Entirety transformation mechanism and topological-type synthesis for heavy-duty gripping devices

Force closure and stability problems exist in heavy gripping devices. Based on a typical gripping device for forging operations, the workpiece and the gripping device are innovatively considered as a single mechanism in this paper, and its global topological configuration is obtained. The changing element method is used to establish the optimized topology geometry of the gripping device by decreasing the degrees of freedom of the gripping mechanism and improving the force closure performance. Therefore, a new idea for the innovative design of heavy-duty forging gripping devices is provided. As the effect of revolute joint friction on loading capacity of the gripping device cannot be ignored, a unified mechanical equation including friction in terms of the topological adjacency matrix is established to analyze the force closure performance and calculate the loading capacity. The conclusions are provided by experiments.