Linear Motors: Miniature direct-drive linear motor helps shrink automation systems

Canton, MA—Copley Controls introduced a new ServoTube small-silhouette STB11 linear motor.

By Control Engineering Staff June 28, 2007

Canton, MACopley Controls introduced a new ServoTube small-silhouette STB11 linear motor. The company claims that the direct drive size 11 motor combines a slim form factor with superior control stiffness, unmatched bandwidth, andforcer width is only 26 mm to aid applications where space is critical and costly, such as desktop, benchtop, and laboratory applications.
The company says that the motors’ combination of powerful drive force and low mass enable them to accelerate light loads to 25g. Specifications include stroke to 372 mm, 46N-to-92N peak force, and 3.1-to-5.2 m/sec maximum velocity. Thrust rod diameter is 11 mm.
Motor compactness-forcer width of 26 mm-provides benefits in applications where space is critical and costly: desktop, benchtop, and laboratory applications for example. STB11 motors lend themselves to integration into compact systems used for inspection, analysis, assembly, and packaging. A small silhouette translates into more production per square foot in hosts of space-critical applications.
The motor’s load-positioning forcer is driven directly by the interaction between its permanent magnet and electrically energized magnetic fields. There are no intervening gear trains, ballscrews, flexible couplings, or drive motors to add inertia and impair responsiveness. STB11’s permanent magnets are sealed into the stainless steel thrust rod. The load-carrying forcer travels on a low friction single rail bearing; motor drive coils are encapsulated within the forcer, which travels in free air and acts as an efficient heat dissipater.
An integral solid-state position sensor eliminates the need for an external encoder, simplifying installation, reducing cost, and improving ruggedness and dependability. Users can optimize servo position control by matching STB11 motors to the company’s Accelnet digital controllers. Accelnet controllers provide powerful stand-alone and multi-axis control choices; networking options include CANopen, EtherCAT, Macro and DeviceNet. Operated from dc power supplies, the controllers deliver the 70 V power needed for optimal motor performance.
Edited by C.G. Masi , senior editor, Control Engineering
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