础上,提出一种基于逆向工程提取齿轮设计参数并对齿轮磨损程度进行分析的方法。使用三维激光扫描技术提取磨损齿轮模型数据,在Geomagic Design X软件中处理齿轮模型,运用面片草图拟合的方法测量齿轮模数,推导出分度圆螺旋角。使用双圆弧轮齿端面齿廓方程,建立双圆弧齿轮精确实体模型。对实际工程中的双圆弧齿轮轴参数进行提取和偏差分析,通过Geomagic Control X将双圆弧齿轮三维模型与扫描模型对齐后分析偏差。结果表明:与手工测量相比,所提方法在保证测量精度的同时降低了测量难度,提高了齿轮测量的效率。     

直线共轭内啮合齿轮泵齿形的结构分析

以直线共轭内啮合齿轮泵的齿轮副为研究对象,通过对外齿轮的设计,并利用齿轮啮合基本定律及共轭齿廓的设计方法推导出内、外齿轮啮合线数学模型及内齿轮的齿形线数学模型,同时针对外齿轮的设计结构确定了外齿轮齿顶圆极限半径、齿形半角的可行范围,为直线共轭内啮合齿轮泵的设计提供理论依据。     

Modeling and analysis of nonlinear guideway for double-ball bar (DBB) measurement and diagnosis

The purpose of this paper is to study nonlinear geometric errors in multi-axis machine tools. A general mathematical model for guideway systems that can be applied to high-precision machine tools such as CNC lathes is introduced. Using this model, most nonlinear error sources in the guideway systems can be diagnosed by measuring the contouring error using a double-ball bar (DBB). Diagnostic software has been developed to identify system parameters based on the least-squares estimation method. Inputting two or three contouring errors pattern data into this software enables parameters to be identified quickly, based on the nonlinear model.     

基于视觉的齿轮齿形参数测量方法

齿轮检测技术是检验齿轮生产和质检能力的有效手段之一,随着近些年对齿轮精度要求的不断提高,非接触式的齿轮参数测量方法被越来越多地应用到实际生产和质检环节中。提出一种利用机器视觉实现齿轮齿形参数测量的方法,实现非接触式齿轮齿形参数测量。此测量系统使用轮廓拟合法来测量齿轮齿形基本参数,使用事件结构编写程序,完成了基于视觉的齿轮齿形参数测量系统。利用USB摄像头,使用背光光源对齿轮进行照明,通过USB接口连接到计算机上,利用Lab VIEW图形化编程平台的IMAQ模块对采集到的齿轮图像进行分析处理;还加入了系统测量误差分析模块,能够实时计算并显示测量误差。实验结果表明:此系统运行稳定,可重复性良好,测量精度高。     

A displacement measurement approach for machine geometric error assessment

It is complicated and time-consuming to evaluate the performance of a machine tool. In this research, a displacement method is proposed to shorten the measurement time and to simplify the measurement. By measuring the positioning errors along the 15 lines in the machine work zone, a total of 21 geometric error components can be determined. Among the 15 lines, seven of them are mandated by the ANSI/ASME standard for the performance evaluation of CNC machining centers. Therefore, only eight additional positioning error measurements are necessary to evaluate the machine's performance. The results from the experimental tests show that the method is feasible and accurate. This method shortens the calibration time and is beneficial, particularly to the reconfigurable machining system, which needs frequent calibration.     

面齿轮齿面检测路径规划方法研究

针对面齿轮齿面检测,根据检测过程中路径规划的原理,提出采用3种不同方法(常规方法、纵向法、横向法)规划路径,分别计算其相对应的测头测量总行程,并在三坐标测量机上进行齿面检测试验.比较理论计算的结果及试验结果,表明常规方法和横向法在实际检测试验中都是可行的,但后者更为快速、高效.     

SSEST: A new approach to higher accuracy cylindricity measuring instrument

The spatial rotation error of a cylindricity measuring instrument (CMI) spindle is one of the biggest obstacles to further improvement of CMI accuracy, and in order to reduce the effect of the spatial rotation error on measurement results, a new single-step spatial rotation error separation technique (SSEST) is proposed and a new spatial rotation error separation system is designed to separate the spatial rotation error of CMI section by section. SSEST proposed can be used to remove the spatial rotation error of an instrument spindle from the measurement results by first measuring the circular profile of a workpiece at i sections and rotating the workpiece through a small angle, then measuring the circular profile of the workpiece after rotation, and finally analyzing and processing the circular profiles. The spatial rotation error separation system designed integrates the functions and structures of circular profile error separation system and CMI spindle rotation system to form a new ultraprecision CMI rotation reference for autonomous separation of spatial rotation errors. Theoretical analyses and numerical experimental results indicate that SSEST can accurately remove the spatial spindle rotation error of CMI from the measured workpiece result in the range of 1–100 upr, and improves the CMI accuracy, and the error separation system based on SSEST simplifies the separation process and the separation system.     

