A recentering device for a rotor shaft for recentering a rotor shaft relative to an axis X of a stator structure in the event of decoupling caused by excessive imbalance. The shaft, in normal operating conditions, lies on the axis X and is radially supported by a bearing support disposed in a bore of the axis X in the stator structure. The bearing support has an outside diameter smaller than the diameter of the bore, to enable the bearing support to orbit about the axis X in the event of decoupling. The bearing support is connected to the stator structure by radially fusible elements. The recentering device recenters the bearing support after decoupling.