An electric machine having a central axis of rotation and comprising: a stator comprising a magnetic core longitudinally crossed by a plurality of stator slots; and a stator winding having a number of phases and comprising a series of rigid bars, which are "U"-shaped and are inserted through the stator slots defining an entry side, in which cusps of the "U"-shaped bars are placed, and an exit side, in which the legs of the "U"-shaped bars are placed; wherein the legs of the "U"-shaped bars coming out from the exit side of the magnetic core are twisted through relative double folds, each of which comprises an internal fold in one direction and an external fold in the opposite direction; wherein ends of the legs of the "U"-shaped bars are electrically connected to one another so as to form the electrical paths of the stator winding; wherein the ends of at least two non-adjacent legs are electrically connected to one another by means of a connection bridge (18; 28; 30; 32; 34), which is made of a flat plate arranged perpendicular to the central axis of rotation and has, for each leg, a corresponding "U"-shaped seat, which is suited to receive the end of the leg; and wherein an insulating support (20; 29; 31; 33; 35) is provided, which is made of an electrically insulating plastic material, houses the connection bridge (18; 28; 30; 32; 34), is arranged under the connection bridge (18; 28; 30; 32; 34) and has a plurality of through holes, into which some legs are inserted, which have to pass through the insulating support (20; 29; 31; 33; 35) itself; the electric machine is characterised in that the insulating support (20; 29; 31; 33; 35) comprises at least one seat, which is suited to receive and mechanically lock the connection bridge (18; 28; 30; 32; 34) in the correct position; and the seat is made up of restraining elements, which project upwards from a base of the support (20; 29; 31; 33; 35) and are arranged in correspondence to the edge of the connection bridge (18; 28; 30; 32; 34). a stator comprising a magnetic core longitudinally crossed by a plurality of stator slots; and a stator winding having a number of phases and comprising a series of rigid bars, which are "U"-shaped and are inserted through the stator slots defining an entry side, in which cusps of the "U"-shaped bars are placed, and an exit side, in which the legs of the "U"-shaped bars are placed; wherein the legs of the "U"-shaped bars coming out from the exit side of the magnetic core are twisted through relative double folds, each of which comprises an internal fold in one direction and an external fold in the opposite direction; wherein ends of the legs of the "U"-shaped bars are electrically connected to one another so as to form the electrical paths of the stator winding; wherein the ends of at least two non-adjacent legs are electrically connected to one another by means of a connection bridge (18; 28; 30; 32; 34), which is made of a flat plate arranged perpendicular to the central axis of rotation and has, for each leg, a corresponding "U"-shaped seat, which is suited to receive the end of the leg; and wherein an insulating support (20; 29; 31; 33; 35) is provided, which is made of an electrically insulating plastic material, houses the connection bridge (18; 28; 30; 32; 34), is arranged under the connection bridge (18; 28; 30; 32; 34) and has a plurality of through holes, into which some legs are inserted, which have to pass through the insulating support (20; 29; 31; 33; 35) itself; the electric machine is characterised in that the insulating support (20; 29; 31; 33; 35) comprises at least one seat, which is suited to receive and mechanically lock the connection bridge (18; 28; 30; 32; 34) in the correct position; and the seat is made up of restraining elements, which project upwards from a base of the support (20; 29; 31; 33; 35) and are arranged in correspondence to the edge of the connection bridge (18; 28; 30; 32; 34).