Gear motor and associated cycle

A gear motor of an electrical assistance device, comprising:

• a gear reducer and an electric motor which are configured to be able to be fitted coaxially on a central shaft, the electric motor comprising a stator and a rotor which are integral in rotation with a shaft forming an input of the gear reducer, the gear reducer comprising:
• a toothed crown which is integral with the stator;
• a satellite-carrier which is fitted such as to pivot via at least one flange bearing around the shaft, the satellite-carrier forming an output of the gear reducer;
• at least two planet wheels which are fitted firstly on respective eccentric cams via a respective bearing, the eccentric cams being integral with the shaft, the planet wheels engaging on the toothed crown while being phase-shifted in rotation;
• a rotor bearing which is configured to center a first end of the shaft on a fixed shaft of the gear motor;
• and
• a bearing device comprising deformable rolling elements, the bearing device being interposed between the satellite-carrier and a cylindrical receptacle which is integral with the stator, for the centering of the shaft in the cylindrical receptacle at a second end,
• wherein the gear motor further comprises a rotatable coupling configured to transmit an output torque of the gear reducer to the central shaft.