An architecture making it possible to provide sufficient absorption of shocks for a power shaft while maintaining rigidity at front bearings so as to not compromise meshing of power teeth of a drive pinion. A compressible dynamic shock absorption is provided in alignment with a downstream shock absorber of an additional meshing. An assembly for dynamically absorbing shocks for a power shaft includes upstream and downstream bearings including power rollers mounted on two casings and flanking a speed-reducing teeth meshing. The downstream bearing is coupled to at least one additional roller bearing associated with a compressible shock absorber to form a downstream shock absorber axially offset relative to the upstream bearing opposite the teeth meshing. Both downstream bearings are connectable by a flexible frame mounted on the common casing. The architecture can be used for power-transmission shafts, for example supercritical shafts in turbine engines.