基于SolidWorks的自动打印机圆柱凸轮间歇运动机构设计

通过对圆柱凸轮间歇运动机构参数的研究及优略性分析,并根据设计任务的效率要求,建立了1个能够使工作台旋转的圆柱凸轮间歇运动机构模型,最后利用SolidWorks软件完成了三维模型的建立和零件的装配,并根据仿真结果对机构进行了优化。该设计能够提高自动打印机的工作效率,对圆柱凸轮间歇运动机构用于不同场合的具体设计有重要的意义。     

基于CAE技术的凸轮轮廓曲线设计

针对目前国内企业在间歇运动机构凸轮轮廓曲线设计中所遇到的困难,采用共轭曲线的设计思想和运动模拟仿真的设计思路,并通过案例,介绍了凸轮轮廓曲线的设计方法.通过实体模型验证可知:用此方法得到轮廓曲线的凸轮作为主动件,其从动件的运动状态与初始设定的运动参数相吻合,这一结果给国内企业在解决间歇运动机构凸轮轮廓曲线设计时提供了一种新的思路.     

间歇分度凸轮机构的凸轮曲线图谱研究

凸轮曲线设计是决定间歇分度凸轮机构性能的核心问题.根据参数的无因次化对各种凸轮曲线进行程序开发,绘制出常用凸轮曲线的运动规律曲线.为他人或企业研究间歇分度凸轮提供了参考,避免了设计人员的重复设计,缩短了设计周期.     

几种间歇机构的连杆曲线实现

在全面了解带近似直线段连杆曲线的基础上,利用连杆曲线的形态特征设计了几种间歇机构:有的行程和回程具有相同运动规律,有的是大行程并带有急回特性的短时停歇运动机构,还有小行程、等时停歇的运动机构.其中等时停歇机构是利用连杆曲线自切鲍尔点的特殊性实现的.由于四连杆机构中与直线四点密切的连杆曲线极易求解,使连杆机构能够替代凸轮机构成为可能,从而实现满足各种运动规律要求的间歇运动.     

带有缓冲凸轮的少齿齿轮机构

带有缓冲凸轮的少齿齿轮机构南京曙光机械厂郑卫间歇运动是机械、仪表中常见的特殊运动。实现间歇运动的机构有：少齿齿轮、超越离合器和槽轮机构。为克服少齿齿轮易产生冲击的弊端．采用缓冲装置、本文介绍了一种带有缓冲凸轮的少齿齿轮机构及其设计。一、工作原理如图１...     

几种间歇机构的连杆曲线实现

在全面了解带近似直线段连杆曲线的基础上，利用连杆曲线的形态特征设计了几种间歇机构：有的行程和回程具有相同运动规律，有的是大行程并带有急回特性的短时停歇运动机构，还有小行程、等时停歇的运动机构。其中等时停歇机构是利用连杆曲线自切鲍尔点的特殊性实现的。由于四连杆机构中与直线四点密切的连杆曲线极易求解，使连杆机构能够替代凸轮机构成为可能，从而实现满足各种运动规律要求的间歇运动。     

圆柱分度凸轮机构参数化设计与仿真

圆柱分度凸轮机构作为间歇运动机构,在自动机械中得到广泛的应用.为了提高圆柱分度凸轮机构的制造品质,减少高成本及设计周期.针对传统CAD/CAM的通用软件难以准确的画出空间曲线的缺点,对圆柱分度凸轮机构的数学模型、参数化设计及仿真加工进行研究,根据从动件的运动规律和从动件的形状推导出圆柱分度凸轮轮廓的曲线方程,求出圆柱分度凸轮的相关参数.基于Pro/E,实现圆柱凸轮的参数化设计和实体建模.     

蜗杆凸轮分度机构设计中的两点商榷

蜗杆凸轮分度机构是一种凸轮式间歇运动机构,它的特点是结构简单、运动可靠、传动平稳,特别适合于高速间歇转动的场合。其设计方法是先根据工作条件选定从动盘的运动规律和运动参数,再按最大压力角的限制条件确定凸轮尺寸。 《机床设计手册》(机械工业出版社1986年版)第三册分度定位机构[3]部分给出了这种机构的全部设计公式,但有两点值得商榷. 一、滚子盘计算圆半径(平均半径)的确定 根据机构结构所容许的尺寸确定蜗杆凸轮 机构的中心距L;按最大许用压力角计算滚子 盘的计算圆半径Rg(如图1),Rg也是滚子中 心A至滚子盘轴线O2的距离;O1～O…     

