摘要 |
A differential gear is structured such that a first differential case and a second differential case overlap one another in the radial direction such that a first joining portion of the first differential case, i.e., a portion of an outward flange that is on the outer peripheral side of a through-hole, is positioned on the outer peripheral side of a second joining portion of the second differential case, i.e., a joining protrusion that is inserted in the through-hole. In addition, the ring gear is arranged facing those joining portions in the direction of the axis, and laser beam welded from the outer peripheral side at the portion where the ring gear faces both of those joining portions. Accordingly, the three members, i.e., the first differential case, the second differential case, and the ring gear, are all integrally joined together by a single welding operation, and manufacturing costs can be reduced. |