Electric motor

1. An electric motor ( 1 ) that comprises a stator ( 2 ) that creates a magnetic field and formed of ferromagnetic laminations (L 1 ) stacked on top of each other, and a rotor core ( 3 ) disposed inside the stator ( 2 ) and formed of ferromagnetic laminations (L 2 ) stacked on top of each other, having more than one winding slot ( 4 ) arranged along the circumference thereof, wherein the windings are placed, and characterized by a rotor sleeve ( 5 ) secured press-fittingly on the cylindrical outer circumference of the rotor core ( 3 ), covering the winding slots ( 4 ) and the windings, formed of ring shaped ferromagnetic laminations (L 3 ) stacked together on top of each other without discontinuity.

2. An electric motor ( 1 ) as in claim 1 , characterized by the rotor sleeve ( 5 ) with inner diameter (r) sized to be approximately same as the outer diameter of the rotor core ( 3 ) and the outer diameter (R) being smaller than inner diameter of the stator ( 2 ) such that an air gap (G) remains between itself and the stator ( 2 ).

3. An electric motor ( 1 ) as in claim 1 , wherein each rotor sleeve lamination (L 3 ) further comprises more than one locking protrusion ( 6 ), so that the laminations (L 3 ) are locked to each other during a stamping operation forming a stacked structure.

4. An electric motor ( 1 ) as in claim 1 , characterized by the rotor sleeve ( 5 ) comprising balancing grooves (B) opened on the outer circumference after the winding processes of the winding slots ( 4 ) and securing the rotor sleeve ( 5 ) on the rotor core ( 3 ) are performed.

5. An electric motor ( 1 ) as in claim 4 , characterized by the rotor sleeve ( 5 ) having a wall thickness ((R−r)/2) that is greater than the maximum depth of the balancing groove (B).

6. An electric motor ( 1 ) as in claim 2 , wherein each rotor sleeve lamination (L 3 ) further comprises more than one locking protrusion ( 6 ), so that the laminations (L 3 ) are locked to each other during a stamping operation forming a stacked structure.

7. An electric motor ( 1 ) as in claim 6 , characterized by the rotor sleeve ( 5 ) comprising balancing grooves (B) opened on the outer circumference after the winding processes of the winding slots ( 4 ) and securing the rotor sleeve ( 5 ) on the rotor core ( 3 ) are performed.

8. An electric motor ( 1 ) as in claim 2 , characterized by the rotor sleeve ( 5 ) comprising balancing grooves (B) opened on the outer circumference after the winding processes of the winding slots ( 4 ) and securing the rotor sleeve ( 5 ) on the rotor core ( 3 ) are performed.

9. An electric motor ( 1 ) that comprises a stator ( 2 ) that creates a magnetic field and formed of ferromagnetic laminations (L 1 ) stacked on top of each other, and a rotor core ( 3 ) disposed inside the stator ( 2 ) and formed of ferromagnetic laminations (L 2 ) stacked on top of each other, having more than one winding slot ( 4 ) arranged along the circumference thereof, wherein the windings are placed, and characterized by a rotor sleeve ( 5 ) having an outer circumference secured press-fittingly on the cylindrical outer circumference of the rotor core ( 3 ), covering the winding slots ( 4 ) and the windings, formed of ring shaped ferromagnetic laminations (L 3 ) stacked on top of each other wherein there is no tubular discontinuity on the rotor sleeve ( 5 ).

10. An electric motor ( 1 ) as in claim 9 , characterized by the rotor sleeve ( 5 ) with inner diameter (r) sized to be approximately same as the outer diameter of the rotor core ( 3 ) and the outer diameter (R) being smaller than inner diameter of the stator ( 2 ) such that an air gap (G) remains between itself and the stator ( 2 ).

11. An electric motor ( 1 ) as in claim 9 , wherein each rotor sleeve lamination (L 3 ) further comprises more than one locking protrusion ( 6 ), so that the laminations (L 3 ) are locked to each other during a stamping operation forming a stacked structure.

12. An electric motor ( 1 ) as in claim 9 , characterized by the rotor sleeve ( 5 ) comprising balancing grooves (B) opened on the outer circumference on any designated region of the rotor sleeve after the winding processes of the winding slots ( 4 ) and securing the rotor sleeve ( 5 ) on the rotor core ( 3 ) are performed.

13. An electric motor ( 1 ) as in claim 12 , characterized by the rotor sleeve ( 5 ) having a wall thickness ((R−r)/2) that is greater than the maximum depth of the balancing groove (B).

14. An electric motor ( 1 ) as in claim 10 , wherein each rotor sleeve lamination (L 3 ) further comprises more than one locking protrusion ( 6 ), so that the laminations (L 3 ) are locked to each other during a stamping operation forming a stacked structure.

15. An electric motor ( 1 ) as in claim 14 , characterized by the rotor sleeve ( 5 ) comprising balancing grooves (B) opened on the outer circumference on any designated region of the rotor sleeve after the winding processes of the winding slots ( 4 ) and securing the rotor sleeve ( 5 ) on the rotor core ( 3 ) are performed.

16. An electric motor ( 1 ) as in claim 10 , characterized by the rotor sleeve ( 5 ) comprising balancing grooves (B) opened on the outer circumference on any designated region of the rotor sleeve after the winding processes of the winding slots ( 4 ) and securing the rotor sleeve ( 5 ) on the rotor core ( 3 ) are performed.

17. An electric motor ( 1 ) that comprises a stator ( 2 ) that creates a magnetic field and formed of ferromagnetic laminations (L 1 ) stacked on top of each other, and a rotor core ( 3 ) disposed inside the stator ( 2 ) and formed of ferromagnetic laminations (L 2 ) stacked on top of each other, having more than one winding slot ( 4 ) arranged along the circumference thereof, wherein the windings are placed, and characterized by a rotor sleeve ( 5 ) having an outer circumference secured press-fittingly on the cylindrical outer circumference of the rotor core ( 3 ), covering the winding slots ( 4 ) and the windings, formed of ring shaped ferromagnetic laminations (L 3 ) stacked on top of each other without discontinuity between the ring shaped ferromagnetic laminations (L 3 ) and wherein the stator ferromagnetic laminations (L 1 ), the rotor core ferromagnetic laminations (L 2 ), and the rotor sleeve ferromagnetic laminations (L 3 ) are stamped from the same steel sheet.