An aircraft drive chain including a plurality of main pinions meshing with each other, a first main pinion including a wall delimiting an inner volume, external teeth being provided on an outer surface of the wall, the external teeth meshing with at least one second main pinion, a gear system being incorporated in the inner volume, the first main pinion and the gear system being jointly configured to form a multiplier or reducer and to ensure a mechanical energy transfer between a driving member and a slave member.