The Servotube from Copley Controls is claimed to be the first three-phase linear motor designed specifically for use as an actuator.
Combining the speed and rugged operation of pneumatics, the controllability of a ballscrew and the inherent reliability of direct drive linear motors, the Servotube is a low-cost, powerful industrial pusher/puller.
It is suited to stacking, cutting, pressing, coating, filling, and pick-and-place applications, particularly in the food and packaging industries. The simple two-part design makes the Servotube very reliable, with a service life up to ten times that of a ball screw. Using linear motor technology, the Servotube is also approximately ten times as fast (5.9m/s) as a typical ballscrew and much quieter too. When used with a matching Copley Controls digital amplifier such as the Xenus, Servotube actuators form a complete plug-and-play positioning subsystem.
Traditional pneumatic actuators can become very complicated to program, requiring elaborate control valves and a complex electro-pneumatic control system to choreograph the positioning function.
In comparison, Copley's intuitive indexing software is used to tune and program a drive system quickly and easily. A PLC can be used to initiate the Xenus' stored motion profiles, simplifying the integration of the Servotube into existing positioning systems.
Alternatively, used in a distributed control system, the Servotube will execute Canopen positioning profiles received by a Xenus drive via a two-wire Canbus.
Conventional U-channel and flatbed linear motor designs with dirt-collecting channels and grooves require regular maintenance to avoid wear and obstruction to the external encoder which would cause positioning errors. However, Copley Controls uses a tubular construction that is inherently compatible with actuator operation. Magnetic drive coils are contained within the metal-enclosed forcer, while the motor's permanent magnets are hermetically sealed in the cylindrical thrust rod. Interaction between the forcer's travelling magnetic field and the thruster's fixed magnet field sets up a magnetic force that drives the thruster.
The Servotube's integral bearing wipes the thrust rod clean with each stroke, prolonging operational life. Hall position sensors embedded within the forcer provide a clear operational advantage compared with external encoders, eliminating the possibility of degradation from tarnishing or soiling, or damage by physical contact a real consideration in factory floor environments.
Servotube continuous force ranges from 51 to 104 N with a peak force of 780 N. The actuator is capable of a maximum 586m/s2 acceleration, and 6 m/s velocity at a resolution down to 12 microns. The actuator produces a 1 V peak-peak sin/cos analogue position signal for simple integration into a variety of systems.
For more information, visit www.copleymotion.com
