新构形硬质合金插齿刀制造模型

随着硬质合金刀具的广泛应用,硬质合金插齿刀的研究越来越受到齿轮制造业的重视。从提高新构形硬质合金插齿刀异形凸曲前刀面铲磨精度的角度出发,根据微分几何的包络理论及新构形硬质合金插齿刀设计模型,推导出铲磨新构形插齿刀异形凸曲前刀面的数学模型。     

Design of nonstandard spur gears cut by a hob

A numerical technique has been developed for determining the individual hob offsets for a pair of spur gears designed to operate at a nonstandard center distance with the maximum ratio of recess to approach action or to balance tooth strengths of the pinion and gear. The numerical technique is based on determining the limit to which the hob is offset to create a full recess-action gearset, to balance the tooth strengths, to maintain a desired contact ratio, and to avoid undercutting. The values of the hob offsets from these design criteria are calculated, and the limiting value selected to produce an acceptable gearset. In this paper, backlash is incorporated into the solution method and a new numerical technique is employed to solve the optimum hob offsets. This paper presents the formulation of the equations for each of the design criteria and the corresponding solution methods, which include backlash, that are used to determine the optimum hob offsets. These design criteria have been incorporated into a Basic program. Example problems and results from the program are presented.     

Mathematical model of S-shaped gear surface

Journal of Mechanical Science and Technology - In this study, an imaginary S-shaped surface rack cutter was used to create a gear pair with S-shaped surface. First, a mathematical model of the...     

采用接刀方法线切割加工大长度齿条刀具

线切割加工是制造齿条刀具的关键工序 ,齿条刀具的全部齿形参数———齿距、齿厚、全齿高、螺旋角、后角、齿形角等均通过该工序一次成形。由于我厂所用ＣＨＡＲＭＩＬＬＥＳ 2 90型线切割机床的行程限制 ,只能加工长度≤ 35 0ｍｍ的齿条刀具 ,而用户订货的齿条刀具最大长度达 4 80ｍｍ ,为了利用现有设备加工出超行程的大长度齿条刀具 ,只能采用接刀方法进行加工。接刀加工是将一把齿条刀具分为两段分别加工。线切割机床的上、下喷嘴是按程序编制的加工轨迹移动 ,喷嘴周围有较大空间 ,因此可根据程序的加工方向将齿条刀具的一端固定在加工…     

Simulating gear and bearing interactions in the presence of faults: Part I. The combined gear bearing dynamic model and the simulation of localised bearing faults

This paper presents a simulation model for a gearbox test rig, in which a range of bearing faults can be implemented. Bearing faults sometimes manifest themselves by their interaction with meshing gears, and to simulate this it is necessary to model a whole system of gears and shafts supported in bearings. This has now been done for an experimental test rig through the incorporation of a time-varying, non-linear stiffness bearing model into a previously developed gear model. The incorporated bearing model is based on Hertzian contact theory, which relates the raceway displacement to the bearing load, and also accounts for the slippage between the elements. It has the capacity to model localised spalls (inner race, outer race and rolling elements), which are discussed in this part of the paper and extended inner and outer race faults (rough surfaces), which are discussed in part II. Even though the whole gearbox has not been modelled in detail, the non-linear time-varying gear-meshing operation is modelled in some detail. Both simulated and experimental localised fault signals (acceleration signals) were subjected to the same diagnostic techniques; namely spectrum comparisons, Spectral Kurtosis (SK) analysis and envelope analysis. The processed simulated signals showed a similar pattern to that observed in their measured counterparts and were found to have a characteristic, referred to in the literature as double pulses, corresponding to entry into and exit from the localised fault. The simulation model will be useful for producing typical fault signals from gearboxes to test new diagnostic algorithms, and possibly prognostic algorithms.     

蜗轮滚刀CAD系统中工作图的自动绘制

研究蜗轮滚刀CAD系统中工作图自动绘制,详细介绍工作图中各视图绘制模块、尺寸标注模块、布局设置模块等的实现方法。通过实际运行表明,其结果满足工作图的规范要求,实现了所有类型滚刀工作图的自动绘制。     

利用代用滚刀加工插齿刀齿形的方法

根据被铣插齿刀的模数和压力角选择代用滚刀齿形,由齿厚变化量(歪变量)的大小来决定加工余量,解决了插齿刀加工费用高、周期长的问题。     

MDT二次开发实现蜗杆蜗轮造型

本文介绍MDT二次开发 ,编程实现蜗杆蜗轮的三维造型 ,造型精度高 ,易于掌握应用     

Numerical computing method of noncircular gear tooth profiles generated by shaper cutters

A simple and accurate numerical method was proposed for calculating the tooth profile of a noncircular gear. This method is directly based on the real gear shaping process, rather than deducing and solving complicated meshing equations used in the traditional method. The tooth profile is gradually obtained from the boundary produced by continuously plotting the cutter profile on the gear transverse plane. The key point of the method is picking up the graph boundaries. The relative position of the cutter profile on the gear transverse plane is determined by the given pitch line of the noncircular gear, parameters of the shaper cutter, and the shaping process data. In comparison with the traditional method, it is universal and is much more efficient and accurate, especially for noncircular gears, which have nontrivial pitch lines. Special problems in gear design and manufacturing, such as tooth pointing, undercut, and fillet interference, are included in the process. As an application example of the numerical method, a square internal gear is chosen from a new type of hydraulic motor with noncircular planetary gears, and the tooth profile of that gear is computed. The gear is successfully machined by electromagnetic discharge (EMD) using the resulting data.     

