Optimal Control of Servo Motors for High-speed Presses

In press applications, accuracy is indispensable. A precise control is also essential to ensure repeatability of the processes and their documentation. The drive controller SD2 by SIEB & MEYER does this particularly well: it enables a flexible process design and fulfills the highest requirements regarding precision and dynamics. In addition, SD2 provides application-specific interfaces and functions that make the development of an individual overall system easier

For more than three decades now, a well-known provider of servo stroke presses has been using servo drives by the Lueneburg based specialists for control and drive technology. These servo spindle presses are equipped with highly efficient AC servo motors, a powerful control, AC servo feeds, a sprocket wheel system and the SIEB & MEYER drive controller SD2. The ram movement of the presses is created by a combination of servo direct drive and roller screw drive. With the special design of the drive unit, the press force is available throughout the whole stroke path.

Precise control for optimal results

The drive controller SD2 by SIEB & MEYER is an essential part of these machines. SD2 ensures highly precise control by means of a bus converter from EtherCAT to SERVOLINK 4 that was developed jointly by SIEB & MEYER and the press manufacturer. In this case, every servo spindle press has up to four servo axes that are synchronously controlled, which allows a machine design with a press force of up to 1250 kN

"Each axis has its own servo drive," explained Ralph Sawallisch, key account manager drive technology at SIEB & MEYER. "The SD2 series is designed as multi axis system. When several axes are in motion, the central power supply module PS2 supplies all connected SD2 drives . Compared to devices with individual power supply units, this saves a considerable amount of energy. At present, we provide numerous device variants in the power range between 7 and 138 kVA.

Only the water-cooled versions of SD2 are used for this particular application because the devices can be exposed to ambient temperatures of > 40 °C in summer. The drive controller must be robust all over to ensure 24/7 operation under harsh industrial conditions – requirements that SD2 fulfills perfectly.