摘要
基于机构的概念,将一种正方体折纸盒折痕等效为铰链,连接折痕的纸板等效为连杆,抽象出新型3自由度并联机构。该新型并联机构由定平台、动平台和4个连接支链组成,各支链结构完全相同,且都含有1个具有特殊结构的六杆球面变胞机构闭环子链。介绍此新型并联机构结构设计,其特点是结构完全对称,只含有单自由度转动运动副。详细描述各支链中闭环子链的结构特点、一般构态及其自由度数。应用螺旋理论,分析运动支链中闭环子链的自由度特性。根据广义运动副的概念,用广义运动副替代各支链中的六杆球面变胞机构,并分析各运动支链末端约束。依据该并联机构的结构对称性,分析其动平台的自由度数和相应的自由度特性,得到动平台相对于定平台具有2个转动和1个移动自由度,并具有连续转轴。
Considering panels as links and creases as revolute joints, a cube paper fold can be taken as a novel 3-DOF parallel mechanism, based on the concept of mechanisms. The parallel mechanism consists of a base plate, a movable platform, and four connecting legs. The connecting legs have the same structure and each of them contains a closed-loop subchain, which is special six-bar spherical metamorphic mechanism. The configuration design of the new parallel mechanism is introduced. The parallel mechanism employs only revolute joints and has characteristics of symmetric structure. The mechanism characteristic, general configuration and mobility of the closed-loop subcbain are introduced. The mobility of the closed-loop subchain is analyzed by using screw theory. The six-bar spherical metamorphic mechanism is replaced by a generalized kinematic pair, and the terminal constraints of the connecting legs are investigated by applying concept of generalized kinematic pair and screw theory. Considering the symmetrical slructure of the parallel mechanism, the mobility characteristics of the movable platform are analyzed. The moving platform has three degrees of freedom, i.e. two degrees of rotational freedom and one degree of translational freedom, with respect to the base plate. The moving platform can rotate with continuously rotational axes.
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2009年第1期68-72,共5页
Journal of Mechanical Engineering
基金
国家自然科学基金资助项目(50675016)。
关键词
变胞机构
并联机构
螺旋理论
自由度
Metamorphic mechanism Parallel mechanism Screw theory Mobility