精密卧式加工中心空间误差的建模、测量与补偿技术

采用空间误差补偿技术,可有效提高数控机床的空间定位精度。以一台精密卧式加工中心为对象,系统阐述其几何误差补偿中的关键问题及解决方案。通过三维误差建模与分析,得到该机床的21项几何误差中有17项需要测量和补偿,另外4项误差对机床定位精度的影响甚微。以此为依据,设计误差测量及补偿方案,并给出误差的具体测量方法和补偿结果。结果表明:经过一次系统地误差测量与补偿,精密卧式加工中心的空间定位精度可以提高50%～70%;合理规划和实施空间误差测量,可大幅提高测量效率。     

曲线圆柱齿轮专用铣削加工装置设计

曲线圆柱齿轮是一种特种传动装置,其具有重合度大、无轴向力、易加工等特性,论文分析了其展成原理以及其常用的加工方法,并对单面加工和双面加工法两类加工方法进行了对比说明.对利用格里森刀盘加工曲线圆柱齿轮时的几何参数进行探讨.在分析铣削加工曲线圆柱齿轮范成运动的基础上提出了曲线圆柱齿轮专用铣削加工机床的总体设计方案与布局,并对范成加工曲线圆柱齿轮过程中各基本运动的具体实现作了详细的设计.所设计的机床能够实现加工曲线圆柱齿轮所需要的基本运动,具有较好的工程应用价值.     

Geometric and force errors compensation in a 3-axis CNC milling machine

This paper proposes a new off line error compensation model by taking into accounting of geometric and cutting force induced errors in a 3-axis CNC milling machine. Geometric error of a 3-axis milling machine composes of 21 components, which can be measured by laser interferometer within the working volume. Geometric error estimation determined by back-propagation neural network is proposed and used separately in the geometric error compensation model. Likewise, cutting force induced error estimation by back-propagation neural network determined based on a flat end mill behavior observation is proposed and used separately in the cutting force induced error compensation model. Various experiments over a wide range of cutting conditions are carried out to investigate cutting force and machine error relation. Finally, the combination of geometric and cutting force induced errors is modeled by the combined back-propagation neural network. This unique model is used to compensate both geometric and cutting force induced errors simultaneously by a single model. Experimental tests have been carried out in order to validate the performance of geometric and cutting force induced errors compensation model.     

基于目标传动比的非圆齿轮数字化设计与实现

提出一种基于目标传动比函数进行非圆齿轮数字化设计的方法。利用微分几何方法推算主动轮与从动轮节曲线上的离散点集,通过三次样条插值拟合得到节曲线的轮廓;根据范成加工原理获取刀具的包络图,提取齿廓曲线后赋予一定的齿宽得到非圆齿轮的三维模型;将主动轮与从动轮模型装配后进行运动仿真;在传动过程中进行动态干涉检查,并比较从动轮角速度响应曲线的理论值与仿真值,验证模型的正确性。结果表明：利用所提方法进行非圆齿轮的设计是可行的,能够促进后续分析、制造等工作的开展。     

Development of a multi-step measuring method for motion accuracy of NC machine tools based on cross grid encoder

Machining accuracy is directly influenced by the quasi-static errors of a machine tool. Since machine errors have a direct effect on both the surface finish and geometric shape of the finished work piece, it is imperative to measure the machine errors and to compensate for them. A revised geometric synthetic error modeling, measurement and identification method of 3-axis machine tool by using a cross grid encoder is proposed in this paper. Firstly a revised synthetic error model of 21 geometric error components of the 3-axis NC machine tools is developed. Also the mapping relationship between the error component and radial motion error of round work piece manufactured on the NC machine tools are deduced. Aiming to overcome the solution singularity shortcoming of traditional error component identification method, a new multi-step identification method of error component by using the cross grid encoder measurement technology is proposed based on the kinematic error model of NC machine tool. Finally the experimental validation of the above modeling and identification method is carried out in the 3-axis CNC vertical machining center Cincinnati 750 Arrow. The entire 21 error components have been successfully measured by the above method. The whole measuring time of 21 error components is cut down to 1–2 h because of easy installation, adjustment, operation and the characteristics of non-contact measurement. It usually takes days of machine down time and needs an experienced operator when using other measuring methods. Result shows that the modeling and the multi-step identification methods are very suitable for ‘on machine’ measurement.