Wound rotor synchronous electric machine

A wound rotor comprising a structure defining a circumferential alternation of teeth and grooves, each tooth receiving a longitudinal winding intended to produce a rotor pole;

• each winding defining, at each longitudinal end of the rotor, a protruding coil head, said rotor also comprising a shaft passing through said structure along a longitudinal direction, said rotor being capable of being cooled by a coolant projected onto said coil heads, said rotor further comprising at least one collar for mechanically holding said rotor windings, installed at a longitudinal end of the rotor so as to define a central opening that opens out onto the coil heads, wherein said collar has at least one escape duct capable of allowing the escape of said coolant projected into the central opening onto said coil heads, said escape duct being made up of an orifice radially passing through said collar, and the longitudinal end of said collar having a constant reduction in its outer diameter.