齿轮传动浅说

齿轮标准是机械互换性基础标准。因为齿轮传动具有运动平稳、传动精确、传动比大、传动效率高等特点,所以是机械产品中应用最广泛的一种传动形式。现结合有关资料,谈几点粗浅体会。1 渐开线齿廓 渐开线齿廓是以渐开线作为齿廓曲线。渐开线则是由直线在圆上作纯滚动 所产生的。所以,该直线始终与基圆相切,其切点是每一瞬时的传动中心,其基圆上的弧长与直线在基圆上滚过线段相等。渐开线的齿廓是取决于基圆大小的,只要基圆大小不变,其传动比亦不变,这给齿轮传动副的安装、制造带来很大的方便。2 传动的基本条件渐开线齿廓保证了啮…     

齿轮法向啮合齿廓及其测量

法向啮合齿廓是齿轮齿面上能反映齿轮的加工与传动质量的一条工程意义独特的曲线,在齿轮滚齿、蜗杆砂轮磨齿等展成法加工中,是齿面加工的形成曲线,在渐开螺旋齿轮传动中,是齿轮传动的工作曲线。然而,现有的齿轮测量仪器并没有法向啮合齿廓的测量功能。结合法向啮合齿廓的形成原理,给出了其理论模型,基于现有齿轮测量中心,提出了法向啮合齿廓偏差测量的四坐标测量法和三坐标测量法。测量实践表明,采用现有的齿轮测量仪器,能方便的实现法向啮合齿廓偏差测量与评定,四坐标法测得的法向啮合齿廓形状偏差、倾斜偏差和总偏差与三坐标法的测量结果相比分别相差0.2、1.3、0.6μm。与渐开线和螺旋线相比较,法向啮合齿廓具有综合性、统一性和唯一性,通过对渐开线偏差和螺旋线偏差的相互补偿,可优化对法向啮合齿廓的控制,有效降低对渐开线和螺旋线的精度要求。     

构建精确的三维渐开线直齿圆柱齿轮的方法

基于CAXA制造工程师软件平台,根据渐开线的参数方程及渐开线直齿圆柱齿轮的形成原理,通过建立精确的渐开线齿轮的齿廓,实现渐开线直齿圆柱齿轮的三维精确造型。该方法为渐开线直齿圆柱齿轮的设计、分析及加工制造提供了依据。     

渐开线齿轮机构齿廓磨损的研究

传统的渐开线齿轮传动理论认为 :齿轮机构运行时轮齿沿齿面均匀磨损 ,磨损后的齿廓仍可保持原渐开线形状。本文通过分析影响齿轮齿廓磨损的各个因素的变化规律 ,对高速及中低速渐开线齿轮机构磨损后轮齿齿廓的变化规律进行了研究。结果表明 :高速及中低速渐开线齿轮机构经长期运行后 ,其磨损的轮齿齿廓不再保持原有渐开线形状 ,因此会加剧齿轮机构的振动和噪音。     

谐波齿轮传动柔轮和刚轮渐开线齿廓间隙的数学模型研究

分析了谐波齿轮传动柔轮和刚轮渐开线齿廓的性质和方程,通过建立柔轮和刚轮渐开线齿廓间隙的数学模型,得出了柔轮和刚轮齿廓的间隙方程,为进一步研究无侧隙谐波齿轮传动及其变位系数提供了依据.     

点接触渐开线少齿差行星传动齿面构建

根据齿轮啮合原理运动学法,提出在渐开线少齿差行星传动共轭啮合副行星轮外齿轮齿面选定上选定一条光滑曲线Γ,以该曲线的等距曲线作为球心运动轨迹形成管状球族包络面。提出用管状球族包络面代替行星轮外齿轮渐开线齿面,得到新的啮合副,并给出啮合副的统一方程式;详细讨论了由管状包络面形成行星轮新齿廓的方法,该新齿廓称为啮合管齿廓。给出了与曲线Γ相共轭的接触线统一方程,讨论了点接触渐开线少齿差行星传动的啮合特性;啮合管与渐开线内齿轮构成点接触啮合副,点接触啮合副具有滑动率低,传动效率高等特点。     

