小径定心矩形花键加工误差分析

国标GBI144-87《矩形花键、尺寸、公差和检验》规定了小径定心方式,国际上已普遍采用,因为小径定心比大径定心容易提高精度,而且有助于提高花键副的接触面硬度,从而保证和提高产品的使用寿命。因此,我国推行小径定心花键势在必行。然而在磨削花键轴小径时,形位公差不易保证,其误差影响着定心精度及装配精度。花键(花键与键     

花键磨床后顶尖偏移引起的分度误差

花键磨床后顶尖偏移引起的分度误差渭阳柴油机厂（陕西虢镇７２１３００）傅子超，朱志勤在花键磨床磨削渐开线花键拉刀及三角形花键拉刀齿形时，为了获得刀齿的侧后角，需将机床后顶尖抬高（一般抬高量为０．３／１０００），在磨削花键环规用的校对塞规时，为了获得每个...     

花键联接

由于花键联接传动具有触面积大、承载能力高、定心性能和导向性能好，键槽浅、应力集中小，对轴和毂的强度削弱小，同时结构紧凑等优点，因此，常应用于传递较大的转矩和定心精度要求高的静联接和动联接。花键的类别、特点与应用按花键齿的形状可分为角形花键和渐开线花键两大类。在角形花键中又可分为矩形花键和三角形花键。从目前应用来看，渐开线花键最多，其次是矩形花键，在装卸工具上用三角形花键居多。①矩形花键：加工方便，可用磨削方法获得较高的精度，但内花键通常要用花键拉刀，对于不通孔的花键就无法加工，只好用插削加工，精…     

钕铁硼永磁材料在车削加工中的应用

新型永磁材料钕铁硼应用于细长轴车削加工，实现了加磁切削。在一般工艺条件下，工件的加工精度，表面质量表明提高，对于长径比４０以上的工件，鼓形误差在０．０２ｍｍ以内，表面粗糙度Ｒａ值在０．００２ｍｍ，圆度误差在０．００１ｍｍ以内。     

圆弧三角花键的加工方法

我厂从国外引进的摩托车变挡传动轴上采用了如图1所示圆弧三角花键（8×10DIN5481，材料30Mn2，HB229～251）。与圆弧三角花键套（精密铸造成形）配合，调整为无间隙配合。图1圆弧三角花键圆弧三角花键的加工比较困难，国外在自动分度数控铣床上用角度铣刀加工，国内尚无较好的加工方法。我厂曾经在立式铣床上用专用分度夹具和角度铣刀加工，缺点是：手工分度，劳动强度大，生产效率低；加工后同一工件上齿槽深浅不一致；因分度累积误差的影响使最后一个齿的齿厚明显增大或减小；花键的轴向相对尺寸较难控制。经过研究试制，在滚齿机上采…     

多键矩形花键拉刀设计的改进

多键矩形花键拉刀设计的改进汉江工具厂（陕西汉中７２３００２）朱斌随着我国汽车工业的不断发展，汽车零配件的加工愈来愈多。万向节滑动叉是汽车传动轴中的主要零件，其联结键大多为１６齿矩形花键，这种花键长度为７５～１４０ｍｍ，内花键的加工采用成形拉削，这种加...     

花键环规精磨加工中的分度误差分析及修正

花键综合量规用于花键孔和花键轴的综合检验。由于量规结构等原因，孔用综合塞规的制造精度较易达到标准要求；但轴用花键环规分度精度要求较高（周节累积误差仅为约８μｍ），加工难度较大。在测量花键环规分度值时，环规分度一周后杠杆表指针往往不能回零，或虽能回零，但装卡带动器后的测量芯轴跳动量比装卡前显著增大（可达１０μｍ之多）。这种装卡带动器后增加的跳动误差将会直接带入环规的分度误差中。虽然这种人为分度误差属系统误差，理论上可从环规各齿上一一剔除，但若在环规分度精磨加工中出现这种人为分度误差，则可能造成精磨…     

贯彻圆柱直齿渐开线花键新国标的示例

GB／T3478．1～3478．9—1995（圆柱直齿渐开线花键》已于1996年5月1日起实施。笔者就我厂ZL3O装载机变速箱中的一对花键副为例，对如何正确贯彻该项新国标向全厂工程技术人员作了宣讲。ZL30装载机变速箱中，ZL30－2－70高低速滑套上为外花键、ZL30－2－2输出轴低速齿轮上为内花键，形成渐开线花键联结。其标记为：花键副；INT／EXT33ZX3mX3OPX6H／6dGB／T3478．1一1995齿宽心一4Omm即齿数为33、模数为3、压力角为3O”的平齿根花键，公差等级和配合类别为6H／6d，花键长度为4O的渐开线花键副。l查表与计算查表与计算见表1。2检…     

