Synchronous rotating electrical machine with permanent magnets and flux concentration

A rotating electrical machine, comprising:

• a stator (10) equipped with stator windings and a rotor (11);
• said rotor comprising a plurality of alternate North poles and South poles formed from permanent magnets (PM) and arranged according to a substantially radial configuration so as to aid flux concentration, first slots (E1) arranged in a magnetic body of said rotor (11) so as to house said permanent magnets (PM);
• said rotor further comprising, in each of said poles thereof, a second slot (E3) arranged substantially radially in said magnetic body of said rotor, between two consecutive of said permanent magnets (PM) delimiting said pole, said second slot (E3) realizing a reduction in the mechanical inertia of said rotor (11);
• said rotor further comprising, in each of said poles thereof, a portion forming a bridge (BR) between two adjacent parts of said magnetic body of said rotor (11) on either side of said second slot (E3), and said permanent magnets (PM) being approximately rectangular in shape with a height (ha) in the radial direction of said rotor (11), a length (Lzs) in the axial direction of said rotor (11) and a width (Ia) having predetermined dimensional values;
• said portion forming said bridge (BR) comprising a magnetic body height (H) not greater than approximately the dimensional value of said width (Ia) of said permanent magnets (PM);
• said part forming a bridge (BR) comprising a magnetic body length (L) greater than approximately one and a half times a unit metal sheet thickness of a packet of metal sheets forming said magnetic body of said rotor (11).

A method for dimensioning a rotor of a rotating electrical machine comprising a stator (10) equipped with stator windings and a rotor (11), said rotor comprising a plurality of alternate North poles and South poles formed from permanent magnets (PM) arranged according to a substantially radial configuration known as with flux concentration, first slots (E1) arranged in a magnetic body of said rotor (11) so as to house said permanent magnets (PM);

• said rotor further comprising, in each of said poles thereof, a second slot (E3) arranged substantially radially in the magnetic body of said rotor, between two of said consecutive permanent magnets (PM) delimiting said pole, said second slot (E3) participating in a reduction in the mechanical inertia of said rotor (11);
• and said rotor further comprising, in each of said poles thereof, a portion forming a bridge (BR) between two adjacent parts of said magnetic body of said rotor (11) on either side of said second slot (E3);
• the method comprising the step of:
• selecting said portion forming said bridge (BR) such that said bridge is defined dimensionally (H, L) such that a magnetic body height (H) of said bridge (BR) is not greater than approximately the dimensional value of a width (la) of said permanent magnets (PM) and a magnetic body length (L) thereof is less than approximately one and a half times the dimensional value of said width of said permanent magnets, so as to obtain an optimum compromise between a maximum mechanical torque (Cmax) provided by said electrical machine and a minimum mechanical inertia of said rotor (11);
• said magnetic body height (H) being greater than approximately a unit metal sheet thickness of a packet of metal sheets forming the magnetic body of said rotor (11).