Motor assembly for railway axle comprising: an axle comprising at least one drive wheel configured to rotate together with said axle around an axis, a planetary carrier fitted on the axle, at least one toothed planetary gear carried by the planetary carrier and movable by rotation with respect to the latter at least around a respective axis distinct from the rotation axis of the axle, a first actuating wheel constrained to the axle and movable by rotation relative to the latter around the rotation axis of the axle, said first actuating wheel having: ∘ a coupling portion actuatable by a first motor configured to rotate said first actuating wheel, ∘ a gear wheel integral with said coupling portion and engaged via meshing with the planetary gear, ∘ an engagement surface interposed between the coupling portion and the gear wheel of the first actuating wheel according to a direction parallel to the axis of the axle, a second actuating wheel - distinct from the first actuating wheel - constrained to the axle and movable by rotation relative to the latter around the axis of the axle, the second actuating wheel having: ∘ a coupling portion actuatable by a second motor configured to rotate said second actuating wheel, ∘ a gear wheel integral with said coupling portion of the second actuating wheel, and engaged via meshing with the planetary gear, wherein the planetary gear is radially interposed between the gear wheels (4b, 6b) respectively of the first and second actuating wheels (4, 6), wherein the second actuating wheel is constrained to the first actuating wheel by means of at least one radial bearing, wherein the engagement surface of the first actuating element externally carrying said at least one radial bearing constraining the first and the second actuating wheel. an axle comprising at least one drive wheel configured to rotate together with said axle around an axis, a planetary carrier fitted on the axle, at least one toothed planetary gear carried by the planetary carrier and movable by rotation with respect to the latter at least around a respective axis distinct from the rotation axis of the axle, a first actuating wheel constrained to the axle and movable by rotation relative to the latter around the rotation axis of the axle, said first actuating wheel having: ∘ a coupling portion actuatable by a first motor configured to rotate said first actuating wheel, ∘ a gear wheel integral with said coupling portion and engaged via meshing with the planetary gear, ∘ an engagement surface interposed between the coupling portion and the gear wheel of the first actuating wheel according to a direction parallel to the axis of the axle, a second actuating wheel - distinct from the first actuating wheel - constrained to the axle and movable by rotation relative to the latter around the axis of the axle, ∘ a coupling portion actuatable by a first motor configured to rotate said first actuating wheel, ∘ a gear wheel integral with said coupling portion and engaged via meshing with the planetary gear, ∘ an engagement surface interposed between the coupling portion and the gear wheel of the first actuating wheel according to a direction parallel to the axis of the axle, the second actuating wheel having: ∘ a coupling portion actuatable by a second motor configured to rotate said second actuating wheel, ∘ a gear wheel integral with said coupling portion of the second actuating wheel, and engaged via meshing with the planetary gear, wherein the planetary gear is radially interposed between the gear wheels (4b, 6b) respectively of the first and second actuating wheels (4, 6), wherein the second actuating wheel is constrained to the first actuating wheel by means of at least one radial bearing, wherein the engagement surface of the first actuating element externally carrying said at least one radial bearing constraining the first and the second actuating wheel. ∘ a coupling portion actuatable by a second motor configured to rotate said second actuating wheel, ∘ a gear wheel integral with said coupling portion of the second actuating wheel, and engaged via meshing with the planetary gear,