切制齿条啮合的渐开线销齿轮圆头梳齿刀设计

采用投影关系探讨切削工况下正前角圆头梳齿刀的设计原理和方法,证明该刀具符合共轭原理,能正确切制出渐开线齿廓的销齿轮。该新齿廓由刀具齿顶刃圆弧r圆心运动轨迹形成的延伸渐开线的等距线和渐开线(两段自然形成的平滑曲线)组成,其传动性和工艺性优于现有技术的两圆弧一渐开线齿廓,尤其是切制的销齿轮能显著改善和提高低速重载的传动性能。用投影法求解梳齿刀各截面齿形最为便捷,为切制渐开线齿廓销齿轮开创了新的工艺方法。     

渐开弧面齿轮的形成原理及数学模型

结合传统渐开线齿轮与圆弧齿轮优点,提出一种新型的渐开弧面齿轮传动。定义了渐开弧面齿轮的概念,即分别在主从动齿轮的渐开线齿廓上选取两条相对应啮合的单值曲线,在两条曲线上的任意点分别用凸凹圆弧替代渐开线齿廓形成新的齿廓。根据微分几何基本原理,运用坐标变换法推导渐开弧面齿轮传动的齿面方程。讨论渐开弧面齿轮的中心距可分性,分析表明即使中心距发生改变,只要一对齿轮齿廓能够啮合传动,就仍能保持良好的传动性能。根据实例的具体参数,建立一对渐开弧面齿轮啮合的三维实体模型。研究结果为进一步开展渐开弧面齿轮传动研究提供了理论基础,对后续齿轮的设计、加工等有很大的参考价值。     

四齿差谐波齿轮传动采用渐开线齿廓的合理性证明

由于齿差系数的不同,四齿差谐波齿轮传动能否采用渐开线齿廓,不能利用以前的结论。本文研究了当柔轮采用渐开线齿廓时,与之共扼的刚轮采用渐开线对其理论齿廓进行拟合所造成的齿形误差的变化规律。通过与普通小模数渐开线圆柱齿轮传动的齿形公差进行比较,表明只要合理选择变位系数,刚轮就可以采用渐开线齿廓,这为在实际工程中研制四齿差谐波齿轮传动装置打下了理论基础。     

滚珠减速器的传动设计原理

本文介绍了在以标准滚珠作为活齿的活齿传动机构中,采用直线近似齿廓代替理论齿廓的传动设计原理,论述了实际齿廓即直线近似齿廓对理论齿廓的拟合程度及采用实际齿廓后传动的平稳性。采用标准滚珠及实际齿廓的滚珠减速器的最大特点是仅用通用设备即可加工生产,加工工艺极为简便,制造成本较低,可广泛用于机械传动。     

Design of intermediate die shape of multistage profile drawing for linear motion guide

The design of an intermediate die shape is very important in multistage profile drawing. In this study, two design methods for the intermediate die shape of a multistage profile drawing for producing a linear motion guide (LM) guide is proposed. One is the electric field analysis method using the equipotential lines generated by electric field analysis, and the other is the virtual die method using a virtual drawing die constructed from the initial material and the final product shape. In order to design the intermediate die shapes of a multistage profile drawing for producing LM guide, the proposed design methods are applied, and then FE analysis and profile drawing experiment are performed. As a result, based on the measurement of dimensional accuracy, it can be known that the intermediate die shape can be designed effectively.     

