Rotary drum apparatus comprising a rotary drum and at least one electric motor for driving the drum, with a stator extending against a part of circumference of the drum

1. A rotary drum apparatus comprising:

a drum rotatable around a longitudinal axis; and

at least one electric drive motor configured to drive the drum in rotation around the longitudinal axis, each of the at least one electric drive motor comprising a stator and a rotor, the rotor comprising at least one ring portion joined together with the drum and extending substantially perpendicularly to the longitudinal axis, wherein each of the at least one electric drive motor comprises a plurality of separate modules distributed along the longitudinal axis, each of the separate modules comprising a rotor member and a stator element, the rotor member comprising at least one ring portion extending substantially perpendicularly to the longitudinal axis and the stator element extending against a part of circumference of the drum,

wherein the stator of each of the at least one electric drive motor extends against a part of circumference of the drum perpendicularly to the longitudinal axis.

2. The rotary drum apparatus according to claim 1 , wherein the part of circumference of the drum against which the stator extends has an angular sector of value less than about 90°.

3. The rotary drum apparatus according to claim 1 , wherein the part of circumference of the drum against which the stator extends has an angular sector of value less than about 60°.

4. The rotary drum apparatus according to claim 1 , wherein the part of circumference of the drum against which the stator extends has an angular sector of value less than about 30°.

5. The rotary drum apparatus according to claim 1 , wherein the at least one electric drive motor comprises two electric drive motors configured to drive the drum in rotation around the longitudinal axis.

6. The rotary drum apparatus according to claim 5 , wherein the stators of both of the two electric drive motors are substantially diametrically opposed with respect to the longitudinal axis, and the rotors of both of the two electric drive motors comprise at least one ring joint with both of the two electric drive motors, the at least one ring being joint together with the drum and extending substantially perpendicularly to the longitudinal axis.

7. The rotary drum apparatus according to claim 1 , wherein each of the at least one electric drive motor is a linear motor.

8. The rotary drum apparatus according to claim 1 , wherein the at least one electric drive motor comprises two electric drive motor, wherein both of the two electric drive motors comprise the same number of separate modules, each stator member of an electric drive motor of the two electric drive motors being substantially diametrically against a corresponding stator element of another electric drive motor of the two electric drive motors, relative to the longitudinal axis.

9. The rotary drum apparatus according to claim 8 , wherein each rotor member of the electric drive motor of the two electric drive motors comprises a ring, the ring being joint with a rotor member corresponding to the other electric drive motor of the two electric drive motors and extending substantially perpendicularly to the longitudinal axis.

10. The rotary drum apparatus according to claim 1 , wherein the drum has, perpendicularly to the longitudinal axis, a maximum diameter of value greater than about 1 meter.

11. The rotary drum apparatus according to claim 1 , wherein the drum has, perpendicularly to the longitudinal axis, a maximum diameter of value greater than about 2 meters.

12. The rotary drum apparatus according to claim 1 , wherein the drum has, perpendicularly to the longitudinal axis, a maximum diameter of value greater than about 4 meters.

13. The rotary drum apparatus according to claim 1 , wherein the at least one ring portion comprises a plurality of ferromagnetic elements angularly offset relative to each other around the longitudinal axis.

14. The rotary drum apparatus according to claim 1 , wherein the rotary drum apparatus is an ore crusher and is configured to receive an ore to be crushed.

15. A drum apparatus comprising:

a drum rotatable around a longitudinal axis;

a first drive motor configured to drive the drum in rotation around the longitudinal axis, the first drive motor having a first stator extending against a part of circumference of the drum perpendicularly to the longitudinal axis, and a first rotor having at least one first rotor element comprising a first ring joined together with the drum and extending substantially perpendicularly to the longitudinal axis; and

a second drive motor configured to drive the drum in rotation around the longitudinal axis, the second drive motor having a second stator extending against a part of circumference of the drum perpendicularly to the longitudinal axis, and a second rotor having at least one second rotor element comprising the first ring.

16. The rotary drum apparatus according to claim 15 , wherein:

the first stator comprises at least one first separate module distributed along the longitudinal axis; and

the second stator comprises at least one second separate module distributed along the longitudinal axis.

17. The rotary drum apparatus according to claim 15 , wherein the first stator and the second stator are substantially diametrically opposed with respect to the longitudinal axis.

18. The rotary drum apparatus according to claim 15 , wherein the rotary drum apparatus is an ore crusher and is configured to receive an ore to be crushed.

19. A drum apparatus, comprising:

a drum rotatable around a longitudinal axis;

a first drive motor configured to drive the drum in rotation around the longitudinal axis, the first drive motor comprising at least one first module distributed along the longitudinal axis, the at least one first module having a first rotor member and a first stator element extending against a part of circumference of the drum perpendicularly to the longitudinal axis; and

a second drive motor configured to drive the drum in rotation around the longitudinal axis, the second drive motor comprising at least one second module distributed along the longitudinal axis, the at least one second module having a second rotor member and a second stator element extending against a part of circumference of the drum perpendicularly to the longitudinal axis,

wherein the first rotor member and the second rotor member each comprise a ring that is joint with respect to the first rotor member and the second rotor member, and which extends substantially perpendicularly to the longitudinal axis.