In principle, the linear drive is a synchronous motor that is cut apart and drawn to length.

In the (rotating) synchronous motor, the alternating current flowing through the coils of the stator (primary part) generates a rotating magnetic field. This interacts with the magnetic field of the permanent magnet in the rotor (secondary part). The superposition of the two magnetic fields produces forces that lead to the rotation of the rotor in the stator.

In the magnetic linear drive the stator (primary part) is laid flat on the track. For the permanent magnet to move linear across the stator, an alternating current has to flow in the primary part, which generates a traveling magnetic field. Special sensors and sophisticated control electronics ensure that the traveling magnetic field with the correct speed is at the right place. Again, the magnetic fields of the alternating current flowing in the primary part and the magnetic field of the permanent magnet in the secondary part overlap. The result is a linear movement of the secondary part and thus, of the aggregate. A linear drive with a permanent magnet as a secondary part is called linear synchronous motor (LSM). This Kind of linear drive is used by the manufacturer Homag in his trimming saw HL86.

By replacing the permanent magnet of an LSM, for example, by a copper plate, a linear induction motor (LIM) is produced. The traveling magnetic field of the primary part induces a current in the copper plate. This current again generates a magnetic field which interacts with the traveling magnetic field of the primary part. The forces that act there move the secondary part and thus the aggregate asynchronous to the traveling magnetic field - like on a rubber band.

While an LSM has a much higher efficiency and allows for higher traveling speeds, the LIM drives weigh much less since the permanent magnet is eliminated. Both drives accelerate an aggregate without contact and with extremely high reliability.

Technical realization, for example in:

• Prisma 6000 (Giben)
• Linear and synchronous technology (Brandt)