Linear motors have been used in wafer handling and pick and place applications for years. Now applications in metalworking, packaging, and medical are on the rise due to the superior speed and accuracy linear motors provide.
But along with the benefits of high speed and acceleration come the associated responsibilities of safe design. Linear motors can develop incredible amounts of kinetic energy in a very short time. Consequently, engineers designing with them must use a combination of electrical safety functions and competent mechanical design at both ends of travel to ensure safe operation.
As with any machine, care must be exercised when the motor is operating. Along with the great speeds and accelerations come temperatures over 100C. So personnel must be warned not to touch the forcer coil when the motor is operating, or during a cool-down period immediately following motor operation.
Fast kinetic energy generation, heat, and powerful magnetic forces are the primary safety concerns for engineers designing with linear motors.
Extra consideration must be given to the powerful magnetic fields created by the magnet tracks. The open magnet track used with flat linear motors is generally more hazardous than U-channel designs, since the exposed magnet track can unexpectedly clamp to an iron-core forcer or any ferrous surface.
Although most of the magnetic attraction in U-channel designs is contained, and the brushless linear motor forcer coil is nonmagnetic, danger still exists. Do not insert any ferrous material into the U-channel or attempt to disassemble the U-channel magnet track.
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