Abstract:The parallel mechanisms with analytical direct position solutions and partial motion decoupling are of great benefits to subsequent research such as error analysis, motion trajectory planning and control, dynamic performance analysis. According to the topological design theory and method of parallel mechanism (PM) based on position and orientation characteristic (POC) equations, a novel threetranslation (3T) PM was designed, which consisted of prismatic joints and revolute joints, and had the advantages of analytical direct position solutions and partial motion decoupling property and larger workspace. Firstly, the main topological characteristics such as the POC, degree of freedom and coupling degree were calculated. Due to the special constraint feature of the threetranslation, the analytical direct position solutions of the PM can be directly obtained without needing to use onedimensional search method although its coupling degree equaled to one. Furthermore, the conditions of the singular configuration of the PM, and the singularity location in the workspace were analyzed according to the inverse kinematics, as well as the velocity and acceleration of the PM were calculated and simulated. The results showed that the simulation curve was changed smoothly and continuously, and it had good dynamic performance.