新型微动工作台的设计与计算

Design and calculation of a novel 2-DOF micro-motion work stage

文章设计了一种新型压电式双自由度微位移工作台,提出了一种采用直角双杆机构代替平行四杆机构实现双自由度运动的方法;基于卡氏第二定理推导了新型工作台在不同方向上的输出刚度解析表达式,在此基础上推导出了工作台的前2阶固有频率;根据得到的输出刚度表达式,定量地分析了柔性铰链参数及连杆长度对工作台输出刚度的影响;同时针对3组不同尺寸参数的工作台,采用有限元法对其进行数值计算,并与理论计算比较,结果表明2种方法计算结果吻合很好,说明了理论模型的正确性。

A novel two-degree-of-freedom micro-displacement work stage derived by PZT is developed. And a vertical two-bar mechanism is designed to replace four-bar parallel mechanism to realize two-de- gree-of-freedom motions. The Castigliano＇s second theorem is used to derive a series of analytical equations for computing the output stiffness and resonant frequency as different directions of the stage are considered. The analytical equations are applied to quantitatively analyze the influence of the parameters of the flexure hinge and the length of the link bar on output stiffness. Three groups of different dimensions of the stage are calculated by the finite element analysis method and compared with the theoretical calculation. The results of the two methods are in good agreement, which indicates that the theoretical models are correct.