Patent attributes
A planetary gear mechanism includes a sun gear, planetary gears, an annular internal gear, a carrier that is fixed to a bracket and includes a second lid, and a support shaft. An output unit is supported to be rotatable by a first bearing attached to the support shaft and a second bearing attached to the bracket, and fixed to the internal gear. The bracket includes a protrusion protruding from a first lid to one side in the axial direction. A radially inside surface of the protrusion includes a first curved surface extending in a circumferential direction as viewed along the axial direction. The carrier includes a second curved surface located radially inside the first curved surface. The second curved surface extends in the circumferential direction as viewed along the axial direction, and contacts with the first curved surface.