Propulsion unit for an electric pedal-assisted cycle and pedal-assisted cycle thereof

A propulsion unit for an electric pedal-assisted cycle (EPAC) comprising:

• an electric machine having a stator and a rotor, the rotor being rotatable about a motor axis a crank pin defining a crank axis being coaxial with the motor axis,
• wherein the rotor is coaxial and external to the stator, the rotor radially enclosing the stator, and
• wherein the propulsion unit comprises:
• at least one electronic unit for operating and controlling a functioning of the electric machine,
• at least a pair of housings defining a containment space which houses the electric machine and at least partially houses the crank pin,
• a transmittor of a movement from the rotor to the crank axis, the transmittor of the movement being arranged in an asymmetrical position overall and decentralised from the crank axis so as to be at least in part outside a projection of the rotor on a projection plane perpendicular to the crank axis,
• the at least one electronic unit is positioned so as to fall inside a projection of the rotor on the projection plane perpendicular to the crank axis, and
• the at least one electronic unit being shaped as a ‘C’ around the crank axis and being arranged to partially surround the transmittor of the movement;
• wherein the transmittor of the movement comprises a first transmission stage having a first input gear, integral in rotation with the rotor and coaxial thereto, and a first output gear rotatable about a first axis parallel and offset in relation to a rotation axis;
• wherein the transmittor of the movement comprises a second transmission stage having a second input gear, integral in rotation with the first output gear and coaxial therewith, and a second output gear, which meshes with the second input gear and is integral in rotation with a second shaft defining a second axis offset and parallel to the rotation axis and to the first axis.