Parallel Mechanism Having Two Rotational and One Translational Degrees of Freedom

摘要

A two rotational and one translational parallel mechanism which comprises a holding bracket; a movable platform; and three branch joint assemblies of the same structure spatially and axis-symmetrically disposed between the holding bracket and the movable platform. Each branch joint assembly comprises a connecting rod, a linear guide, a driving device and a carriage. The linear guide and the driving device both are secured on the connecting rod. One end of the connecting rod is connected with the movable platform through a hinge having three rotational degrees of freedom. The carriage and the linear guide are connected with each other by a sliding joint, and the carriage is connected with the holding bracket by a hinge having one rotational degree of freedom. As in the mechanism of the invention, the linear guide and the connecting rod are integrally formed together, the size of the holding bracket along the linear guide can be effectively reduced, thereby achieving the same degrees of freedom and ensuring the same stiffness, as well as reducing entire mass of the module.