2. Operational structures for linear and rotary actuators

2.1 Electromagnetic effect actuators

Electromagnetic effect machines and actuators exploit the reciprocal mechanical actions experienced "at a distance" by sources located on either side of an air gap. These sources, which form the armatures of the converter, can be either magnetized media or current-carrying conductors. If the direction of movement is perpendicular to the interface separating the two armatures, the coupling in question is referred to as normal (as is the case with most electromagnets), whereas the term tangential coupling is used when the movement takes place by "shearing" the air gap. As a result, tangential coupling is the interaction mode most commonly used in electromagnetic effect converters, whether rotary or linear. In these structures, the air gap separating...