 The AC polynoid derives its name from the solenoid but the similarity stops there. Unlike a solenoid, the polynoid is a linear electric motor.
The AC Polynoid provides a constant force for the entire length of its stroke. Its direction of travel is reversible by switching with equal force in both directions. Switching requires the swapping of any two of three motor leads in three-phase units while single-phase reversing is done by the swapping of one line lead to the opposite side of the capacitor lead. Electrical force reversal can be used for dynamic braking.
A polynoid is comprised of two basic parts, a rod and a stator. The rod is copper clad steel, the end of which can feature a tapped mounting hole. An optional holding coil is available for end holding at one or both ends. The stator is a series of coils wound on bobbins. Coils are interconnected. The stator is housed in a smooth cold rolled steel assembly. It is also available finned for greater heat dissipation.
The polynoid is an electrical induction motor. A sweeping magnetic field along the length of the stator coils induces linear motion of the rod through the stator or stator along the rod. The rod reacts to energization in less than 10 msecs accelerating to a limited speed. The time to reach this speed depends upon the net force available and the mass being moved. Normal operating speeds to 1.3 m/s (50 in/sec) for single phase units with three-phase units going to 2.3 m/s (90 in/sec).
The rod can be of infinite length when provided with proper support. Output force can be as high as 445 N (100 pounds) per stator with design capability for greater. The force can be controlled by varying the applied voltage (force varies by the square of the voltage) resulting in a degree of speed control.
FINNED SERIES provides maximum heat dissipation and higher duty cycle.
SMOOTH SERIES is designed for applications where space is restricted. The smooth finned series provides force equal to the finned series, but at a lower duty cycle.
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