行星齿轮减速器优化设计的数学模型

通过对2K-H型行星齿轮系传动的分析,建立了以重量最轻为优化目标的行星齿轮减速器优化设计数学模型,并提出了求解方法。     

New theoretical and experimental probes of tribochemistry in model bearing contacts

The differential effects of temperature, pressure and flow induced strain on diatomic (Cl₂) and polymer (polyethylene)bond cleavage reactions are modeled by combining hydrodynamics and molecular statistical mechanics. A new experimental technique, based on vibrational spectroscopy, is used to measure the pressure induced force along C=C and Si-O bonds in 1-octene and hexamethyldisiloxane. This revised version was published online in June 2006 with corrections to the Cover Date.     

改善蜗杆传动的性能

根据某小家电产品运行试验和检测中反映该蜗杆传动系统的主要问题 ,在不改变产品传动整体结构条件下 ,有针对性地提出相关参数、尺寸、结构和材料的改进方案。实践证明 ,新方案充分满足了产品的技术性能要求。     

精确图解法确定滚刀法向齿形

利用AutoLisp程序,用图解法确定滚刀法向齿形。介绍了确定矩形花键滚刀法向齿形的程序及绘图过程。     

在微机上实现滚刀检查仪调整参数的计算

本文介绍了GDY型和PWF型滚刀检查仪,并在AST微机上编写程序进行调整参数计算,还给出了应用实例。     

浅释蜗轮蜗杆传动中齿形的影响与改善

指出在蜗轮蜗杆减速装置中,齿形是否准确,是影响蜗轮蜗杆传动质量的主要原因之一。文章先对蜗杆的齿形进行了分析,又指出如何提高蜗轮蜗杆齿形的准确性问题,其他是有效提高蜗轮蜗杆的传动效率、降低传动噪声和温升的重要手段。并针对ZA型蜗轮蜗杆齿形的加工工艺及齿形的成形加以分析和探讨,总结出了ZA型蜗轮蜗杆齿形传动中的问题,提出了改善的方案,即在ZA型蜗轮蜗杆传动中,采用磨削蜗杆的齿形,克服由于齿形不准所造成的不良影响,来改善传动质量,提高产品品质。     

Effect of hob wear on the sounds emitted in the gear hobbing process

Increasing demand for precision and economy in gear manufacture necessitates control of the essential parameters in the hobbing process. Recognizing this necessity, research was undertaken to develop a hob wear detector. Using an empirical procedure, the acoustic signal emitted in hobbing was assessed with respect to its capacity to provide information about the extent of hobbing cutter wear. It was shown that signals from measurement of acoustic pressure in full bandwidths are unsuitable for the purpose. Frequency analysis of the acoustic signal enabled a third-octave frequency range with a centre frequency of 160 Hz to be singled out, wherein the acoustic signal level showed a close correlation with hob wear. The suitability of the signal is independent of most of the basic machine and process parameters and, for the purposes of hob wear detection, is reduced with higher values of module pitch of the hobbed gear     

双渐开线齿轮齿廓参数优化及滚刀设计

双渐开线齿轮是一种新型渐开线齿轮。这些齿轮的齿廓由两组渐开线和连接它们的过渡曲线组成,形成阶梯形。基于等强度原则,利用有限元关于接触强度、弯曲率强度分析计算结果,建立了双渐开线齿轮齿廓参数优化数学模型,并进行优化,给出双渐开线齿轮滚刀前刀面齿廓方程,并利用优化结果,设计、加工出双渐开线齿轮滚刀。     

Effect of hob wear on the surface layer properties of hobbed gear teeth

Results of investigations of the effect of hob wear on the surface layer properties of hobbed gear teeth are presented in this paper. The influence of hob wear on the microhardness, surface roughness, residual stresses and surface layer thickness were investigated. On the basis of the experimental results it was found that hob wear has a significant influence on the surface layer properties of the gear teeth. This influence is most noticeable on the dedendum and root fillet where the gear tooth space is shaped by the bluntest part of the hob cutting edges.     

加工修缘斜齿轮插齿刀的专用滚刀及磨齿样板的设计

1　引言加工带修缘斜齿轮插齿刀的关键工序是滚齿及磨齿 ,其刀具的齿形需要修正。通过修正计算可知 ,这种斜齿轮插齿刀左、右齿形表面的分度圆压力角不相等 ,为满足这一要求 ,则必须修正加工斜齿轮插齿刀所需滚刀的齿形。在磨齿过程中 ,可通过磨齿样板来控制插齿刀的齿形及修缘     

Parametric analysis of the end face engagement worm gear

A novel specific type of worm drive, so-called end face engagement worm gear(EFEWD), is originally presented to minimize or overcome the gear backlash. Different factors, including the three different types, contact curves, tooth profile, lubrication angle and the induced normal curvature are taken into account to investigate the meshing characteristics and create the profile of a novel specific type of worm drive through mathematical models and theoretical analysis. The tooth of the worm wheel is very specific with the sine-shaped tooth which is located at the alveolus of the worm and the tooth profile of a worm is generated by the meshing movement of the worm wheel with the sine-shaped tooth, but just the end face of the worm(with three different typical meshing types) is adapted to meshing, and therefore an extraordinary manufacturing methods is used to generate the profile of the end face engagement worm. The research results indicates that the bearing contacts of the generated conjugate hourglass worm gear set are in line contacts, with certain advantages of no-backlash, high precision and high operating efficiency over other gears and gear systems besides the end face engagement worm gear drive may improve bearing contact, reduce the level of transmission errors and lessen the sensitivity to errors of alignment. Also, the end face engagement worm can be easily made with superior meshing and lubrication performance compared with the conventional techniques. In particular, the meshing and lubrication performance of the end face engagement worm gear by using the end face to meshing can be increased over 10% and 7%, respectively. This investigate is expect to provide a new insight on the design of the future no-backlash worm drive for industry.