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About Linear Motors...
The idea is simple enough. Take a conventional rotary servo motor and unwrap it. What was the stator is now a
forcer and the rotor becomes a magnet bar. With this design, the motor is connected directly to the load. Direct linear motion is achieved without any rotary to linear transmission. The forcer is a set of windings
which conduct current, while the stator is a linear path of rare earth magnets mounted in alternating polarity. Commutation is electronic, either with hall effect sensors or sinusoidal drives.
There are three
main types of brushless linear motors: iron core, ironless, and slotless. Each has certain performance advantages - the slotless however, exhibits the best combination of attributes for the majority of applications.
These include good linear force, smooth translation, thermal stability and low cost. Brushless linear servo motors offer the speed of belt drives plus the precision of ground ballscrew drives. With only two primary
elements, they are considerably less complicated than the ballscrew which has more than a dozen components in the drive train. As a result, the response rate can be 10 times faster. This means faster acceleration
and settling times which translates into higher throughput.
About Linear Motor Tables...
Linear motors cannot function on their own. Before motion can occur, a platform must be engineered to
provide support, direction, and feedback for the linear motor. Bearings, cables, connectors, encoder, travel stops, homing sensor and other components must be performance matched and integrated to achieve desired
motion and control. With Daedal tables, the linear motor magnet rail is mounted to a stationary base and the forcer is mounted to the moveable carriage. High precision square rail bearings connect the carriage to
the base, providing load support, low-friction translation, and precise linear direction. A high resolution linear encoder, with scale mounted to the base and reader head to the carriage, provides the required
velocity and positional information to the motor controller. Unlike screw driven tables, the only contact between the moving carriage and the stationary base is through the linear support bearings.
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