【作者】 宋东；

【导师】 聂松辉；

【作者基本信息】 湘潭大学 ， 机械制造及其自动化， 2007， 硕士

【摘要】 Zero-Max型脉动无级变速器是一种四相并列连杆式无级变速传动装置,它具有传动可靠、变速范围大、静止或运动均可调速、结构紧凑、重量较轻等优点,广泛地应用于各类传动系统中。由于其结构特点,输出速度存在波动,会产生冲击载荷,影响机械的传动性能。本文对Zero-Max型脉动无级变速器进行了深入研究,通过MATLAB的仿真、优化工具箱对其进行运动学、动力学分析、尺寸参数优化,使其传动性能达到更优。首先,在对Zero-Max型脉动无级变速器的结构特点和工作原理分析基础上,推导出了其传动机构各构件角速度、角加速度矩阵方程,并建立了机构的运动学数学模型。运用MATLAB的SIMULINK仿真工具箱建立了该运动系统的运动学仿真模型,经仿真运算得到传动机构的运动特性。对其运动规律分析表明,该传动机构为具有急回特性的非对称机构,其脉动率、角加速度突变量与输出角速度成反比。其次,运用动态静力学分析方法推导了该机构各构件所受力、力矩的矩阵方程,并建立机构的动力学数学模型,运用MATLAB的SIMULINK仿真工具箱建立该机构动力系统的动力学仿真模型,经仿真运算得到该机构动力特性。对其动力特性进行分析显示,各铰链处所受约束反力波动值较大,尤其在输出端各铰链所受约束反力明显高于输入端的铰链。最后,运用MATLAB的优化工具箱,在确定设计变量、约束条件、目标函数的基础上,选择约束非线性最小化函数fmincon对该机构尺寸参数进行优化,使机构输出摆杆的角速度脉动率、波谷处角加速度突变量均大大降低。因此,优化后的机构有利于变速器的平稳运转,减少了对各轴承的冲击,使传动效率得以提高。更多还原

【Abstract】 Zero-Max type pulse CVT is a quadrinomial side-by-side connecting rod type infinitely variable speed transmission. It has been widely applied to all kinds of transmission system, because it has many advantages, such as reliable transmission, broad adjustable-speed rang, timing at rest or movement, compact structure and lighter weight, and so on. Due to its particular structure, output speed pulsation coefficient and impact load affect mechanical transmission property. In this dissertation, Zero-Max type pulse CVT has been lucubrated. Analysis of kinematics and dynamics of mechanism and parameter optimization have been done for better transmission property.Firstly, on the basis of analysis of structure characteristic and working principle of Zero-Max type pulse CVT, deduce angular velocity and angular acceleration matrix equation of every component of transmission structure and build mechanical kinematic mathematical model. Kinematic simulation model of locomotor system has been built through SIMULINK toolbox of MATLAB. Obtain kinetic characteristic of this drive mechanism after simulation operation. Analysis of kinetic law indicates that this drive mechanism is a quick return asymmetrical mechanism and has a inverse proportion relation between pulsation coefficient, abrupt change of angular acceleration and output angular velocity.Secondly, deduce force and torque matrix equation of every component by kinetostatics analysis method and build mechanical dynamic mathematical model. Built dynamic simulation model of power system through SIMULINK toolbox of MATLAB. Dynamic characteristic of this drive mechanism has been obtained after simulation operation. Analysis of dynamic characteristics indicates that wave value of every joint constraint reaction is relative bigger. Constraint reaction of output end is obviously bigger than it of input end.Finally, based on confirming design variable, constraint condition and optimization function, use fmincon function of optimization toolbox of MATLAB to optimize dimensional parameter of this mechanism. Therefore the mechanism can run more stably after optimization,with less impact to bearings and higher machine efficiency.更多还原