2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/22951We present the first space-filling bearing in three dimensions. It is shown that a packing which contains only loops with even number of spheres can be constructed in a self-similar way and that it can act as a three dimensional bearing in which spheres can rotate without slip and with negligible torsion friction.4 pages, 4 figures, accepted for Physical Review LettersCondensed Mattertext