LIM (Linear Induction Motor) operators

Ever heard of LIM (Linear Induction Motors) ? This is a type of electric motors the produces a linear force along a line. If you want to know more, the WikiPedia article 'Linear motor' is a good start. One practical application is for moving high speed trains, starting from the late 1980s.

Recently, the VMAG LLC company of Texas, introduced a high speed sliding gate operator specifically designed for security-priority locations.

In this case, high speed means 6 to 8 feet per second (1.8 to 2.4 meters per second). This is really impressive as it is roughly 10 times faster than typical sliding gate operators and 2 to 3 times faster than conventional high speed sliding gate operators.

Furthermore, the operator has no moving parts and this should make for increased reliability. Actually, the company states that a test installation at the San Antonio International Airport has managed more than 250,000 operation cycles no equipment problems and no signs of wear.

You can find more information and videos at the site of VMAG

These are some screen captures from one of the VMAG introduction videos:


Apparently (A) is the winding and (B) is the passive conductor plate. You can think of (A) as the motor and (B) as the rack of a conventional sliding gate operator installation, but in reality the "motor" in this case is composed of both (A) and (B).

Anyways, the important thing is that the winding can move the conductor plate and, along with it, the gate.

This is a closeup view of the winding. Notice that it is in close proximity to the conductor plate.

Also note that the conductor plate is perforated at the bottom. This should relate to the encoder that the operator obviously employs for the soft-start and soft-stop functions (in the world of gate operators an encoder is a device that identifies relative or absolute position of the gate)