Servomotor with built-in screw drive is ‘unique’
The German miniature servomotor specialist Wittenstein cyber motor has come up with a “unique” servomotor design which has a screw drive built into its housing. The motor, spindle drive, linear guide and encoder system form a ready-to-mount integrated linear actuator system suitable for use as a dynamic positioning axis, especially where space is limited. When combined with servo controls, the motors can form servo axes with multiple fieldbus interfaces.
The permanently-lubricated, maintenance-free actuators offer a high power density and a much lower mass inertia than is possible if a screw is simply attached to a servomotor. The spindle drive and reinforced bearings allow tensile or compressive forces to be applied.
Wittenstein says that, compared to pneumatic cylinders, its new actuators allow precise, flexible position control, without needing to retool machinery. They are also energy-efficient and leak-proof, as well as being quieter than pneumatics. The actuators are suitable for applications requiring frequent format changes, and can be optimised for either stroke or force.
The stainless-steel, IP54-protected motors come in four sizes (with outer diameters from 17–40mm), each with a choice of two different screw pitches and two stroke lengths. A 32-bit absolute single-turn encoder is available for all versions, with an optional compact multi-turn encoder for the two largest motors.
When used with Wittenstein’s simco servodrives, the actuators can act as small, high-performance servo axes, with rapid commissioning resulting from the use of electronic identification plates. End-positions are limited automatically, preventing mechanical stops from being approached dynamically. The servodrives can be integrated with higher-level controls via CanOpen, EtherCat, Profinet RT/IRT or Ethernet/IP.