槽轮间歇机构的参数化设计与运动仿真

槽轮间歇机构是传递间歇运动的常见机构,其结构参数关联多,动力学特性计算复杂。通过三维设计软件CREO 2．0建立槽轮间歇机构的主要构件模型,由模型里建立的“关系”实现机构的主要参数之间的关联。在CREO 2．0“机构”中设置部件之间的“销钉”和“凸轮”运动链接,设定“凸轮”的“允许脱离”弹性系数,实现对该机构的“非连续”运动仿真和结果数据的输出。通过对输出结果的位移、速度和加速度分析,提出减小运动加速度冲击的曲线槽轮方案。     

间歇分度凸轮机构的选型设计

介绍了间歇分度凸轮机构的分类及其基本工作原理与优缺点。针对PCB自动化检测设备,对间歇分度凸轮机构的选型设计进行阐述。选型采用经验设计法,主要考虑凸轮分割器在实际工作中转矩的大小。经设计计算所选择的凸轮分割器在实际工作中运转稳定,能实现所需的效率和精度要求,可为工程实际中间歇分度凸轮机构的选型提供指导。     

凸轮传动机构的振动分析

凸轮机构是常用的传动控制机构，这里建立了凸轮传动机构的振动模型，分析了从动件的运动规律。分析表明由于从动件具有弹性元件的特性，因而运行过程中会产生振动，从而导致其实际运动位置与给定位置发生偏差，在凸轮机构的设计和应用中必须重视这一问题。     

Dynamic modeling and simulation of electrodynamic tether system in stationkeeping phase

Dynamics is one of the fundamentally important aspects of all space tether research. This paper derives the dynamic equations of electrodynamic tether system (EDT) in stationkeeping phase using Newton’s laws. This paper further analyzes the tether system motion rules under electrodynamic drag, gravity induced force, and tether tension. Numerical simulation of electrodynamic tether system in station-keeping phase is calculated using an approach that combines the central difference method, fourth-order Runge-Kutta method, and predictor-corrector method, among others. The simulation results show that the motion of electrodynamic tether in stationkeeping phase not only contains librations caused by the motion of endmass, but also contains vertical and longitudinal vibrations of tether. If the motion of endmass is ignored, it is much similar to the vibration of cable with two immovable pinned-supports, in which the mid-span has the largest amplitude of vibration. Based on this, the main satellite and the endmass at both ends of tether can be treated as immovable pinned-supports when the tether vibration and tension of electrodynamic tether system in impermanency are investigated.     

预紧垫层结构振动环境下层间转动试验

振动环境下预紧回转体结构的层间相对转动滑移问题,一直是困扰工程设计领域的难题。为研究预紧回转体结构在振动环境下的层间转动现象,笔者设计了多层回转体预紧垫层结构,并基于Hamilton原理建立了该结构的动力学模型,分析了该类结构发生转动现象的机理。在此基础上,开展了振动环境下试验件层间转动试验,获得了确定的层间转动现象,并通过调整结构参数研究了振动量级、振动频率、预紧载荷和偏心结构等因素对层间转动的影响。试验结果验证了理论的正确性,深化了预紧回转体结构层间相对转动机理的认识可为该类结构的防转设计提供支撑。     

Mechanism of Spine Motion About Contact Time in Quadruped Running

The current research of quadruped robot focuses on the quadruped robot with spine motion. Contact time is a very important part of system performance. However, the mechanism of spine motion about contact time has not been clearly elucidated. In this paper, the e ect of spine motion on contact time is studied deeply from dynamic view.Firstly, a simplified model of the quadruped robot with spine joint is set up, its dynamic equations are derivated, and a method that can generate passive periodic locomotion is proposed. Secondly, according to the vertical spring oscillator model, the two-dimension planar locomotion of the simplified model is regarded as a special vibration in the vertical direction, and the approximate formula of calculating contact time is obtained. Finally, the approximate formula of calculating contact time is verified by the simulation results of passive periodic locomotion, and the e ect of spine motion on contact time is deeply discussed based on the approximate formula of calculating contact time. The discussion proves that spine motion indeed has little e ect on contact time, but spine motion can slightly reduce body pith movement and regulate the leg sti ness in leg contact phase. This research proposes an e ective research method which can be used to study the motion mechanism of the quadruped robot with spine motion,and the mechanism of spine motion about contact time is clearly elucidated which is helpful to set the parameters of mechanical structure and study control algorithm about the quadruped robot with spine motion.     

