Abstract: A mechanical speed reducer, in particular for a device for driving at least one wheel of an aircraft landing gear, this reducer including a first sun gear including external toothing, first planet gears meshed with the external toothing of the first sun gear, these first planet gears being carried by a first planet carrier, a stationary ring gear meshed with the planet gears, and second planet gears meshed with a ring gear and with an external toothing of said first planet carrier, these second planet gears being carried by a second planet carrier.

Abstract: A device for driving at least one wheel of an aircraft landing gear including at least one landing gear wheel, this wheel including a rim, an electric motor including a shaft, a mechanical transmission system between the shaft of the motor and the rim, this mechanical transmission system including a mechanical reducer including a sun gear secured in rotation to the shaft of the motor, a ring gear, and planet gears which are carried by a planet carrier and which each includes three external toothings, including a median external toothing which is meshed with a toothing of the sun gear, and two lateral external toothings which are respectively meshed with toothings of the ring gear.

Abstract: A device for driving at least one wheel of an aircraft landing gear is provided. The device includes at least one wheel having a rim, an electric motor having a shaft, and a mechanical transmission system for mechanical transmission between the shaft of the motor and the rim. The mechanical transmission system includes a mechanical reduction gear. The mechanical reduction gear includes a sun gear secured in rotation to the shaft and having an external toothing, a stationary ring gear with internal toothing, a movable ring gear secured in rotation to the rim and having an internal toothing, and planet gears that are meshed with the sun gear and each have two external toothing meshed respectively with the toothing of the stationary and movable ring gears.