Internal Rotor Including a Grooved Shaft Intended for a Rotary Electric Machine

1 . A buried-magnet internal rotor for an electric rotating machine, the rotor comprising:

a shaft;

a plurality of polar parts made of a magnetic material and surrounding the shaft, the polar parts delimiting housings between them; and

a plurality of permanent magnets placed in the housings;

wherein the shaft comprises a plurality of longitudinal splines interacting with radial tenons of the polar parts.

2 . The rotor according to claim 1 , wherein the shaft comprises as many longitudinal splines as the rotor has poles.

3 . The rotor according to claim 2 , the rotor being a hexapolar rotor, the shaft comprising 6 longitudinal splines.

4 . The rotor according to claim 2 wherein, the radial walls of each longitudinal spline of the shaft are parallel to one another.

5 . The rotor according to claim 1 , wherein the polar parts consist of a stack of metal sheets, each metal sheet extending substantially radially from the shaft and comprising a radial projection, said radial projection forming a portion of said tenon.

6 . The rotor according to claim 1 , further comprising a lateral shroud axially on either side of the polar parts along the shaft, said lateral shrouds axially clamping the polar parts with tie-rods, the centrifugal forces exerted on the polar parts being absorbed by said lateral shrouds.

7 . The rotor according to claim 6 , wherein the central opening of one of the lateral shrouds ( 5 ) comprises a shoulder capable of interacting with an internal shoulder of the shaft in order to define an axial position of the polar parts on the shaft.

8 . The rotor according to claim 7 , wherein the lateral shrouds are mounted slidingly in rotation on the shaft.

9 . An electric rotating machine comprising a buried-magnet rotor according to claim 1 .