Wheel for pedal-assisted bikes

1. A wheel for pedal-assisted bikes, the wheel comprising:

at least a fixed structure associable with the frame of a bike having a driving pedal crank;

at least a circle element mounted on said fixed structure in a rotatable manner around a main rotation axis;

at least a propulsion disc mounted on said fixed structure in a rotatable manner and connectable to said driving pedal crank;

motion transmission means for the transmission of the rotary motion from said propulsion disc to said circle element; and

at least an electric motor associated with said fixed structure and configured to cooperate with said propulsion disc to motorize said circle element;

wherein said motion transmission means comprises at least a first detection device configured to detect the force transmitted to said circle element from said propulsion disc, said first detection device comprising:

at least a first plate associated in rotation with one of the propulsion disc and the circle element,

at least a second plate associated with the other of the propulsion disc and the circle element through a prismatic coupling of rib and recesses on the outer surface of the second plate and on the inner surface of a support device associated with the circle element, the prismatic coupling of ribs and recesses being configured to make the second plate rotatable around said main rotation axis and to slide along a sliding direction substantially parallel to said main rotation axis,

at least a motion transmission part between said first plate and said second plate, the motion transmission part being associated with at least one of the first plate and the second plate, the motion transmission part being configured to engage a grip ramp, disposed at the other of the first plate and the second plate,

the grip ramp being inclined with respect to a plane transversal to said main rotation axis,

engagement of said grip ramp by said motion transmission part causing the sliding of said second plate along said sliding direction until the second plate is disposed in a position corresponding to the transmitted force, and

at least a detection sensor configured to detect the position of said second plate along said sliding direction.

2. The wheel according to the claim 1 , wherein said first detection device comprises elastic means providing elastic force against the second plate when the second plate moves away from said first plate.

3. The wheel according to the claim 1 , wherein said first plate is rotatable around said main rotation axis and is configured to operate in rotation by the motion of said propulsion disc, said second plate being associated with said circle element.

4. The wheel according to claim 1 , wherein said detection sensor is associated with said fixed structure.

5. The wheel according to claim 1 , wherein said detection sensor is a contactless distance sensor configured to measure the distance from a dish associated with said second plate.

6. The wheel according to claim 1 , wherein said wheel comprises at least a processing and control unit associated with said fixed structure,

the processing and control unit being operatively connected to said first detection device and to said electric motor,

the processing and control unit being configured to command the start of said electric motor depending on the force detected by said first detection device.

7. The wheel according to claim 1 , further comprising at least a power supply unit associated with said fixed structure, the power supply unit being configured to electrically supply power to said electric motor.

8. The wheel according to claim 1 , further comprising:

at least a processing and control unit associated with said fixed structure,

the processing and control unit being operatively connected to said first detection device and to said electric motor,

the processing and control unit being configured to command the start of said electric motor depending on the force detected by said first detection device; and

at least a power supply unit associated with said fixed structure, the power supply unit configured to electrically supply power to said electric motor,

wherein said circle element comprises at least a central boxed casing configured to contain at least said motion transmission means, said electric motor, said power supply unit, and said processing and control unit.

9. The wheel according to claim 1 , wherein said motion transmission means comprises at least a speed gear device configured to change the motion transmission ratio from said propulsion disc to said circle element.

10. The wheel according to claim 1 , wherein said motion transmission means comprises at least a freewheel mechanism.

11. The wheel according to claim 1 , wherein:

said motion transmission means comprises

at least a speed gear device configured to change the motion transmission ratio from said propulsion disc to said circle element, and

at least a freewheel mechanism,

wherein said propulsion disc is associated with said speed gear device, the speed gear device being associated with said freewheel mechanism, the freewheel mechanism being associated with said first detection device, the first detection device being associated with said circle element.

12. The wheel according to claim 9 , wherein said motion transmission means comprises a second detection device configured to detect the rotation speed at exit from said speed gear device.

13. The wheel according to the claim 12 , wherein said second detection device comprises a phonic wheel.

14. The wheel according to claim 1 , further comprising a circle element speed detection device configured to detects the speed of said circle element.

15. The wheel according to claim 6 , wherein said processing and control unit is associated with a wireless data transmission device to interface an external electronic device usable by a user.

16. The wheel according to claim 6 , wherein said processing and control unit is operatively associated with a detection appliance for the detection of the environmental pollution which is associated with said fixed structure.

17. The wheel according to claim 1 , wherein said electric motor comprises

a statoric element associated with said fixed structure, and

a rotoric element associated with said circle element,

said statoric element and said rotoric element being substantially ring-shaped and arranged substantially around said motion transmission means.