Abstract: A rotor centering device comprising two radial bearings each one constituted of first and second opposing members with angular contact races, mounted with axial clearance so that if one of the said members is in abutment, the other member has a radial clearance. The first angular contact centering members of the first and second bearings are also opposing, and the second angular contact centering members of the first and second bearings are likewise opposing, so that by relative axial movement of the inner and outer contact races of both first and second centering means belonging to the two bearings, simultaneous contact of the inner and outer faces is achieved either with the first centering members or with the second centering members which happen to be opposing on the two bearings.