一种大转角柔性铰链的设计与分析

Design of a Flexible Hinge with Large Rotation Angle and Its Analysis

针对单自由度转动柔性铰链设计方法不完善和转角不足的问题,基于自由度约束拓扑(FACT)理论,提出了杆、板约束下柔性铰链的设计思路,并以此为基础设计了一种大转角柔性铰链。基于约束空间、交点和交距的概念,依据约束所在位置的不同,对杆约束条件下的单自由度转动柔性铰链进行了分类,并提出了杆约束的添加思路,此思路可应用于杆约束条件下柔性铰链的设计;基于板约束和杆约束的相互关系,考虑板约束位置和变形形式对柔性铰链的不同影响,对板约束条件下的单自由度转动柔性铰链进行了分类,给出了板约束的添加思路,并且应用于弯曲相交柔性铰链和扭转不相交柔性铰链的设计。通过对这2种铰链的串联组合,得到了一种大转角单自由度转动柔性铰链。有限元仿真分析结果表明,当安全系数为12时,该柔性铰链的转角可达到±20°,径向平移刚度为43.20N/m。该柔性铰链具有较大的转角和平移刚度,经过对比分析,可知其转角优于现有柔性铰链。

A design idea of flexible hinge under the constraints of bar and plate is proposed to solve the problem that the design method of flexible hinge with single rotation degree of freedom is imperfect and its rotation angle is small,based on the theory of freedom and constraint topologies（FACT）.Flexible hinges with large rotational angles are designed according to the proposed design idea.Single rotation degree of freedom flexible hinges under bar constraints are classified based on the concepts of constraint space,intersection point and intersection pitch.The idea of adding bar constraint according to the position of the constraint is applied to the design of flexible hinges under bar constraint.Flexible hinges with single rotation degree of freedom under the plate constraint are classified based on the relationship between plate and bar constraints,and the idea of adding plate constraint is given by considering different effects of the position and the deformation of the plate on flexible hinges.This idea is applied to the design of a bendintersection flexible hinge and a torsion non-intersection flexible hinge.A kind of flexible hinges with single rotation degree of freedom and a large action angle is put forward through a series combination of these two kinds of hinges mentioned above.Finite element simulation and analysis are performed on the rotational angle and the rotational accuracy.It is shown that when the coefficient of safety is 12,the rotational degree of the flexible hinge achieves±20°and the radial translational stiffness is 43.20 N/m,i.e.,the flexible hinge has a large rotational angle and high translational stiffness.A comparison with the existing flexible hinge shows that the rotational angle of the resulting hinge is larger than that of the existing flexible hinge.