A new design method for single DOF mechanical presses with variable speeds and length-adjustable driving links

This paper proposes a new design method for obtaining or improving the desired output motion characteristics of single-degree-of-freedom mechanical presses by appropriate design of the speed trajectory and length of the adjustable driving links. This approach adds a ternary link to the original mechanism. The ternary link is adjacent to the driving link, roller link, and connecting link, making use of a sliding pair, revolute pair, and a second revolute pair, respectively. The roller link is adjacent to the ternary link and fixed link by a revolute pair and a rolling pair. It is guided by a specially designed slot in the fixed link while the driving link is driven by a servomotor with a specific speed trajectory. A Bezier curve is used to design the input speed trajectory and the contour of the slot. Examples are given to demonstrate the feasibility of this work. (C) 2009 Elsevier Ltd. All rights reserved.