在普通滾齿机上加工高精度齿輪的途径

随着科学技术的发展,对齿轮的承载能力和运动速度提出越来越高的要求,因而对齿轮的加工精度要求也越来越高。如何在普通滚齿机上加工高精度齿轮已成为经常碰到的问题。一、用滚齿机加工齿轮时精度分析滚齿机在滚切齿轮时,主要由下面几个因素影响齿轮的误差(见图1)。     

在普通滚齿机上加工高精度齿轮的途径

随着科学技术的发展,对齿轮的承载能力和运动速度提出越来越高的要求,因而对齿轮的加工精度要求也越来越高。如何在普通滚齿机上加工高精度齿轮已成为经常碰到的问题。一、用滚齿机加工齿轮时精度分析滚齿机在滚切齿轮时,主要由下面几个因素影响齿轮的误差(见图1)。 1.滚切法的理论误差; 2.滚齿机从滚刀到蜗轮副之间的传动链误差; 3.滚齿机走刀丝杆与差动挂轮系的传动误差(加工螺旋齿时);     

无差动滚齿法

尽管新技术、新工艺发展很快,数控滚齿机已经普及,而如何在普通滚齿机上不用差动交换齿轮也能加工出斜齿轮,更能全面地考量一个人的综合水平与能力。因此在普通滚齿机上掌握无差动滚齿法也是很有必要的。     

基于PLC对YB3180滚齿机传动链的数控改造

本文介绍采用数控法改造YB3180滚齿机,减少并缩短了传动链的数量和长度,提高了滚齿机的加工精度,扩宽了加工范围,并且还可以用于特种圆锥齿轮加工。     

三例非普通齿轮的加工方法

1.普通机械滚齿机加工小锥度齿轮小锥度齿轮在测量仪器设备上大量应用,用数控滚齿机加工小锥度齿轮或鼓形齿轮是很简单的事情,但是数控滚齿机价格高昂,成本高,还没有被广泛应用。在一些工具书上介绍的“靠模法”用普通机械滚齿机加工小锥度齿轮,即把仿形靠模安装在滚刀刀架轴向     

滚齿直齿圆锥齿轮齿形的研究

对滚齿直齿圆锥齿轮提出了在其范成齿条的法面内,将一对滚齿直齿圆锥齿轮的啮合关系,与齿轮和范成齿条的加工啮合关系相结合的研究方法.在此基础上,利用包络法分析建立了滚齿直齿圆锥齿轮轮齿的齿面方程、滚齿直齿圆锥齿轮和范成齿条啮合的接触线方程.研制了可调倾角式滚切圆锥形齿轮加工装置.进行了直齿圆锥形齿轮滚切加工试验.结果表明加工的齿轮齿面形状与建立的齿面方程一致.     

普通滚齿机弧形齿轮加工的辅助装置设计与分析

弧形齿轮是鼓形齿联轴器的基础零件,弧形齿轮的加工一般需要在专用弧形滚齿机上才能完成。通过对弧形齿轮及普通滚齿机结构特点的分析,设计出了一种辅助普通滚齿机加工弧形齿轮的装置,从而实现了在普通滚齿机上加工弧形齿轮的可能。     

凹形圆锥渐开线齿轮的滚齿法

凹形圆锥渐开线齿轮 (ConcaveConicalInvoluteGear)是一种新型的圆锥渐开线齿轮 (ConicalInvoluteGear) [1～ 3 ] 。圆锥渐开线齿轮的齿面间呈点接触[4] ,所以齿面强度比低 ,而凹形圆锥渐开线齿轮的齿面呈凹状 ,齿面间呈椭圆状面接触[3 ] ,克服了圆锥渐开线齿轮齿面强度低的弱点 ,同时又具备圆锥渐开线齿轮的全部优点。这种新型齿轮不仅能实现平面齿轮机构的功能[5] ,也能实现空间齿轮机构的功能[6] ,具有替代传统的非渐开线型空间齿轮机构的可能性 ,所以是一种极具发展前景的机械传动零件。目前加工凹形圆锥渐开线齿轮均采用先滚齿成圆锥渐开线齿轮然后再逐一把齿面磨齿成凹形的加工方法[7] ,这种两步加工方法 ,比传统的手工修型加工方法 ,已是极大的进步 ,可是凹形圆锥渐开线齿轮的加工依然存在成本高 ,周期长 ,精度低等问题。为此有必要确立凹形圆锥渐开线齿轮的高精度的一步加工方法。本研究首先从理论上确立了凹形圆锥渐开线齿轮的滚齿加工法 ,然后利用上述理论 ,实际加工了一组凹形圆锥渐开线齿轮 ,以证明了凹形圆锥渐开线齿轮的滚齿加工法的可行性及正确性     

