Design of Nonoverconstrained Energy Efficient Multi Axis Servo Presses for Deep Drawing Applications1

Abstract

Servoactuated presses may provide maximum pressing force at any ram position in the same manner that hydraulic presses do, while offering several benefits in terms of precision, energyconversion efficiency, and simplicity, due to their lack of hydraulic circuitry and oil. Several press builders have developed servoactuated presses; however, issues relating to overconstrained multiaxis architecture have been disregarded. This study proposes an innovative method to avoid overconstrained architectures in multiaxis presses, by implementing a family of modular parallel mechanisms that connect multiple servoaxes to the press ram. Parallel mechanisms, which can be applied in several fields of robotics and industrial automation, exhibit important benefits for the application at hand, including highload capacity, stiffness, and compactness. A biaxial industrial servo press prototype with a nonoverconstrained and modular architecture was built and presented as a proof of concept. Each axis comprises a servomotor, a gearbox reducer, and a ballscrew transmission. It is shown that such a press may be constructed from commercially available components, achieving high energy efficiency and high press force with relatively simple construction. A direct comparison with an equivalent hydraulicpress model is carried out, thus highlighting the servo press energy efficiency.