Drives such as voice coil, linear, or torque motors are electromagnetic direct drives. In direct drives, the force of the drive element is transmitted directly to the load to be moved (e.g., to a linear or rotary table, without mechanical transmission elements such as coupling, drive screw, or gearhead). Electromagnetic direct drives consist of a winding body (coil) in which a magnetic field is formed when current runs through it and a carrier or magnet assembly on which the magnets are mounted.
The force or torque for the acceleration of the load is generated by the Lorentz force. This force is proportional to the magnetic field strength and the current passing through the current-carrying conductor. The electrical energy is converted here into mechanical energy. The generated force acts bidirectionally depending on the direction of the current. In principle, either the winding body (“moving coil”) or the magnet assembly (“moving magnet”) can be moved. The moving part is referred to as the secondary part, the static part as the primary part.