用微机改装滚齿机加工变齿厚齿轮

在现代机器制造中和引进国外机械设备图纸时,常遇到变齿厚齿轮。如图1轧钢机接轴联轴器外齿套鼓形齿就是这样的齿轮。 普通滚齿过程中,只能加工出轴向齿厚不变的齿轮。为了加工出变齿厚齿轮,机床改装工作量比较大,还要按照齿厚变化规律制作靠模。微机数控技术的应用,大大简化了滚齿机改装的工作量,加工时只要根据齿轮齿厚变化规律,输入相应的程序,就可实现加工要求,使机床的加工柔性大为提高。 一、工作原理和软件硬件设计 微机数控该齿机是在原有滚齿机基础上增加单板计算机、步进电机及其驱动电源、脉冲发生器等主要硬件和控制软件所组成…     

基于Pro/E Wildfire的直齿圆锥齿轮虚拟制造

利用Pro/NC提供的数控编程功能,创建出了直齿圆锥齿轮精加工刀具轨迹,针对普通数控铣床利用普通铣刀,提出了“分块加工”的思想,改变了整体加工时的“过切”和“欠切”走刀错误现象,提高了加工精度。经过后置处理来生成直齿圆锥齿轮精加工的数控程序,并利用VERICUT软件进行加工仿真,验证了产品设计和加工的正确性。     

Minimal Realization of Linear Graph Models for Multi-physics Systems

An engineering system may consist of several different types of components,belonging to such physical"domains"as mechanical,electrical,fluid,and thermal.It is t...     

On the Relation of Load to Average Gap in the Contact Between Surfaces with Longitudinal Roughness

A computer simulation model for the contact between longitudinally-oriented rough surfaces has been formulated. This model closely duplicates the actual surf ace contact deformation behavior by taking into account the elastic interactions between the asperities. There were no assumptions made about the shapes, or any deformation behavior of the asperities, except for their obeying the laws of elasticity. The plastic deformations on the high asperity peaks were taken into account by setting a ceiling on their contact pressures at the material hardness value. The simulations used real surface profiles which were digitized from unworn circumferentially ground steel surfaces. Each pair of these profiles was mathematically combined to form an equivalent rough profile pressing against an infinitely rigid flat and having the appropriately adjusted elastic modulus. A total of 28 different pairs of profiles were used in the simulations. Each contacting pair was subjected to 30 different load levels and the local contact pressures and deformations were calculated. The contact simulations yielded some important mathematical relationships between parameters, such as the real area of contact, average gap, and average asperity load through statistical curve fitting. Two analytical functions were generated to relate the average load to average gap and the real area of contact to load.     

三绕组变压器的双绕组等效建模及在Matpower中的应用

针对实际电网存在着大量的三绕组变压器,但国际上一些著名商业软件,如BPA仿真软件、Matpower这一权威潮流计算开源软件,均只提供双绕组变压器模型,限制了其在具有三绕组变压器的电力系统中的应用的问题,潮流计算是自主开发的电力系统各种应用软件的核心模块,因此依托国际权威开源程序进行二次开发,是一种较好的选择。对Matpower要求的数据格式进行了归纳,对变压器的一般的等值电路及带理想变压器的等值电路和带标幺值的等值电路进行了分析研究,提出了三绕组变压器转换为双绕组等效模型的建模方法,使得原先只适应双绕组变压器的潮流计算软件可以适用于三绕组变压器电网的潮流计算;最后以Matpower软件为例进行了案例计算,并用PSASP仿真软件进行对比验证。研究结果证明,所提出的建模方法是有效的。     

Quantum Cooperative Robotics and Autonomy

The intersection of Quantum Technologies and Robotics Autonomy is explored in the present paper.The two areas are brought together in establishing an interdisci...     