AutoCAD中齿轮渐开线齿廓绘制的探讨

虽然绘制渐开线齿廓的方法很多,但AutoCAD中还没有一种现成的绘制渐开线齿廓的方法,给绘制齿轮零件图带来了不便。本文利用渐开线的原理及AutoCAD的基本绘图命令,探索了一种绘制齿轮渐开线齿廓的方法,解决了齿轮零件图绘制中的困难。     

Drawing motion profile planning and optimizing for heavy servo press

An efficient drawing mode for heavy servo press was proposed with four sections which are defined on the whole slide motion stroke. Four key control points, which represent the requirements of drawing process, were employed to realize the eccentric drawing motion profile planning. To reduce the power requirement of the servo motor, a flexible acceleration and deceleration control algorithm was proposed, and the eccentric motion profile of the servo press was constructed based on the algorithm. Then, the optimization model of the drawing eccentric motion profile was established to maximize the production rate, taking into account all boundary conditions including the maximum velocity and acceleration of slide, the space and time limit of feeder, the torque and thermal limit of servo motor. This optimization model was solved by the combination of the penalty function and the complex method, which need the least time. The program of the drawing motion profile optimization was developed and applied on a 2,500 t servo press. Finally, the experimental validation of the body side panel drawing was carried out. The results show that the proposed efficient drawing mode and the optimization method could obtain the optimal motion profile and the maximum production rate. This research provides the theoretical foundation and optimization method for the drawing motion profile optimization design for heavy servo press.     

The design of blank’s initial shape in the near net-shape deep drawing of square cup

Deep drawing process is very useful in industrial field because of its efficiency. The deep drawing is affected by many process variables, such as blank shapes, profile radii of punch and die, formability of materials and so on. Especially, in order to obtain the optimal products in deep drawing process, blank shape is very important formability factor. In this paper, the finite element method is used to investigate the cup height of the square cup drawing process. In order to verify the prediction of FEM simulation of the product’s height and forming load in the square cup drawing process, the experimental data are compared with the results of the current simulation. A finite element analysis is also utilized to acquire the designed profile of the drawn products, a reverse forming method for obtaining the initial blank’s shape according to the forward square cup drawing simulation is proposed. The design of initial blank’s shape is also certified to obtain the designed profile of drawn cups by experiment. The influences of the blank’s shape on the height of product, the forming load, the maximum effective stress and the maximum effective strain are also examined.     

球锥相贯线最右点的计算机辅助求解与解析证明

球体和锥体相贯线上的点,通常可用辅助平面法或辅助球面法求解.利用圆锥内切辅助球面法得到最右点投影的作图方法,并通过pro/ENGINEER软件和空间解析法验证该作图方法的正确性.     

VC++和Matlab混合编程实现索道工程图的参数化绘制

根据“悬索曲线”理论，从数学意义上分析要绘制的工程索道线路纵断面图实质上是用若干段直线及曲线去拟合高低起伏的纵断面地面线，这在Matlab中很好实现；索道其它工程图在Matlab里绘制也比用AutoCAD方便。以Visual C＋＋和Matlab为新的开发工具混合编程，实现了Windows下可视化的单索循环式索道工程图的参数化绘制。     

轮廓度公差控制车身装配间隙的图样标注研究

针对如何使用轮廓度公差控制汽车装配间隙及其均匀性时的图样标注问题,首先以汽车前后车门装配为例分别研究了复合轮廓度和附加"OZ"符号的组合轮廓度在控制装配间隙时的图样标注和应用特点.其次,以面板和按钮装配为例研究了复合轮廓度和附加"OZ"的组合轮廓度在控制半封闭轮廓装配间隙及其均匀性方面的差异,指出对于封闭/半封闭或曲率...     

直齿锥齿轮粗铣刀齿形的设计计算方法

介绍了一种计算与作图相结合的直齿锥齿轮粗铣刀齿形设计方法,推导了精确计算公式,详述了计算步骤和计算机作图方法,并给出了设计实例。     

高精度成形车刀的自动设计

提出了高精度成形车用刃形设计的数学模型,阐述了自动设计和参数化绘图方法。此方法大大减小了工件加工时的双曲线误差,实现了各种成形车刀的自动绘图,提高了设计速度和绘图质量。     

一种新型拉深凹模型腔曲面的理论探索及试验研究

利用塑性理论和数学方法得出一种新的拉深凹模型腔曲面。通过拉深工艺试验证明该曲面凹模可以达到很小的极限拉深系数。