0级平尺直线度检定工具的选定

通过误差分析与计算，论证了分度值为０．０１ｍｍ／ｍ的合象水平仪及０．００５ｍｍ／ｍ电子水平仪不能满足０级平尺直线度检定精度要求；采用分度值为０．００５ｍｍ／ｍ的自准直仪或０．００１ｍｍ／ｍ电子水平仪获得满意的检定精度结果。由此得出正确选择检定工具，对于保证０级平尺检定质量有重要意义。     

M8612A小径磨床砂轮修整器的改进

矩形花键采用小径定心方式，可以克服大径定心在热处理时造成的矩形内花键大径严重变形而无法修整的缺陷，并能采用热处理后进行磨削的工艺方案，使花键获得较高的加工精度，提高以花键作为基准孔的渐开线圆柱齿轮配合的精度。具有加工工艺性好、稳定性高，精度易于保证的特点。     

In-process out-of-roundness measurement probe for turned workpieces

A new in-process and non-contact probe is proposed to measure the diameter and the roundness of turned workpieces. The initial probe discussed in previous publications exhibited diameter measurements with good accuracy (uncertainty 5 μm over 100 mm). This paper discusses the implementation of roundness measurement into the initial probe and its performance. The principle of the roundness measurement is based on the relationship between the displacement and the light intensity. The probe delivers a maximum error of 0.5 μm with an uncertainty of 1 μm for roundness measurement over a range of 100 mm diameter.     

基于双激光位移传感器的超长深孔圆度检测研究

面向超长深孔管道内壁截面圆度的高精度与快速检测难题,针对基于单个激光位移传感器的传统检测方式存在效率 低,受轴心晃动影响大的不足,本文提出了基于两个激光位移传感器的点式检测方案,并通过建立数学模型与数值仿真的方式, 对检测装置旋转轴的偏心参数与两个激光位移传感器的安装偏差参数进行了仿真,分析了各参数对深孔管道圆度评价结果的 影响。 在此基础上,提出了存在安装误差的两个激光位移传感器数学校正模型,并搭建了管道圆度检测实验系统,验证了该模 型的有效性。 结果表明,相比于两个激光位移传感器所采集的数据直接进行圆度评价,对校正之后的数据进行圆度评价,其圆 度值从 0. 30~ 0. 50 mm 范围降低到 0. 05~ 0. 15 mm 范围,测量时间由 18. 7 s 缩短到 9. 8 s。     

超声振动切削超薄壁精密零件的圆度误差试验研究

试验研究了超声振动车削直径为47.75mm壁厚为0.8-1.5mm的照相机导向筒超薄壁精密零件的圆度形成规律及切削参数对圆度误差的影响。研究表明:超声车削精密超薄壁零件,圆度误差最小是普通精密切削的1/3。     

刀片钝化半径对高温合金切削质量影响的研究

通过不同钝化半径的刀具对GH4169高温合金进行车削正交试验,结果表明:随着钝化半径的增加,表面残余应力先降低后增加;工件环向残余应力随着钝化半径的增加,工件内部残余压应力最大值增大,影响深度随之增加。由表面粗糙度和表面残余应力的敏感程度可知,进给量是影响表面完整性的最主要因素,其次是切削速度和切削深度。分析了不同钝化半径和切削参数对表面完整性特征的影响规律,建立了表面粗糙度表面残余应力的经验公式,得到了用于精加工GH4169高温合金较好的钝化半径范围0.02~0.03mm,以及较优的切削参数vc=60~70m/min,fn=0.05~0.075mm/r,ap=0.2~0.5mm。     

基于小波变换软测量技术在大型回转体中的圆度误差方法研究

针对大型回转体圆度误差难以检测的问题,采用非接触式软测量技术以相对测量方法采集大型回转体零件回转面的实测信号,基于小波变换消噪滤波的方法,快速分解提取实测信号中的圆度误差信号,通过圆度误差的评定计算大型回转体的圆度误差。结果表明:该方法能够有效提取大型回转体实测信号中的圆度误差信号,通过实例计算,某2000 mm直径回转体的圆度误差为0.32 mm,该方法为大型回转体圆度误差计算提供一定的理论依据,具有一定的实际应用性。     

