Monophase electromagnetic rotary actuator of travel between 60 and 120 degrees

A monophase electromagnetic rotary actuator of angular travel between 70/N and 110/N degrees comprising:

• a rotor exhibiting 2N magnets, N being equal to 1 or to 2, and a core of a material of high magnetic permeability;
• a stator exhibiting two pole pieces joined by at least one connecting part supporting at least one coil, the two pole pieces and the core of the rotor defining between them an air gap of constant length E, wherein the 2N magnets have a reversible permeability close to 1 and wherein a relation between a magnetized width Y.sub.a of one of the 2N magnets measured on a mean diameter of the magnets, a width of an angular arc C through which the rotor passes on the mean diameter of the magnets, a width S measured on the mean diameter of the magnets between two adjacent stator poles and a constant length E of the air gap is
• Y.sub.a =C+S+2 E'
• where:
• E' is between E/2 and E
• and wherein:
• C+2 E'/E
• and wherein
• L/E>0.75;
• L designating a radial length of one of the 2N magnets;
• to obtain a high torque/mass ratio and a torque that is approximately independent of the angular position of the rotor.