A new series of small servo motors with an integrated screw was recently launched at SPS IPC Drives by Wittenstein cyber motor for use in highly dynamic positioning axes, especially when the machine has to be installed in a confined space. It is the screw drive, fully integrated in the actuator housing, that makes this series so unique: the servo motor, spindle drive, linear guide rail and encoder system form a closed, highly integrated and ready-to-mount unit. The series is offered in four sizes, each with two different screw pitches and two stroke lengths for short or long-stroke applications. When combined with the servo regulators in the Wittenstein simco drive series, these motors can be configured as complete small servo axes with multiple fieldbus interfaces for maximum connectivity to the automation environment.

The small servo motors have an integrated screw and are permanently lubricated, so that no maintenance is required; they make a perfect complement to the existing portfolio of rotary servo motors and actuators in the cyber dynamic line family. They are used, for instance, for positioning, joining, bending, gripping and dispensing in reshaping and handling applications, the semiconductor industry, packaging machinery or assembly automation. The 100% stainless steel design with IP65 protection also creates numerous interesting applications for the new, integrated linear actuator in food and beverage plants, such as in highly precise bottling lines.

With their high power density and dynamics, the new small servo motors with an integrated screw are particularly impressive in action. Each of the four sizes (outside diameter 17 mm, 22 mm, 32 mm or 40 mm) achieves excellent acceleration values, cycle rates and machine throughputs in a very small space. This is due to the compact design, which results in much lower mass inertia than is possible, for instance, if the screw is simply attached to the servo motor. The strictly industrial design was another top priority. The complete actuator is accommodated in a robust stainless steel housing with IP54 protection and can be mounted in any position. The screw itself is maintenance-free with an anti-rotation mechanism and fits inside a closed thrust tube. The spindle drive and reinforced bearings allow both a tensile and a compressive force to be applied. An absolute single-turn encoder system with 12-bit resolution is available for all sizes. If the 32 or 40 size is installed, the functionalities of what is currently the smallest integrated multiturn encoder in the market can additionally be implemented as an option. All sizes are moreover designed using EMC shielded single-cable technology which is suitable for cable carriers. Thanks to these innovative features, the actuators are perfect for industrial applications.

Unlike pneumatic cylinders, the new linear actuators permit precise and flexible position control regardless of the application without any retooling on the machine. They are thus ideal whenever frequent format changes are required. The servo technology offers better controllability by design; together with the easy connection to a higher-level controller, this facilitates reproducible processes which can be either stroke or force optimized. The actuators are leakproof and far more energy efficient in normal operation – after all, compressed air is not only expensive to produce but a significant share of it is lost. Finally, servo technology is virtually maintenance-free and also quieter – two further benefits compared to pneumatics.