Abstract RCM (remote center of motion) rotational compliant mechanisms are of great use in precision machines, especially when a pure rotation about a virtual center is required. The accuracy of the mechanisms is an essential consideration for mechanical design in applications. In this paper, a family of RCM rotational compliant mechanisms is designed to compensate parasitic motion of the trapezoidal four-bar mechanism by taking advantage of center shift of generalized cross-spring pivot. Firstly, parasitic motion of the trapezoidal four-bar mechanism is modeled based on kinematics analysis. Then, the compensation principle for the parasitic motion is proposed on the basis of compensation motion analysis. In addition, nine topological structures of the RCM rotational compliant mechanisms are presented by adopting generalized cross-spring pivot as a building block, and compensation model for geometric parameters of these flexural pivots are obtained. Furthermore, the validation and effectiveness of the proposed method are verified by finite element analysis (FEA). The results show that the RCM rotational compliant mechanism proposed in this paper is capable of offering an ultra-high-precision rotation and providing a promising application prospect in precision engineering.

中文翻译：

---

一系列基于寄生运动补偿的新型 RCM 旋转柔顺机构

摘要 RCM（远程运动中心）旋转柔顺机构在精密机械中非常有用，特别是当需要绕虚拟中心进行纯旋转时。机构的精度是应用中机械设计的一个重要考虑因素。在本文中，设计了一系列 RCM 旋转柔顺机构，利用广义交叉弹簧枢轴的中心偏移来补偿梯形四杆机构的寄生运动。首先，基于运动学分析对梯形四杆机构的寄生运动进行建模。然后，在补偿运动分析的基础上，提出了寄生运动的补偿原理。此外，以广义交叉弹簧支点为积木，提出了RCM旋转柔顺机构的9种拓扑结构，并得到了这些挠性支点几何参数的补偿模型。此外，通过有限元分析（FEA）验证了所提出方法的有效性和有效性。结果表明，本文提出的RCM旋转柔顺机构能够提供超高精度旋转，在精密工程中具有广阔的应用前景。