Precise Control of Servo Motors for Servo Stroke Presses

The company Nidec SYS GmbH specializes in the automation and optimization of punching and forming processes and offers customers system solutions from a single source – from planning to implementation. Since its foundation, the company with headquarters in Grafenau (Germany) has cooperated with SIEB & MEYER, the specialist for control and drive technology based in Lueneburg (Germany).

The cooperation covers several business areas. The most important business fields are Nidec SYS / Kyori high-speed presses on the one hand and the general overhaul of older automatic punching presses in various tonnage sizes on the other hand. Nidec SYS has equipped all these products with servo amplifiers by SIEB & MEYER.

Kyori high-speed presses with Nidec SYS press control

The complete production system is based on presses by the Japanese manufacturer Kyori, a sister company of Nidec SYS. The experts at Nidec SYS adapt these high-speed presses to the European standard. For this purpose, the presses are equipped with high-efficiency AC servo motors, the powerful press control PCS100, AC servo feeds, a sprocket wheel system and the drive system SD2 by SIEB & MEYER.

Nidec SYS servo stroke presses (SHP)

"On account of the good market demand, we have significantly extended our product range of powerful spindle presses," explained Werner Borth, managing director for technology & sales at Nidec SYS GmbH. "The SHP is used for cutting, bending and pulling processes. Thanks to the temperature compensation and the integrated displacement measuring systems, we can guarantee our customers a very high BDC accuracy." The ram movement of the servo spindle press 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 system SD2 is an essential part of this machine, since the controlled AC servo drive moves the ram and creates the press force. "For the highly precise control of the servo motor, we use the SD2 by SIEB & MEYER," said Werner Borth. "The SD2 is connected via a jointly developed bus converter from EtherCAT to SERVOLINK 4." Every press has up to four servo axes that can be synchronously controlled. This machine design allows a press force of up to 1250 kN. "Each axis has its own servo amplifier," 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 drive amplifiers. Compared to devices with individual power supply units, this saves a considerable amount of energy." Nidec SYS has the full range of SD2 serial devices in use: SIEB & MEYER supplies numerous device variants in the power range between 7 and 138 kVA.

A problem solver for Nidec SYS

In press applications, precision is indispensable. A precise control is also essential to ensure repeatability of the processes and their documentation. The drive system SD2 can do 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

Nidec SYS uses only the water-cooled versions of SD2 because the devices can be exposed to ambient temperatures of > 40° C in summer. The drive system must be robust all over to ensure 24/7 operation under harsh industrial conditions. SD2 meets these requirements easily. "The price-performance ratio of the drive system is very good," stated Werner Borth. "And we are very satisfied with the service as well. Even for older devices, we receive optimal support. The direct line to the development is also a big plus for us." In conclusion, the cooperation is at eye level and grows with increasing requirements – clearly an added value for both partners.

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Punch packaging with modern presses and production systems

Nidec SYS also relies on the drive system SD2 by SIEB & MEYER in machines for punch packaging (production of electric motors). These special production systems are mainly used in the automotive industry for producing electric motors (skewed rotors and stators). They make the so-called punch packaging possible, which combines the processes punching, forming and mechanical joining in one production process: the machine punches individual plates from a strip material, forms their connecting elements (knobs) and puts the parts together into a rotor or stator.