On the improvement design of dynamic characteristics for the roller follower of a variable-speed plate cam mechanism

Without modifying the cam contour, a cam mechanism with a variable input speed trajectory offers an alternative solution to flexibly achieve kinematic and dynamic characteristics, and then decrease the follower’s residual vibration. Firstly, the speed trajectory of cam is derived by employing Bezier curve, and motion continuity conditions are investigated. Then the motion characteristics between the plate cam and its roller follower are derived. To analyze the residual vibration, a single degree of freedom dynamic model of the elastic cam-follower system is introduced. Based on the motion equation derived from the dynamic model, the residual vibration of the follower is yielded. The design procedure to improve the kinematic and dynamic motion characteristics is presented and two design examples with discussions are provided. Finally, the simulations of the kinematic and dynamic models by ADAMS are carried out and verified that the design models as well as the performances of the mechanism are feasible.     

3-SPR并联机构的隔振性能分析验证

对航天器或者雷达天线进行隔振是减少其受到振动载荷的有效方法.采用一种基于3-SPR并联机构的稳定平台进行主动隔振.建立上平台坐标系、下平台坐标系、全局坐标系,分析推导3个坐标系的姿态变换矩阵,将3-SPR并联机构作为稳定平台进行运动学和静力学特性分析,建立包含下平台和上平台同时运动的运动学公式及其静力平衡方程和静力传递...     

Fast drive of displacement magnification mechanism with flexure hinge using loading type impact damper

A displacement magnification mechanism which uses flexure motion guide using elastic hinges can realize smooth frictionless motion but has poor vibration damping capability. An impact damper is a damping mechanism which uses collision energy to dissipate vibration energy. If the damper is used for vibration control of the flexure mechanism, it may be able to dissipate unexpected vibration without killing the merits of the flexure mechanism. In the paper, a loading type impact damper is applied to settle down transient vibration of a displacement magnification mechanism. We investigate differences of damping effect by setting conditions of the damper. It is shown that the impact damper can eliminate residual vibration at step response effectively without steady state error. The experimental displacement magnification mechanism with impact damper can settle down less than 1/5 of the response without the damper under appropriate setting conditions. Influence of natural frequency ratio between damper and displacement magnification mechanism is investigated. Influences of indentation at impact point are also examined.     

复杂接触运动下非线性摩擦力的求解

提出了复杂接触运动下求解接触非线性摩擦力的数值轨迹跟踪方法,利用该方法对几种复杂接触运动下的非线性摩擦力进行了计算。计算结果表明:数值方法在分析二维接触椭圆运动时可以得到更准确的结果;计算接触面摩擦力时不能忽略法向运动与切向运动之间的相位差,该相位差对接触状态的转变、摩擦力的大小以及迟滞回线的形状都有很大的影响;对于接触面的三维运动,必须同时考虑法向运动与接触面内两个方向切向运动之间的耦合;数值轨迹跟踪方法可以方便地求解一维、二维以及三维接触运动下的非线性摩擦力,为求解带干摩擦阻尼结构的动态响应提供了一种实用算法。     

基于并联机构的三平移隔振平台设计研究

为了解决交通运输和航天领域中的三平移隔振问题，设计了一种基于并联机构的新型三平移隔振平台，介绍了其结构及有关参数的设计和分析方法，制作了样机并进行了试验分析。理论和试验分析结果表明，该平台能实现三平移隔振，其设计和分析方法可应用于其他多维隔振平台的设计。     

An integrated design of quasi-zero stiffness mechanism

Nonlinear Quasi-zero stiffness (QZS) mechanisms were studied to overcome the weakness of linear isolators. This paper presents an integrated design of the QZS mechanism. First, various types of QZS vibration mechanisms are analyzed and a generalized model for QZS mechanisms is derived. The generalized model consists of two main parts: link and horizontal spring. The motion equation of the QZS mechanism is a Duffing equation with nonlinear stiffness. Based on the generalized model, the design problem of the QZS mechanism is converted into the kinematic design of a link element. For simplicity, the link is generalized with a cam-roller mechanism. The integrated design approach shows that the QZS mechanism can have desired QZS characteristics with properly designed cam geometry.