测头读数及定位误差对三点法圆度测量精度的影响

研究三点法测量圆度时测头的读数及角位置误差对圆度测量精度的影响。从三点法的原理出发对测量过程进行误差分析,导出了圆度测量误差方程,并通过计算机仿真详细研究了测头的读数及角位置误差对圆度测量精度的影响。圆度测量精度主要决定于读数误差;如果３个测头间的夹角选择不当,将使测头读数误差在某些谐波上被大大放大。必须恰当选择３个测头间的夹角,使读数误差对圆度各次谐波测量结果的影响都较小。     

Approach to accuracy improvement and uncertainty determination of radius of curvature measurement on standard spheres

In high accuracy radius of curvature (ROC) measurement, significant discrepancy may exist in results on the same optical surface obtained by different techniques. Metrological standard sphere is a potential solution to this problem. Mathematical models are built up to characterize the relationship between the ROC of standard spheres and the roundness error as well as the aperture angle. Equations for calculating the uncertainty of ROC are derived and tested on several ROC measuring methods. The reason for the inconsistency between results of different techniques is analyzed and solutions are proposed. A method is developed which can remarkably reduce the uncertainty of ROC. Experiments are carried out on a set of high quality spheres whose diameters are from 11 mm to 93 mm and roundness below 0.1 μm, measured by instruments with relative accuracy of 10⁻⁵–10⁻⁶, which are a length measuring machine, a profilometer and a homemade differential confocal system. Relative uncertainties of ROC are calculated and analyzed against several factors. Experimental results show good consistency with theoretical analysis. Approaches to trace the ROC to the metrological length standard area discussed.     

Plane kinematic calibration method for industrial robot based on dynamic measurement of double ball bar

A new calibration method is proposed to improve the circular plane kinematic accuracy of industrial robot by using dynamic measurement of double ball bar (DBB). The kinematic model of robot is established by the MDH (Modified Denavit-Hartenberg) method. The error mapping relationship between the motion error of end-effector and the kinematic parameter error of each axis is calculated through the Jacobian iterative method. In order to identify the validity of the MDH parameter errors, distance errors and angle errors of each joint axis were simulated by three orders of magnitude respectively. After multiple iterations, the average value of kinematic error modulus of end-effector was reduced to nanometer range. Experiments were conducted on an industrial robot (EPSON C4 A901) in the working space of 180 mm × 490 mm. Due to the measuring radius of DBB, the working space was divided into 30 sub-planes to measure the roundness error before and after compensation. The average roundness error calibrated by the proposed method at multi-planes decreased about 21.4%, from 0.4637 mm to 0.3644 mm, while the standard deviation of roundness error was reduced from 0.0720 mm to 0.0656 mm. In addition, by comparing the results of positioning error measured by the laser interferometer before and after calibration, the range values of motion errors of end-effector were decreasing by 0.1033 mm and 0.0730 mm on the X and Y axes, respectively.     

Development of externally pressurized small-size conical-shaped gas bearings for micro rotary machines

We have developed externally pressurized small-size conical shaped gas bearings for micro rotary machines such as gas blowers, compressors, and medical devices. The bearings are lightweight and enable machines and devices to be downsized by reducing the number of parts, since the journal and thrust loads can be supported by a pair of bearings. The conical bearings (diameters 8 mm and 10 mm) were designed and the manufacturing techniques were considered. The bearing type is a double-row inherent orifice bearing with four feed holes per row. The shape accuracy of the manufactured bearings is within the design limits, being less than 0.005 mm in both roundness and cylindricity. The surface roughness (arithmetic average roughness) of the parts is 0.0002 mm. The static characteristics were calculated and validated by testing on manufactured bearings. Comparative agreement was obtained between the measured and designed values. The proposed calculation method presents as a relatively simple approach for predicting the bearing characteristics. The test rotor exceeded 350 Hz (21,000 rpm) in the rotational test, and whirl vibration was absent. During testing, the maximum rotor vibration amplitude was 0.0125 mm (corresponding to an eccentricity ratio of 0.89).     

A study of the wear of explanted metal-on-metal resurfacing hip prostheses

Due to their recent introduction there are few studies of retrieved resurfacing hip prostheses. Nine such components associated with groin pain in patients, and five associated with early fracture of the femur, were obtained and analysed using a roundness measuring machine. While the ‘fracture’ components showed no more than 3 μm out of roundness, components associated with groin pain showed between 15 and 92 μm out of roundness values. These latter results indicate wear and correlated with high metal ion levels in these patients, therefore the groin pain was likely associated with an adverse reaction to excessive metal wear debris.