基于螺旋理论的新型6杆并联机构的自由度分析

摘要

基于螺旋理论对一种新型6杆空间并联机构进行了自由度分析。该机构由虎克铰构成，力图改善以转动副为主的2自由度平动机构在垂直于运动平面方向上的刚度较差的问题。基于螺旋理论中运动螺旋与力螺旋的对偶关系，通过运动链等效，完成了该机构的自由度计算与分析。结果表明：该机构可实现2自由度平动。该方法避免了采用Kutzbach—Grubler公式进行计算时必须的公共约束、冗余约束、局部自由度，不仅易于掌握，且适用于其它并联机构自由度的分析。%The degree of screws. This mechanism freedom of a novel six-link spatial consists of universal joints, and is perpendicular to the motion plane. Based on the reciprocal parallel mechanism was analyzed based on the theory of designed for improving the stiffness along the direction relationship between motion screw and force screw and using equivalent transformation, the degree of freedom of this mechanism was calculated. The result shows that it can accomplish 2-DOF translational motion. This method avoids the determination of common constraints, redun- dant constraints and passive degree of freedom in using the Kutzbach-Grubler formula. This method is not only easy to use, but also applicable to other parallel mechanisms.