电站锅炉模糊风险评价方法研究与应用

针对电站锅炉风险等级评价问题,将模糊综合评价技术应用到电站锅炉风险等级评价中。开展了电站锅炉失效影响因素及模糊评价因素的重要程度分析,建立了一套科学合理适于在线评价的电站锅炉风险评价体系,提出了模糊综合评价技术与改进的模糊层次分析法相结合的模糊风险评价方法,利用改进的模糊层次分析法计算了指标体系中各层指标权重。对某一台电站锅炉的实际运行工况影响子因素进行了模糊风险评价,采用模糊合成算子进行模糊综合运算得到电了站锅炉运行工况影响子因素的评价向量。研究结果表明:电站锅炉的运行工况影响子因素的风险评价等级为第6级,失效可能性等级为小,该电站锅炉运行工况良好。     

考虑进油孔有限长滑动轴承油膜力的近似解析解

针对具有进油孔的有限长滑动轴承油膜力求解问题,采用变分原理和分离变量法,求得了有限长滑动轴承油膜压力分布的近似解析表达式。将油膜压力分布的近似解析表达式在油膜存在区域上进行积分,即得到了油膜力。将提出的计算有限长滑动轴承油膜力方法与无限长轴承模型、有限元方法的计算结果进行了比较,发现了提出的方法与有限元方法的计算结果很接近。最后,研究了进油孔位置和进油压力对油膜存在区域、油膜力等的影响,研究结果表明进油孔位置和进油压力对油膜存在区域和油膜力有较大的影响。     

Fifth International Summer School on Screw-Theory Based Methods in Robotics

正3-11 September,2014University of Bologna,Bologna,Italy www.summerscrews.org summerscrews2014.ing.unibo.it SUMMER 20SCREWS 14In 2014,our screw-theory school comes to the world's oldest university.In early September,Summer Screws'14 will gather six experts in the application of screw theory in robotics and up to 40 participants at the University of Bologna,Bologna,Italy.The school will teach attendees how to apply existing methods and empower them to develop new ones in their own research.The basic theoretical notions will be introduced in a rigorous manner,emphasizing examples,applications,and exercises.Scholarships are available.     

交通荷载作用下桥梁结构参数识别方法

应用动力节点加载法,将作用在桥梁上的交通荷载转化为等效节点荷载,再用两步构造法识别结构物理参数.第1步,用Newmark-β方法变换结构运动方程,并用结构的加速度响应求得变换空间内的位移、速度和加速度响应;第2步,基于最小二乘原理,构造出变换空间内求解结构参数的递推式,进行结构物理参数识别.数值模拟结果表明,在交通荷载作用下,该方法能够快速、准确地进行桥梁结构参数识别.     

INDUSTRIAL ENGINEERING AND VISUALISATION-A PRODUCT DEVELOPMENT PERSPECTIVE

Taking the actual project of teaching and researching process for example, the relationship between the industrial engineering and product development is discussed. And use the novel visualization technology to support the industrial engineering and product development. How to use the new computer modeling and simulating technologies to support the product development and industrial engineering, is introduced especially. The support includes both domestic products and industrial systems. The visualization and computer technologies take a very important role in some system or multi-direction modeling, those technologies mentioned above can help the industrial engineers study the effect of design on the whole life circle, including the producing steps. So the engineers can avoid making the wrong decision which may cause bad effects on the whole industrial engineering.     

Non-monotonic material contrast in scanning ion and scanning electron images

30 keV Ga⁺ focused ion beam induced secondary electron (iSE) imaging was used to determine the relative contrast between several materials. The iSE signal compared from C, Si, Al, Ti, Cr, Ni, Cu, Mo, Ag, and W metal layers does not decrease with an increase in target atomic number Z₂, and shows a non-monotonic relationship between contrast and Z₂. The non-monotonic relationship is attributed to periodic fluctuations of the stopping power and sputter yield inherent to the ion–solid interactions. In addition, material contrast from electron-induced secondary electron (eSE) and backscattered electron (BSE) images using scanning electron microscopy (SEM) also shows non-monotonic contrast as a function of Z₂, following the periodic behavior of the stopping power for electron–solid interactions. A comparison of the iSE and eSE results shows similar relative contrast between the metal layers, and not complementary contrast as conventionally understood. These similarities in the contrast behavior can be attributed to similarities in the periodic and non-monotonic function defined by incident particle–solid interaction theory.